5.2. ecological impact of fisheries and aquaculture · · 2016-09-135.2. ecological impact of...

5.2. ECOLOGICAL IMPACT OF FISHERIES AND AQUACULTURE5.2.1. The effects of fisheries on the environment

FAIR-CT95-0208

Biological and fisheries study of the Mediterraneanand adjacent deep-seas� shrimps

OBJECTIVES

In this summary the results of the seminars and workshops of the concerted ac-tion ‘Biological and fisheries study of the Mediterranean and adjacent deep-seas’ shrimps’are presented. Specialists in red shrimps fisheries and biology, aswell as invited speakers of other science domains, attended the seminars. Theygave key talks on the biology of red shrimps and on geological and oceano-graphic aspects related to the ecology of red shrimps. The state of the art on cur-rent knowledge on the biology, ecology and fisheries of red shrimps in theMediterranean was presented and future lines of research were identified.

Deep shrimp resources in the Mediterranean are mainly constituted of redshrimp species: the Peneids Aristeus antennatus and Aristaeomorpha foliacea,and Pandalids of the genus Plesionika. The fisheries for red shrimps representa sizeable amount of the demersal trawl fishing in Italy and Spain, in volumeand economic value, and to a lesser extent in Portugal and France. The redshrimp resources are also locally abundant off northern Africa (Tunisia andAlgeria) and Greece. In Greece, although no directed red shrimp fishery existsat the moment, scientific trawl surveys have shown the existence of importantred shrimp resources deeper than 500 m.

Red shrimp fishing in Spain and Italy is a highly selective activity, targetingprimarily Aristeus antennatus and Aristaeomorpha foliacea. In Italy, the pro-portion of both species in the catch varies to a great extent locally and sea-sonally. In the Spanish Mediterranean only Aristeus antennatus is of commer-cial importance. In Portugal and France, red shrimps are subject to mixed fish-ery with other deep-water crustaceans and in Greece they are not exploited.

Analysis of fisheries data using yield per recruit models, for areas wheredetailed information is available, indicates that the resource of Aristeus anten-natus is slightly overexploited. For this species, it is the female fraction of thepopulation which is most affected by fishing, as females predominate in thepopulation at commercial fishing depths (usually from 500 to 800 m).Aristaeomorpha foliacea is also slightly overexploited, but in this case, as nosegregation by sex is found, fishing affects the entire population.

The knowledge on the basic biology of both species is locally satisfactory, ingeneral, although specific issues requiring further research were identified. Thebroad geographical distribution of the two main species, Aristeus antennatusand Aristaeomorpha foliacea, is known for the Mediterranean and adjacent At-lantic waters. However, the lower end of the depth distribution is not known formany areas, due to the lack of deep samplings (beyond 1 000 m) in most areas.

Contract No: FAIR-CT95-0208Total cost: EUR 100 000EC contribution: EUR 100 000Starting date: 1.12.1995Duration: 18 months

COORDINATOR

Dr Francisco Sarda AmilisConsejo Superior de InvestigacionesCientíficasInstituto de Ciencias del Mar deBarcelonaPlaça del MarE-08039 BarcelonaTel. (34) 932 21 64 50Fax (34) 932 21 73 40

III. Fisheries and aquaculture: Ecological im

pact of fisheries and aquaculture

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Temporal variations in the abundance and location of the resource are also important. Fluctuations in the abundance ofAristeus antennatus have been detected over several timescales, from day–night migrations along submarine canyons toseasonal and long-term cycles of changes in abundance (six to seven years). The wide fluctuations in Aristeus antenna-tus populations and the existence of different population structures by habitats are potential sources of uncertainty, espe-cially regarding the computation of growth parameters. These differences cause problems in the application of assess-ment models leading to significant errors. The current opinion among scientists puts the maximum age for this speciesbetween four and eight years, which is too wide a range and a source of controversy.

The environmental factors that were identified as determining the complex spatio-temporal dynamics of deep shrimpswere the following:

• Bottom geomorphology: Presence of large-scale features such as canyons and channels may determine the large-scaledistribution of the resource.

• The dynamics of sediment movement along canyons and near-bed flows may affect the distribution and temporal evo-lution of red shrimps at several scales.

• The hydrology of the area (movements of water masses and currents), coupled with the bottom morphology, causestransient phenomena which may be responsible for the fluctuations in red shrimp abundance over short and mediumtemporal scales. The local oceanographic conditions may also account for the local abundance and relative propor-tions of species of red shrimps.

• In relation to the previous three points, the overlying production conditions and particle fluxes to the deep sea areimportant in determining the availability of food resources for deep-water shrimps.

Multidisciplinary studies on the distribution, seasonality and migrations of deep shrimp resources in relation to environ-mental factors are necessary in order to contribute to a better understanding of the evolution of the resource and to imple-ment sound assessment and management strategies.

Future lines of research identified during the concerted action are summarised as follows:

• The hypotheses advanced during the seminars on possible links between environmental factors and spatio-temporalvariations on red shrimp resources need to be further elaborated and tested.

• Basic research in aspects of the biology and ecology of red shrimps is necessary. Specifically, detailed studieson trophic ecology, early stages of development and differential ecological preferences of the main red shrimpspecies (Aristeus antennatus and Aristaeomorpha foliacea) are fundamental.

• Two main areas of methodological research were highlighted: the use of time- and space-explicit models to study thecomplex dynamics of red shrimp resources, and research on adequate models allowing the estimates of populationparameters (such as growth parameters) required when applying assessment methods to be improved.

• To apply correctly current assessment models, it is necessary to monitor more extensively the fishing activity and toobtain reliable catch statistics. The use of scientific observers aboard commercial vessels is essential to optimise theuse of official statistics.

During this concerted action, the scientific guidelines were concretely presented at various thematic sessions, discussingthe ideal methodological approach to each subject.

Mobility: A correct management strategy has to incorporate a deep knowledge of the mobility patterns of red shrimps,considering both their population structure and their space–time dynamics.

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Methodology: Determine the spatial and temporal population structure of red shrimp inside and outside submarinecanyons over the 400–900 m depth range. Preliminary research on the possibilities of successful mark-recapture meth-ods.

Causes of mobility: The causal mechanisms of mobility in red shrimps have to be investigated. The knowledge acquiredduring the concerted action point to hydrographic, geomorphologic and trophic factors as central to explain the mobilitypatterns.

Methodology: (i) Establish the relationship between water masses and red shrimp presence; (ii) link the geomorphologicstructure and activity of canyons with red shrimp presence; (iii) determine the structure of benthic food resources andtheir use by deep-water shrimps.

New explorations: The eastern Mediterranean and the deep-sea harbour virgin stocks that have as yet been little explored.An integrated study including biological and fishery aspects is required, in view of the sustainability of the resource, asdeep-water resources are very sensitive to new exploitation.

Methodology: Prospecting surveys in areas of the Aegean and Ionian Seas where the presence of red shrimps has beenestablished. Experimental prospecting surveys along a longitudinal axis across the Mediterranean at depths greater than1 000 m.

Fisheries biology and resource management: Precise knowledge on the reproductive lifespan and growth of the animalis essential in conducting a sound management of the resource. The current deficiencies in the precision and accuracy ofeffort and catch data should also be overcome.

Methodology: Estimates of growth parameters by using alternative mathematical models. Investigate the use of new bio-chemical methods. Study the eco-physiology and reproductive metabolism of deep-water shrimps and their relation toenvironmental factors such as photoperiod. Obtain reliable local maps of abundance, effort and accompanying species inrepresentative ports of the Mediterranean.

In summary, in the present concerted action, it has been established that:

• knowledge on the bio-ecology of deep-water shrimps, which are the object of an important fishing industry, is rela-tively low, especially regarding their complex life cycles, behaviour and auto-ecology;

• research effort is required to establish the basis of efficient regulatory management, and studies of the bio-ecologicalcharacteristics of red shrimp fisheries need to be promoted;

• in this context, we propose an integrated and multidisciplinary framework. The study includes the definition of themost important subjects and the ideal methodology. The scientific scope of the study, the geographical framework andthe scientific, technical and administrative coordination are also analysed.

All aspects emphasised in the course of this concerted action should be studied in concrete geographical areas wherethe existing background is a guarantee of success for the research. Research actions should also be undertaken simultaneously and coordinately. A pragmatic approach to the research actions includes vertical actions and hori-zontal actions. The vertical actions should be conducted in specific areas of well-defined scientific and technicalcharacteristics and should be complementary among them, and extendable to other areas if required. Horizontal actions should be developed homogeneously on all the areas and should employ simultaneous research and stan-dardised methodology.

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FAIR-CT95-0208




FAIR-CT95-0523

Assessment and reduction of the by-catchof small cetaceans

OBJECTIVES

1. To develop methodologies for assessing the magnitude of marine mammalby-catch in selected EU fisheries.

2. To develop a framework for assessing the ecological importance of this by-catch, and collect relevant data.

3. To investigate the way in which the risk of by-catch varies in relation togear type, environmental factors and season.

4. To develop a framework for assessing the relative costs and benefits ofgear modifications and area closures for reducing by-catch, and the socio-economic impacts of such measures.

DESCRIPTION OF WORK

The effectiveness of a range of techniques for determining by-catch rates hasbeen evaluated. Astandardised technique, using independent observers placed onparticipating fishing vessels, has been agreed and used to estimate by-catch ratesin British, Danish and Swedish bottom-set gill-net fisheries in the North Sea andthe Kattegat/Skagerrak, and in the Irish drift-net fishery for tuna. The ecologicalimportance of these by-catches is being evaluated, first by estimating the addi-tional mortality on individual cetacean populations caused by the by-catches andthen by evaluating the likely consequences of this for the status of each species.

The relationship between by-catch rates and various operational features ofeach fishery is being investigated. Trials of various modifications to gear,especially the use of acoustic alarms, have been carried out in the Danish gill-net fishery in the North Sea. A set of computer programs, which can be usedto establish a framework for evaluating the implications of various manage-ment actions, is being assembled.

STATE OF PROGRESS

Progress in year 1 of the project was slow because of delays in appointing newstaff, illness of key staff members, and difficulties in establishing the inde-pendent observer scheme in some fisheries. Permission to extend the project byan additional 12 months was sought from the Commission and this was granted.

Estimates of by-catch rates are now available for all the target fisheries althoughit has only been possible to estimate total by-catch for the Swedish gill-net fish-ery in the Kattegat/Skagerrak. Genetic analysis of material from by-caught andstranded animals has been used to identify at least two distinct populations of



Contract No: FAIR-CT95-0523Total cost: EUR 1 407 413EC contribution: EUR 899 998Starting date: 1.12.1995Duration: 36 months

COORDINATOR

Prof. John HarwoodNatural Environment ResearchCouncilSea Mammal Research UnitGatty Marine LaboratoryUniversity of St AndrewsSt AndrewsFife KY16 8LBUnited KingdomTel. (44-1334) 46 26 30Fax (44-1334) 46 26 32E-mail: [email protected]

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harbour porpoises in the North Sea, and to demonstrate differences between these populations and those in the Baltic andthe Kattegat/Skagerrak. Additional information on population structure from an analysis of contaminant levels, variation intooth structure, and the composition of fatty acids in blubber supports this division.

There have been only one or two dedicated surveys of cetacean abundance in the areas used by the fisheries that are beingstudied in this project. In order to assess the ecological impact of the levels of by-catch estimated in this project, infor-mation on a more detailed spatial and temporal scale is required. Studies are now under way to obtain this informationfrom observations of cetaceans that have been collected opportunistically from surveys directed at other marine species.Studies of the movements of harbour porpoises using satellite-linked telemetry have been conducted.

Participants in the By-Care project have made a major contribution to discussions about the ecological consequences ofthe reported by-catches of porpoises in the Scientific Committee of the International Whaling Commission and in theAdvisory Committee of the Agreement on the Conservation of Small Cetaceans of the Baltic and North Seas. A modelframework for evaluating these impacts has been developed and will be implemented in year 3.

Trials of acoustic alarms, to deter porpoises from becoming entangled in nets, have been conducted successfully in theDanish bottom-set gill-net fishery.

Preliminary work has begun on developing a model framework to evaluate the effects of changes in fisheries practice oncetacean populations and the catches and profitability of relevant fisheries.

ACHIEVEMENTS

A standardised methodology for monitoring the by-catch of small cetaceans using independent observers has been devel-oped and used to estimate by-catch rates in all the target fisheries. These results have been used to estimate total by-catchin the Swedish bottom-set gill-net fishery in the Kattegat/Skagerrak.

Satellite-linked telemetry has been used to follow the movements of a harbour porpoise for 42 days.

Trials of acoustic alarms have indicated that use of these devices can result in a significant reduction in the by-catch ratefor harbour porpoises in bottom-set gill-nets.

FUTURE ACTIONS

Independent observers will continue to monitor by-catch rates in the British and Danish gill-net fisheries and in the Irishdrift-net fishery. Samples from by-caught and stranded animals will continue to be analysed to determine the nature ofthe by-catch and to investigate population structure.

Estimates of total by-catch for each fishery and estimates of cetacean abundance at appropriate spatial and temporalscales will be made,

A model framework for investigating the effects of by-catches on population status (particularly for the harbour porpoise inthe North Sea) will be implemented. The relationship between by-catch rates and operational factors will be investigated.

The model framework for analysing the socioeconomic implications of various management options designed to reduceby-catch will be developed.

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FAIR-CT95-0655

Developing deep-water fisheries: data for theirassessment and for understanding their interactionwith an impact on a fragile environment

INTRODUCTION

In December 1992 the Council of Fisheries Ministers requested the EuropeanCommission (DG XIV) to initiate a study on the state of knowledge on deep-water fisheries, particularly aimed at the possibility of implementing a man-agement system. A meeting of experts was held in June 1993 to review thefisheries and make recommendations. A major recommendation of the reportwas that a precautionary approach should be adopted. ICES also recognisedthe growing importance of these new fisheries and in 1994 a study group onthe ‘Biology and assessment of deep-sea fisheries resources’ was convened. Inreviewing the reports of this group the ACFM has consistently advised that acautious approach should be adopted and that ‘fishing effort should be kept ata low level until sufficient information is gathered from existing fisheries toenable scientifically-based management decisions. The ACFM also recom-mended that a comprehensive data-collection system should be urgently initi-ated and that research on the stocks should be increased to provide the datanecessary for assessment’.

