jo king: managing fisheries to conserve groundfish and benthic invertebrate species diversity...
TRANSCRIPT
Jo King:Jo King:
Managing Fisheries to Conserve Groundfish and Benthic
Invertebrate Species Diversity(MAFCONS): An introduction to the
project
Simon Greenstreet
“MAFCONS” Project Objective
• The goal of the “MAFCONS” project is:– To provide Fisheries Managers with the
capability to adopt an “ecosystem approach” to management which enables them to set and achieve species diversity goals, with respect to fish and benthic communities, alongside their more traditional single species objectives for commercial fish stocks
Introduction
• What is this project all about?
• What is the rational behind it?
• Why are we doing it?
• What do we hope to achieve?
• What exactly are we going to do?
Introduction
• Lets start with a bit of scientific background………...
Effects of Fishing on Fish Communities?
• Fishing mortality is not directed evenly across all fish in the community: individuals of a limited size range belonging to selected species are removed preferentially. – Changes relative population sizes.– Alters balance between numbers of predators and prey.– Alters balance between competing species.– Alters size frequency distributions of particular populations.
• Changes in the relative abundance of species can lead to changes in community structure and ecosystem function.
Long-term trends in the groundfish assemblage
• Partitioned the North Sea into zones based broadly on hydrographic and topographic characteristics.
• Analysed groundfish survey data for three areas in NW North Sea where reasonably long-term records of fishing effort were available.
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In two areas where demersal fishing effort has steadily increased…
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… species diversity has shown a long-term decline.
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In a third area, where fishing effort has declined in recent years,
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Groundfish species diversity has also decreased here!
So we observe both positive and negative relationships between fishing effort and species diversity!
Problems with this correlative approach
• No hypotheses relating fishing disturbance to species diversity have been tested.
• This “correlative” approach does not even prove that fishing caused the observed changes in groundfish species diversity.
• Even if cause and effect can be demonstrated, these results cannot be used to predict the future consequences of changes in fisheries management practice on species diversity.– Both positive and negative relationships between species
diversity and fishing effort were found.
– No insight was provided which could allow us to predict the direction of the relationship under certain
circumstances.
Addressing these problems
• Is there any other evidence which might help to confirm a “causative relationship”?– That fishing really has caused the observed changes in
diversity?– That there really is a potential management issue?
Does Fishing affect Fish Species Diversity?
• In areas 1 and 2…
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• where effort has increased over recent decades…
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• and species diversity has declined,
Does Fishing affect Fish Species Diversity
HAD (42.85%)
LRD (9.35%)WHI (8.06%)
NPO (25.61%)
CDA (1.20%)SPU (3.27%)
OTHERS (9.66%)Area 1: 1925-39
HAD (30.69%)
LRD (1.91%)WHI (7.66%)
NPO (55.71%)
CDA (0.52%)SPU (0.00%)
OTHERS (3.50%)
Area 1: 1982-96
HAD (40.15%)
LRD (11.58%)
WHI (17.29%)
NPO (16.90%)CDA (7.79%)SPU (0.51%)
OTHERS (5.78%)Area 2: 1925-39
HAD (28.24%)
LRD (1.81%)WHI (22.01%)
NPO (41.60%)
CDA (4.32%)SPU (0.02%)
OTHERS (2.00%)Area 2: 1982-96
• these changes in groundfish assemblage structure have been associated with marked changes in species composition.
Some Theory
• More vulnerable– large ultimate size– slow growth rates– large size at maturity– older age at maturity– low fecundity
• Less vulnerable– small ultimate size– fast growth rates– small size at maturity– younger age at
maturity– high fecundity
There is a growing body of theory which suggeststhat particular life history traits render a speciesmore or less vulnerable to fishing mortality.
A Hypothesis
• If increasing fishing pressure were the cause of these changes in species composition, then species whose life history traits render them more vulnerable to fishing mortality should have decreased in abundance relative to species with the opposite characteristics.
• Over time the groundfish assemblage should have become more dominated by fish with small ultimate size, fast growth rates, and an early age and small size at maturity.
