chapter 4: east scotland (duncansby head to dunbar)...

Marine Nature Conservation Review: benthic marine ecosystemsBennett & McLeod: East Scotland (Duncansby Head to Dunbar) (MNCR Sector 4)

Chapter 4: East Scotland (DuncansbyHead to Dunbar) (MNCR Sector 4)*

Teresa L. Bennett and Colin R. McLeod

Citation: Bennett, T.L. & McLeod, C.R. 1998. East Scotland (Duncansby Head to Dunbar) (MNCR Sector 4). In: MarineNature Conservation Review. Benthic marine ecosystems of Great Britain and the north-east Atlantic, ed. by K. Hiscock, 123154.Peterborough, Joint Nature Conservation Committee. (Coasts and seas of the United Kingdom. MNCR series.)

SynopsisThe north part of the east coast of Scotland is broken bythree major inlets, the Moray Firth (including theDornoch, Cromarty and Inverness/Beauly Firths), theFirth of Tay and the Firth of Forth, and a few smallerinlets. The coastline is predominantly rocky withextensive intertidal sediment areas occurring mainlywithin the inlets. Information on the marine biology of

inshore areas on the open coast is sparse but a widerange of studies describe littoral and sublittoral areas,mainly sediments, within the various inlets. Some partsof the Moray Firth, the Ythan Estuary and parts of thefirth and estuary of the Forth are well studied andcommunities described.

4.1 Introduction and overall studiesThe east Scotland sector extends from Duncansby Headin the north to Dunbar in the south, encompassing awide range of marine habitats and including severalmajor indentations and inlets, such as the Moray Firth(including the Dornoch, Cromarty and Inverness/BeaulyFirths), the Firth of Tay/St Andrews Bay and the Firth ofForth (Figure 4.1).

A few studies have been carried out for the whole eastcoast of Scotland. A series of reports commissioned bythe Countryside Commission for Scotland from theUniversity of Aberdeen, Department of Geography,described the physical environment and recreationaland other human pressures influencing unconsolidated(sediment and pebble) beaches and their maritime fringearound the entire Scottish coast. Relevant reportscovering the east coast are: Ritchie & Mather (1970)(Caithness); Smith & Mather (1973) (East Sutherland andEaster Ross); Ritchie, Smith & Rose (1978) (Highland andGrampian Regions between Inverness and Inverbervie);Wright (1981) (Tayside); Ritchie (1979) (Fife); and Rose(1980) (Lothian and Borders Regions). Mather & Ritchie(1977) provided a summary and overview for beachesnorth of Inverness. Eleftheriou & Robertson (1988)

surveyed 11 sandy beaches between Sinclair s Bay(Caithness) and Belhaven (East Lothian) and describedtheir environmental conditions and faunalcharacteristics. Buck (1993) reviewed the conservationstatus and human uses of 16 estuaries in Sector 4. Smith(1984) assessed saline lagoons (in the widest sense) withrespect to the Mollusca. The distribution of littoral andsublittoral Mollusca for east Scotland was reviewed andmapped by McKay & Smith (1979), who provide animportant bibliography of published records. Muchoffshore survey work has been related to the fishingindustry; although Dawson (1870) listed marineMollusca of Aberdeenshire, Banff and Moray, it was theadvent of trawling which enabled Simpson (1896) toextend this list to include offshore records. Since thattime, the Marine Laboratory at Aberdeen (now part ofthe Scottish Office Agriculture, Environment andFisheries Department) has carried out extensive surveywork throughout the northern North Sea.

The sediments and benthic fauna of three fishinggrounds off the Scottish east coast were surveyed byMcIntyre (1958). Areas off Aberdeen and St Andrewshad fairly uniform deposits varying from muddy to fine

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Bennett & McLeod: East Scotland (Duncansby Head to Dunbar) (MNCR Sector 4)

* This review was completed from published sources of information on benthic habitats and communities as well as interviews withrelevant workers undertaken up to 1991 and published in Bennett (1991). It has been further revised to take account of major additionalstudies by the second author up to the end of 1994 and up to the end of 1996 by the series editor. It does not include benthic surveyinformation summarised for or published in the MNCR Regional Reports series or work now being undertaken to map biotopes incandidate Special Areas of Conservation. For information on conservation status and an analysis of rare and scarce seabed species, thereader is referred to the Coastal Directories series.

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Marine Nature Conservation Review: benthic marine ecosystems

Figure 4.1. The east coast of Scotland showing location of areas mentioned in the text.

sand, with that of the Aberdeen areas being slightlycoarser. The fauna in the two areas was dominated bybivalve molluscs and polychaete worms, and was foundto be richer off Aberdeen. The third area sampled wasthe Smith Bank, in the northern part of the outer MorayFirth, where the sediments varied from sandy mud togravel and the fauna was numerically dominated by thesea urchin Echinocyamus pusillus but dominated bypolychaetes and molluscs in terms of biomass.

Major studies of the offshore benthic environmentand benthos of the northern North Sea were reported byBasford & Eleftheriou (1988) and Basford, Eleftheriou &Raffaelli (1989, 1990). The abundance and distribution ofepifauna was found to be determined primarily bydepth and secondarily by sediment granulometry andorganic content, with the 100 m depth contour being of

prime importance as a dividing line between differentepifaunal assemblages, although they were often seen tograde gradually into one another (Basford, Eleftheriou &Raffaelli 1989). Infaunal distribution was more complexand less influenced by depth, being primarilydetermined by sediment granulometry (Basford,Eleftheriou & Raffaelli 1990).

The development of the North Sea oil industry sincethe early 1970s provided the impetus for numerousstudies, both ongoing monitoring projects whichfrequently include many sites over a wide area, and site-specific environmental impact assessments. In the morepopulous southern part of this sector, many studies havebeen related to pollution, from both pipeline dischargesand offshore sewage dumping. The results of some ofthese studies are reviewed below.

4.2 Moray Firth4.2.1 IntroductionThe Moray Firth is generally regarded as that area ofcoastline and open sea falling within the area boundedby Duncansby Head in the north, Beauly Firth in thesouth-west and Fraserburgh in the south-east, making itone of the largest indentations of the British coast(Figure 4.2). The coastline of the Moray Firth varies fromhigh cliffs and rocky shores to sweeping sandy beachesand dunes, together with the sheltered inlets of LochFleet, the Dornoch, Cromarty, Inverness and BeaulyFirths, and Findhorn Bay. Tidal streams flow in aclockwise direction around the Moray Firth on floodtides and anticlockwise on ebb tides. Inshorehydrography and plankton were investigated by Craig& Adams (1967, 1969) and Adams & Martin (1986).

In the inner Moray Firth, increasing industrialisationand population growth during the late 1960s promptedthe commissioning, principally by the Highlands andIslands Development Board, of the Moray FirthDevelopment Ecological Survey, commencing in 1969.This resulted in an important series of interim reportswith the emphasis on estuarine and littoral habitats andthe impact of the oil industry in particular (University ofAberdeen, Department of Geography 1970a & b, 1971,1972, 1974, 1975, 1976, 1978, 1981a & b). Natureconservation issues and sites of nature conservationimportance (coastal and inland) in this area wereconsidered in a Nature Conservancy Council report(NCC 1978).

A summary of the available information on theoceanography, geology, topography and intertidal andcoastal habitats of the Moray Firth was given by Probert& Mitchell (1980). They described the main communitiescharacteristic of rocky and sediment shores of varyingexposure to wave action and considered shores ofnature conservation importance. These shores aredescribed below. A bibliography covering the marinelife, coastal environment and industrial impactsaffecting the Moray Firth was given by Clokie (1981). In1985 the Royal Society of Edinburgh held a symposiumon the marine environment of the Moray Firth which

brought together the current knowledge at the time(Ralph 1986). Topics included coastal topography (Smith1986), hydrography and plankton (Adams & Martin1986), rocky and sedimentary shores (Terry & Sell 1986;Rendall & Hunter 1986), the sublittoral environment andbenthos in the vicinity of the Beatrice Oilfield (Hunter &Rendall 1986; Hartley & Bishop 1986; Bishop & Hartley1986) and pollution, especially in relation to the oilindustry (e.g. MacLennan 1986). Harding-Hill (1993)provided a comprehensive bibliography and review ofcurrent knowledge for the whole of the Moray Firth,covering coastal, littoral, sublittoral and pelagic habitatsand communities, together with marine mammals, thephysical environment and human activities.

4.2.2 Open coast and offshoreIt is convenient to consider the relatively exposed opencoastline of the Moray Firth separately from the moresheltered, predominantly estuarine conditions of itssmaller inlets. These firths and enclosed bays tend tocontain sedimentary shores while the open coast tendsto be rocky. The coast between Duncansby Head andGolspie is predominantly rocky, often backed by highcliffs, and largely unbroken, with Sinclair s Bay north ofWick being the only major indentation. Many streamsand rivers, such as the Rivers Wick, Helmsdale andBrora, meet the sea along this coast, but there are noopportunities for the development of extensiveestuarine conditions north of Loch Fleet. Sedimentshores in east Sutherland between Kilmote in the northand Cuthill Links in the south were described by Smith& Mather (1973) in relation to tourism, recreation,development and conservation value. The 11 areasstudied were found to be relatively stable but all undersome form of human pressure. Similar findings weremade at eight shores in East Ross between Morrich Moreand Rosemarkie. The study did not investigate the faunaof the beaches.

