Firth Of Forth Research Articles

Excavations south of Bernard Street, Leith, 1980

The excavation located an extensive midden, laid down in the second half of the 15th century to reclaim an area previously below the tide-line of the Firth of Forth. Some contemporary and later structural evidence also survived. Finds included an important hoard of 15th-century billon pennies.

The impact of oily discharges on the meiobenthos of the North Sea

The impact of hydrocarbon discharges on the intertidal and subtidal meiobenthos of the North Sea is examined primarily by a consideration of two field investigations. The first study examines the effects of an oil refinery discharge on intertidal meiofauna in the Firth of Forth, while the second describes the impact of oil platform discharges on the surrounding meiobenthos. The impact of the refinery effluent is only clearly distinguishable upstream of the discharge, as downstream the effects are confused with those of a second petrochemical discharge. The meiofaunal community is only strongly affected on the upper shore and this appears to be chiefly the result of an organic enrichment effect causing a raising of the redox potential discontinuity (RPD) layer. All meiofaunal taxa examined are sharply reduced in density and species richness within 320 m of the discharge but at 600-900 m from the discharge meiofaunal densities are enhanced or depressed, relative to clean sediments, dependent upon the seasonal pattern of the RPD layer. Farther down the shore the impact is only felt at most by a slight reduction in species richness and subtle change in species abundance patterns on the middle shore for a distance of about 600 m. The meiofaunal responses to the petrochemical discharges seem similar to those described for the macrofauna in the same area, although a small meiofaunal population persists in the most polluted sediments in the absence of macrofauna. The discharge of drilling cuttings, contaminated with oil-based drilling mud, was found to strongly modify meiofaunal densities within 800 m of the Beryl A Platform. Nematode densities are strongly reduced in the vicinity of the platform and it is thought that the impact on this infaunal taxon may be due to slow degradation within the sediment of toxic fractions of the diesel base of the drilling mud. By contrast copepod densities were greatly enhanced in one survey and the difference in impact is considered to be due to the epibenthic habit of the species involved, enabling them to flourish in conditions of high food or low predation and competition or all three. The species involved seem typical members of meiofaunal communities of organically enriched sediments. Some improvement in meiofaunal densities throughout the period 1984-85 is thought to be possibly the result of a switch from diesel-based to lowtoxicity drilling muds. It is concluded from these and other studies that hydrocarbon discharges into the North Sea are unlikely to be causing extensive damage to meiofaunal communities.

Preliminary studies of man-made litter in the Firth of Forth, Scotland

Short-term studies on man-made litter deposited on the beaches of the Edinburgh coastline of the Firth of Forth, Scotland, have demonstrated that containers of all kinds, plastic bags, plastic sheeting and clothing, comprise the main and dominant components of the nineteen categories of litter analysed. Most of the litter is of local origin either deposited in situ or washed ashore from neighbouring water's-edge tips. Very little evidence was found of litter washed ashore being of foreign origin or having been tipped overboard from ships at sea. Much of the smaller items of litter are discarded by visitors to the beach. The solution to the problem is seen as one of education at all levels rather than ineffective punitive measures.

Water circulation in the Firth of Forth, Scotland

SynopsisThe Firth of Forth, in terms of physical oceanography, is part of the North Sea. The general circulation pattern in the firth must be regarded as largely speculative. There have been insufficient measurements of insufficient quality, and what evidence exists leads to the view that what circulation there is, is sluggish and varies from season to season and from year to year.A description is given of the three principal mechanisms that contribute to circulation. Tides, due initially to astronomical forces, manifest themselves in the Firth of Forth through the rise and fall of the adjacent open sea. This rise and fall, periodic in mid ocean, is no longer strictly so in the firth and neither are the tidal currents. The wind-driven currents in the sea are influenced by the earth's rotation. In the Firth of Forth, some of this influence is retained. Naturally, wind-driven currents are larger near the surface. Finally, when water of different densities meets, overturning causes convection currents. All of these effects are present to some extent in the Firth of Forth. In addition, specific account has to be taken of complicated coastal and bottom topography and river outflow. Some attempt to bring together these effects and available measurements is made in this paper. Lastly, several theoretical models are proposed which account for the magnitudes and directions of the observed steady circulation. Mathematical details are given in appendices.