The Test
• The average ultimate length of fish in the groundfish assemblage has decreased,
• and the average growth rate has increased.
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The Test (continued)
• And average age and length at maturity have both declined.
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Conclusions
• Trends in life history traits averaged across the whole groundfish assemblage provide much stronger evidence that the changes in species composition, and the coinciding decline in species diversity (in this area), have occurred as a consequence of increased fishing mortality.
• So what!!• Is the impact of fishing on the species diversity
of Fish (and Benthic) Communities an issue that fisheries management needs to take into account?
Political Backgound
• To answer this question we need to review (very briefly) the political developments over the last two decades………...
Overview of some major Global Conventions
Convention/ Treaty Year Objectives
UN Law of the Sea 1982 Regulation of management of all living resources;establishment of Exclusive Economic Zones
Bonn Convention 1983 Protection of migratory (crossing national borders) stocksof wild species
CITES Prevention of trade in endangered species
GATT Reduction of environmental impact
Convention on Bio-logicalDiversity (CBD)
1992 Protection of Biodiversity at genetic, species and habitatlevels
Agenda 21-Chapter 17 1992 Protection of marine and coastal areas
FAO Code of Conduct 1995 Responsible fisheries management; precautionaryapproach to account for ecosystem and socio-economicaspects
Jakarta Mandate 1997 Elaboration of CBD – designation of Marine ProtectedAreas
OSPAR Convention(Annex V)
1998 Protection of the Marine Environment of the North-EastAtlantic (Protection and Conservation of the Ecosystemsand Biological Diversity of the Maritime Area)
UN Convention on Mig-ratory and straddling fishstocks
NIA Conservation and protection of border crossing and highseas fish stocks
North Sea Ministerial Conferences
• Five “full-blown” North Sea Ministerial Conferences to date– Bremen in 1984– London in 1987– The Hague in 1990– Esbjerg in 1995– Bergen in 2002
• Plus two “Intermediate Ministerial Meetings”– Copenhagen in 1993– Bergen in 1997
• These are political events– The decisions of the Ministers are recorded in Ministerial
Declarations– These are political commitments
North Sea Ministerial Conferences
• Bremen 1984, London 1987: – dealt mainly with pollution issues through Oslo/Paris Commissions
• Hague 1990: (just prior to Rio Summit, CBD Agenda 21)– pollution mainly addressed
– turned attention to protection of species and habitats
– impact of other human activities (fishing) on the ecosystem
• Copenhagen 1993, Esbjerg 1995: (following Rio, coinciding with FAO Code of conduct)– fisheries management to safeguard NS ecosystem as a whole
• introduction of concept of ecosystem objectives• integration of fisheries and environmental policies • adoption of precautionary approach
– all marine environment matters addressed through OSPAR
• Bergen 1997: (attended by Fisheries and Environment Ministers, just prior to OSPAR Annex V)– need to develop and apply and “ecosystem approach to management”
• laid down guiding principles for such an approach• invited competent authorities to develop this approach
Developing an Ecosystem Approach to Management
• Following the 1997 Intermediate Ministerial Meeting, a workshop on the “Ecosystem Approach to Management and Protection of the North Sea” was organised in Oslo in June 1998– need for objectives at the “general” level obvious;– but also the requirement for “specific” objectives, as detailed
operational goals, was recognised.
• Three further workshops set up to establish a methodology for describing “Ecological Quality” and setting “Ecological Quality Objectives”.– The most important of these was the workshop on “Ecological
Quality Objectives (EcoQOs) for the North Sea” held at Scheveningen, The Netherlands, in September 1999
– Here the basic “template” for a proposed “ecosystem approach to management” was effectively confirmed
North Sea Ministerial Conferences
• Bergen 2002: – Ministers recognised the need to manage all human activities in the North
Sea so as to conserve biological diversity and ensure sustainable development
– they agreed to implement an ecosystem approach based on the setting of EcoQOs as tools for setting clear operational environmental objectives and serving as indicators of ecosystem health
– they agreed to use the EcoQOs already developed for the North Sea and invited OSPAR to review progress by 2005
EcoQ Issues
• Ten issues for setting EcoQOs for the North Sea have been proposed
Structural Functional
2. Threatened/declin ing species3. M arine m am m m als4. Seabirds
1. Com m ercia l species
5. F ish com m unities6. Benth ic com m unities7. P lankton com m unities8. Habita ts
9. Nutrients/production10. O xygen consum ption
SPEC IES
C O M M U N ITIES & H ABITATS
EC O SYSTEM
What EcoQOshave been setcurrently forFish and BenthicCommunities?