It was against this background that this proposal for research on deep-waterfish and fisheries was developed. Although many of the main concerns relatedto the Atlantic, it was recognised that deep-water fishing was also increasingin importance in the Mediterranean. The fisheries in the two areas are some-what different but it was considered that their joint study would yield newinsights into this poorly known ecosystem.

OBJECTIVES

The objectives of the three-year project, which began in December 1995, areas follows:

1. To describe the deep-water fisheries presently being prosecuted byMember States with particular reference to geographic area, depth ofoccurrence, seasonal distribution, migration patterns, aggregations andother parameters. To record and describe the gears, both mobile and static,which are currently being used for specified fisheries.

2. To make an inventory of existing survey data on deep-water resources andensure that historical data sets are archived. To support the exchange andcollection of survey data.



Contract No: FAIR-CT95-0655Total cost: EUR 3 242 599EC contribution: EUR 1 768 209Starting date: 1.12.1995Duration: 42 months

COORDINATOR

Dr John D. M. GordonScottish Association for MarineSciencePO Box 3ObanArgyll PA34 4ADUnited KingdomTel. (44-1631) 56 78 22Fax (44-1631) 56 55 18E-mail: [email protected]

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3. To describe and quantify the by-catch of unwanted species and undersized fish of target species in the fisheries iden-tified in objective 1.

4. To sample at the markets and accurately record the quantities of species landed with particular reference to fishes thatare not presently identified at species level.

5. To use the information collected by research and commercial surveys and, from past and present market sampling, toprovide data on biological parameters (e.g. age, growth and reproduction) of both target and by-catch species, whichwill be of value for the assessment and management of the resource. An underlying theme will be to consider howthe special environmental factors of the deep waters influence the biological parameters of these species and to under-stand how the fishery will impact on what is generally considered to be a fragile ecosystem.

RESULTS

Objective 1

This task was undertaken by six partners and has resulted in valuable descriptions of these new and rapidly devel-oping fisheries. One of the greatest problems with these fisheries is that they tend to be spasmodic and it is oftendifficult from landing data to determine the target and by-catch species and hence catch and effort data are unreli-able. Good examples are the French fishery for roundnose grenadier (Coryphaenoides rupestris), which in ICES sub-area VI is sometimes targeted and at other times is the by-catch of a targeted blue ling (Molva dypterygia) fishery,and some Spanish deep-water longline fisheries where the degree of targeting of deep-water sharks can depend ontheir market value and the status of the hake (Merluccius merluccius) fishery. In the Mediterranean many of thedeep-water fisheries tend to be more artisanal in nature and the need for their description was only identified forGreece.

Objective 2

This task is being undertaken by seven partners. The work content varies between partners. Some partners (e.g. thosein Germany and Iceland) are compiling all the data from earlier surveys into a database. Others, such as those inIreland and Spain, are compiling both historical and new data into new dedicated databases. At the first meeting ofall the partners, it was recognised that data exchange between partners was of considerable importance and it wasagreed that a data exchange format was a priority. The new exchange format is based on the ICES international bot-tom-trawl survey system but has been expanded to allow for the exchange of biological data such as age and ma-turity. A coding system for new species was developed for the project because no existing system covered the fullrange of deep-water species.

Objective 3

One of the major problems with discard studies on deep-water fish is the correct identification of the species beingdiscarded. The use of terms such as ‘various sharks’ or ‘grenadiers’ is of limited value. There is also the problemof secrecy within the fishing industry, especially in the early development phase. Different partners have addressedthe problem in different ways. Some, such as those in France, Norway and Scotland have had considerable successin sending scientists to sea on commercial vessels. These discard trips have also yielded information and materialfor objective 5. Others, such as those in Greece and Italy, have estimated discard rates by using data collected fromresearch surveys. The composition and quantity of discards depend on the mesh size of the trawl and this is espe-cially important in countries, such as Italy, where the target species are deep-water crustaceans. The discard ratesresulting from the use of different trawls and mesh sizes are being analysed.

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Objective 4

Five partners are undertaking this task. Sampling the landings is usually relatively simple when the fishery is carried outby vessels that remain at sea for long periods and land in one of a limited number of ports. Good examples are the deep-water trawl fisheries of northern Europe. Problems can arise when a by-catch species is only landed occasionally andwithout advance warning. Some deep-water longline fisheries, which are undertaken by smaller vessels on a daily basis,are also relatively easy to sample because they tend to use specific ports. Examples of these are the black scabbardfish(Aphanopus carbo) of Portugal and the deep-water fisheries of Cantabria, Spain. Artisanal fisheries, such as are found inparts of Greece, are more difficult to sample because deep-water species are only landed spasmodically.

Objective 5

This task is being undertaken by all partners but with varying timescales. Considerable emphasis has been placed on sea-sonal aspects of both the geographical and vertical distribution of target and non-target species. It is generally consideredthat deep-water fish are slow growing, live to a great age, have a high age at first maturity and have low fecundity.However, the evidence is often lacking and a key objective of this task is to undertake research on age estimation andreproduction. An ageing workshop was held within the project and the topics covered were wide-ranging. Further work-shops are planned.

DISCUSSION

This is a large project involving 13 partners from 10 Member States and it is perhaps inevitable that each partner shouldwork independently. This is especially true for objectives 1 to 4 where the information is specific to a Member State. Theproject also depends on the willingness of the fishing industry, catchers, marketers and processors, to cooperate. Withonly a few exceptions, their cooperation has been very positive. The opportunities for scientific collaboration are great-est in objective 5 and there have been some useful cooperative ventures especially in the area of age estimation. Theresults will be of great value to organisations with responsibility for giving advice on these fisheries, such as theEuropean Commission and ICES.

DISSEMINATION

Partner 1: Scottish Association for Marine Science, United Kingdom

Publications

Coggan, R. A. (1997), ‘Designation of fishing areas in the north-east Atlantic for deep-water fisheries surveys’, ICES CM1997/Y:11.

Coggan, R. A., Gordon, J. D. M. and Merrett, N. R. (in press), ‘Abundance, distribution, reproduction and diet of nota-canthid fishes (Pisces: Notacanthiformes) from the north-east Atlantic’, Journal of Fish Biology.

Gordon, J. D. M. and Swan, S. C. (1997), ‘The distribution and abundance of deep-water sharks on the continental slopeto the west of the British Isles’, ICES CM 1997/BB:11, 23 pp.

Gordon, J. D. M. and Swan, S. C., ‘Deep-water sharks and rays in the waters to the west of the British Isles’, manuscriptsubmitted for the proceedings of the third European Elasmobranch Conference.

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Partner 2: France(a) Ifremer, Lorient and Boulogne-sur-Mer

Publications

Allain, V. and Kergoat, B. (1998), ‘Biodiversity and demographic strategies of exploited deep-sea fish populations fromthe north-east Atlantic’, Life and Environment (in press).

Dupouy, H. and Biseau, A. (1997), ‘Le grenadier de roche, biologie et état d’exploitation’, in Fiches des éspaces de pois-sons du nord-est Atlantique.

Lorance P. (in press), ‘Structure du peuplement ichtyologique du talus continental a l’ouest des îles Britanniques etimpact de la pêche’, Cybium.

Allain, V., Kergoat, B. and Quiniou, L. (1997). ‘Preliminary studies on discards, reproduction and fecundity of deep-seafishes from Rockall Trough’.

Partner 3: ISH, Germany

None.

Partner 4: Fisheries Research Centre, Ireland

Scientific publications

Connolly, P. L. and Kelly, C. J. (1996), ‘Irish research linked with the development of deep-sea fisheries in the north-eastAtlantic’, proceedings of the Irish Marine Science Symposium, Galway, 1995, Royal Irish Academy.

Connolly, P. L. and Kelly, C. J. (1996), ‘Catch and discards from experimental trawl and longline fishing in the deepwaters of the Rockall Trough’, Journal of Fish Biology, Supplement A, 49, pp. 132–144.

Connolly, P. L. and Kelly, C. J. (1997), ‘Deep-water trawl and longline surveys in 1995’, Marine Institute, FisheryLeaflet, 173, September 1997.

Kelly, C. J., Connolly, P. L. and Bracken, J. J. (1996), ‘Maturity, oocyte dynamics and fecundity of the roundnosegrenadier from the Rockall Trough’, Journal of Fish Biology, Supplement A, 49, pp. 5–17.

Kelly, C. J., Connolly, P. L. and Bracken, J. J. (1997), ‘Age estimation, growth, maturity and distribution of the round-nose grenadier from the Rockall Trough’, Journal of Fish Biology, 50, pp. 1–17.

Kelly, C. J., Clarke, M. and Connolly, P. L. (1997), ‘Catch and discards from a deep-water trawl survey in 1996’, MarineInstitute, Fishery Leaflet, 175, October 1997.

Kelly, C. J., Connolly, P. L. and Bracken, J. J. (in press), ‘Age estimation, growth, maturity and distribution of the blue-mouth rockfish Helicolenus dactylopterus from the Rockall Trough’, ICES Journal of Marine Science.

Maier, K., Gormley, T. R., Connolly, P. L. and Autry, M. (1997), ‘Assessment of underutilised fish species’, Farm andFood, Vol. 7, No 2, summer 1997.

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In preparation

Connolly, P. L., Kelly, C. J., Clarke, M. and Hareide, N. R. (in prep), ‘Deep-water longline survey on the eastern slopesof the Rockall Trough in 1997’, Marine Institute, Fishery Leaflet (in prep).

Clarke, M., Kelly, C. J. and Connolly, P. L. (in prep), ‘Deep-water trawl survey on the eastern slopes of the RockallTrough in 1997’, Marine Institute, Fishery Leaflet (in prep).

Partner 5: University of Bari, Italy

No publications.

Partner 6: NCMR, Greece

No publications.

Partner 7: Ipimar, Portugal

Publications

Figueiredo, I. and Correia, J. P. (1996), ‘Primeira aproximação ao estudo do crescimento do leitão, Galeus melas-tomus’, Rafinesque, 1810 (‘First approach to the study of growth from blackmouth catsharks, Galeus melastomus’,Rafinesque, 1810), Relatórios Científicos e Técnicos do Instituto Português de Investigação Marítima, 17,pp. 1–16.

Correia, J. and Figueiredo, I. (1997), ‘A modified decalcification technique for enhancing growth bands in deep-conedvertebrae from sharks’, Env. Biol. Fish., 50, pp. 225–230.

Viriato, A., Figueiredo, M. J., Figueiredo, I. and Correia, J. (1997), Atlas de apoio à pesca de arrasto na vertente conti-nental portuguesa Instituto de Investigação das Pescas e do Mar, 51 pp.

Figueiredo, I., Figueiredo, M. J. and Correia, J. (in press), Distribuição geográfica e batimétrica de recursos de profun-didade na região algarvia e suas variações sazonais em 1994. Parte I: Peixes ósseos. Instituto de Investigação das Pescase do Mar.

Correia, J., Figueiredo, I., Figueiredo, M. J. and Machado, P. (in press), Distribuição geográfica e batimétrica de recur-sos de profundidade na região algarvia e suas variações sazonais em 1994. Parte II: Peixes cartilagíneos, Instituto deInvestigação das Pescas e do Mar.

Figueiredo, M. J., Correia, J. and Figueiredo, I. (in press), Distribuição geográfica e batimétrica de recursos de profun-didade na região algarvia e suas variações sazonais em 1994. Parte III: Crustáceos, Instituto de Investigação das Pescase do Mar.

Partner 8: Fisheries Research Services, Marine Laboratory, United Kingdom

Scientific papers

Newton, A. W. (1997), ‘Deep-water fishing — A cautionary tale’, SAMS Newsletter No 15, March 1997.

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Partner 9: CSIC, Mallorca, Spain

Scientific papers

Morales-Nin, B., Massutí, E. and Stefanescu, C. (1996), ‘Distribution and biology of Alepocephalus rostratus from theMediterranean Sea’, Journal of Fish Biology, 48, pp. 1097–1112.

Morales-Nin, B., Massutí, E. and Stefanescu, C. (1996), ‘Bathymetric distribution and growth patterns of Ba-thypterois mediterraneus from the north-western Mediterranean Sea’, Journal of Fish Biology, 49, Supplement A,pp. 276–288.

Cartes, J. E. and Sorbe, J. C. (in press), ‘Temporal population structure of deep-water cumaceans from the westernMediterranean slope’, Deep-Sea Research.

Partner 10: More Research, Norway

Reports

Hareide, N.-R., Rasmussen, H. and Thomsen, B. (1996), ‘Report from Exploratory Fishery on the Reykjanes Ridge withthe commercial longliner M/S Borgarin, April–May 1996’, Report No Å9614 from Møre Research, 19 pp. (inNorwegian).

Hareide, N.-R., Dyb, J. E., Dyb, S. and Barstad, S. (1996), ‘Report from Exploratory Fishery on the Mid-Atlantic Ridgewith the commercial longliner M/S Loran, August–September 1996’, Report No Å9701 from Møre Research, 53 pp. (inNorwegian).

Hareid, N.-R. and Thomsen, B. (1997), ‘Common fish stocks — New resources. deep-water fish in international waters’,Report from Nordic Atlantic Cooperation (NORA), 99 pp. (in Norwegian and Danish).

Langedal, G. and Hareide, N.-R. (1997), ‘Report from Exploratory Fishery on the Reykjanes Ridge/Mid-Atlantic Ridgewith the commercial longliner M/S Skarheim, July 1997’, report from the Directorate of Fisheries, 58 pp. (in Norwegian).