Both sedimentary and rocky shores betweenDuncansby Head and Peterhead were surveyed by theScottish Marine Biological Association/Marine Biological

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Association Intertidal Survey Unit for the NCC (Bartropet al. 1980) as part of a survey of the littoral zone ofGreat Britain. Shores were described and sitesconsidered to be of marine biological importance wereidentified. None of the sedimentary or rocky siteschosen for their scientific interest were considered ofnational importance for their marine ecology, but theywere considered to be representative of the area.Sediment shores of note were Loch Fleet, lowerCromarty Firth, Munlochy Bay, Ardersier, Culbin Barsand Findhorn Bay. All of these sites were sheltered orvery sheltered from wave action, except Culbin whichrated as moderately exposed. Bartrop et al. (1980)divided the sedimentary shores into four maincategories, each characterised by an associatedcommunity:

a crustacean-polychaete community occurring inareas of moderate exposure to wave action andcontaining a low-density amphipod-isopod and/orpolychaete worm fauna;

a Tellina (now Angulus) community characteristic ofclean sand and including the bivalves Tellina (nowAngulus) tenuis and Donax vittatus, the polychaetesArenicola marina and Nephtys caeca and the amphipodBathyporeia spp. ;

an Arenicola community occurring in muddy sand,which included the polychaetes Arenicola marina andNephtys hombergii and the bivalves Macoma balthicaand Cerastoderma edule;

a Scrobicularia community occurring in muddysediments, characterised by the bivalves Scrobiculariaplana and Mya arenaria, and the ragworm Nereis (nowHediste) diversicolor.

Rocky shores considered to be of conservation interestby Bartrop et al. (1980) were Helmsdale, Tarbat Ness,Cullen, Gardenstown and Pennan. These sites were allexposed or moderately exposed to wave action (shoresof extreme shelter or extreme exposure to wave actionwere absent) and supported a moderately rich fauna

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GRAMPIANGRAMPIAN(now Moray)(now Moray)

InvernessInvernessFirthFirth

ABERDEENSHIREABERDEENSHIRE

GolspieGolspie

CAITHNESSCAITHNESS(now part of Highland)(now part of Highland)

WickWick

BeaulyBeaulyFirthFirth

SUTHERLANDSUTHERLAND(now part of Highland)(now part of Highland)

Wick RiverWick River

Enlarged in Figure 4.3Enlarged in Figure 4.3

RiverHelmsdale

River Brora

N

0 20

km

Burghead

33 22

5858

5830'5830'

Dunbeath

Helmsdale

Kilmote

Peterhead

PennanGardenstown

Findhorn

Inverness

Beauly

Cromarty Firth

Bonar Bridge

DuncansbyHead

River Deveron

River Spey

10W

60N

55

50

5 0

N

Based on Admiralty Chart 219 with the permission of theController of Her Majesty's Stationery Office. Crown Copyright.

3 2

58

5830'

Dunbeath

Helmsdale

Golspie

Kilmote

CAITHNESS(now part of Highland)

Wick

Fraserburgh

Peterhead

PennanGardenstown

MacduffCullen

GRAMPIAN(now Moray)

RattrayHead

Lossiemouth

BurgheadFindhorn

InvernessFirth

Inverness

Beauly

BeaulyFirth

Cromarty Firth

Bonar Bridge

Tarbat NessDornoch Fi

rthLoch Fleet

BeatriceOilfield

SmithBank

Sinclair's Bay

DuncansbyHead

SECTOR4

River Deveron

River Spey

MorayFirth

50

50

100

50100

SECTOR 3

RiverHelmsdale

River Brora

SUTHERLAND(now part of Highland)

Spey Bay

100

ClythNess

0 20

km 50

50

Wick River

Enlarged in Figure 4.3Balintore

ABERDEENSHIRE

MunlochyBay

50

Figure 4.2. The Moray Firth showing location of places mentioned in the text.

representative of rocky shores within the Moray Firth.Exposed rocky shores supported a well developed lichenzone, an abundance of the periwinkle Littorina saxatilisagg., the fucoid alga Fucus vesiculosus f. linearis, themussel Mytilus edulis, the barnacle Semibalanusbalanoides, a range of red algae including Gigartina (nowMastocarpus) stellatus and Ceramium shuttleworthianumand the kelps Laminaria digitata and Alaria esculenta. Thecoast south of Tarbat Ness was identified as the onlycontinuous length of rocky shore in over 150 km ofsedimentary coastline in the inner Moray Firth, with amixture of rock types, and a very extensive kelp forestoff Balnabruach. The rare subarctic fucoid alga Fucusdistichus ssp. edentatus was recorded at Macduff Harbour,its only known location on the British mainland.

The upper shore regions of sheltered rocky shoreswere generally poor in species diversity, attributable tothe desiccating conditions that prevail in summer. Thebrown algae Pelvetia canaliculata, Fucus spiralis andAscophyllum nodosum were either poorly developed orsparsely distributed on these shores. The middle andlower shore regions tended to include a range ofhabitats including boulders, cobbles, overhangs and rockpools as well as bedrock at varying inclinations.Consequently these shores supported a wide variety ofspecies such as the brown algae Fucus vesiculosus, Fucusserratus, Halidrys siliquosa and Laminaria digitata, the redalgae Laurencia pinnatifida, Plumaria elegans,Membranoptera alata, Odonthalia dentata and Ptilotaplumosa, the green algae Enteromorpha intestinalis andCladophora rupestris, the periwinkles Littorina saxatilisand Littorina littorea, the barnacle Semibalanus balanoides,the limpet Patella vulgata, mussels Mytilus edulis, thedogwhelk Nucella lapillus, the sponges Halichondriapanicea and Grantia compressa and tubeworms,Pomatoceros triqueter and Spirorbinidae.

In 1981 a major rocky shore monitoring programme inthe Moray Firth was initiated (Sphere EnvironmentalConsultants Ltd 1981a). Thirty-four shores betweenDuncansby Head and Fraserburgh were selected tocover the range of predominant physiographic featuresin the Moray Firth and transects were established. Theseshores were mainly rocky but also included boulder andcobble shores and encompassed a range of exposures towave action. The shores selected were described alongwith their associated species by Sphere EnvironmentalConsultants Ltd (1981a) in 36 separate reports to theBritish National Oil Corporation (Britoil) (summarisedby Terry & Sell (1986)). Monitoring of the shoresinvolving analysis of species distribution withinpermanent quadrats and quantitative studies onbarnacle, limpet and mussel populations was carried outuntil 1986 (Aberdeen University Marine Studies Ltd.1983, 1984a, 1985a, 1986; Terry & Sell 1986; Terry 1987).Comparisons made between the data over the yearsshowed most observed changes to be natural.

Smith (1981) briefly described 17 (predominantlyrocky) shores on the northern side of the Moray Firthbetween Dunbeath and Ballintore with particularreference to Mollusca. A notable find at four sites wasthe gastropod Rissoella diaphana, previously recorded forthe east coast of Scotland only from Cruden,Aberdeenshire. The shores in this area were found to be

similar to those between Aberdeen and the Firth of Taybut were poorer in species compared with the shores onthe south side of the Moray Firth. Smith (1984)considered the fully marine Rosemarkie lagoon to beimportant for molluscs, it being the only known eastScottish site for Leucophytia bidentata and the west coastlimit for Calliostoma zizyphinum as a shore species.McKay (1977) and Palmer (1977) described molluscrecording and listed the coastal and offshore speciesknown in the Conchological Societys marine censusarea S5, which includes the Moray Firth and theoffshore area of the North Sea to the east of the Firth.

Intertidal angiosperms in the Moray Firth weresurveyed in a series of monitoring projects by theUniversity of Aberdeen, Department of Geography(1970a&b, 1972, 1974, 1976, 1978, 1981a & b). A detailedstudy was undertaken of the environmental conditionsand vegetation on saltmarshes and sand/mudflats withparticular reference to the seagrasses Zostera noltii,Zostera angustifolia and Ruppia sp., and glasswortSalicornia sp.

The south coast of the Moray Firth from Fort Georgeto Fraserburgh comprises a sequence of sandy bays,more common and larger in the western part, and rockyshores, often backed by cliffs, mainly in the lesssheltered east. Beaches of north-east Scotland fromInverness to Inverbervie, Kincardineshire, weredescribed in terms of their physical environment andrecreational pressures by Ritchie, Smith & Rose (1978).Major sand bars have formed off Culbin, a dynamiccoastline backed by a formerly highly mobile expanse ofdunes, now afforested (Comber, Hansom & Fahy 1994).Several major rivers join the sea along this coast,including the Rivers Nairn, Findhorn, Spey andDeveron. Findhorn Bay is an extensive, largely enclosedestuary, a proposed local nature reserve. Bartrop et al.(1980) considered the communities present to berepresentative of sheltered muddy sand with reducedsalinity. The complex and shifting delta of the RiverSpey at Spey Bay is part of the largest shingle complexin Scotland. Most of the villages and small towns alongthis largely undeveloped coast are fishing settlements,with tourism locally important near sandy beaches, forexample at Nairn, Findhorn, Spey Bay and Cullen.Pollution effects are generally limited to the vicinity ofoutfalls. There is an oil platform construction yard atWhiteness Head, an accreting system of saltings, sandand mudflats and saltmarsh, just outside the InvernessFirth; its environmental effects were assessed by theUniversity of Aberdeen, Department of Geography(1974).

A survey of the distribution and abundance of littoralinvertebrates in sediment shores on the south side of theMoray Firth between Alturlie Point and Findhorn Baywas carried out by Wells & Boyle (1974). This coastbenefited from the work of Victorian conchologists.Gordon (1854) and Dawson (1870) described theMollusca of this section of coast, while Macgillivray(1843) covered the whole of what was, until 1996,Grampian Region. Other papers on the Moray Firth,particularly the Burghead area, by Gordon include earlyaccounts of crustaceans (Gordon 1852a), echinoderms(Gordon 1853) and fish (Gordon 1852b, 1852c).

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The Beatrice oilfield is located on the south-westcorner of Smith Bank just 23 km from the coast south-south-east of Clyth Ness. Being so close to the coastthere is a potential threat to marine life in shallowwaters and on the coast from oil pollution. Inconsequence, an environmental impact analysis wascarried out by Sphere Environmental Consultants Ltd(1977), involving a survey of the benthic fauna in thevicinity of Beatrice oilfield and a littoral sediment surveyat potential terminal sites. The sand of Smith Bank wasfound to support an infauna dominated by the hearturchin Echinocyamus pusillus, the bivalve Moerellapygmaea and the polychaete Ophelia borealis. To thenorth-west the sediments were fine and supported thebivalves Angulus tenuis, Nuculoma tenuis and Thyasiraflexuosa, the scaphopod Antalis entalis and the sea penVirgularia mirabilis. Further work on the benthic fauna inthe area has been carried out by several other workers(Hartley 1978; Bishop & Hartley 1986; Hartley & Bishop1986; Cranmer 1987). Prior to oil production the benthiccommunities were found to be stable (Hartley & Bishop1986). Drilling at the Beatrice oilfield resulted in drillcuttings polluting the seabed causing a gradient of effecton the benthos with distance from the platform. Drillingceased in 1985 and the environmental conditionsimproved as hydrocarbons on the seabed continued todegrade. Comparisons of survey data collected in 1985and 1987 showed that the benthic macrofauna hadresponded to the improved conditions (Cranmer 1987).