This is the basisfor an ecosystemapproach to man-agement acceptedat the Bergen 2002NSMC
EcoQOs for Fish and Benthic Communities
• Tables A and B, Annex 3 Bergen Declaration– Issue 5: Fish Communities
• Ecological Quality Elements– Changes in the proportion of large fish and hence the average
weight and average maximum length of the fish community
• EcoQOs– none set as yet!
– Issue 6: Benthic Communities• Ecological Quality Elements
– Changes/kills in zoobenthos in relation to eutrophication– Inposex in dog whelk (Nucella lapillus)– Density of sensitive (e.g. fragile) species– Density of opportunistic species
• EcoQOs– There should be no kills in benthic animal species as a result
of oxygen deficiency and/or toxic phytoplankton species– A low(<2) level of imposex in female dog whelks as measured
by the Vas Deferens Sequence Index
Authority over North Sea waters
• Only the European Commission and Norway have the authority to determine legally binding legislation with respect to the control of fishing activities in the non-territorial waters of the North Sea– acknowledged in the Esbjerg 1995 Ministerial
Declaration– confirmed in Article 4 of Annex V of the OSPAR
convention
• European Union policy impinges directly on the exploitation and management of the North Sea in several ways
EC policy/legislation
• Common Fisheries Policy– conservation of available and accessible living marine aquatic
resources– sustainable use– accounting for marine environmental implications
• Birds Directive– part of EU Ramsar convention– protects wild birds and their natural habitat within EU area– includes seabirds
• Habitats Directive– selection of areas to protect species and/or habitats– member states required to designate Special Areas of
Conservation (SACs)– these SACs should create a network of protected areas (Natura
2000)– includes many marine sites
WOW!!!
• And that is it - so far!!!
Treaty/Convention/Declaration objectives
• Sustainable use of natural resources
• conservation of biodiversity
• protection of species and habitats
• reduction of pollution
• minimisation of detrimental effects of anthropogenic activities
• restoration of degraded systems
Treaty/Convention/Declaration principles
• Integrated management
• An “Ecosystem Approach” to management
• The “Precautionary Approach”
• Polluters should pay
Current EcoQOs for fish and benthic communities
• Will the current ecosystem approach conserve species diversity and restore degraded systems?
• If it can’t, why is this the approach being adopted?
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Problems with this correlative approach
• No hypotheses relating fishing disturbance to species diversity have been tested.
• This “correlative” approach does not even prove that fishing caused the observed changes in groundfish species diversity.
• Even if cause and effect can be demonstrated, these results cannot be used to predict the future consequences of changes in fisheries management practice on species diversity.– Both positive and negative relationships between species
diversity and fishing effort were found.
– No insight was provided which could allow us to predict the direction of the relationship under certain
circumstances.
“MAFCONS” Purpose in Life
• We currently have no conceptual framework that links, through cause and effect mechanisms, the response of fish and benthic communities, in terms of changes in species diversity, to variation in fishing disturbance
• At present therefore we cannot advise managers how to achieve specific diversity objectives
• THIS IS WHAT “MAFCONS” SEEKS TO PROVIDE– How will the project achieve this goal?
The “MAFCONS” Approach
• “MAFCONS” seeks to develop the necessary theory upon which to base testable hypotheses relating fishing disturbance to ecosystem characteristics, such as species diversity.
• Such theory would enable the ecosystem consequences of fisheries management actions to be predicted and quantified.
• Application of such theory should therefore provide fisheries managers with the necessary “tool” to enable them to adopt a species diversity based “ecosystem approach” to fisheries management.