Partner 11: IEO, Vigo, Spain

Publications

Piñeiro, C., Casas, J. M., Bañón, R., Serrano, A. and Calviño, A. (1997), ‘Resultados de la Acción Piloto de PescaExperimental en el talud de la Plataforma Continental Gallega (Noroeste de la Península Ibérica)’, Datos y ResúmenesInst. Esp. Oceanogr.V:3, 57 pp.

Bañón, R. and Casas, J. M. (in evaluation), ‘New northern limit for the distribution of N. melanurum and in the northAtlantic’, Miscelanea Zoologica.

Bañón Díaz, R., Casas Sánchez, J. M., Piñeiro Álvarez, C. G. and Covelo, M. (in evaluation), ‘Capturas de peces de afini-didades tropicales en aguas Atlánticas de Galicia (NO de la Peninsula Ibérica)’, Bol. Inst. Esp.Oceanogr.

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Partner 12: Marine Research Institute, Iceland

Publications

Magnússon, J. (1996), ‘The deep scattering layers in the Irminger Sea’, Journal of Fish Biology, 49 (Supplement A),pp. 182–192.

Magnússon, J. V. (1996), ‘Biological parameters — Greater silver smelt, Argentina silus, in Icelandic waters’, Journal ofFish Biology, 49 (Supplement A), pp. 259–275.

A preliminary report of a deep-water cruise in June–July 1997 is in press in an Icelandic fisheries journal.

Magnússon, J., Vilhelmsdóttir, V. and Jakobsdóttir, K. B. (1997), ‘Könnun á djúpslóD . LeiDangur á Reykjaneshrygg áb/v Kaldbaki EA 301, í júni–júlí 1997’, ÆGIR, 1997, 90.arg, 11 t l

–ubl., November, pp. 28–31 (in press).

SigurDsson, ˚., Hjörleifsson, E., Björnsson, H., Magnússon, J. and Pálsson, O. K. (1996), ‘Handbók um Stofnmælingubotnfiska aD haustlagi 1996’, mimeo.

SigurDsson, ˚., Hjörleifsson, E. and Björnsson, H. (1997), ‘Handbók um Stofnmælingu botnfiska aD haustlagi 1997’,mimeo.

The 1997 cruise was also mentioned in: Fisheries, Newsletter of the Union of Fishing Vessel Owners, 6.arg., 5.tbl.,September 1997, p. 7.

In preparation

Magnússon, J., Vilhelmsdóttir, V. and Jakobsdóttir, K. B., ‘Djupslod a Reykjaneshrygg. Könnunarleidangrar 1993 og1997’, (‘Deep-water area at the Reykjanes Ridge. Research cruises in 1993 and 1997’) (in press, HafrannsoknastofnunFjölrit).

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FAIR-CT95-0753

A study of roundfish and Nephrops survival afterescape from commercial fishing gears

OBJECTIVES

1. To investigate the survival of roundfish and Nephrops after escaping fromcommercial fishing cod-ends and Nephrops survival after being discardedfrom the vessel’s deck.

2. To quantify the effects of demersal trawling tow duration on the survivalof commercially important roundfish after their escape from the cod-endand to determine whether the results of these experiments are influencedby the length of time over which the escaping fish are collected in the smallmesh cover that encloses the cod-end.

3. To assess the implications of this information for fisheries management offish and Nephrops stocks.

RESULTS

The sea trials were carried out in the Gairloch area of north-west Scotland inJuly and August of the years 1996–98 aboard a 550 HP commercial trawler. A‘rockhopper’ roundfish trawl fitted with 70 mm and 100 mm cod-ends wasused in 1997–98 to catch haddock and whiting. Cod-end catch weights werelow mean 126 kg and range 21–219 kg. A ‘dual purpose’ Nephrops fish trawlwas used to catch Nephrops and was tested in 1996–97 with three differentcod-ends of 70 mm and 100 mm diamond mesh and 60 mm square mesh. Cod-end catch weights were higher mean 351 kg and range 41–837 kg.

SURVIVAL RATES OF FISH ESCAPING FROM THE COD-END

Prior to the start of each trial, three cages were filled with control fish caughton barbless hooks. Only 13 of these 405 controls died during captivity. Anacoustic release system was developed that remotely closed the aft end of thecover collecting fish escaping from the cod-end and then detached it after agiven collection time. The tow was terminated immediately after release of thecover. The escapees from each survival tow were transferred to a separateseabed cage then fed and monitored for 8 to 10 days.

Eleven of the tows gave similar high haddock survival rates in the range87–97 %; for the other three tows this reduced to 63–78 %. All the tows gavehigh whiting survival rates in the range 90–100 %. A direct comparison of one-hour and three-hour tows in 1998 revealed that tow duration had no significanteffect upon the survival rate for either species.


COORDINATOR

Mr Nicholas LowryDanish Institute for FisheriesTechnology and AquacultureNordsøcentretPO Box 59DK-9850 HirtshalsTel. (45) 98 94 43 00Fax (45) 98 94 22 26E-mail: [email protected]



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Generalised linear modelling was carried out using all measurements of haddock and whiting cod-end escapee survivalrates obtained in the years 1992–98 in the Gairloch area. Mesh size and collection time were found to have a significanteffect upon survival rates of both haddock and whiting. The resultant model predicted that haddock survival rate for a100 mm cod-end would be 90 % with a 15-minute collection time, dropping to 65 % with a 60-minute collection time.Survival rates in a 70 mm cod-end were predicted to be 8 and 18 % lower respectively. It was further found that lengthhad a significant effect with survival rate increasing with haddock length. The model for whiting was more complicatedas collection time and towing speed interacted and fishing depth and total catch weight were also significant.

COD-END SELECTIVITY FOR FISH

Mean selection factors for haddock were in the range 2.7–2.9 and selection ratios (selection range/mesh size) in the range0.48–0.66 in line with previous measurements. A comparison was made of towing times of two hours’ and three hours’duration with the 100 mm cod-end. It was found that there was no significant difference in haddock 50 % retentionlengths but that the selection range was significantly smaller in the three-hour tows (4.4 cm as opposed to 6.0 cm).Further analysis revealed that the selectivity was solely dependent upon the catch weight in the cod-end with the selec-tion range decreasing with increasing catch weight and the 50 % retention length not being significantly changed.

COD-END SELECTIVITY OF NEPHROPS

The mean selection factors for the 70 mm and 100 mm diamond mesh cod-ends were 0.33 and 0.28 based on carapacelength. That for the 60 mm square mesh cod-end was significantly higher at 0.40. The corresponding selection ratios were0.15, 0.19 and 0.17.

SURVIVAL RATES OF NEPHROPS ESCAPING FROM THE COD-END AND DECK DISCARDS

Arandom sample of 96 of the Nephrops escapees in a tow were transferred from the cod-end cover to a pen containing isolatedartificial burrows for each Nephrops. The pens were monitored for 14 days. Creel-caught animals were used as controls andsubjected to the same transfer processes. Only 3 of 576 controls died in captivity. The mean survival rate for cod-end escapeeswas 82 % (range 73–95 %) and for deck discards was 31 % (range 20–41 %). These were not significantly dependent uponcod-end mesh size/type or Nephrops length. The survival rates of discards were significantly lower for females than males.

NEPHROPS DAMAGE ASSESSMENT

An analysis was made of the relationship between mortality and visual body damage. Mortalities showed a significant-ly higher amount of visual damage on the abdomen compared with the survivors for discards but not for cod-endescapees. Total body water content was measured and found to be reduced for cod-end escapees and further reduced fordeck discards with the reduction increasing with time on deck. Deck discards also showed significant reductions in bloodvolume and blood pressure compared with controls.

Nephrops escape from threatening stimuli using a tail-flip mechanism. The number of tail flips that could be elicitedreduced by 53 % on average for cod-end escapees and by 90 % for discards emersed for two hours. The severe exercise

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of trawling and exposure to air on deck were found to result in high l-lactate levels in the blood and muscle tissues (anaer-obiosis), low muscle glycogen levels, high blood D-glucose levels and high blood ammonia levels.

MANAGEMENT IMPLICATIONS

The measured cod-end escapee mortality rates for fish and Nephrops have little effect on results from stock assessmentscompared with uncertainties in natural mortality. The 60 mm square mesh cod-end was found to give a higher 50 %Nephrops retention length than the 70 mm diamond mesh cod-ends currently used commercially. The predicted maxi-mum long-term yield in the Kattegat–Skagerrak is 35 % higher with the square mesh cod-end and can be achieved witha smaller reduction in effort.

PUBLICATIONS

Harris, R. R., Andrews, M. B., Sangster, G. I., Ulmestrand, M., Valentinsson, D., Lowry, N. and Soldal, A. V. (1998),‘Damage and physiological stress in Nephrops norvegicus cod-end escapees and discards’, in Proceedings and abstractsof the fourth International Crustacean Congress, Amsterdam, 20 to 24 July 1998.

Ulmestrand, M. (1998), ‘An assessment of square mesh cod-ends as a conservation strategy in the Skagerrak/KattegatNephrops fishery’, in Proceedings and abstracts of the fourth International Crustacean Congress, Amsterdam, 20 to 24July 1998.

Breen, M., Sangster, G. I. and Soldal, A. V. (1998), ‘Evidence of cover induced mortality in fish survival experiments —A cautionary note’, ICES Annual Symposium, Lisbon, Portugal, September, 1998.

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FAIR-CT95-0817

Monitoring biodiversity in the North Sea usinggroundfish surveys

OBJECTIVES

1. To establish the value of existing national groundfish surveys of the NorthSea as monitors of fish and epibenthic biodiversity.

2. Where possible, to link trends in fish and epibenthic biodiversity forselected non-commercial species as revealed by these surveys with trendsin fishing effort and methods, and/or environmental and ecologicalfactors.

3. To try out and recommend practical methods for enhancing groundfishsurveys so that they better monitor fish and epibenthic biodiversitywithout disrupting their primary functions in the management andassessment of commercial fish stocks. Where necessary, to produce taxo-nomic aids suitable for use on survey vessels using the recommendedmethods.

4. To recommend protocols for the reporting and assessment of trends in bio-diversity in order to monitor the well-being of North Sea fish and epiben-thic ecosystems in relation to commercial fishing.

SUMMARY

Several nations undertake groundfish surveys in the North Sea. This three-year project is intended to show how value may be added to these surveysby monitoring biodiversity of non-commercial species in support of theConvention on Biological Diversity (Rio de Janeiro, 1992). The project isdivided into four tasks. Firstly, existing groundfish survey data on non-commercial fish, and where possible, epibenthic invertebrates, wereanalysed for information on biodiversity. It was concluded, as expected,that fish survey trawls are not good sampling tools for monitoring biodi-versity. Secondly, a 2 m beam trawl constructed from steel was tested atstations throughout the North Sea, and found to be a rugged and depend-able survey tool for epibenthic biodiversity. Attempts are now being madeto standardise towing distances. Thirdly, taxonomic material is being pre-pared to assist scientists on groundfish surveys to readily identify benthicspecies caught by the beam trawl. This is taking the form of a com-puterised database with photographs. A fourth task, to be addressed in thefinal year of the project, is the development of protocols for the reportingand assessment of trends in biodiversity so that the results of any futuremonitoring can be as relevant and accessible as possible.




COORDINATOR

Dr John CotterCentre for Environment, Fisheries andAquaculture Science (CEFAS)Pakefield RoadLowestoftSuffolk NR33 0HTUnited KingdomTel. (44-1502) 52 43 23Fax (44-1502) 51 38 65E-mail: [email protected]

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INTRODUCTION

New political significance was given to biodiversity (1) by the Convention on Biological Diversity signed by Heads ofState at Rio de Janeiro in 1992. Since fishing in the North Sea under the common fisheries policy has been intense inrecent years, and several commercial stocks are reported to be overexploited (Anon., 1994), significant mortalities ofnon-target and rare species are likely to have occurred as well. Changes in the balance of species could have led to a rad-ically altered ecosystem, particularly on and near the sea bottom, parts of which are towed over repeatedly each year byheavy trawling gear. A recent review of global marine biological diversity (Norse, 1993) endorses this point, and statesthat there has been ‘astoundingly little study of the effects of intense fishing pressure on sustainability’ (of the marineecosystem).

Several national groundfish surveys are conducted in the North Sea, and are likely to continue in some form for the fore-seeable future. Aside from their main purpose for estimating abundance indices of commercial fish, they provide recordsof the occurrence of a variety of non-commercial fish and, in some cases, epibenthic (i.e. living on the sea bottom) inver-tebrates which can be caught by the commercial-type trawling gear (usually of the GOV design) fitted with small meshcod-end liners which is used on these surveys. The species collected form a subset of the full range of species present inthese groups in the North Sea, but existing data extend over many years (back to the 1920s for one set). Studies of fishspecies were reported by Greenstreet (1992) and Greenstreet and Hall (1994).

Using small beam trawls, grabs, and/or sonic devices capable of identifying characteristics of the sea bottom, it is possiblethat future information on biodiversity coming from groundfish surveys could be considerably enhanced without necessarilydisrupting normal working practices or adding significantly to costs. It is necessary that special gear be deployable quicklyand easily, and that resources for taxonomic identification are available. Provided that the inconvenience and extra costs ofmonitoring biodiversity could be kept small, countries participating in this project could consider augmenting their surveysfor this new purpose.

Rees (1994) recently conducted epibenthic surveys in the North Sea and elsewhere around England and Wales using a 2m beam trawl with a 10 mm square mesh belly, 3 mm mesh cod-end liner and three tickler chains. More than 300 specieswere found; considerably more than would have been taken by a GOV or similar commercial trawling gear. Comparablebut more intensive surveys of the North Sea epifauna have been reported by, for example, Dyer et al. (1983), Frauenheimet al. (1989) and Duineveld and van Noort (1990). Rees (1994) reports that despite differences in sampling methodology,all have identified a broad division between a ‘northern’ and ‘southern’ fauna approximately along the northern edge ofthe Dogger Bank. This division was similar to that proposed by Glenmarec (1973) for the North Sea, based upon ther-mal stability of the water column.