Earll (1983) provided a review of information on theshallow sublittoral zone of the Moray Firth based onpublished data, interviews with local marine researchersand species records collected by divers. The shallowsublittoral was described in terms of the physicalenvironment, habitats, communities and conservationimportance. Information on the nearshore sublittoralwas sparse, but available data suggested the area to belacking in terms of habitat diversity.

The Moray Firth is notable as the home range of oneof only a handful of resident populations of bottlenosedolphins Tursiops truncatus in British waters, andprobably the only resident population in the North Sea.Since 1989, a research programme on this populationhas been carried out by the University of Aberdeen,Department of Zoology, in collaboration with the SeaMammal Research Unit, St Andrews. Hammond &Thompson (1991) gave a minimum estimate ofpopulation size, and current studies are enabling moreaccurate counts and also investigating the dolphinshealth and diet (e.g. Thompson & Hammond 1992;Curran, Wilson & Thompson 1996). Similar studies arebeing carried out on common and grey seals in theMoray Firth (e.g. Pierce et al. 1991).

4.2.3 Marine inletsThe inner part of the Moray Firth includes three majorinlets, the Dornoch, Cromarty and Inverness/BeaulyFirths, and two other important estuaries, Loch Fleetand Findhorn Bay. All are of considerable natureconservation importance, primarily for theirornithological significance (Ratcliffe 1977; NCC 1978;Davidson et al. 1991).

4.2.3.1 Loch FleetLoch Fleet, situated between Golspie and Dornoch,forms the estuary of the River Fleet, and is a smallshallow loch with predominantly sediment shores. Astudy of the distribution and abundance of littoralinvertebrates in the loch was carried out by Wells &Boyle (1975). Most of the sediments consisted of muddysand, although clean sand occurred at the mouth and ona large sandbank. Mud patches and stony scalps werealso present. The most common species recorded wereoligochaetes, the polychaetes Arenicola marina, Fabriciasabella, Nephtys spp., Nereis (now Hediste) diversicolor,Pygospio elegans and Scoloplos armiger, the amphipodsBathyporeia spp. and Corophium volutator, the snailHydrobia ulvae, and the bivalves Cerastoderma edule,Mytilus edulis, Macoma balthica and other tellinids. Smith(1984) considered the molluscan fauna to be interesting,including the opisthobranch Akera bullata, not recordedelsewhere in east Scotland. Construction of the presentA9 road embankment in 1816 sealed off an expanse ofthe upper estuary, which developed into a mixture ofalder carr woodland and open fen, with saline lagoonssupporting saltmarsh vegetation grading into freshwaterswamp (NCC 1978). This wetland is now part of MoundAlderwoods National Nature Reserve. Loch Fleet andadjacent woodlands are a Scottish Wildlife Trust naturereserve.

4.2.3.2 Dornoch FirthDornoch Firth consists of a series of generally shallowbasins and narrows extending into the narrow Kyle ofSutherland above Bonar Bridge, with the promontory ofTarbat Ness marking its seaward limit. The Firth islargely unspoilt, with wide sandy beaches in the largebays at the entrance to the Firth. Large sections arenotified SSSIs. The abundance and distribution of littoralinvertebrates in sediment shores was studied by Wells &Boyle (1973). They identified 41 species, the mostcommon ones being similar to those found in Loch Fleet.Rendall & Hunter (1986) studied the littoral fauna at twosites in Dornoch Firth, in Cambuscurrie Bay andArdjachie. The principal species found were thepolychaetes Scoloplos armiger and Pygospio elegans, theoligochaetes Tubificoides benedeni and Aktedrilusmonospermathecus and the tellin Macoma balthica. A list ofthe littoral algae was compiled by Currie (1974a). Asurvey of the distribution and density of theangiosperms Zostera angustifolia, Zostera noltii, Ruppiamaritima and Salicornia spp. was carried out in 1986 (Fox,Yost & Gilbert 1986). Zostera noltii was very abundant onEdderton Sands while Ruppia maritima occurred on themud and muddy sand of the Dornoch and Tain Sands.Zostera angustifolia was the most common of the fourspecies recorded and Salicornia spp. the least common.

The sublittoral sediment fauna at eight stations in theDornoch Firth was investigated by Highland RiverPurification Board (Hunter & Rendall 1986). Thesediments of the Firth were predominantly mediumsands with low organic content except at the mostlandward site, Newton, where estuarine silt occurred. AtNewton a sparse brackish water fauna of thepolychaetes Fabricia sabella, Nereis (now Hediste)diversicolor, Pygospio elegans, tubificids and nemertean

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worms was recorded. Ardmore had greater speciesdiversity, although conditions here were still brackish.Extensive Mytilus edulis beds occurred in the middle ofthe Firth. Species characteristic of coarse or sandysubstrata were prominent in the samples, including thepolychaetes Nephtys cirrosa, Chaetozone setosa and Glyceracapitata, the bivalves Tellina (now Angulus) tenuis andVenus (now Chamelea) gallina and the amphipodCorophium crassicorne. At sites exposed to wave action inthe outer Firth, the fauna was sparse and dominated bythe bivalves Tellina (now Fabulina) fabula and Venus (nowChamelea) gallina. Commercial cockle harvesting at InverBay has recently given cause for concern, as at siteselsewhere in the Moray Firth (P. Wortham pers. comm.;Harding-Hill 1993).

4.2.3.3 Cromarty FirthCromarty Firth is a long natural harbour, used duringthe two World Wars as an anchorage for the Royal Navy.Since the 1970s it has served as an anchorage for oilplatforms, and an oil rig construction yard and oil

terminal have been established at Nigg, next to thedeep-water channel. Industrial development has takenplace on the northern shore, and the Firths long-standing importance as an anchorage resulted in ahistory of frequent oil-spills (Currie 1974b). However,throughout the Moray Firth, both the frequency andimpact of oil pollution incidents has decreased since the1970s (MacLennan 1986), and Cromarty Firth remains ofinternational ornithological importance. The Firth isestuarine above Invergordon but seaward of this pointthe salinity is stable and the water deep, reaching about50 m between North and South Sutor, where strong tidalstreams occur. Collar (1978) considered Cromarty Firthto be a partly mixed estuary approaching a stratifiedcondition.

Two large intertidal bays, Nigg and Udale, lie withinCromarty Firth. Jointly, they include a National NatureReserve and RSPB reserve, primarily for theirornithological importance, although it is not possible toconsider the reserves conservation value in isolationfrom the Firth as a whole (Wortham & Brown 1990).

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DornochDornochSandsSands

NewtonNewtonPointPoint

LongmanLongmanPointPoint

AlturlieAlturliePointPoint

MorrichMorrichMoreMore

CromartyCromarty

ShandwickShandwick

River Nairn

Beauly

GolspieRiver Fleet

Kyle of Sutherland

Mound Alderwood

5858

N

DornochBonarBridge

Ardmore

Cambuscurrie Bay

Edderton SandsArdjachie PointArdjachie Point

TainSands

Nigg BayNigg

Invergordon

Cromarty Firth

Dingwall Bay

Munlochy Bay

Beauly Firth

Inverness

Ness estuary

Ardersier

Culbin Bars

Findhorn

Burghead

Udale Bay

0 10 20

km

Kessock

Nairn River Findhorn

Inver Bay

Rosemarkie

Chanonry Point

BLACK ISLE

11

N

Based on Admiralty Chart 219 with the permission of theController of Her Majesty's Stationery Office. Crown Copyright.

5050

Golspie

Loch Fleet

Dornoch

DornochSands

NewtonPoint

BonarBridge

Ardmore

Cambuscurrie Bay

Edderton SandsArdjachie Point

Balintore

TarbatNess

Dornoch Firth

TainSands

Nigg BayNigg

North SutorSouth Sutor

Invergordon

Cromarty Firth

Dingwall Bay

Munlochy Bay

Beauly Firth

Beauly

Inverness

Ness estuary

LongmanPoint

AlturliePoint

Ardersier

Fort GeorgeCulbin Bars

Findhorn

Findhorn Bay Burghead

MORAY FIRTH

Udale Bay

0 10 20

km

0

0CuthillLinks

0

Kessock

Nairn

River Nairn

River Findhorn

River Fleet

Kyle of Sutherland

Mound Alderwood

MorrichMore

Inver Bay

Rosemarkie

InvernessFirth

Chanonry Point

BLACK ISLE

1

58

Cromarty

Shandwick

Whiteness Head

Balnabruach

Figure 4.3. The inner Moray Firth and inlets showing location of places mentioned in the text.

Surveys of the abundance and distribution of littoralmacrofauna in the sediment shores and theenvironmental factors affecting their distribution havebeen undertaken in the two bays (Anderson 1971).Anderson recorded 34 species, only six of which wereabundant. Similar studies were carried out as a baselinefor a biological monitoring programme to detect anychanges as a result of industrial development in NiggBay (Boyle & Raffaelli 1981). Work was continued in1982, 1983 and 1985 and comparisons made between thedata (Raffaelli & Boyle 1982, 1985). These studiesshowed an increase in the silt content of sediments inNigg Bay from 1981 to 1983 and a decrease in 1985.Changes in the infauna mirrored those of the sedimentswith an increase in species density from 1981 to 1983and a subsequent decline in 1985. Raffaelli & Boyle(1985) concluded that these changes were largelynatural. The intertidal macrofauna of Nigg Bay was alsostudied by Raffaelli & Boyle (1986) who considered thebay to have a rich fauna and to be biologically similar toother bays within the Moray Firth. The intertidalmacrofauna of three sites in Cromarty Firth, Udale Bayand the east and west sides of Nigg Bay, was studied byRendall & Hunter (1986). Samples were taken from threedifferent levels on the shore. The upper shore stations atUdale Bay and Nigg West were dominated by a singlespecies, Hydrobia ulvae, while the middle shore stationsat Nigg East were characterised by Tubificoides benedeni.Other frequently occurring species were Scoloplosarmiger and Macoma balthica.