“MAFCONS” Objectives
• Thus, the principal objective of “MAFCONS” is - To produce a “Management Protocol” which would allow managers to predict the consequences to fish and benthic community species diversity of setting specific TACs, thereby enabling them to achieve species diversity goals as well as fish stock size objectives– This protocol will be soundly based in well-tested
ecological theory
Huston’s Dynamic Equilibrium model
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• Huston noted that two unimodal relationships concerning species diversity could be derived from the theoretical ecology literature, one related to disturbance and the second related to productivity.
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Huston’s Model cont.
• Huston combined these two relationships to produce a three dimensional model relating species diversity simultaneously to both productivity and disturbance.
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It is quite clear from this model that the relationship between disturbance and diversity can differ markedly, depending on the level of productivity.
Testing Huston’s model using spatial data
• Can we test Huston’s model using spatial data?• Spatial distribution of effort?
– Done and do-able!
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Testing Huston’s model using spatial data
• Spatial distribution of species diversity?– Done and do-able!
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Testing Huston’s model using spatial data
• Spatial distribution of productivity?– Difficult but, using recently published size spectra
based methods, maybe not as hard as one would first imagine!
• “MAFCONS” will derive estimates of benthic secondary production by ICES rectangle throughout the North Sea.– Sampling benthic invertebrate infauna and epibenthos
on research vessel cruises– samples all analysed by size (length/weight) category– size specific P/B ratios applied to estimate productivity
The Test of Huston’s Dynamic Equilibrium model
• Group rectangles by productivity level.• Within each productivity group, examine the
relationship between effort and species diversity.• Are the relationships predicted by the model for
different productivity levels found in the field data?
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“An Ecosystem Approach”
• If Huston’s model holds up to critical examination, then it could be used as the basis for a mathematical tool to enable fisheries managers to predict the ecosystem consequences (effects on species diversity) of their actions.
• Application of the “tool” could then become part of the annual assessment, advice, management round.
• If the project is successful and this becomes part of the assessment process, benthic sampling would become part of the standard GFS routine.
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“MAFCONS” Objectives
• Before a species diversity protocol can be implemented within the current assessment/management process, one further step is required– Any theoretical community model produced by
“MAFCONS” will almost certainly deal in the currency of “ecological disturbance” based on fishing effort
– Currently the EC CFP deals in the currency of Total Allowable Catches
• “MAFCONS” needs to determine the relationship between catch and effort. This is the role of WP6– this will allow conversion between these two currencies– produce an algorithm that converts specific TACs to
the effort level (including spatial distribution of effort) required to attain them
“MAFCONS” Management Protocol
C urrent Annua lIC E S F ish S tockA ssessm ent P rocess
S ing le SpeciesTAC s
W P 6 A lgorithm P attern o f fish ingeffo rt requ ired toach ieve TA C s
W P 3 A lgorithm Level o f "EcosystemD isturbance" caused by fish ing activity
W P 2 A lgorithm C onsequences toS pecies D iversityassocia ted w ith se tTAC leve ls
A re Species D iversityC onsequencesA cceptab le ?
Y es
N o
D ecide AcceptableSpecies D iversityLevels
W P 2 A lgorithm P erm itab le Leve lo f E cosystemD isturbance
W P 3 A lgorithm P attern o f fish ing activ itya llow ab le by th isD isturbance Leve l
W P 6 A lgorithm S ing le Species TAC sach ievab le underg iven patte rn o ffish ing activ ity
Announce TACs
A re TA C s acceptab leto m anagem ent?
Y es
N o
R econsiderA cceptab le S peciesD iversity Leve ls
W P 4 D ataS urvey da ta neededby m odel
WP1 product: a management protocol
“MAFCONS” Work Package Arrangement
O bjective 3W P 3F ishing D isturbance
O bjective 4W P 4Benthic d iversityand productivity
O bjective 5W P 5G roundfish d iversity
O bjective 2W P2Theoretica lcom m unity m odel
O bjective 1W P1M anagem ent too l
O bjective 6W P 6E ffort - C atchrelationships
WP 7 covers all Co-ordination activities
No More!!!!