Fish communities in the North Sea, as revealed by Scottish trawl surveys, were studied by Greenstreet (1992) andGreenstreet and Hall (1994). Differences in diversity and size spectra were found among three north-western regions nearScotland, and between the periods 1929–56 and 1975–93. This implies that existing groundfish survey data can provideuseful information on biodiversity of fish, and that fuller analyses of a wider range of data will be worthwhile. Examplesof special ecological studies of fish communities in the North Sea have been published by Bergstad (1990) and Albert(1993).

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(1) Biodiversity is defined in the convention as ‘the variability among living organisms from all sources including, inter alia, terrestrial, marine andother aquatic ecosystems and the ecological complexes of which they are a part; this includes diversity within species, between species and ofecosystems’.


PROGRESS

1. Analyses of existing national groundfish survey data for biodiversity data about the North Sea were undertaken byeach national partner, and presented at a project symposium held at Aberdeen, Scotland, in March 1997. Specialistsin related fields also presented papers. The collected papers will be submitted to the European Commission as a proj-ect report, and a selection of them is also being assessed for publication. A general conclusion of the work was thatgroundfish surveys using commercial trawling gear catch only a subsample of the marine fauna, and additional gearmust be deployed when monitoring biodiversity is the objective. A 2 m, lightweight steel beam trawl catches addi-tional fish and epibenthic invertebrates, and was recommended as the supplementary gear.

2. Fishing effort by beam and otter trawlers in the North Sea from all fishing nations except Belgium and France hasbeen compiled regionally (by ICES rectangle) for the years 1990–95, and for Norway, Scotland, England and Walesfor 1977–89. These data will permit variations in trawling effort to be compared with variations in epibenthic com-munities and demersal fish.

3. The 2 m beam trawl has been extensively fished on a wide range of substrate types in the North Sea, and found to bea rugged and dependable device for sampling the epifauna. A device to monitor the time spent actually fishing on thebottom has satisfactorily undergone preliminary trials, and is being developed further to permit the distance trawledto be standardised, an important consideration when assessing the occurrence of rare species. Trials have also beenmade with benthic grabs but these are less satisfactory because of variable performance on different substrates, thesmallness of the sample, and the time and expertise taken to process the sample. This may mean that the infauna arenot routinely sampled by a biodiversity monitoring programme as part of a groundfish survey. In addition, equipmentto assess the sea floor acoustically has been tested. These are likely to provide a useful supplement to trawl samples.A photographic archive of over 100 epibenthic species has been assembled for preparation of a taxonomic guide. Thephotos are being edited electronically and put into a computerised database to assist rapid identifications at sea witha minimum of specialised knowledge.

4. A working group has been arranged for April 1998 to test possible methods of analysing and reporting epibenthic bio-diversity data. The data recently collected with the survey trawl by several project participants will be used.

DISCUSSION

Experience in the first two years of this three-year project has indicated that monitoring of epibenthic biodiversity dur-ing national groundfish surveys in the North Sea is definitely feasible. Additional costs would be minimal. The epiben-thic environment is, of course, only part of the marine system, and a recommendation to monitor the species present thereas part of a groundfish survey would not be meant to deny the importance to biodiversity of the benthic infauna, plank-ton, pelagic fish, marine mammals, sea birds, etc. The problem with including these components in a monitoring pro-gramme is that they require special facilities and/or large amounts of time, which may not be available on all groundfishsurveys. The epibenthos also have particular relevance to studies of fish and fishing because they are directly vulnerableto heavy trawling gear, and because they form a component of fish diets.

An environmental concern about the North Sea is that many epibenthic species are opportunistic scavengers feeding onthe living material broken or exposed by trawls, or on the fish caught and subsequently discarded from the fishing ves-sels. A time series of epibenthic monitoring data obtained from a good spread of localities in the North Sea, as would bepossible using groundfish surveys, could help us to assess this concern, particularly if good figures on the locations oftrawling effort can be obtained for the same time periods. The data collected so far on fishing effort by ICES rectanglereflect a valuable new international effort. Finer resolution geographically may be obtainable from national enforcementactivities such as aerial spotting, but so far data from only one country have been obtained.

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There are undoubtedly several other factors, apart from trawling effort, which help to shape epibenthic communities. Aregular and complete series of monitoring data could provide the raw material for many academic and applied studies ofthese factors. One interesting study already begun in association with this project concerns the influence of life historystrategies of different species on their present-day survival in the North Sea. However, in addition to the needs of scien-tists, a biodiversity monitoring programme should also provide information in summarised form to fisheries managers,other marine authorities, and interested members of the public. It is these people who will decide whether somethingshould be done to alter any ecologically unsatisfactory situations which come to light. The challenge will be to captureand hold their attention with some kind of annual report on biodiversity monitoring data.

REFERENCES

Albert, O. T. (1993), ‘Ecology of some small demersal fish of the north-eastern North Sea and Skagerrak’, D.Sc. thesis,Department of Fisheries and Marine Biology, University of Bergen, Norway.

Anonymous (1994), ‘Report of the Working Group on the Assessment of Demersal Stocks in the North Sea andSkagerrak’, ICES C.M. 1994/Assess: 6.

Bergstad, O. A. (1990), ‘Ecology of the fishes of the Norwegian deep: distribution and species assemblages’, Netherl. J.Sea Res., 25, pp. 237–266.

Duineveld, G. C. A. and van Noort, G. J. (1990), ‘Geographical variation in the epifauna of the southern North Sea andadjacent regions’, mimeo, ICES CM 1990/Mini: 9, 11 pp.

Dyer, M. F., Fry, W. G., Fry, P. D. and Cranmer, G. J. (1983), ‘Benthic regions within the North Sea’, J. Mar. Biol. Ass.UK., 63, pp. 683–693.

Frauenheim, K., Neumann, V., Thiel, H. and Turkay, M. (1989), ‘The distribution of the larger epifauna during summerand winter in the North Sea and its suitability for environmental monitoring’, Senckenbergiana Marit., 20, pp. 101–118.

Glenmarec, M. (1973), ‘The benthic communities of the European north Atlantic Shelf’, Oceanogr. Mar. Biol. Ann. Rev.,11, pp. 263–289.

Greenstreet, S. P. R. (1992), ‘Changes in the fish community of the North Sea between 1972 and 1991’, working paper,ICES Study Group on Ecosystems Effects of Fishing Activities, April 1992.

Greenstreet, S. P. R. and Hall, S. J. (1994), ‘Examining fish community structure in the north-western North Sea: a pre-liminary analysis’, working paper, ICES Study Group on Ecosystems Effects of Fishing Activities, April 1994.

Norse, E. A. (1993), Global marine biological diversity. Center for Marine Conservation, Island Press, 1718 ConnecticutAvenue, Washington DC, 383 pp.

Rees, H. L. (1994), ‘Surveys of the epifauna in UK and adjacent waters’, in Aquatic Environment Monitoring Report1994, Directorate of Fisheries Research, Burnham on Crouch, Essex, United Kingdom (in press).

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PUBLICATIONS

Nine papers from the symposium held in Aberdeen in March 1997 are being assessed for publication in FisheriesResearch.

‘The effects of fishing on marine ecosystems’ by S. Jennings and M. Kaiser has been prepared and accepted for publi-cation by Advances in Marine Biology.

‘Life history correlates of responses to fisheries exploitation’ by S. Jennings, J. Reynolds and S. Mills has been preparedand accepted for publication in Proceedings of the Royal Society.

DISSEMINATION ACTIVITIES

Symposium of project participants and other European scientists with related interests held in the Marine Laboratory,Aberdeen, on 18 and 19 March 1997.

Nine papers from this symposium are being assessed for publication in Fisheries Research.

‘The effects of fishing on marine ecosystems’ by S. Jennings and M. Kaiser has been prepared and accepted for publi-cation by Advances in Marine Biology.

‘Life history correlates of responses to fisheries exploitation’ by S. Jennings, J. Reynolds and S Mills has been preparedand accepted for publication in Proceedings of the Royal Society.

The principal outputs from the project, concerning sampling protocols, taxonomic aids, and reporting protocols, whenfinalised, will be circulated to other groundfish survey countries.

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FAIR-CT96-1452

Evaluation of mesh measurement methodologies forfisheries inspection and research

OBJECTIVES AND DESCRIPTION OF WORK

The overall objective of the concerted action was to evaluate the present meshmeasurement procedures for fisheries inspection and for research as used inthe EU, to identify the problems related to these measurements and to definethe requirements for a mesh gauge suitable for both inspection and scientificpurposes.

To fulfil this objective a detailed review and comparison was made of presentmesh measurement methodologies in and outside the EU, involving problemsarising from the use of specific netting. Essential in the evaluation process wasthe organisation in each participating country of hearings involving fishermenand netmakers to define the problems encountered in the industry. Based on allinformation gained, the requirements for a model mesh gauge were describedand recommendations for future work, i.e. the development of a new gauge tobe used by both fisheries inspectors and scientists in the EU, were made.

RESULTS

Most of the participants agreed that the present EU legislation for mesh sizemeasurement is not sufficiently precise and allows for variation in both theconstruction of the official wedge gauge and the operational procedures. Thismay lead to different results due to the use of mesh gauges that differ or tohuman influences when performing the measurement.

This does not mean that all inspection agencies reject the present EU meas-urement technique. A number like the simplicity of the EU wedge gauge andoppose drastic change. Others think that in the present situation it is not pos-sible to make objective measurements. The majority of the participants are ofthe opinion that the essential requirements for reliable mesh measurementscannot be fulfilled by one of the existing instruments and recommend thedevelopment of a new mesh gauge.

The hearings organised in each country demonstrated that the industry’s viewon the problem runs remarkably parallel with that of the inspectors and scien-tists. The problems seem to be related to the targeted fish species and the fish-ing methods used.

The netting manufacturers and netmakers are in a particularly difficult posi-tion. Some groups of fishermen request netting with a mesh size as close as


COORDINATOR

Mr Ronald FonteyneMinisterie van Middenstand enLandbouwDepartement voor ZeevisserijAnkerstraat 1B-8400 OostendeTel. (32-59) 32 08 05/32 03 88Fax (32-59) 33 06 29E-mail: [email protected]



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possible to the legal minimum to fish legally with minimal losses of marketable fish. Both the changes in mesh size dueto use and variability in the results of mesh size measurement make this difficult to accomplish. In this respect, the intro-duction of quality standards for netting materials would be a major step forward.

There was a broad agreement between most inspectors, scientists, fishermen and the netting industry on the followingpoints about the wedge gauge:

• the description in the EU regulations of the wedge gauge allows for differences in the construction of the instrument;• the EU wedge gauge does not allow an objective measurement due to the use of hand force;• skippers rarely contest the outcome of the measurement by hand as measurement with a weight mostly yields lower

average mesh sizes;• most courts in the EU member countries do not accept mesh measurements made with the use of a dynamometer;• some shapes of weight are claimed to be impractical and unsafe when boarding vessels.

The inspectors made the following comments on the measuring procedure:

• the procedure is too complex and time-consuming;• it is not clear whether fishermen are allowed to clean the nets before inspection;• the selection of 20 successive meshes in large mesh cod-ends can be difficult;• the position of the mesh gauge relative to the knots should be specified;• the position on the gauge to read the mesh size should be specified;• the procedures for most EU waters and the Baltic Sea area are slightly different and should be uniform.

In general, scientists use the ICES mesh gauge. Due to the fixed measurement force, this instrument is much lesssusceptible to human influences. The measuring force is determined by a spring, a principle that is generally not ac-cepted by courts. The instrument needs regular calibration to ensure that the correct force is used. This can be re-garded as a drawback but is also a guarantee of a consistent mesh measurement procedure. The ICES gauge needsmore maintenance and the instrument is known to be liable to wear. The instrument is regarded as being too frag-ile for inspection purposes. There is a lack of uniformity in the measuring procedures used in research and there isa need to define the spring forces appropriate to different twine sizes.

The ICES gauge gives lower average mesh openings than the wedge gauge (either by hand force or 5 kg weight). Thisshould be taken into account when defining minimum mesh sizes based on selectivity research in which the ICES gaugehas been used.

Although the report does not exclude the use of different gauges, which may be preferred and used by enforcement agen-cies and scientists, the majority of the partners were of the opinion that the use of two instruments to determine the samemeasure was illogical and inefficient.

The industry strongly criticised the mesh measuring procedures used for inspection, in particular:

• that the measurement is not objective, due to the use of hand force. It leads to inconsistency between individualinspectors and between fisheries inspectorates;

• that the 5 kg weight is too small to stretch the mesh completely in thick twine netting and could be increased;• that mesh size is not measured in the same way at all stages from netting manufacturer to inspector;• that the imprecision of the mesh gauge be taken into account by inspectors.

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The participants in the concerted action rejected the argument for a tolerance to be applied to the average measured meshsize. It was feared that if this was allowed fishermen would work towards the smallest possible mesh size. The idea ofcertificated netting or cod-ends was regarded as unworkable since it obscures responsibility for undersized netting.

The wedge gauge and to a lesser extent the ICES gauge are not always suitable instruments to measure the mesh sizes ofsome types of netting. Differences in construction and material properties, such as elasticity, stiffness and friction, canlead to different readings being obtained from different netting with the same mesh size.

Determination of the mesh size of fine netting was not discussed in detail since the gears using this netting now fall underCommission Regulation (EC) No 2550/97 of 16 December 1997. The participants regretted that the instrument describedin the new regulation has the same shortcomings as the EU wedge gauge. The description allows for too much variationin the construction of the instrument and it was felt that a better defined gauge for passive gears is needed. Since theinstrument should be operated by hand force only, the objectivity of the measurement may again be questioned.Furthermore, it was stressed that the introduction of any new measuring instrument or procedure should be preceded bycareful testing.