Zostera communities of Nigg Bay were studied andtheir distribution mapped by Sphere EnvironmentalConsultants Ltd (1981b). An intensive study of Zosteraangustifolia, Zostera noltii, Ruppia maritima and Salicorniaagg. in Cromarty Firth was carried out in 1986 (Fox, Yost& Gilbert 1986). Zostera angustifolia was the mostcommon seagrass in the Firth although Zostera noltii wasfound to be very dense in Nigg and Udale Bays.Salicornia spp. was locally abundant farther up the Firth,in Dingwall Bay. The distribution of littoral algae inCromarty Firth was studied by Currie (1974a).

Studies in relation to industrial (oil, gas and chemical)developments in Nigg Bay involved a description of thehydrology of the area and intertidal ecology withrespect to saltmarshes, Zostera beds, the macrofauna andconservation interests (OSullivan & Kelly 1981). Therich variety of invertebrate fauna was thought to berelated to the diversity of sediment types present withinthe bay. Other work in Nigg Bay has been in directassociation with the Nigg Terminal. Fouling of the NiggTerminal jetty pilings was studied by AberdeenUniversity Marine Studies Ltd. (1984b, 1985b). Foulingwas analysed by surveying the distribution of speciesand community composition at different depths,measuring the growth of the organisms, evaluatingpatterns of fouling and predicting future fouling. Thiswork was summarised by Picken (1986). From 0 m to 6 mbelow chart datum (bcd) fouling consisted of musselsMytilus edulis overgrown with seaweed; from 6 m to26 m bcd barnacles and tubeworms were overgrown byanemones, soft corals and hydroids. Over the studyperiod there were no significant changes in compositionof fouling organisms but substantial increases in the

thickness of fouling was observed. Buoys in theapproaches to Cromarty Firth were completely coveredby algae and mussels.

Sublittoral sediment fauna was monitored by theHighland River Purification Board (Hunter & Rendall1986). Six stations within Cromarty Firth were studied.At Invergordon the sediment tended to be sandy withthe bivalves Fabulina fabula and Gari fervensis. Furtherseawards the seabed consisted of stable mud withscattered clinker and a fauna characterised by thebivalve Abra alba. The Firth narrows where it enters thesea between North and South Sutor, resulting in strongtidal currents; here the sediment consisted of firm sand.Species recorded in this area included the polychaeteworms Ophelia borealis, Aonides oxycephala, Glyceracapitata, Prionospio cirrifera, Microphthalmus sp. andNephtys longosetosa and the amphipod Atylus falcatus.East of the entrance to the Firth the sediments werefiner and species richness and diversity was low. AnMNCR sublittoral survey was carried out in the narrowsin May 1992; preliminary assessment suggests agenerally more diverse if unexceptional fauna, withmany species additional to those recorded by Hunter &Rendall (1986), including hydroids and anemones. Aricher epifauna was recorded on sandy mud east of OldShandwick (MNCR, unpublished data).

4.2.3.4 Inverness FirthInverness Firth extends from the narrows at Kessock,Inverness, to those between Chanonry Point and FortGeorge. On the north side lies Munlochy Bay, a localnature reserve where the distribution and abundance oflittoral invertebrates has been studied (Boyle &Goodman 1977). Characteristic species of the areaincluded glasswort Salicornia spp. , the green algaEnteromorpha spp. and the bivalves Mytilus edulis andCerastoderma edule. The intertidal muddy sand atArdersier was found to be fairly rich in species with welldeveloped tellinid and polychaete communities (Bartropet al. 1980). Strong tidal streams occur near the mouth ofInverness Firth. Monitoring within the Firth in relationto the Inverness main drainage scheme involved studiesof the hydrography, water quality and communities(Highland River Purification Board 1985a, 1985b). Thefauna of the beaches by the sewage outfall at LongmanPoint was found to be damaged by pollution. Fewerspecies than normal occurred and large numbers ofpollution-tolerant worms such as the polychaeteCapitella sp. were found, as well as Enteromorpha spp.Rendall & Hunter (1986) studied seven sediment siteswithin Inverness Firth in relation to the Invernesssewage discharge. Samples were taken from threedifferent levels on the shore. The lower shore stationlocated by the outfall was severely affected by thedischarge, having a very low species diversity. Thisstation was dominated by Capitella capitata. Specieswhich commonly occurred at other sites were thepolychaete Pygospio elegans, the oligochaete Tubificoidesbenedeni, and the molluscs Hydrobia ulvae and Macomabalthica in addition to Capitella capitata.

The sublittoral sediment fauna in Inverness Firth wasalso investigated by Highland River Purification Board(Hunter & Rendall 1986). In the inner part of the Firth

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the seabed consisted of stones overlying clay. AlturlieDeep was muddy with a community of the bivalves Abraalba and Nucula spp. and the polychaetes Terebellidesstroemi and Nephtys hombergii. Farther seaward thesediment became coarser and sandy with species such asthe amphipod Corophium crassicorne and the polychaetesMyriochele oculata and Lanice conchilega. In the narrowsbetween Chanonry and Fort George the seabedconsisted of firm sand with some coarser particles. Avariety of species occurred in the strong currentsincluding bryozoans and the polychaetes Aonidesoxycephala, Glycera capitata and Microphthalmus similis,although some patches of sand supported very little life.Just outside the Firth at Fort George the sediment wassandy and dominated by the bivalve Spisula solida.

4.2.3.5 Beauly FirthBeauly Firth lies between Beauly and Inverness, formingan inland extension of the Inverness Firth. The intertidal

mudflats are of particular ornithological importance. Anintensive study of the distribution and density of Zosteraangustifolia, Zostera noltii, Ruppia maritima and Salicorniaspp. was carried out by Fox, Yost & Gilbert (1986). Themost common seagrass within the Firth was found to beZostera angustifolia.

Hunter & Rendall (1986) studied the sublittoralsediment fauna at three sites towards the seaward endof Beauly Firth. The Beauly basin consisted of muddysand with a rich fauna. In the River Ness estuary thesediment was found to be black and anoxic withcontamination by sewage solids. The polluted conditionswere reflected in the species found, which includedtubificid worms, capitellids and nematodes. Towards theentrance of Beauly Firth at Kessock, the seabed wasstony with a fauna containing the epifaunal polychaetesLepidonotus squamatus, Harmothoe spp. and Lepidonotusclava, bryozoans and the hydroid Dynamena pumila,which was colonised by the mussel Musculus discors.

4.3 East coast4.3.1 Introduction, general studies andthe open coast

This section covers the coastline from Fraserburgh at thesouth-eastern point of the Moray Firth to Fife Ness atthe northern point of the Firth of Forth (Figure 4.4). Thecoast comprises a mixture of cliffs, rock and sand brokenby several estuaries, including those of some ofScotlands largest rivers. There are numerous, oftenextensive, bays and sandy beaches. Although thissection includes Scotlands third and fourth largestcities, the coast away from the cities and towns is largelyunspoilt, and most rivers entering the sea are relativelyunpolluted. They include several famous salmon-fishingrivers such as the Don, Dee, North Esk and Tay.

The marine algae of Grampian Region were recordedin 1975 (Wilkinson 1979). Eighty species not previouslyrecorded for the area were found, including the firstBritish record of the brown alga Sorapion kjellmanii.

The vertical and horizontal distribution of themeiofauna in the sediments at Collieston was studied bySeaton (1975). The meiofauna showed a patchydistribution probably due to local variation in sedimentstructure.

The distribution of fucoid algae was described for theUgie (Peterhead), the Ythan (Newburgh), the Don(Aberdeen) and the Dee (Aberdeen) estuaries (Chater1927). The Ugie and the Don were similar in that theywere both small estuaries supporting an abundance ofthe fucoid alga Fucus ceranoides. Much of the Ythanconsisted of muddy shores but where rock occurred itsupported a variety of fucoids. A range of fucoid algaealso characterised the lower part of the Dee estuary butonly Fucus ceranoides, which can tolerate reducedsalinity, penetrated the estuary beyond Victoria Bridge,Aberdeen. The Don was formerly heavily polluted bypaper mill effluent, but since the installation of abiological treatment plant, water quality has much

improved, and the estuary was declared a Local NatureReserve in 1993.

The invertebrate fauna of the Dee estuary was studiedby Eleftheriou (1964). As might be expected, themaximum densities of marine, estuarine and freshwaterspecies were found at the mouth, middle and head ofthe estuary respectively. Analysis of faunal samplestaken from intertidal stations along the Dee revealedthat the Dee estuary supported only 10% to 20% of themacrofaunal diversity common to long estuaries such asthe Tees in Cleveland; this was attributed to variablesalinity and the absence of mudflats (Milne 1940).

Aberdeen serves as a base for the North Sea oilindustry and is an important fishing port, althoughmuch less so than formerly. The local sediment shore ofNigg Bay has been a site for many investigations, mainlyon individual species, by students of the University ofAberdeen. The intertidal macrofauna of Aberdeen Beachwas found to be dominated by the spionid Nerine (nowScolelepis) sp. and the amphipod Haustorius arenarius(Hart 1971).

The only major study of the marine environment ofMontrose Bay is a confidential report prepared byAURIS Environmental (1991), who also investigatedLunan Bay to the south; this study found the fauna to betypical of exposed intertidal sediments of the north-eastcoast of Scotland, with a low species diversitydominated by amphipods and spionid polychaetes.More diverse faunal communities were found at onetransect to the south of the mouth of the River NorthEsk. There have been studies of anadromous fish in theRiver North Esk, for example Shearer (1990).