The influence of inputs to the Firth of Forth on the concentrations of trace metals in coastal waters

The distribution of copper, lead and cadmium in dissolved and particulate phases has been investigated in the Firth of Forth, Scotland, an embayment of the North Sea. The effect of riverine and anthropogenic trace metal inputs on concentrations in the Firth of Forth and adjacent North Sea is examined. For the dissolved phase the effect of such inputs is confined to the immediate area of discharge. Concentrations in the outer Firth are indistinguishable from those in coastal waters of the North Sea, ca. Cu, 0·2 μgdm −3 ( 3·1 n m ); Pb, 0·025 μgdm −3 ( 0·12 n m ) and Cd, 0·020 μgdm −3 ( 0·18 n m ). There is evidence that particulates enhanced in trace metals, relative to bottom sediments, are leaving the Forth and entering the North Sea. Predictions of the total metal concentrations in the waters of the inner Firth, based on riverine, industrial and sewage associated inputs, show reasonable agreement with observed values.

The intertidal benthos and sediments of particulate shores in the Firth of Forth, Scotland, with particular reference to waste water discharges

SynopsisThe paper summarises and briefly discusses published and unpublished data relating to the physicochemical characteristics of the sediments and the occurrence and distribution of the intertidal macrobenthos of paniculate shores in the Firth of Forth. In general, the shores described are poor faunistically and in some areas this results partly from the influence of waste water discharges. Detailed information is available for only a limited number of the numerous beaches in the Firth of Forth. In consequence, this paper focusses attention on the results of a long term study of four beaches along the south shore of the firth which was undertaken as part of an environmental impact assessment in relation to the introduction of improved sewage treatment and disposal for the City of Edinburgh. Edinburgh Sewage Scheme and the firth into which it discharges are briefly described and data pertaining to changes in the intertidal sediments and the intertidal macrobenthic communities, which occurred in the Seafield Bay area of the firth following pollution abatement, are presented and discussed.

The estuary and Firth of Forth, Scotland: uses and aims

SynopsisThe waters and coastal margins of the estuary and Firth of Forth are important and very valuable biological and recreational resources. They also receive, directly or indirectly, the aqueous domestic and industrial wastes of a quarter of the population of Scotland. It is one task of the Forth River Purification Board to minimise and eventually eliminate any conflict between the effects of these discharges and the various legitimate uses of the waters. Some of the main causes of environmental stress are briefly outlined and the basic strategy by which the problems will be overcome is described.

The breeding seabirds of the Firth of Forth, Scotland

SynopsisThe seabird colonies in the Firth of Forth are spectacular. Although the total numbers of individual birds of most species are relatively small, the populations of gannet, herring and lesser black-backed gulls, sandwich, roseate, little and common terns make up more than 10% of the Scottish total. Numbers of fulmar, shag, cormorant, great black-backed gull, kittiwake, guillemot, razorbill and puffin have all increased, the rates varying from 4% per annum (kittiwake) to 20% p.a. (puffin). The numbers of cormorants stabilised soon after the species colonised the Forth in 1957. The period of rapid increase in guillemot numbers may now be over. Numbers of little terns have probably increased, but roseate and common terns have both declined and the number of sandwich terns is more-or-less stable. Herring and lesser black-backed gulls both increased dramatically up to 1972, since when breeding birds have been culled. The herring gull then decreased significantly, but the situation is less clear in the lesser black-backed gull. We set these changes in a wider context and discuss some possible reasons for the observed population trends.