Thick twine netting causes problems for mesh measurement: positioning of the gauge relative to the knots; reading themesh size off the scale; handling the cod-end to make the measurements; selecting 20 consecutive meshes.

In small mesh cod-ends attaching the weight can be a problem.

Some types of netting can reduce the selectivity of the cod-end although the mesh size may be legal. The use of specialnetting to reduce selectivity can best be discouraged by legislation to ban the use of such material. The use of special net-ting or devices to improve selectivity, however, may require instructions on how to measure the mesh size, e.g. Swedishexit windows.

Other existing ways of measuring mesh sizes were considered but none was found to have major advantages over thewedge gauge or ICES gauge.

The one-dimensional nature of current mesh measurements does not penalise the use of netting designed to reduce selec-tivity. A two-dimensional measurement method is needed but the problems identified by the participants in developingsuch a device, e.g. a cone gauge, suggest that it will be a long-term task.

The participants agreed on the requirements for a model mesh gauge. It was recognised that none of the existing meshgauges met these requirements. Hence, it was recommended that such an instrument be developed, preferably in theframework of an EU research programme.

Considering that the development, testing and implementation of a new instrument may take a long time, a number ofimprovements to the existing EU gauge were proposed, aimed at further standardisation of the instrument and the oper-ating procedure.

DISSEMINATION ACTIVITIES

Hearings were organised in all 13 participating countries to inform the fishing industry (fishermen and netmakers) aboutthe project and to learn the industry’s view of the problem. A list with venues and dates is given below.

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As an introduction to the hearings articles on the project were published in most national fisheries journals. Some jour-nals also reported on the hearings proper.

The project was presented in Fishing News International (March 1997).

A small press conference was held after the first project meeting in Sweden (January 1997).

The progress of the project was presented to the ICES Working Group on Fishing Technology and Fish Behaviour(FTFB) at its 1997 and 1998 meetings (Hamburg, Germany, 14 to 17 April 1997; La Coruña, Spain, 20 to 23 April 1998).

As a result of the concerted action, ICES was asked to review the procedure for measuring mesh sizes with the ICESgauge at the 1998 Annual Science Conference (Cascais, Portugal, 16 to 19 September 1998). The request was acceptedand a recommendation on this topic was made to Working Group on Fishing Technology and Fish Behaviour.

The project and its outcome were presented to the working group involved in the drafting of European standards on fish-ing nets (CEN — TC 248/WG 3: Fishing nets) at its meetings in Brussels on 3 February 1998 and in Paris on 13 October1998. The results of the project will be taken into account when drafting a standard on methods for the determination ofmesh size.

After approval of the final report by the Commission, the national partners will disseminate the results to the fishingindustry in their respective countries. The results will also be communicated to the international fishing press.

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FAIR-CT96-1531

Selectivity database

OBJECTIVES

This proposal is a concerted action with 13 partners which aims to define thespecifications and conditions for use and maintenance of a selectivity database.The creation of such a database is a wish expressed by various groups within theInternational Council for the Exploration of the Sea (ICES), but which has notyet materialised. This project brings together several disciplines in many EUMember States with relevance to the subject, i.e. fishing gear technology andselectivity, information technology and database expertise, and fish stock as-sessment biology. ICES is actively participating as possible host for the data-base, with fisheries institutes and universities in the Netherlands, Scotland,Denmark, Belgium, Sweden, Norway, Portugal, Greece, Germany and France.The project is managed through three plenary discussion meetings, and in be-tween work is to be done by correspondence. Participants will collect informa-tion on available computer facilities and software, as well as selectivity data.The result of the project will be a document containing information on how toset up a database with selectivity data, including its specifications, and esti-mates of the costs for creating and maintaining the database, as well as recom-mendations as to where it should be housed.

SUMMARY

Selectivity data are used in mesh assessments by assessment biologists. Estimatesof fleet selectivity are necessary to calculate fishing mortality rate at age. The ob-jective of this feasibility study was to define the specifications and conditions forcreation, use and maintenance of a database containing fishing gear selectivity in-formation. The project was split into 16 tasks, among which three were plenarydiscussion meetings, an inventory of needs with potential users, an inventory ofavailable computer facilities and software, an inventory of available selectivitydata, and cost estimates for creating and implementing the database as well as fill-ing it with data. A total of 20 experts participated. Database options consideredwere: an on-line catalogue only; an on-line catalogue with an exchange format; anon-line catalogue with a user data screening program; a central store of ASCIIfiles with an on-line catalogue (website) and extract bunch of data; a hosted data-base with an on-line catalogue (website) and extract subset of data. The variousoptions were scored against a set of criteria involving quality, availability, secu-rity, ease of management, relevance, ease of use, data extensibility, function ex-tensibility, effort for data provider, and turnaround time, after which the hosteddatabase with an on-line catalogue (website) and extract subset of data seemed tooffer the best value for money, although the costs for software development, datahandling and future management are the highest of all the options compared. Thegroup also produced draft lists of variables at experimental and at haul level withfield specifications, and thoroughly discussed a follow-up project proposal.


COORDINATOR

Dr Bob Van MarlenDienst Landbouwkundig OnderzoekRijksinstituut voor VisserijonderzoekHaringkade 1Postbus 681970 AB IJmuidenNetherlandsTel. (31-255) 56 46 46Fax (31-255) 56 46 44E-mail: [email protected]



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FAIR-CT96-1994

Improving technical management in Baltic cod fishery

OBJECTIVES

1. To provide quantitative measurements of dominant factors which causevariability in trawl cod-end selectivity in Baltic cod fishery, and to developcod-end modifications and operational approaches that will improve trawlsize selection relative to present designs.

2. To develop, test and apply improved methodology for estimating theescape-survival of cod under commercial fishing conditions, and to iden-tify cod-end designs which may enhance survival.

3. To develop a model for assessing biological and socioeconomic conse-quences of improved selectivity in the Baltic fishing fleet.

DESCRIPTION OF WORK

The project consists of the following specific tasks:

Task 1.1: Development of a new cod-end cover;Task 1.2: Development of methodology for assessing fish survival;Task 2: Assessment of optimal window position and window/cod-end mesh

size;Task 3: Effect of season, vessel size and vessel gear interaction on selectiv-

ity;Task 4: Effect of vessel type/hauling technology on selectivity;Task 5: Escape mortality and skin injury of cod under commercial fishing

conditions;Task 6: New innovative cod-end designs;Task 7: Data processing;Task 8: Modelling of biological and socioeconomic impacts;Task 9: Project management and technology transfer.

ACHIEVEMENTS

The top-panel window cod-ends showed higher L50 values than the corre-sponding standard cod-ends. In window cod-ends a pronounced positive cor-relation was observed with L50 and selection range (SR). The confidenceregions, however, were relatively large for the 125 mm and 135 mm windowcod-ends.

The cod-end without the cover caught on average 15 % more cod than the cod-end with the cover. The variation in catches between the hauls, however, was




COORDINATOR

Dr Petri SuuronenFinnish Game and Fisheries ResearchInstitutePukinmäenaukio 4PO Box 6FIN-00721 HelsinkiTel. (358-9) 205 75 12 20Fax (358-9) 205 75 12 01E-mail: [email protected]

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fairly large. The cod-end with the cover caught significantly less cod below 45 cm than the cod-end without the cover.The hauls made without the cover had a substantially larger variability in individual selection curves, and the L50 andSR of the combined hauls were higher.

A large between-haul and between-vessel variability in selectivity was obtained in vessel size experiments. Vessel size,however, was not found to have any clear effect on the L50. On the other hand, indications were obtained that vesselhauling technology can be a potentially important factor causing variability in selectivity. The best selectivity in terms ofL50 was found on a side trawler. This difference is probably connected to the duration for which the gear is slack duringthe haul-back. Indication of a negative correlation with catch size and L50 was obtained.

A slightly higher survival was obtained in the ultra-cross window cod-end escapees (99.2 %) than in the Danish exit win-dow cod-end escapees (94.6 %). Generally, the survival of trawl escapees was very high. No seasonal or catch size effectin mortality was noticed. It is noteworthy, however, that hauls were conducted with fairly small catches in 1998.

Fish length was the main factor affecting the probability of fish being injured; the bigger the fish the more probable itwill have an injury. Fish escaping from a conventional diamond mesh cod-end had a higher injury probability than thoseescaping the Danish exit window cod-end. Cod-end catch weight (kg) negatively affected the injury probability and inparticular net marks and bleeding lesions. Water temperature strongly and positively affected the scale loss probabilitybut had no effect on bleeding lesions.

The turned-mesh-cod-end configuration appeared to be a simple and efficient way to open the cod-end meshes andimprove the cod-end selectivity. More experience and data, however, are required for final conclusions. Possibilities toimprove on-deck handling should be investigated.

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FAIR-CT96-2001

A review of acceptable means by which towed geardiscards may be reduced in ICES areas VII and VIII

OBJECTIVES

The main objective of this concerted action was to find a framework withinwhich discards could be reduced in the towed gear fisheries of any given fish-ing area. Specifically the work aimed to:

• review the fisheries being prosecuted in areas VII h and j and VIII a and b;• review the available information on seasonal catch profiles and discard

rates;• determine the main biological and commercial aspects of those fisheries;• agree national priorities for change through industry liaison groups; and• seek consensus on the discard reduction priorities from the fisheries in

question through a liaison group of fishermen from all four countriesinvolved.

RATIONALE

The concept behind this project was fairly novel. It sought to find ways offorming a partnership between practising fishermen, fishing gear technologistsand other researchers. The work programme involved looking at variousaspects of the motivation and incentives for fishermen to behave (as regardsfish) in certain ways, at the market forces affecting the operational decisionstaken by fishing skippers in a given fishing area, and at the management pro-tocols affecting that area. It took advice on the biological (stock) priorities thatshould influence management policies and tried to match the existing suite ofby-catch reduction devices to those biological priorities.

On the ground, the work offered ownership of this process and its conclusionsto national groups of involved fishermen and then brought those nationalgroups together so that they could start to identify common objectives. Theconclusion of the process was the identification of a research programme thatcould be proposed to the Commission for funding.

When the proposal was being formulated, it was recognised that many aspectsof the work would need to be handled carefully. A lot of relevant informationwas known to be commercially sensitive and fishermen may be reluctant tocommit themselves to a process with long-term implications. For these rea-sons, much of the early exploratory work in this contract was not brought intothe public domain.




COORDINATOR

Mr John Edward TumiltySea Fish Industry AuthoritySeafish Technology18 Logie MillLogie Green RoadEdinburgh EH7 4HGUnited KingdomTel. (44-1482) 32 78 37Fax (44-1482) 22 33 10E-mail:[email protected]

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The report on this contract deals mainly with the proceedings of the international workshop that was the culmination ofthe project. At that meeting the various national delegations discussed, and eventually agreed, how they wanted to takethe initiative forward. It became clear at the meeting that the fishing communities of the various partners were both will-ing and able to act cooperatively. This was demonstrated by the fishermen agreeing to cooperate in a research programmethat should lead them towards a future of more sustainable and profitable fishing.

A workshop took place at the end of March 1998 in the UK. It was attended by fishermen, vessel owners, biologists andtechnologists from each of the partner nations and a fisheries economist. It involved presentations by each of the sectoralgroups. The information presented covered the industry views of the state of their fisheries as well as available data ondiscarding practices and the technical measures that could be used to reduce them.

CONCLUSIONS

After this phase of the discussion, the group went on to consider the ways in which a research proposal could be framedthat would be acceptable to all concerned. The group agreed a number of general points about such a proposal whichwould cover three main areas over a three-year period:

• development and demonstration of technical measures intended to increase selectivity and reduce discards in appro-priate fisheries;

• economic and biological modelling of the consequences of introducing these measures to the fleet; this would exam-ine the economic effects at boat and fleet level and consider medium- and long-term predictions;

• examination of a range of other factors which may affect the feasibility of introducing improved selectivity. Thesemight include market dynamics, the import of small fish and the potential to devise ‘hybrid’ packages — for exam-ple, a combination of new technical measures and quota swap arrangements.

Working out the proposal would require liaison groups to be set up which would bring together each country’s fishingindustries and researchers. These groups would be responsible for reviewing the draft research proposals and amendingthem as necessary before agreeing a final version to be submitted to the Commission.

As for the sea trials that would be used to evaluate the candidate technical measures, it was agreed that they should becarried out with:

• modified standard commercial gear;• coverage of all fishing seasons;• provision for independent observers — swapping trials’ staff;• regular by-catch/discard sampling of other boats in the fleet;• scientific rigour and full statistical analyses;• a representative range of boats, gear types and ground conditions; and• adequate financial support for the trials’ vessels.

Regarding the economic aspect of changed selectivity, it was agreed that the study should include:

• building economic models of the operations of representative boats;• extrapolating boats’ economic performance to sub-fleet and fleet levels;

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• identifying the short-term losses associated with the introduction of new technical conservation measures;• identifying and calculating the medium- to long-term biological benefits for the stocks concerned;• identifying the realities of market conditions and influences; and• determining the range of economic impacts that would be commercially acceptable to the boats and fleets involved.

In addition to the liaison groups discussing gear technology, there would need to be forums in which to discuss the econo-metric and fish stock aspects of the work. Accordingly, there would be ad hoc sub-groups set up for these purposes. Theeconomists would generally be drawn from the European Association of Fisheries Economists and the biologists fromappropriate ICES working groups.

The group also agreed the fisheries where there was the most urgent need to reduce discards. These were Nephrops(prawn) trawling where there was a by-catch of small finfish with little or no commercial value, general benthic trawl-ing showing high by-catch levels of small megrim, monkfish, sole and ray — all of which were discarded, general dem-ersal trawling with a discarded by-catch of small haddock, and general demersal trawling showing poor size selection forhake. It was tentatively agreed that the prime responsibility for the above tasks should be Nephrops trawling (Ireland),general benthic trawling (France), haddock discards (UK), and hake selectivity (Spain).