The algae of the district of Arbroath, a rocky coastlineincluding high sandstone cliffs and bays with floors shore platforms with rockpools bounded by Red Headin the north and Arbroath Bay in the south, were listedby Jack (1890). McLusky & Roddie (1984) investigatedthe brackish pond at Elliot Links, Arbroath. A limited

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132


Sands ofForvie

Figure 4.4. The east coast of Scotland, except the Moray Firth and Firth of Forth, showing location of places mentioned in the text.

benthic fauna was found, comprising a mixture of fresh-and brackish-water species, with a rich planktonic faunadominated by the mysid Neomysis integer. To the south-west, the rocky shores and rockpools near East Havenare a favoured site for educational field studies. DundeeMuseum holds unpublished species lists dating from the1930s to the 1970s; Smith, Light & Killeen (1990)provided one of the few published lists.

The sublittoral sediments and fauna near theInchcape or Bell Rock, 18 km south-east of Arbroath,have been extensively studied in relation to sewagesludge dumping grounds in this area (various reportson behalf of Lothian Regional Council summarised byMoore & Davies (1987), and continuing on an annualbasis, reported most recently by Hull & Webster (1991)).The monitoring involves chemical analysis of thesediments, quantitative analysis of the fauna and videorecording of the benthos. The sediments consisted offine to medium grained sands. Over 300 species havebeen recorded from the area. Moore & Davies (1987)considered that the sediments and benthic macrofaunain the vicinity of Bell Rock did not appear to have beenadversely affected by the dumping of sewage sludge.Hull & Webster (1981) reported similar findings, andnoted that species diversity in 1990 was the highestrecorded since 1981, although the polychaeteMyriochele oculata had declined significantly inabundance.

4.3.2 Ythan estuaryThe Ythan estuary, which is particularly important forits waders and wildfowl, forms part of the Sands ofForvie and Ythan Estuary National Nature Reserve. Theestuary has been intensively studied by the Universityof Aberdeen; a full list of publications and thesesrelating to the Ythan estuary was compiled by theUniversitys Culterty Field Station (University ofAberdeen, Department of Zoology [1992]),supplementing an earlier bibliography by Raven (1978).The estuary is considered one of the best documented inthe world, and the research was briefly summarised byGorman & Raffaelli (1993). Many studies haveinvestigated the distribution and feeding of various birdspecies in relation to the distribution and productivity ofthe invertebrate fauna in the mudflats (for exampleChambers 1965; Goss-Custard 1966; Heppleston 1968;Milne & Dunnet 1972; Joffe 1978; Greenstreet 1986;Raffaelli, Falcy & Galbraith 1990). The amphipodCorophium volutator, the gastropod Hydrobia ulvae, thepolychaete Nereis (now Hediste) diversicolor and the tellinMacoma balthica were found to be widely distributedwhile other species such as the cockle Cerastoderma edule,the periwinkle Littorina littorea, the crab Carcinus maenasand the mussel Mytilus edulis had a more localiseddistribution. However, mussels are of considerableimportance within the estuary as a major source of foodfor eider duck. Other investigations have covered theecology, distribution and abundance of particular groupssuch as crustacean predators (Raffaelli et al. 1989) orindividual species, such as the sand goby Pomatoschistusminutus (Healey 1971), the common goby Pomatoschistusmicrops (Healey 1972; Jaquet & Raffaelli 1989) and theflounder Platichthys flesus (Raffaelli et al. 1990).

Long-term changes in nutrients, weed mats andshorebirds in the Ythan estuary were reviewed byRaffaelli, Hull & Milne (1989). It was found that nitrogenlevels in the River had increased by some 200300% overa 25-year period, associated with an increase in theproportion of farmland under cereal production. Inputsfrom sewage pollution were localised and small bycomparison. Biomass of Enteromorpha also increased overthis period, to the extent that green algal mats coveredmuch of the intertidal area. The polychaete Capitellacapitata became more abundant under these mats, butother species such as Cerastoderma edule and Corophiumvolutator decreased, with Corophium declining markedlywhere the algal biomass (wet weight) exceeded 1 kg m2

and disappearing at 3 kg m2. Although Corophium canrecolonise mudflats after weed mats become dispersedor buried, this requires areas of uncovered sedimentfrom which the species can spread. Raffaelli, Hull &Milne (1989) suggested that further eutrophication couldresult in algal mats blanketing most of the intertidal areathrough the summer months. The absence of weed-freerefuges could cause the disappearance of Corophium, themain prey species for most of the fish and shorebirds inthe estuary (Milne & Dunnet 1972; Baird & Milne 1981),with serious implications. However, 1989 levels ofnutrient enrichment appeared to have enhancedproductivity, reflected in an increase in shorebirdpopulations. As a result of concern over nitrate pollutionfrom agriculture, a major part of the Ythans catchmentarea was proposed by the Scottish Office for designationas one of Scotlands first Nitrate Vulnerable Zones in1994.

4.3.3 Montrose BasinMontrose Basin is the estuary of the River South Esk,linked to the sea by a narrow channel (a second channelwas infilled during the 1970s). It is shallow and drainsalmost completely at low water exposing approximately8 km2 of mudflats of ornithological importance. MusselsMytilus edulis were formerly extensively cultivated inthe Basin for line bait (Fullarton & Scott 1888; Fullarton1894), and there is still a mussel farm. The Basin is alocal nature reserve, and most recent work has beenundertaken for the Scottish Wildlife Trust, who managethe reserve. An investigation of the fauna and flora in1982 showed the Basin to have a rich estuarine fauna(McLusky & Roddie 1982). The fauna was dominated byHydrobia ulvae, Corophium volutator and the sabellidworms Manayunkia sp. and Fabricia sabella. Based on thisfirst study, a further quantitative survey of theinvertebrate community was carried out (Milligan 1984).Population levels varied spatially depending on localconditions. Changes in abundance of certain species hadoccurred compared with the previous survey owing to adrop in the level of organic enrichment.

The 1982 study was updated and expanded by Atkins,Caudwell & Herbert (1992). This study found domesticsewage contamination to be widespread, and increasingnutrient enrichment was identified as a potentiallyserious problem. The estuary was found to beapparently more marine-influenced than previousstudies had indicated, with major differences from the1982 results observed in the fauna and flora. Despite

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organic pollution, there had been a marked increase inspecies diversity, with some marine species alsoincreasing in density and/or extending their rangewestwards, notably the cockle Cerastoderma edule andspionid polychaetes. Fourteen additional species ofpolychaetes were recorded, many of them typicallymarine rather than estuarine. The abundance of theestuarine Hydrobia ulvae had remained unchanged, andtherefore of much less relative importance than in 1982,while the density and extent of Zostera spp. haddeclined. Mytilus edulis remained the dominant bivalve.A further five-year programme of work to monitorbiological conditions on the tidal flats was commencedin 1993 (for instance, Caudwell & Jones 1994a).

4.3.4 Firth of TayThe River Tay meets the sea as a major Firth between thesandy peninsulas of Buddon Ness on its north side, andTentsmuir on the south. The Firth of Tay can be dividedinto the relatively marine influenced outer Firth,downstream from the Tay Rail Bridge at Dundee, andthe more estuarine inner reaches upstream towardsPerth (Figure 4.5). Khayrallah & Jones (1975) identified amiddle estuary region between Invergowrie andBroughty Ferry Castle; this was found to be the regionof maximum variation in salinity, and also of mostpollution. However, as a whole, the estuary is a partiallymixed one, strongly influenced by freshwater input. TheTay has by far the largest flow of any British river, with a

mean flow rate of 198 m3 s1 and a normal rangebetween 94276 m3 s1 (Williams & West 1975);furthermore, the true entrance to the Firth is extendedfurther seawards beyond the apparent mouth by theGaa and Abertay sandbanks, which restrict waterexchange with the open sea. Consequently, although theinfluence of ordinary spring tides penetrates almost asfar as the confluence of the Rivers Tay and Almond,4 km upstream from Perth, and 50 km inland, salineconditions only penetrate the estuary as far asNewburgh, even under low-flow conditions (Williams &West 1975). Typically estuarine conditions thus occurrelatively far downstream, around Dundee, and the highflushing rate means nutrients are rapidly carried out tosea, resulting in an impoverished fauna compared withmany estuaries; however, the high flushing rate alsoproduces generally unpolluted conditions. Theapplication of remote sensing techniques has shown theTay estuary to be a much more complex system thanpreviously known, with many complex frontal systemswhich have implications for the dispersal of effluent, inaddition to natural processes such as sandbankformation (for example, Anderson 1989; Ferrier &Anderson 1990, 1992; Jiao & Anderson 1992).

The majority of studies in the Firth of Tay have beencarried out by the Tay Estuary Research Centre andUniversity of Dundee; physical aspects, sedimentology,hydrography and chemistry have generally receivedmore attention than biological aspects, although work

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InvergowrieInvergowrieInvergowrie

EdensideEdensideFlatFlat

N

ANGUS

Motray Water

Arbroath

Kingoodie

Perth

Kincaple Flat

Elliot LinksPERTH &KINROSS

SeasideShellyPoint

Coble Ho Point

33

0 10 20

km

MonifiethDundee

River Earn

River Tay

RiverAlmond

Bridgeof Earn

Newburgh

Mugdrum Island

NewportTayport

River Eden

CarnoustieCarnoustie

FIFE

St. Andrews

WormitFirth of Tay

Guardbridge

N

Arbroath

RedHead

MonifiethDundee

Broughty FerryInvergowrie

Kingoodie

Perth

River Earn

River Tay

RiverAlmond

Bridgeof Earn

Newburgh

Mugdrum Island

NewportTayport

River Eden

St. Andrews Bay

Abertay Sands

Buddon NessGaa Sands

CarnoustieEast Haven

FIFE

St. Andrews

Wormit

Motray Water

Firth of Tay

Guardbridge

EdensideFlat

Kincaple Flat

Fife Ness

Eden estuary

Tentsmuir

0

0 10 20

km

Based on Admiralty Chart 2182B with the permission of theController of Her Majesty's Stationery Office. Crown Copyright.

Lunan Bay

ANGUS

Riverside

0

Elliot LinksPERTH &KINROSS

SeasideShellyPoint

Coble Ho Point

3

5630'

Figure 4.5. St Andrews Bay and the estuary and Firth of Tay showing location of places mentioned in the text.

has included investigations on the environment,plankton, bacteriology, species distribution, singlespecies and pollution, including heavy metals (e.g.Jones, Jones & Stewart 1972). A number of recent studieshave concentrated on the impact of sewage pollutionfrom outfalls at Dundee. Other work has been carriedout by the Tay River Purification Board (TRPB), and isdescribed below.