Climatic conditions over the estuary and Firth of Forth, Scotland

SynopsisThe pattern of climatic variation over estuaries and their environs is, to a considerable extent, controlled by aspect, slope and elevation in addition to orientation of the major relief features with respect to the movement of principal weather systems. Data from the few climatological stations within the immediate vicinity of the estuary and Firth of Forth demonstrate the essentially maritime nature of climate, and indicate also that there is a dominantly west–east gradient of change in most climatological variables. Below the high water mark the movement of water in tidal ebb and flow and river inflow modify atmosphere–surface interactions over relatively short spatial and temporal scales. Observations from a fixed instrument tower on Skinflats in the middle estuary and from Inchkeith Lighthouse indicate that tidal water movements exert varying degrees of control over sub-surface heat fluxes, air movement in the atmospheric boundary layer and the inland penetration of coastal weather systems such as the typical east coast haar.

Microbial measurements in relation to sewage pollution of the Firth of Forth, Scotland

SynopsisThe history of Edinburgh's sewage disposal to the sea from the open ditch system of the 17th century to the present day, together with the changes in legislation affecting sewage discharges to the firth, are reviewed. During the last thirty years sewage discharges have been monitored monthly for levels of faecal coliform bacteria at approximately thirty-four shore sites and twenty offshore sites. These coliform counts are used as bacteriological indicators of sewage pollution, in order to assess the risk to humans of infections that might result from the consumption of contaminated shellfish or from bathing in sewage-polluted waters. Most of the areas sampled from the inner firth were shown to be grossly polluted, particularly in late summer, and regularly to exceed guideline levels throughout the year. Since the commissioning of the new Seafield sewage works in 1979, a general improvement in bacterial and viral counts has been recorded on the south shore of the inner firth. In the last decade two European Community directives relating to the quality of seawater for bathing and shellfish growing have been promulgated, which set guideline and mandatory levels for the number of faecal coli in seawater. The Scottish Development Department has recently designated five beaches as bathing beaches and two areas on the north and south shores of the firth as shellfish growing areas. These areas have been regularly monitored by the Forth River Purification Board and the published results of both surveys are analysed. The virological studies carried out by the Forth Pollution Group of Napier College before and after the major change in the sewage discharge pattern into the Firth of Forth are reviewed.

Wading birds and wildfowl of the estuary and Firth of Forth, Scotland

SynopsisThe estuary and Firth of Forth support an outstanding number and variety of wildfowl and waders at migration seasons and in midwinter. Although populations of wildfowl and waders fell from 25–35,000 and 50–65,000 respectively in the 1970s, to 10–15,000 and 30–40,000 by the mid-1980s, the Forth remains one of few British estuaries to support more than fifteen waterfowl species of national importance for conservation. The ecology and decline of diving ducks off Edinburgh and population studies of shelduck have been given particular attention by researchers. Among waders, distributions, movements and feeding have been studied in detail. The causes of the recent declines amongst waders, notably for knot (Calidris canutus) and dunlin (Calidris alpina) on the estuarine Forth, remain uncertain, but are likely to include natural factors as well as those linked to man's activities.

Fishery studies in the estuary and Firth of Forth, Scotland

SynopsisRecent fishery studies in the estuary and Firth of Forth stem from the late 1970s and have largely been carried out by the Institute of Terrestrial Ecology, the Forth River Purification Board and Heriot-Watt University. This paper briefly reviews these studies, which may loosely be divided into work done at power stations, general demersal and pelagic studies of the estuarine fish populations, studies on particular species (lamprey, eelpout, whiting, cod and flatfish, especially the plaice), pollution- orientated studies (hydrocarbons in flatfish and mercury in eelpout) and more general work including ichthyoplankton surveys. Most work has been done on the ecology of flatfish, especially the plaice and it is examined in most detail.A total of fifty species of fish have been recorded of which thirty-six occurred in the estuary and thirty-nine in the firth. Others are however known to occur. Of the twenty-eight species entrained into the intakes of local power stations, the sprat, herring, whiting and sand goby were most numerous, while other common species were sandeels, eelpout and pogge. Sand gobies, whiting, common dabs and sprats were the most numerous species taken by Agassiz trawling with herring, cod, eelpout, butterfish, pogge, flounders and plaice also commonly taken. Only herring, sprat, whiting, cod and fatherlasher were recorded using a midwater trawl and only the clupeoids occurred in all the catches. The catches of the 2 m beam trawl used in sandy bays in the firth were dominated by plaice, common dabs, sand gobies and sandeels. The ichthyoplankton surveys undertaken in 1986 have caught twenty-three species as eggs and twelve species as larvae. The majority of the eggs were those of the common dab, whiting, flounder, rock ling and sprat, while the majority of larvae were sandeels and clupeoids.