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FAIR-CT98-3536

Selective white fish grid system for demersal towedgear fisheries in the North Sea and adjacent waters

OBJECTIVES

To develop a selective, user-friendly grid system for the bottom-trawl andseine net fisheries for white fish in the North Sea and adjacent waters, with theaim of reducing the by-catch of juvenile fish, and thus provide a more sus-tainable exploitation pattern for demersal gadoid fish species.

The catches and discarding of juveniles and the by-catch of both fish and otherspecies are two of the major problems in the North Sea fisheries. The ultimateobjective of the project is to develop a selective grid system for demersaltowed fishing gears that reduces this waste of resources to a minimum.


COORDINATOR

Dr Ole Arve MisundInstitute of Marine ResearchNykirkekaien 1PO Box 1870N-5024 BergenTel. (47) 55 23 68 05Fax (47) 55 23 68 30E-mail: [email protected]



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FAIR-CT97-3805

Sustainable fisheries � How can the scientific basisfor fish stock assessments and predictionsbe improved?

OBJECTIVES

The objective of the project is to examine whether existing scientific knowl-edge can be better utilised for reducing the uncertainties and increasing thetime horizon of fish stock assessments carried out by ICES and other stockassessment agencies/institutions, and to evaluate the implications for fisherymanagement. The long-term goal is to develop stock assessment and predic-tion models which utilise all relevant knowledge of importance for fish popu-lation dynamics, including species interactions and the effects of a fluctuatingenvironment, and thereby increase both the time horizon and reliability of ourpredictions. The short-term goal is to identify key variables to be used in pre-dictive relationships and coordinate research to establish such relationshipsand gradually implement them into the assessment models. The projectincludes the following sub-objectives:

1. to identify the main causes for shortcomings in present fish stock assess-ments and predictions;

2. to consider the limits set by nature on predictability of fish stock develop-ment;

3. to review the state of the art within relevant research areas and identify thekind of scientific knowledge potentially useful in fish stock predictionswhich exists without being effectively used at present, and to discuss howsuch knowledge could most effectively be used and propose future coordi-nated research for expanding the scientific knowledge relevant for fishstock assessment;

4. to carry out case studies for selected areas and stocks with the aim ofdemonstrating the potential for improvements in quality and time horizonof fish stock predictions;

5. to evaluate how communication/cooperation between fish stock assess-ment experts and experts within various fields of basic marine sciences canbe improved.

Assessing fish stocks and predicting their development are complicated tasksfor two main reasons: there are great methodological difficulties in estimatinghow many fish there are in the sea at any given time, and our knowledge ofthe dynamics of the stocks and key environmental driving forces is insufficientfor making precise predictions of the development. A large research effort hasbeen devoted in recent decades to the various aspects of stock estimation, pop-ulation dynamics and environmental effects, but a concerted effort towardsintegrating the various aspects of scientific knowledge in an attempt to




COORDINATOR

Prof. Øyvind UlltangUniversity of BergenDepartment of Fisheries and MarineBiologyHIB, Thormøhlens Gate 55N-5020 BergenTel. (47) 55 58 44 57Fax (47) 55 58 44 50E-mail: [email protected]

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identify key variables and relationships for improving our stock predictions is needed. However, present fish stockassessment practice is characterised by too sharp a de facto separation of fish stock assessment experts and experts with-in various fields of basic marine sciences. This hampers the optimal use of available scientific knowledge in the stockassessment process. Therefore, the project involves experts within the following three broad research areas (topics):

Topic 1: Variability of the marine physical environment and its effects on fish stocks;Topic 2: Population dynamics including species interactions;Topic 3: Population dynamics/stock assessment models, including multispecies models.

An attempt has also been made to involve experts from very different geographical areas. In the north–south direction,the following three major areas are represented:

Area 1: Norwegian and Barents Seas and Icelandic waters;Area 2: North Sea, the Skagerrak/Kattegat and the Baltic;Area 3: Areas west of the Iberian peninsula and the Mediterranean.

The project will coordinate activities with the aim of conducting critical investigations of possible predictive relation-ships to be used in stock assessments. This will include scrutinising published literature where such relationships are sug-gested, or where analyses are given which may be used to construct relationships. In addition to evaluating the sound-ness of proposed relationships from published material and discussions, the project will carry out its own investigations,using long time series of physical and biological data, either from published literature or from available databases, as onemain source for testing proposed relationships.

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FAIR-CT97-3809

Reduction of adverse environmental impactof demersal trawls

OBJECTIVES

EU-funded research has shown that commercial beam trawling has detrimen-tal effects on the structure and composition of benthic communities in theNorth Sea, as does otter trawling for Nephrops in the Irish Sea. It appears thatshort-lived species are favoured while longer-lived species are more adverse-ly affected, with the result that the disturbed communities may favour scav-engers and predators other than fishery target species. Reducing potentialdamage to longevous benthic invertebrates could result in more viable stand-ing crops of prey for target species. This project seeks to find technical solu-tions whereby the adverse effects of demersal trawls on benthic organisms canbe significantly reduced.

The main objective is to assess methods to reduce the adverse impact of dem-ersal trawls on benthic marine organisms through changes in net design andalternative methods of stimulation. The work programme will therefore:

• review alternative techniques that could reduce the adverse effects of dem-ersal trawls on marine benthic organisms, and to identify, in cooperationwith the fishing industry, those with most promise for further investigation;

• investigate the practical feasibility of the identified alternative techniqueswith respect to the following criteria: reduction of fish/benthos by-catch,effectiveness, economy; acceptability to the fishing/scientific community;and the refining of selected alternatives, driven by the requirement thatcatch levels can be maintained with emergent new gear designs;

• evaluate the impact of the modified gear by taking representative benthossamples prior to and after their passage along accurately demarcated transects.The results will be disseminated to the fishing industry and the scientific com-munity, using appropriate paper documentation and a dedicated video/CD.

Modification to existing techniques and novel approaches will be explored bothin liaison meetings with fisheries and those with scientific interests and in flumetank experiments, prior to a programme of planned sea trials. Approaches iden-tified for study at this time (i.e. ahead of a planned review of this whole area ofactivity) include changes in stimulation systems (e.g. new chain arrangements,water jet injection and electrical stimulation) and in net design (e.g. the incor-poration of benthos release holes or separating panels). The practical feasibilityof the most promising techniques (including considerations of equipment han-dling, durability and maintenance) will be investigated through sea trials. Ef-fects on benthos mortality will be determined in the field by taking benthic sam-ples before and after the passage of the gear. Recommendations will then bemade on the most effective and acceptable solutions to these problems.




COORDINATOR

Dr Brendan F. KeeganUniversity College GalwayThe Martin Ryan Marine ScienceInstituteUniversity RoadGalwayIrelandTel. (353-91) 70 53 51Fax (353-91) 52 50 05E-mail: [email protected]

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FAIR-CT98-4044

Selectivity database-2

SUMMARY

This proposal is a logical follow-up to the concerted action FAIR-CT96-1531selectivity database (Seldat), in which the specifications and conditions for useand maintenance of a selectivity database were investigated. Fishing geartechnology and selectivity, stock assessment, information technology anddatabase experts from 14 organisations in the Netherlands, Scotland,Denmark, Belgium, Sweden, Norway, Portugal, Greece, Germany, and Francewill cooperate in three small teams to define a detailed requirements’ specifi-cation and acceptance tests for the selectivity database. A consultant will becontracted by means of a tender to carry out the physical design, and imple-mentation and testing, as well as development of a data-entry program. Datawill be typed in using this data-entry program by the participating institutes.The database will be demonstrated to users in a workshop at the end of theproject. An international steering group will be established with leading fish-ing gear and stock assessment scientists, to give approval to major decisionswithin the project and to ensure that the end product fulfils the defined speci-fication. The project duration is 28 months.


COORDINATOR

Dr Bob Van MarlenDienst Landbouwkundig OnderzoekRijksinstituut voor VisserijonderzoekHaringkade 1Postbus 681970 AB IJmuidenNetherlandsTel. (31-255) 56 46 46Fax (31-255) 56 46 44E-mail: [email protected]



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FAIR-CT98-4164

Nephrops trawl discard reduction using activatingselection grids

INTRODUCTION

The fishery, whilst having a high economic value, suffers from a large by-catch of undersize commercial fish species and other organisms. This can beup to half the live catch, comprising a mix of unwanted fish and undersizeNephrops, which can be as much as 60 % for Nephrops discards. This highlevel of discarding is attributable to the smaller mesh sizes permitted inNephrops trawls as compared with white fish trawls. These fisheries can occuron the same grounds, and white fish by-catch limits often apply to Nephropstrawl fisheries.

OBJECTIVES

The overall objective of the project is to develop a semi-rigid grid system toreduce the by-catch of fish and immature Nephrops (Nephrops norvegicus)from Nephrops trawl fisheries. The northern and southern North Sea, and theAegean Sea will be targeted. Species and size selection will be used to reducediscard levels.

KEY OBJECTIVES

1. To develop a primary grid system to separate fish from Nephrops.2. To develop a secondary grid system to release immature Nephrops.3. To conduct fishing trials with a view to confirming discard reduction.4. To inform industry and receive advice from industry about the commercial

viability of the research.




COORDINATOR

Mr Colin Clive Spencer RadcliffeUniversity of Lincolnshire andHumbersideFood Research Centre61 BargateGrimsby DN34 5AAUnited KingdomTel. (44-1472) 34 88 27/87 41 40Fax (44-1472) 75 14 04E-mail: [email protected]

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FAIR-CT98-4338

A study to identify, quantify and ameliorate theimpacts of static gear lost at sea

OBJECTIVES

This project follows on from work of the study Faantared (DG XIV, ContractNo 94/95) which assessed the ecosystem impact of ‘ghost fishing’ by bottom-set gill-nets which had been abandoned or lost, and the impact of these nets onbenthic habitats in shallow waters. The project extends these investigations tofisheries operating at depths greater than 40 m and attempts to quantify theimpact of ghost fishing mortality on stocks of commercially important speciesin the gill-net fisheries considered in the project. The impact of lost traps willalso be considered to a limited extent in this project.


COORDINATOR

Mr Philip Henry MacMullenSea Fish Industry AuthoritySeafish TechnologySt Andrew’s DockHull HU3 4QEUnited KingdomTel. (44-1482) 32 78 37Fax (44-1482) 58 70 13E-mail: [email protected]



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FAIR-CT98-4465

Evaluation and improvement of shellfish dredgedesign and fishing effort in relation to technicalconservation measures and environmental impact

OBJECTIVES

To review operating conditions in a number of shellfish dredge fisheries anddevelop techniques appropriate to each fishery to study the selectivity andenvironmental effects of dredging. To examine the physical impact of dredg-ing and study the incidental mortality, stress, ecological, physical and chemi-cal environmental effects on a seasonal basis.

1. To review dredge fisheries, their operating environments and environmen-tal effects in all the nations considered.

2. To develop the means for describing the physical, chemical, physiologicaland ecological effects of shellfish dredging.

3. To describe the physical, chemical, physiological and ecological effects ofshellfish dredging on a seasonal basis.

4. To develop dredges with reduced environmental effects on affected speciesand the seabed.

5. To compare the environmental effects of dredges designed (arising fromobjective 4) with standard dredges.

6. To quantify the role of dredge components in the selectivity of scallopdredges catching Pecten maximus and Aequipecten opercularis in UKwaters.

7. To quantify the role of dredge components on the selectivity of clamdredges catching Spisula solida, Venus striatula, Donax truncatus andEnsis siliqua in Portuguese fisheries.

8. To compare the environmental effects of dredge components which arefound to play a part in dredge selectivity in UK scallop and Portugueseclam dredges.

Dredge fisheries face stock and environmental management pressures. Sizeand species selectivity and non-catch (incidental mortality) are importantissues concerned with technical measures. Environmental issues are likely tobecome of increasing influence, in particular in relation to seabed degradation.This is particularly important as many dredge fisheries take place in coastalwaters which are increasingly managed in terms of multiple resource use.

This project aims to study the interactions between shellfish dredges, affectedspecies and the marine environment. The work will be oriented towards thegoals of improving selectivity and understanding, and reducing incidental




COORDINATOR

Mr William John LartSea Fish Industry AuthoritySeafish TechnologySt Andrew’s DockHull HU3 4QEUnited KingdomTel. (44-1482) 32 78 37Fax (44-1482) 58 70 13E-mail: [email protected]

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mortality and undesirable environmental effects. Ultimately, the intention is to develop dredge designs and managementstrategies with reduced environmental impacts.

Two main groupings of species will be studied: scallop fisheries in northern Europe and clam fisheries on the Adriaticand the Iberian peninsula. Hydraulic (‘turbo-soffianti’) dredging for Chamelea gallina pursued by fisheries in theAdriatic, and towed dredge fisheries for Spisula solida, Venus striatula, Donax trunculus and Ensis siliqua on the Iberianpeninsula.

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5.2. ECOLOGICAL IMPACT OF FISHERIES AND AQUACULTURE5.2.2. The effects of aquaculture on the environment

FAIR-CT96-1703

Risk assessment of antimicrobial agent usein aquaculture

OBJECTIVES

The aim of this work is to investigate the degree of variation in the tetracyclineresistance encoding plasmid population in strains isolated in the aquatic envi-ronment and those isolated in the human compartment. From this data, a one- ortwo-compartment model will be constructed which best describes the distribu-tion of tetR genes and movement of R+ plasmids between compartments of thetotal environment. This model will then be used to provide an estimate of thepossible extent to which the use of antimicrobial agents in aquaculture will havean impact on the use of these agents in human medicine. The choice of tetracy-cline resistance for construction of this model is based on two considerations:

• the agent is used in both human and veterinary medicine;• the mechanisms of resistance and the genetic determinants of resistance

towards this agent have been well characterised.