Several important single volumes contain much of thepublished information. Corlett (1972) gave an appraisalof knowledge for the Firth of Tay at that time, and aRoyal Society of Edinburgh (RSE) symposium held inOctober 1971, provided an environmental assessment ofthe Tay and Forth estuaries; a total of four RSEsymposium volumes covering the Tay estuary have beenpublished (Anon. 1972, 1975, 1980; McManus 1987). Anumber of studies relating to the inner estuary weresummarised by ECOS Countryside Services (1992) in areport investigating the estuarys potential for a localnature reserve. ECOS Countryside Services (1996)reviewed the natural heritage (biological, earth sciencesand landscape aspects) of the Firth of Tay, including theEden Estuary. The report series of the Tay EstuaryResearch Centre is another useful source of information,mainly on physical aspects of the estuary and Firth ofTay but including some papers on the biota, such asalgae (Peek 1982a) and planktonic copepods (Peek1982b).

Cunningham (1895) provided one of the firstdescriptions of the physical environment of the Tayestuary covering the dimensions, sediments, catchmentarea, tides and currents. The salinity of the Tay and StAndrews Bay was first reported by Mill (1884), whileMcManus (1966, 1972) provided an account of thegeological and geomorphological development of theTay with reference to sediments in the bed of theestuary. At the limit of tidal influence upstream of Perth,the bed of the river was found to consist of highlycompacted clays over which boulders, pebbles and sandwere found. Below Perth coarse sands and fine gravelsformed bars. Bedrock occurred in the channel and alongthe south side of the estuary between Perth andNewburgh, with coarse debris from the River Earndeposited as a river-mouth bar. From Mugdrum Islandto Invergowrie Bay there was a wide expanse ofmudflats. The channel was found to be lined withwaved coarse sands. These studies were continued andreported by Buller & McManus (1975) and McManus,Buller & Green (1980).

The bathymetry, sediments and species of the Taywere described and mapped by Buller, McManus &Williams (1971). Sediments were divided into threezonational areas; saltmarshes, upper tidal flats, andlower tidal flats. The north shore of the estuary wascomposed of mud- and sandflats while the south shoreranged from bedrock to mud. Muddy sand occurs nearTayport, while the shores of the outer Firth are mainly ofclean sand. Bedrock outcrops in the littoral zone at a fewplaces in the Firth, mainly on the south shore.

There are extensive mudflats, 90% of which are in theinner estuary between Seaside and Kingoodie, andmajor beds of the reed Phragmites communis on theupper shore, mainly between Kingoodie and the

confluence of the Earn and Tay, the northern shore, andaround Mugdrum Island (Alizai & McManus 1980);introduced to the estuary in the 18th century, this is themost extensive continuous stand of brackish Phragmitesreedswamp in Britain, and is commercially harvested forthatching.

Alexander (1930) provided an early account of thebenthic fauna and flora between Bridge of Earn and theAbertay lightship. An investigation of the sediments andfauna on the southern shore of the outer Firth of Taybetween Tayport and Tentsmuir Beach showed that thedistribution of both live and dead organisms gave agood indication of sediment type and stability (Green1975). Clelland (1988) briefly surveyed the intertidalbiota of Wormit Bay, and TRPB has also carried outbiological surveys and investigation of sediments on theforeshore near Dundee (B. Clelland pers. comm.).Microscopic fungi living in the estuarine sediments weredescribed by Gaertner (1980) and Ulken (1980).

The distribution of fauna and flora in the littoral andsublittoral zones was surveyed during the spring andsummer of 1973 (Khayrallah & Jones 1975). Salinity andsubstratum type were the main factors affecting thedistribution of species. A study of Bathyporeia pilosa inthe estuary showed it to be widely distributed in thelittoral sediments of the Tay (Khayrallah 1977).Unusually euryhaline populations of the amphipodsCorophium volutator and Bathyporeia pilosa extendedabove Newburgh into a region with a maximum salinityof 0.26 , well below the normal lower salinity limit forthese species (Khayrallah & Jones 1975). Much of thesublittoral had little or no infauna owing to theinstability of the coarse sediments present (Khayrallah &Jones 1975). The most prominent sublittoral populationswere found to be Mytilus edulis in the middle and outerestuary (Figure 4.6).

The Firth of Tay is relatively unspoilt and unpolluted(Khayrallah & Jones 1975), with substantial untreatedsewage discharges occurring only at Dundee. Theseoutfalls are being collected into several new longoutfalls, the first of which commenced operation in 1992,but full sewage treatment is likely to be some years off(Ferrier & Anderson 1992). Perths sewage is treated.

A high-density population of the polychaeteMarenzelleria viridis discovered at Invergowrie Bay was

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Musselbed

Figure 4.6. The distribution of major mussel Mytilus edulis bedsin the Tay estuary (from Khayrallah & Jones 1975).

notable as one of the first European records of thisNorth American species (Atkins, Jones & Garwood 1987);its distribution and density around the Invergowriesewer outfall was negatively correlated with all otherspecies.

The macrofauna of the sediments at Invergowrie andMonifieth were studied in relation to the Invergowriesewage outfall (McManus et al. 1985; Jones, McManus &Herbert 1986). Only species in the immediate vicinity ofthe outfall appeared to be affected by the discharge. Arepeat study in 1989 (Jones, Herbert & McManus 1989)was carried out with the objective of determining thepollution status of Invergowrie Bay prior to thereduction and eventual cessation of discharges throughthe outfall there. It was found that the macrofauna inthe eastern part of the Bay had decreased in abundance,with much of the decline occurring in one species, theamphipod Corophium volutator. It was not possible toidentify the underlying cause of this change, although ageneral decline in crustaceans in the Bay and therelative abundance of worms suggested organicpollution. No consistent spatial trends were apparent innematodes in the sediment. The results indicated thatthe overall state of Invergowrie/Kingoodie Bay was anenvironment showing increasing evidence of sewagepollution, exacerbated by poor dispersion and dilutionowing to the shallowness of the water. It was also notedthat the sediments had varied considerably over thecourse of the three investigations in 1984, 1986 and 1989,but by 1989 had become quite similar to those originallyfound. These variations in sediment particle size andorganic content were probably attributable to wind andtidal processes. The same report (Jones, Herbert &McManus 1989) described significant levels of sewagecontamination farther east, at Riverside; this wasattributed to pollution being carried westwards fromother outfalls at Dundee. This region of the estuary wasexpected to improve considerably after commissioningof a new outfall.

Jones, Atkins & Caudwell (1992) found the westernhalf of Invergowrie Bay to have a much richer faunathan a restricted tidal flat to the south of DundeeAirport at Riverside. They attributed this to organicenrichment from sewage in the Bay, and closure of theoutfall there was expected to have a negative impact onthe infauna and on the birds which feed on theintertidal invertebrates.

The effects of sewage pollution farther east betweenBroughty Ferry and Monifieth were investigated byJones, Herbert & McManus (1990). This study includedsampling along littoral and sublittoral transects, testingof mussels Mytilus edulis for metals, and microbiologicalstudies. Mussel beds were present at the majority of thesublittoral stations, several supporting abundant starfishAsterias rubens and other predators on mussels and theirassociated fauna. One station in the main shippingchannel was almost totally encrusted by spongecolonies, supporting a high species diversity, includingthe sea spider Nymphon rubrum, various scaleworms, andthe amphipods Parajassa pelagica and Ampithoe rubricata.Polychaete and oligochaete worms were important ordominant at most of the littoral sites, with Bathyporeiapilosa dominant at some stations, diversity tending to

increase lower on the shore. Testing of shore-collectedmussels for metals found variable levels ofcontamination, with only levels of mercury and possiblynickel at some stations representing values of possibleconcern. A further sublittoral survey using grabsampling was undertaken in 1991 by TRPB and theScottish Office Agriculture and Fisheries Department(SOAFD) as part of the work of the North Sea Task ForceUK National Monitoring Programme (A.J. Downie pers.comm.).

The Tay is a famous salmon fishing river, but themajority of studies on salmon Salmo salar relate to theTays upper reaches and tributaries (e.g. Webb 1989); itssea trout Salmo trutta were described by Walker (1990).Thomas & Sackville (1972) recorded a diverse estuarinefish community, and Maitland & Smith (1987)considered the Tays fish community, particularly theestuarine component, to be the River s most outstandingbiological feature. It included one of only threepopulations of smelt Osmerus eperlanus in Scotland, andthe only one on the east coast. Dundee Museum formeda collection of fish entrained on the intake screens ofCarolina Port Power Station at Dundee between Januaryand April 1979 (Sage 1979). Over 9000 individuals of 24species were collected and measured, with sprat Sprattussprattus and small herring Clupea harengus comprising41% and 39% respectively of the total numbers caught.

At the mouth of the Firth of Tay, the Abertay Sandsform a seaward extension of Tentsmuir Point NationalNature Reserve and provide a regular haul-out forcommon seals Phoca vitulina.

4.3.5 St Andrews Bay and the EdenestuaryMany studies have been undertaken in the vicinity ofthe Gatty Marine Laboratory at St Andrews. However,work on the marine life in the area commenced in themid-19th century before the establishment of thelaboratory with the interest of Professor W.C. MIntosh,who produced a series of papers on the fauna of StAndrews Bay, and later workers studied the algae of thearea. A compilation of records of fauna and flora for StAndrews Bay (defined by a line between Arbroath andFife Ness), incorporating earlier work and including animportant bibliography, was produced by Laverack &Blackler (1974).

The littoral zone of the Eden estuary was studied inrelation to shorebird feeding (Johnston, Cobb & Bell1979). The sediment shores mainly fell into two areas,the Edenside Flat to the west of Martins Point, andKincaple Flat to the east. Three main sediment typesoccurred:

firm sand was located at the high water mark;

heavy black mud and mud covered the majority ofthe area;

firm sand occurred farther seaward.