Model construction will be based on the analysis of a master strain set ofmesophilic Aeromonads and general heterotrophic bacteria. The choice of twoseparate bacterial groups to be included in the master strain set will providetwo levels of analysis:

• data from the general heterotrophs will provide information of the generalplasmid population structure of each environmental compartment;

• data from the mesophilic Aeromonads will allow comparison of specificplasmid population structures in related bacteria present in both compart-ments.

WORK AND ACHIEVEMENTS

Standard operating procedures for the sampling of fish farm effluent/hospitaleffluent, processing of field samples and pre-screening of isolates for transfer-able tetracycline resistance have been developed, validated and distributedamong the partners. The validated protocols essentially represent the backboneof any future analysis. Thus, the work of the first year was primarily concen-trated on ensuring that the data generated by these protocols would be compa-rable across the three countries and that the two environmental compartmentsand the master strain sets would be suitable for, and generate meaningful datafrom, the analysis to be undertaken in the second and third years of the project.

In the first year validation was carried out on a limited strain panel of generalheterotrophic organisms and mesophilic Aeromonads from both environ-




COORDINATOR

Dr Peter R. SmithNational University of Ireland,GalwayUniversity RoadGalwayIrelandTel. (353-91) 52 44 11Fax (353-91) 75 05 14E-mail: [email protected]

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ments. This decision was inspired by the desire to maximise resources while producing protocols of relevance to the pro-gramme. The validity of the project is totally dependent on the application of identical methods by each of the three part-ners.

Through this work, a number of problems were identified that required the implementation of some minor changes to theoriginal work plan. These were primarily concerned with the most appropriate media to use for isolation of the masterstrain set and the most appropriate pre-screening technique for identification of isolates containing transferable oxytet-racycline resistance. While significant progress has been achieved on the isolation of general heterotrophs, the problemsencountered with the isolation media for mesophilic Aeromonads has impeded progress in their isolation. The data forthe resolution of this problem has been accumulated by partners 2 and 3 and will be finally resolved at the meeting ofpartners scheduled for March 1998. Filter mating has been adopted as the primary method for pre-screening due to itsgreater reliability over the other methods examined.

Analysis of the master strain set will be of three types:

• Identification of tetR determinant type through DNA probe hybridisation with specific PCR primers and probes foreach determinant.Partner 1, and to a lesser extent partner 2, has begun analysis of the master strain set for specific tetR genes usingprimer sequences obtained from the Primer 3 web-based program. A complete set of bacterial strains containing allof the known tetracycline resistance genes (with the exception of the recently discovered Tet V determinant) has beencollected by partner 1. Primer sequences have been obtained for all the determinants from Primer 3 and are current-ly awaiting delivery.

• Identification of R+ plasmid types (incompatibility) on which tetR determinants are encodedDue to the problems encountered with the isolation of mesophilic Aeromonads partner 2 has delayed implementationof R+ plasmid analysis until the second year.

• Identification and classification of both mesophilic Aeromonads and general heterotrophic bacteria containing trans-ferable tetracycline resistance.

Partner 3 has commenced the preliminary identification and classification of the master strain set as outlined in the origi-nal proposal. Preliminary biochemical classification of the field isolates has been determined during the first year withmore detailed identification due to commence in the second year.

In the first year of the programme the majority of the scheduled work in the original work programme has been completed.The major exception to this completion of the methods phase has been the isolation of tetracycline-resistant mesophilicAcromonads but mechanisms to resolve this problem are in train. At the end of the first year a total of 650 of the 1 200strains that will comprise the master strain set have been collected and stored. Preliminary analysis of these strains has be-gun and is ahead of schedule with regard to their antibiotic susceptibility profiles. Thus, progress in this area is highly sat-isfactory. In agreement with the change of emphasis outlined, the progress made in collecting strains is actually in advanceof that planned originally. As a consequence, the analysis of these strains is slightly behind the original schedule.

CONCLUSIONS

It is considered that this project is proceeding at a pace that will allow its completion within the three-year timescale allot-ted to it. During this year, minor modifications have been made to the original work programme which, it is believed,have facilitated a more efficient use of the available manpower and resources.

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FAIR-CT97-3498

Performance and ecological impacts of introducedand escaped fish: physiological and behaviouralmechanisms

OBJECTIVES

The culture of fish is an important European industry. However, there is nowa growing awareness that releases of cultured fish for stocking may be inef-fective and may also have detrimental impacts on wild populations. In the tar-get species for this project, Atlantic salmon (Salmo salar) and brown trout(Salmo trutta), such effects are well documented, but the physiological andendocrinological mechanisms underlying the domestication process are poor.As a consequence, it is not possible to predict with confidence the ecologicalimpact of domestication.

The objectives of this project are:

1. to identify how domestication affects the interrelation between physiologyand behaviour and how this relates to performance (i.e. growth, survivaland reproduction) under natural and semi-natural conditions;

2. to assess genetic and environmental impacts of cultured fish on wild con-specifics at various life stages through competition and interbreeding.

These objectives will met by three complementary approaches:

Physiology and behaviour: basic performance (task 1)

The first group of experiments concentrates on comparative physiology andbehaviour, with special emphasis on: (i) genetic effects of hatchery selection;(ii) environmental effects of the hatchery; and (iii) effects of increased ener-getic needs. These experiments will reveal how domestication alters someimportant physiological and behavioural mechanisms.

Source of variation: effects of phenotypic expression of growth-related characters (task 2)

The second group of experiments includes measurements of heritability and ge-netic correlations for a number of physiological and behavioural traits that areknown to be important for fitness. The measures are crucial for evaluating thepotential effects of domestication and their incidence in natural populations.

Ecological impacts on wild populations (task 3)

The third group of experiments is linked to the previous two tasks as it focus-es on the ecological impact of domesticated traits of hatchery fish on wild con-specifics in nature.




COORDINATOR

Prof. Torbjorn JarviNational Board of FisheriesInstitute of Freshwater ResearchStellan HamrinS-178 93 DrottiningholmTel. (46-86) 20 04 43Fax (46-87) 59 03 38E-mail:[email protected]

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FAIR-CT97-3827

Impacts of marine xenobiotics on Europeancommercial fish � Molecular effectsand population responses

OBJECTIVES

The aim of this project is to produce a synthesis of the literature on the impactsof xenobiotics, from the biochemical to community level, in commercial fishand thereby develop a conceptual model with which to evaluate and assess theconsequences of low-level pollution exposure on population and yield. Thiswill be done by producing state-of-the-art reports on 10 thematic tasks exam-ining individual aspects of pollution impact and their links to other levels oforganisation. Through workshops and other forms of communication, theresults of the thematic reports will be synthesised into a coherent whole.Within each thematic task, the literature on European commercial and non-commercial fish will be synthesised. The outcomes of the project will be dis-seminated through the publication of thematic reports, a book, an internationalconference, a database of relevant literature and a website.

INTRODUCTION

Extensive work has been undertaken to examine the impact of a wide range ofxenobiotics on various individual aspects of marine fish and invertebrate bio-chemistry, physiology and population structure (Bayne et al., 1988; Forlin etal., 1995). These studies have been performed throughout Europe and world-wide to achieve various objectives. They may have been performed to deter-mine the toxicity of a specific chemical or compound to assess the potentialhazard to individual species or ecosystems from the disposal of waste (Donkinand Widdows, 1986), or they may have been developed to provide a rapid bio-marker for pollution (Goksoyr, 1991; Depledge, 1993; Lawrence andNicholson, 1998) or to act as bioassays of health, fitness, and growth, undervaried complex environmental parameters (Lawrence and Poulter, 1996,1998). In some cases, commercial fish and shellfish have been used, while inothers species of ecological importance or that fulfil various monitoring crite-ria may have been chosen (Elliott et al., 1988).

Sub-lethal anthropogenic effects may lead to severe consequences for popula-tions or species occupying the area (Moller and Dieckwisch, 1991; Bernat etal., 1994). Consequences at the ecosystem level may display a long responsetime and when effects are detected it may be too late to take countermeasures.Pollution exposure may also lead to decreased growth rates and increasedinfection, but even these responses are preceded in time by effects at themolecular level (Blackstock, 1984; Boon et al., 1992).


COORDINATOR

Dr Andrew John LawrenceUniversity of HullDepartment of Biological SciencesCottingham RoadHull HU6 7RXUnited KingdomTel. (44-1482) 46 53 98Fax (44-1482) 46 54 58E-mail:[email protected]



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However, direct links between xenobiotic effects at the molecular level and population/yield response are yet to be demon-strated and there is currently no predictive capability in extrapolation between the two levels of observation. The need toimprove our understanding of the links among the hierarchic levels of pollution response has recently been highlighted(Anderson et al., 1994). However, no study has currently attempted to link each of the response criteria (biochemical, cel-lular, physiological, reproduction, population/yield) to evaluate the ramifications of low-level, sub-lethal effects to popu-lation and community structure and hence the socioeconomic impact to communities exploiting the resources.

The aim of this study is to produce a synthesis of the literature on the impacts of pollution at hierarchic levels of organ-isation in commercial fish to:

• identify, and where possible quantify, the links between the hierarchic levels of impact (genetic, biochemistry,growth and physiology, reproduction and fecundity, population and community, fishery resource implications);

• identify the most suitable fish species with which to study the hierarchic responses. The species will ideally be ofcommercial importance, already have been studied extensively and be representative;

• identify the weak or missing links in the hierarchic chain of responses in studies on commercial fish performedto date (including gaps in methods);

• collate information from commercial fish population studies from European estuaries and inshore waters;• examine information from non-commercial species to identify appropriate methods for the missing/weak link in the

chain of responses;• determine any homeostasis in the system as an ability to absorb any effects of change; thus the level of change at

lower levels will not be presumed to have an effect which is transferable to higher biological levels.

From this, direct links between xenobiotic effects at the molecular level and population/yield response will be identifiedwith the aim of developing a conceptual model with some predictive capability.

MATERIALS AND METHODS

The study will be concentrated under the themes listed in Table 1. These themes will form the topics for task groups whowill produce status reports on the subject. Different project partners will take the lead in particular topics but workshopsand other gatherings will be used to bring the topics together in a coherent structure. Where appropriate, best technicalapproaches and standardisation of methods will be encouraged.

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Theme number Thematic topic

1 Genetic damage by xenobiotics at the individual level2 Biochemical response to pollution and the use of biomarkers3 Physiological and energetic response of individuals to xenobiotics4 Impacts of pollution on the immune system/physical health of species5 The influence of endocrine disrupters on reproduction6 Impacts of xenobiotics on reproduction and fecundity7 Impacts of pollution on the population ecology and yield of the species8 The impacts of pollution exposure on population genetics9 The state of the art in socioeconomic impact modelling

10 Identification of the best model species based on the available information

Table 1: The thematic tasks to be reported on within the concerted action


RESULTS

The study will provide a Europe-wide database and assessment of the subject and identify key areas for future research.It will produce a status report on pollution impacts on commercial fish in European waters, bringing together scientiststhroughout Europe to allow the collation of their ongoing and previous studies without duplicating effort within any sin-gle laboratory.

The concerted action will result in the production of 10 thematic reports which will be regarded as progress reports andthus contributions to the final report. The project will also result in the publication of a conceptual model linking the hier-archic levels of pollution impact. This will be published either as a major component of the final report or separately. Thefinal report will bring together all the thematic reports and provide a synthesis of work on the impacts of xenobiotics athierarchic levels of organisation on fish and commercially used shellfish in Europe. The report will give a comprehen-sive bibliography of pollution impact both throughout Europe as a whole and, where relevant, elsewhere.

The greater contact between the participants will result in a directory of pollution studies in European waters and a data-base of known pollution impacts on European fish. This database will be openly accessible. In addition, the project willproduce an Internet site and maintain a bulletin board.

REFERENCES

Anderson, S., Sadinski, W., Shugart, L., Brussard, P., Depledge, M., Ford, T., Hose, J., Stegeman, J., Suk, W., Wirgin, I.and Wogan, G. (1994), ‘Genetics and molecular ecotoxicology: a research framework’, Env. Health Perspectives, 102,pp. 3–8.

Bayne, B. L., Clarke, K. R. and Gray, J. S. (eds) (1988), ‘Biological effects of pollutants’, Mar. Ecol. Prog. Ser., 46, Nos1–3.

Bernat, N., Kopcke, B., Yasseri, S., Thiel, R. and Wolfstein, K. (1994), ‘Tidal variation in bacteria, phytoplankton, zoo-plankton, mysids, fish and suspended particulate matter in the turbidity zone of the Elbe estuary: interrelationships andcauses’, Netherlands Journal of Aquatic Ecology, 28, pp. 467–476.

Blackstock, J. (1984), ‘Biochemical metabolic regulatory responses of marine invertebrates to natural environmentalchange and marine pollution’, Oceanogr. Mar. Biol. Ann. Rev., 22, pp. 263–313.

Boon, J. P., Everaarts, J. M., Hillebrand, M. T. J., Eggens, M. L., Peijnenburg, J. and Goksoyr, A. (1992), ‘Changes inlevels of hepatic biotransformation enzymes and haemoglobin levels in female plaice (Pleuronectes platessa) after oraladministration of a technical PCB mixture (Clophen A40)’, The Science of the Total Environment, 114, pp. 113–133.

Depledge, M. H. (1993), ‘The rational basis for the use of biomarkers as ecotoxicological tools’, in Fossi, M. C. andLeonzio, C. (eds), Non-destructive biomarkers in vertebrates, Boca Raron, FL, Lewis Publishers, 1993, pp. 271–293.

Donkin, P. and Widdows, J. (1986), ‘Ecotoxicology — Effects of chemicals on the aquatic environment’, Chem. & Ind.,22, pp. 732–737.