Only a few estuarine species, such as the polychaeteNereis (now Hediste) diversicolor and the isopodCorophium volutator, both tolerant of low salinity, werefound towards the head of the estuary 3 km upstream

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from Guardbridge. High densities of Corophium volutatoroccurred at Edenside Flat, while in the more saline areaof Kincaple Flat the bivalves Cerastoderma edule andMacoma balthica were widespread. Seagrass Zosteramarina occurred in limited abundance on Kincaple Flatonly. On the north side of the estuary between Coble HoPoint and Shelly Point the shores were dominated byfucoids. Mussel beds (formerly harvested commercially)occurred on the banks of the river channel. A furthersurvey of the invertebrate fauna and algal flora in theinner estuary was undertaken by TRPB in 1989. Thislargely confirmed the findings of earlier surveys, butalso recorded an abundance of oligochaetes, notpreviously surveyed. An area of soft mud to the east ofthe Motray confluence was found to be devoid ofmacrofauna in places; this was probably due to organicpollution. The location and composition of green algal

mats in the estuary was undertaken by Caudwell &Jones (1994b). Adams & Grierson (1974) investigatedhydrography and pollution.

The Eden estuary was designated a local naturereserve in 1978, and the management plan (North-EastFife District Council 1987) drew together existinginformation. A programme to eradicate introduced cord-grass Spartina anglica has been underway since the mid-1980s (L. Hatton pers. comm.).

The coast south-east of St Andrews is largely rocky,with a number of small bays. An artificial saline lagoonat Fife Ness, probably originally a lobster pond butsubsequently silted-up with muddy sand, was found tohave been very successfully colonised by severalbivalves tolerant of brackish water, including Myaarenaria (Smith 1984). This site was described as acuriosity.

4.4 Estuary and Firth of Forth4.4.1 IntroductionThe estuary and Firth of Forth is defined as the area fromthe upper tidal limit at Stirling seaward to Fife Ness inthe north and Dunbar in the south. The estuary isregarded as the area from Stirling to the Forth Bridges,with the section from Stirling to Kincardine Bridge asthe upper estuary and the area between Kincardine andForth Bridges as the lower estuary. The Firth comprisesthe area from the Forth Bridge to the seaward limits, andis considered an inlet of the sea rather than an estuary(McLusky 1987a) (Figure 4.7). There is a small estuarywhere the River North Tyne meets the sea at

Tyninghame, in the south-east part of the Firth, whichretains the largest surviving area of saltmarsh in theFirth of Forth; more restricted estuarine conditions alsooccur on the south shore at Aberlady Bay. Both of thesesites have been studied by various workers, and thiswork was summarised in descriptive management plans.(Tyninghame Technical Working Party 1976; AberladyBay LNR Working Party 1977).

Much industry has developed around the Firth ofForth especially near Edinburgh and in the estuary atGrangemouth. The wide opening of the Firth narrows atQueensferry but is navigable through the deep channel

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BraefootBraefootBayBay

33

5656

44

River Avon Kinneil Mudflat Cramond

N

0 10

km

Skinflats

Cockenzie &Port Seton

StirlingAlloa

GrangemouthGrangemouth

KincardineCulross Torryburn

LimekilnsArberdour

Burntisland

Inverkeithing

Kirkcaldy

Leven Elie

Pittenweem

DunbarTyninghame

SeacliffNorth Berwick

DirletonGullane

Edinburgh

Carriden

Queensferry

PERTH & KINROSS

CLACKMANNAN

FIFE

EAST LOTHIANWEST LOTHIAN

Dronachy Burn

River CarrRiver Carron

River EskRiver Esk

River North Tyne

River Leven

Musselburgh

Dalmeny

River Almond

Port EdgarBlackness

Seafield

Methill

STIRLING

N

Based on Admiralty Chart 2 & 2182B with the permission of theController of Her Majesty's Stationery Office. Crown Copyright.

Skinflats

Cockenzie &Port Seton

StirlingAlloa

Grangemouth

KincardineCulross Torryburn

LimekilnsArberdour

Burntisland

Inverkeithing

Kirkcaldy

Leven Elie

Pittenweem

FifeNess

DunbarTyninghame

SeacliffNorth Berwick

DirletonGullane

JoppaPortobello

Edinburgh

Inchkeith

FIRTHOF

FORTH

Bo'ness

Carriden

QueensferryCramond

Granton

Newhaven

LeithSeafield

Cramond Island

PERTH & KINROSS

CLACKMANNAN

FIFE

EAST LOTHIANWEST LOTHIAN

Dronachy Burn

River Carron

River Avon

River Esk

River North Tyne

River LevenLargoBay

Seton Sands

Canty Bay Bass Rock

0 10

km

Isle of May

0

0

0

0

50

Musselburgh

BelhavenBay

ScoughallRocksGullane Bay

Gullane Point

Aberlady Bay

Dalmeny

River Almond

Port EdgarBlackness

North QueensferryHound Point

Donibristle BayDalgety Bay

Barnhill Bay

Seafield

Methill

STIRLINGTorryBay

Longannet

56

4 3

Kinneil Mudflat

Inchmickery

BraefootBay

10W

60N

55

50

5 0

Figure 4.7. The estuary and Firth of Forth showing location of places mentioned in the text.

up to Grangemouth. The shores and sublittoralenvironment of the Forth estuary are mainlysedimentary. The coastline of the Firth of Forth is anindented series of sandy bays and rocky headlands, withsome more extensive cliffed rocky shores. In generalrocky shores occur mainly in the outer parts of the Firth.The sublittoral environment is predominantlysedimentary apart from the rocky islands ofInchmickery, Inchkeith, Bass Rock and Isle of May, andshallow areas off the rocky coast at North Berwick.There are several other islands in the Firth, of whichCramond Island and Inchcolm are the largest. Mostsublittoral benthic investigations relate to sedimentsampling.

The number of marine studies escalated in the early1970s with the establishment of the Universities ofStirling and Heriot-Watt and the Forth River PurificationBoard (FRPB). Most work in the estuary and Firth ofForth has therefore been concentrated in the periodsince 1970. Heriot-Watt Universitys Institute of OffshoreEngineering (IOE) has carried out a number of projectsin the Firth. The estuary has been particularlyintensively studied by the two universities; McLusky etal. [1991] provide a bibliography of this work carried outby the University of Stirlings Department of BiologicalSciences. Additional research has been carried out byNapier College (now University), Edinburgh. Asymposium held in 1985 on the natural environment ofthe estuary and Firth of Forth brought together availableknowledge at the time (McLusky 1987a), supplementingan earlier symposium volume (Anon. 1972). Goodman,Ferbrache & Martin (1984) reviewed studies in theestuary sponsored by BP since 1973. Many investigationsin the estuary have been related to pollution,particularly the effect of effluents on the distribution ofspecies. Many impact studies have focused on pollutionfrom existing or possible future sources, and haveincluded shore monitoring projects (e.g. Goodman 1982;McLusky 1992; McLusky & Berry 1992). Other studieshave concentrated on individual species or taxonomicgroups. The Forth Estuary Forum was established in1993 by a range of public and private sectororganisations and support from Scottish NaturalHeritages Focus on Firths initiative. The Forum producespapers on various topics including information andresearch.

The geography and geology of the estuary and Firthof Forth was described by Browne (1987), andhydrography and water quality were described by Craig(1972), Collett (1972) and Covill (1972). Much work onthe hydrography and water quality of various parts ofthe Forth has been undertaken by FRPB (1979).

Poxton (1987) summarised work on fish studies inboth the estuary and Firth of Forth. A total of 50 specieswere recorded, 36 of which occurred in the estuary and39 in the Firth. Studies on entrained fish have beencarried out at Cockenzie, Methil, Longannet andKincardine power stations. At Cockenzie in 1977, 28species were recorded, with the catch dominated by justa few, notably sprat Sprattus sprattus, herring Clupeaharengus, whiting Merlangius merlangus and sand gobyPomatoschistus minutus, and with far more species andindividuals being entrained during the winter than the

summer months (Maitland, East & Morris 1980). Work iscontinuing under the auspices of the Fish ConservationCentre, Stirling (P. Maitland pers. comm.).

4.4.2 The Forth estuary

4.4.2.1 IntertidalThe sediment shores and macrofauna in the Forthestuary were described by McLusky (1987b). Intertidalsediments predominantly consisted of fine-grainedmuds and covered an area of 23.3 km2, the majorityoccurring at Skinflats, Kinneil and Torry Bay. Thesalinity ranged between 0 and 32 along the lengthof the estuary (McLusky 1987b), and in the upperestuary, the stressed freshwaterseawater interface, witha much reduced fauna, was particularly acute andextensive (McLusky, Hull & Elliott 1993). In the upperestuary the shores were narrow and organicallyenriched which favoured the abundance of oligochaetes.The middle estuary was the most productive area interms of biomass of macrofauna while the lower estuaryhad the greatest diversity of species although a muchlower biomass. The production/biomass ratio for severalspecies in the Forth estuary was relatively low comparedwith other estuaries, which may be attributable to thelevel of pollutants in the area (McLusky 1987b).

The meiofauna of Kinneil mudflats at Grangemouthhas been intensively studied with respect to the effect ofindustrial effluent outfalls on species diversity anddensity (Long 1985). Mills (1988) found that meiofaunalspecies composition changed along a pollution gradienton Kinneil mudflats. Moore (1987) surveyed themeiofauna on the lower shore at 21 sites in the Forthestuary in 1982. The main groups of meiofauna foundwere nematodes, copepods, polychaetes andoligochaetes (Figure 4.8). Distribution of species wasrelated to salinity and three zones were distinguished inthe estuary with species characteristic of poly-, meso-and oligohaline conditions. In general the number ofspecies decreased with increasing distance from the seaalthough a local decrease in species diversity wasobserved at the industrial location of Grangemouth.

The fauna of the Kinneil mudflats situated betweenGrangemouth and Boness have been monitored inrelation to oil refinery and chemical effluent by StirlingUniversity since 1975 (summarised by McLusky 1987cand reported most recently by McLusky 1992). Thedistribution of species on the mudflats were describedand comparisons made between data from differentyears. Data on the Kinneil mudflat fauna for the period19761986 showed that faunal changes could be relatedto changes in the effluent discharge (McCrory 1987;McLusky 1987c; McLusky & McCrory 1989). In 1979 theold British Petroleum chemicals effluent pipe closed andthe pattern of effluent discharge changed withsubsequent dominance by the polychaete Manayunkiasp. Within the ten-year period there was an increase inspecies diversity and abundance in response to theimproved environmental conditions. The area of severepollution has further reduced in extent since 1989(McLusky 1992) and in 1992 showed an increase inabundance of typical marine species (e.g. thepolychaete Nephtys, the cockle Cerastoderma, and various

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polychaetes), whilst numbers of typical estuarinespecies (e.g. the polychaete Nereis (now Hediste), theamphipod Corophium) were unchanged or diminished.Dry weather, which reduced river-flow and allowedgreater penetration of salt water from the Firth of Forth,is suggested as the reason for this change. Theoccurrence of the North American polychaeteMarenzelleria viridis in the estuary in 1982 was the firstEuropean record of this species (McLusky, Hull & Elliott1993).

The fauna of the mudflats at Skinflats, Carriden,Torryburn, Torry Bay, Culross and Blackness has alsobeen studied (McLusky & Brown 1974; McLusky 1978a;McLusky & Bryant 1979). The mudflats betweenCarriden and Blackness were dominated by Macomabalthica and Cerastoderma edule (Teare 1975) while thoseat Skinflats, Kinneil and Torry Bay were characterised byManayunkia aestuarina. The meiofauna of intertidalsediments at Kincardine, Limekilns and Boness wasinvestigated by Mulhern (1982).

Pollution effects in the Forth estuary as a whole wereconsidered by McLusky, Elliott & Warnes (1978). Theyreported that the fauna upstream of Alloa, where anoxygen sag occurred, was dominated by oligochaetes,while below Kincardine Bridge mudflat populationswere characterised by the snail Hydrobia ulvae, Nereis

(now Hediste) diversicolor, and the bivalves Macomabalthica and Cerastoderma edule. In the lower estuary thedistribution of Hydrobia ulvae, Macoma balthica, thepolychaetes Nereis (now Hediste) diversicolor, Nephtyshombergii, and the bivalves Cerastoderma edule, Mytilusedulis and Mya sp. was described with reference to birdpredators (McLusky et al. 1976). The seasonaldistribution and abundance of oligochaetes and smallpolychaetes in the estuary was described by Phizacklea(1978) and Bagheri & McLusky (1982). The mostabundant species were the oligochaetes Tubificoidesbenedeni, Amphichaeta sannio and Paranais litoralis and thepolychaete Manayunkia aestuarina. Breeding cycles andthe availability of phytoplankton food influencedseasonal abundance. In the most polluted parts of theestuary oligochaetes were the only inhabitants of themudflats, whereas in the least polluted parts thenumbers of oligochaetes decreased as the density anddiversity of macrofauna increased (McLusky, Teare &Phizacklea 1980).

Sampling in the upper estuary produced evidence oflarge spatial and temporal variations in macrofaunalabundance and species composition (McLusky, Hull &Elliott 1993). Reductions in the formerly very largeorganic inputs from sewage and industry since the early1980s have reduced oligochaete populations. These

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Figure 4.8. Composition of intertidal meiofauna by dry weight along the Forth estuary in summer 1982; open circles indicatesublittoral survey sites (from Moore 1987).

changes have allowed further penetration of non-oligochaete estuarine species into the intertidal of theupper and middle reaches of the estuary, producing anapparent increase in diversity. Subtidally, a substantialdecrease in oligochaete density was recorded, but withno corresponding penetration of estuarine species,possibly because highly unstable sediments in the mainchannel prevented successful colonisation (McLusky,Hull & Elliott 1993).

Distribution and population recovery of the lugwormArenicola marina, Hydrobia ulvae and Macoma balthica afterbait digging was investigated at Blackness (McLusky,Anderson & Wolfe-Murphy 1983). Arenicola marinarapidly recolonised holes created by digging but areascovered by mounds were not fully repopulated untilthey had been eroded. In contrast Hydrobia ulvae andMacoma balthica showed enhanced populations on themounds.

Hard substrata are very restricted in extent. Thedistribution of algae on rocks in the vicinity of theeffluent outfall at Grangemouth was studied byCollington (1986). A gradient of change in algalcommunity composition was observed in the algalcommunity to the west of the outfall. The lack offilamentous algae in the vicinity of the outfall wasconsidered to be due to the effects of effluent.Observations on vertical algal distributions in the Esk,Almond, Avon and Carron estuaries showed distinctbands of algae (Wilkinson et al. 1981). The main factorinfluencing these zones was considered to be salinity.

4.4.2.2 SubtidalThe Forth River Purification Board (FRPB) thoroughlysurveyed the sediments and benthic fauna in the Forthestuary (Elliott, Taylor & Davies 1981; Elliott 1983; FRPB1991b, 1992e). Sediments consisted of sands and mudswith shells, clinker, fly-ash and other debris. A decreasein species diversity was found with decreasing salinityand from deep to shallow water. In general polychaetes,principally Nepthys, Polydora and Ampharete, dominatedthe lower estuary and oligochaetes the upper estuaryalthough certain groups such as tellinids and spionidsdominated isolated patches of the estuary bed. Thelowermost part of the estuary, off Port Edgar, was foundto be characterised by a higher species diversity andabundance owing to the presence of many marinespecies, and was dominated by the phoronid Phoronissp. and the bivalve Abra alba (FRPB 1992e). Four speciesassociations were recognised by classification analysis inthe Forth estuary (Elliott & Kingston 1987) (Figure 4.9).These were:

a supra-estuarine association, characterised by thepolychaetes Dodecaceria concharum and Neoamphitritefigulus and the bivalve Abra alba which occurred inthe central and southern part of the estuary east ofBoness and into the main channel east to Inchcolmand westwards off Culross and Torry Bay;

a similar but impoverished, in terms of speciesrichness and abundance, supra-estuarine associationwhich occurred along the northern and central partof the estuary east of Boness;

a stressed transition region off Kinneil Baycharacterised by the polychaetes Nephtys hombergiiand Eteone longa;

a Polydora-oligochaete association characterised bythe polychaetes Polydora ligni, Polydora ciliata,Marenzelleria wireni and tubificid oligochaetes at thefreshwater/brackish interface.

The sublittoral sediments and fauna in the vicinity ofthe BP refinery production water discharge diffuser offKinneil, which began discharging in 1982, have beenmonitored by FRPB since 1979 (FRPB 1982, 1983b, 1984b,1985, 1986b, 1987b, 1992b). Sediments in the vicinity ofthe diffuser were found to be very mobile, resulting inmarked fluctuations in faunal composition betweenyears. Consequently, no significant impact on themacrofauna from the discharge has been identified, withchanges in the macrofauna being attributable to naturalfluctuations. Sediments at this location werecontaminated by hydrocarbons, but it was unclear ifthese derived from the diffuser or from transport ofsediment from the polluted Kinneil mudflat (FRPB1987b).

The upper Forth estuary between Stirling andKincardine Bridge has been less intensively studied, butFRPB (1991b) reports the findings of a two-yearsublittoral sampling programme. The fauna wascharacteristically impoverished, and was dominated inthe upper reaches by high abundances of theoligochaetes Limnodrilus spp. and Tubifex tubifex,although densities had declined since a 1983 survey,possibly reflecting reduced levels of organic enrichment.Salinity was considered to be the primary factorgoverning the distribution of the upper estuarycommunities.

4.4.2.3 FishThe lower Forth estuary was found to have a lowerdiversity of fish than other less polluted estuarine areas,with low species richness probably being a result of lowwater temperature (Elliott and Taylor 1983, 1986, 1989;FRPB 1984c). Studies showed that the estuary wasimportant as a nursery ground for flatfish and gadoidsand an overwintering ground for clupeids. Migratoryfish populations showed large fluctuations over the yearand variations from year to year, with peak populationsoccurring during the winter months. The estuarysupported approximately 0.5% of the North Sea stocksof certain size-classes of some commercially importantspecies (Elliott, OReilly & Taylor 1990).

4.4.2.4 PlanktonThe zooplankton along the length of the Forth estuary,from freshwater to fully marine conditions, was studiedover an eighteen-month period by Taylor (1983, 1987) todetermine its composition and variability. Thezooplankton was found to be dominated by a fewgenera of calanoid copepods. The estuary of the Forthwas considered rare among British estuaries in that itsupported a truly pelagic self-maintaining assemblage ofzooplankton species; the lower estuary and Firthreceived incursions of neritic species, especially during

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the summer months. Taylor (1993) hypothesised that thezooplankton of the upper and middle estuary wasdependent for food not upon phytoplankton, but oneither anthropogenic inputs of distillery waste andsewage, or upon the microphytobenthos.

4.4.3 The Firth of ForthThe biology of the Firth of Forth has been studied sincethe 1830s, and the findings of Victorian naturalistsprovide a valuable base-line for comparison with morerecent studies. Traill (1880, 1881, 1882, 1883, 1885) broughttogether records of the algae of the Firth of Forth, givingthe habitat and locations where each species was found.Traill also studied the algae at specific locations includingJoppa, Elie and Dunbar (Traill 1886, 1888, 1890). Elie andDunbar were considered to be two of the richest localitiesfor algae in the Firth of Forth. Rattray (1886a & b)described the distribution of algae from shores anddredged sublittoral areas. Rattray noted that the numberof species and average size of species increased from theestuary seawards. Algae on the coast of Fife wererecorded by Lowe (1935). Algae were surveyed at Joppaand Dunbar in 1961 and 1971 (Johnston 1972; Knight &Johnston 1981). A reduction in the number of species andsize of individuals compared with the records of Traillwas found at Joppa, formerly a very rich shore, whichwas considered to be due to the discharge of untreatedsewage in the area. In contrast, at Dunbar, the 74 speciesselected for comparative study with Traill (1890) were stillpresent in the 1961 and 1971 surveys. These findingswere confirmed when the marine algae were recordedfrom 11 shores in the vicinit

chapter 4: east scotland (duncansby head to dunbar)...

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