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Elliott, M., Griffiths, A. H. and Taylor, C. J. L. (1988), ‘The role of fish studies in estuarine pollution assessment’, J. FishBiol., 33, pp. 51– 61.

Forlin, L., Andersson, T., Balk, L. and Larsson, T. (1995), ‘Biochemical and physiological effects of bleached pulp milleffluents in fish’, Ecotox. Environ. Safety, 30, pp. 164–170.

Goksoyr, A. (1991), ‘A semi-quantitative cytochrome P-450IA1 ELISA: a simple method for studying the monooxyge-nase induction response in environmental monitoring and ecotoxicological testing of fish’, The Science of the TotalEnvironment, 101, pp. 253–261.

Lawrence, A. J and Nicholson, B (1998), ‘The use of stress proteins in Mytilus edulis as indicators of chlorinated efflu-ent pollution’, Water Science and Technology (in press).

Lawrence, A. J. and Poulter, C. (1996), ‘The potential role of the estuarine amphipod Gammarus duebeni in sub-lethalecotoxicology testing’, Water Science and Technology, 34 (7–8), pp. 93–100.

Lawrence, A. J. and Poulter, C. (1998), ‘Development of a sub-lethal pollution bioassay using the estuarine amphipodGammarus duebeni’, Water Research (in press).

Moller, H. and Dieckwisch, B. (1991), ‘Larval fish production in the tidal Elbe 1985–86’, J. Fish Biol., 38, pp. 829–838.

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FAIR-CT98-4160

Development of recirculating mariculture productionsystems designed to minimise environmental impact

OBJECTIVES

At present technology exists to grow marine fish in intensive recirculatingsystems in which excess ammonia is removed by bacterial nitrification.There are also bacterial denitrification systems in use in freshwater aqua-culture to remove excess nitrate and phosphate from the effluent stream.The research objective of this project is to develop an intensive recirculat-ing system for use in mariculture in which organic matter is reduced andexcess nutrients are removed by means of a fluidised bed reactor (FBR).Laboratory experiments will be carried out to define and optimise the op-erational conditions for the FBR, including the factors that might promotethe (undesirable) production of hydrogen sulphide. The data from these ex-periments will be used to describe mathematically the principal processeswithin the anaerobic modules for use in a computer simulation model ofthe entire system. Because hydrogen sulphide is very toxic to marine fish,it is planned to develop procedures for the indication of its presence in thesystem and to degrade and remove it if it were accidentally formed. Thesepreliminary experiments will be put together into a pilot-plant fish culturesystem built in Eilat, Israel, involving recirculating water between a fishtank, an aerobic, nitrifying filter, an anaerobic sedimentation/fermentationtank, an FBR and a cartridge containing iron oxide to prevent hydrogensulphide poisoning. The operation of the pilot plant will be monitored andphysical and chemical data collected over an annual cycle. Using data gen-erated by this project, and by earlier literature and other data available onthe fish culture and nitrification modules, a mathematical model will be de-veloped. This model, which will represent a quantitative understanding ofthe operation of the integrated system, will be calibrated using the data col-lected during the annual cycle of the pilot plant and will be used to testour understanding of the operation of the system. Tests will be carried outon the robustness of our understanding of the fish culture system by car-rying out short-term changes in the pilot plant such as altering residencetimes in certain components to see how the model predictions and themeasured data agree. After 18 months’ operation of the initial pilot plant,a second advanced pilot plant will be built in Greece. The plant will be op-erating in such a way as to compare its performance with the first pilotplant and with an intensive open mariculture system operating close by inGreece. The recycling and open systems in Greece will operate with simi-lar operating protocols, the same physical forcing factors, the same food,and fingerlings from the same batch, enabling a comparison of the per-formance of the new system, both in terms of economic parameters and ef-fluent discharged, to be made.


COORDINATOR

Dr Michael D. KromUniversity of LeedsSchool of Earth SciencesWoodhouse LaneLeeds LS2 9JTUnited KingdomTel. (44-113) 233 52 13Fax (44-113) 233 52 59E-mail: [email protected]



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METHODOLOGY AND RESEARCH TASKS

Three stages are proposed.

1. Laboratory studies of the anaerobic components of the biofilter system to examine the processes of denitrification,organic matter breakdown, phosphate removal and H2S generation/oxidation, and to develop a quantitative under-standing of the processes involved.

2. The construction and operation of a pilot fish culture system using aerobic and anaerobic biofilters; development andrefinement of the mathematical model.

3. Transfer of the technology into an advanced pilot system based on stage 2. Further refinement to the mathematicalmodel including the development of a user-friendly version to use with the advanced pilot plant. Comparison of per-formance with an open intensive system.

The gilthead sea bream Sparus aurata will be cultured in the pilot-scale studies.

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FAIR-CT98-4201

Effects of shellfish culture and optionsfor sustainable exploitation (Essense)

OBJECTIVES

The overall objective of the project is to improve the scientific basis for anincreased and sustainable exploitation of bivalve resources in the EuropeanCommunity. To this end we want to:

• investigate conditions for successful recruitment;• quantify the interaction between filtration, nutrient cycling and hydrody-

namics and the consequences for mussel production;• quantify the environmental impact of mussel exploitation for birds, and the

impact of birds on mussel stocks;• integrate the obtained knowledge in a model allowing for an optimal

exploitation of resources.


The approach consists of comparative analyses of different mussel culture areasby carrying out field studies, supported by laboratory experiments and models.Laboratory studies are carried out for quantification of processes that cannot bemeasured in the field. The models will focus on optimisation of exploitation ofan area for mussel culture while minimising the impact of this culture.

The project will be carried out in the following research areas: Koljöfjord(north-west coast of Sweden), Limfjord (Denmark), Pertuis Breton (France),Wadden Sea (sites in Germany and the Netherlands) and the Oosterschelde(south-west Netherlands). All investigated areas can be regarded as meso/eu-trophic but vary greatly in terms of mixing intensity of the water column.Swedish and Danish fjords have low tidal amplitudes and mixing of the watercolumn is primarily wind-driven. In the Wadden Sea, the Oosterschelde and thePertuis Breton, mixing of the water column is primarily governed by tidal cur-rents. The areas have in common that there is extensive shellfish exploitation,which is carried out as off-bottom culture in the fjords (Sweden, Denmark,France), and on-bottom culture/fisheries in the Limfjord (Denmark), WaddenSea (Germany, Netherlands) and Oosterschelde (Netherlands).

The following are the research tasks.

Task 1: Mussel culture and recruitment success

Sub-task: 1.1: Mussel larvae and spatfall dynamicsSub-task: 1.2: Spatfall in relation to mussel dredged areas


COORDINATOR

Dr Aad SmaalDienst Landbouwkundig OnderzoekRijksinstituut voor VisserijonderzoekSectie AquacultureKorringaweg 54400 AB YrsekeNetherlandsTel. (31-118) 67 22 30Fax (31-118) 61 65 00E-mail: [email protected]



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Task 2: Filtration, nutrient cycling and mussel yield

Sub-task: 2.1: Filtration capacity and mussel yield of different culture typesSub-task: 2.2: In situ estimation of feedbacks through mussels

Task 3: Predation of mussels by seabirds and interference with mussel fishery

Sub-task: 3.1: Effects of mussel resources on seabird populationsSub-task: 3.2: Effects of seabird predation in relation to fishery on mussel populations

Task 4: Integration

Sub-task: 4.1: Verification of existing mussel-carrying capacity models for bottom and rope culture sitesSub-task: 4.2: Development of sub-models for the Limfjord experimental areaSub-task: 4.3: Development and validation of a sub-model on bird predationSub-task: 4.4: Combining sub-models into a dynamic generalised ecosystem model and validation for the dif-

ferent sites

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FAIR-CT98-4266

Genetic diversity in the European lobster (Homarusgammarus): population structure and impacts ofstock enhancement

OBJECTIVES

1. To develop and test microsatellite and mitochondrial DNA markers and tooptimise screening conditions to enable high-resolution studies ofEuropean lobster genetics.

2. To determine intra- and interpopulation genetic diversity based onmicrosatellite, mitochondrial DNA and allozyme markers in samplesobtained from throughout the geographical range of the European lobster.

3. To evaluate the use of genetic tagging for determining the contribution ofranched individuals in mixed wild and ranched harvests and to determinethe potential genetic impact of stock management and enhancement onnatural populations.

4. To determine the paternity of egg masses from individual females and thuselucidate the breeding structure in various European lobster populations.

5. To produce a plan for the conservation and management of geneticresources in European lobster fisheries taking into account natural popula-tion diversity, extant industry practices, previous and current enhancementactivities, and the future potential for farming and/or ranching.


The overall methodology relies on the development and optimisation ofmicrosatellite and mitochondrial DNA markers for the European lobster andof the large-scale screening of these markers using manual and automated gelelectrophoresis systems. These genetic markers will be used to quantify pop-ulation genetic variation in samples of lobsters obtained from throughout thegeographical range. The genetic markers will also be tested as a means of dif-ferentiating between wild and stocked individuals. Microsatellite DNA profil-ing will be used to determine paternity in egg masses from individual females.Genetic data will be used to produce detailed recommendations for the man-agement of the European lobster resource.


COORDINATOR

Prof. Andrew FergusonThe Queen’s University of BelfastSchool of Biology and Biochemistry97 Lisburn RoadBelfast BT9 7BLUnited KingdomTel. (44-28) 90 27 20 55Fax (44-28) 90 23 65 05E-mail: [email protected]



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FAIR-CT98-4300

Monitoring and regulation of marine aquaculture

OBJECTIVES

There is a current need for concerted action to develop scientific guidelines forbest environmental practice in relation to the regulation, control and monitor-ing of marine aquaculture (including shellfish and finfish culture, extensiveand intensive systems, onshore and offshore practices, and expansion of exist-ing species and likely new species) in Europe. This can be achieved throughstudy and analysis of current strategies and practices, in the context of social,economic and policy issues, and through the collaboration of all national par-ticipants with a broad representation of stakeholders, including environmentalregulatory authorities and aquaculture producers. This project addresses thisneed and specifically has the following objectives:

1. To prepare a critical review of:• current and proposed licensing, regulatory and monitoring guidelines

and procedures with specific reference to changes since earlierreviews;

• effluent quantity and quality control (including key parameters, suchas chemotherapeutants and organic and inorganic nutrients, and envi-ronmental variables);

• monitoring strategies for the assessment of environmental impactwhich are being developed or have been implemented (including keyparameters, such as chemotherapeutants and organic and inorganicnutrients, and environmental variables).

2. To analyse the scientific basis for approaches to minimise the impacts ofmarine fish and shellfish culture on the natural marine environment.

3. To evaluate licensing, regulatory and monitoring guidelines and proce-dures in the context of social, economic and policy issues.

4. To define scientific guidelines for best environmental practice for har-monised regulatory, control and monitoring strategies which would bewidely applicable, including the use of hydrodynamic models and benthicecological models.


The evaluation and review of current practices relating to regulation, controland monitoring of marine aquaculture will be achieved through a process ofliterature review, consultation and networking with experts, regulatory author-ities and the marine aquaculture industry in EU Member States, and a series ofworkshops. Communication between participants and other experts in thisfield throughout the EU will be promoted through the establishment of a




COORDINATOR

Prof. Paul ReadNapier UniversityDepartment of Biological Sciences10 Colinton RoadEdinburgh EH10 5DTUnited KingdomTel. (44-131) 455 26 25Fax (44-131) 455 22 91E-mail: [email protected]

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register of experts and their expertise, a computerised network using the Internet (e.g. an information page on the WWWlinked to a newsletter and bibliography), circulation of a newsletter, compilation of a computerised bibliography of rel-evant publications (making use of already existent electronic databases), publication of topic papers on specific issues byworking groups and a series of European workshops (three over the two-year period of the programme). Workshops willbe used to discuss, analyse and present reviews of current practice, and provide a forum in which the scientific basis forbest environmental practice can be established.

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5.2. ECOLOGICAL IMPACT OF FISHERIES AND AQUACULTURE5.2.3. Modelling

FAIR-CT96-1555

Development of a predictive model of cod-endselectivity

OBJECTIVES

1. To develop a design tool which provides the capability to assess the influ-ence on cod-end selectivity of:• the cod-end design and catch size;• the netting material properties;• the trawl rigging and towing speed;• the sea state.

2. To develop an investigative tool to enable a greater understanding of theselection process and to help explain the variation observed in experimen-tal trials.

3. To develop a predictive model of cod-end selectivity for use in:• the development of more selective trawls;• the study of fishing mortality and hence fishing effort;• the assessment of the selectivity of commercial fleets from the selec-

tivity parameters obtained from experiments.4. Since, to date, sea trials are the only means of assessing the selectivity of

novel cod-ends, a capacity to assess, at the design stage, the influence of:• the cod-end design;• the netting material properties;• the trawl rigging, and towing speed;• the sea state on the selectivity of a cod-end;would permit the initial testing of novel designs ‘onshore’ and lead to con-siderable savings and the ability to react more quickly to new challenges.

Such a design tool would prove invaluable to gear technologists and result ina more targeted approach to cod-end selectivity.

The design tool proposed here will be able to assess the effect of varying aparameter, and compare the relative influence of different parameters on theselectivity of a cod-end.

The predictive model of cod-end selectivity proposed here will enable theresults of experimental selectivity trials to be probed in relation to theseparameters and will help explain the large amount of variation usuallyobserved in such trials. It is envisaged that future developments will also per-mit fish behaviourists to examine the selection process by modifying and vary-ing the environmental parameters at work, leading to new insights and to agreater understanding of the role of fish behaviour in selectivity.




COORDINATOR

Dr François TheretIfremer — DITI/GO/TPCentre de BrestLaboratoire Technologie de PêcheBP 70F-29280 Plouzané CedexTel. (33) 297 87 73 29Fax (33) 297 83 41 06E-mail: [email protected]

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5.2. ecological impact of fisheries and aquaculture · · 2016-09-135.2. ecological impact of...

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