Selection and management of sites of nature conservation importance in the Forth estuary and Firth, Scotland

SynopsisThe Forth is of great importance for nature conservation. More than half of the coastline of the estuary and the Firth of Forth is assessed to be sufficiently important for designation as Sites of Special Scientific Interest (SSSIs). The basis of the selection of these sites is discussed. The SSSIs are then described, including those which are managed as nature reserves. Wider aspects of conservation in the Forth are referred to. The main threats to wildlife sites and species are indicated, together with possible solutions, and opportunities for conservation.

Maritime litter studies in the Firth of Forth

Maritime litter studies in the Firth of Forth

Hydrocarbons and their microbial degradation in the Firth of Forth

Hydrocarbons and their microbial degradation in the Firth of Forth

The determination of the internal structure of an effluent plume using MSS data

Abstract Multispectral scanner (MSS) data from a series of four flights over the Edinburgh sea outfall in the Firth of Forth have been analysed. The data reveal the existence of an integrated surface sewage plume resulting from discharge from a number of sub-surface vertical riser pipes connected to an outfall tunnel. After further processing, the structure of the plume is delineated and the existence of discrete sources of discharge within the plume is demonstrated. The capability to locate such sources with processed MSS data and thereby to monitor the performance of the outfall has significant commercial implications. Failure of the outfall system to discharge as designed (i.e. fully through all risers) can lead to marine growth and sedimentation within it and eventual long-term damage. The methods used ( principal components analysis, contrast stretching, etc) to process the MSS data to serve as monitoring tools are described.

The physical geography and geology of the estuary and Firth of Forth, Scotland

SynopsisThe Upper Palaeozoic bedrock, which is of sedimentary and volcanic origin, is briefly described. The origin of the Forth as a series of depressions in the bedrock surface probably owes much to erosion of a pre-existing Tertiary landscape during phases of Quaternary glaciation. The late Quaternary history of the area is described, relating the distribution of the sediments deposited in the Forth to climatic events and changes in relative sea-level. Since the acme of the last main glaciation about 20,000 years ago, late Devensian marine and estuarine sediments have been deposited on the underlying glacial till sheet at altitudes ranging from more than 120 m below O.D. to at least 46 m above O.D. Similarly, raised and buried beaches and their deposits occur at altitudes from 40 m above O.D. down to around 10 m below O.D. in the estuary. During the Flandrian, sea-level has fluctuated, reaching its maximum (about 11 to 15 m above O.D.) about 6500 years ago. The typical deposit of this period is the carse clay which forms a series of extensive, fertile raised mudflats around the estuary. The calcareous marine faunas of the carse clay and older deposits are outlined.

Monitoring the effects of the disposal at sea of Lothian Region sewage sludge

SynopsisUntil the late 1970s Edinburgh and the surrounding areas employed a series of relatively short sea outfalls to dispose of sewage to tidal waters. A centralised sewage treatment facility was provided in 1977, with disposal of liquid effluent by long sea outfall. The residual wet solids are dumped at two sites in the North Sea off the Firth of Forth. The sites, one near Bell Rock (56 25N 02 10W) and one ten miles north of St Abb's Head (56 04·5N 02 07·25W) are used on a rotational basis. The macrofauna at both sites shows a normal polychaete-dominated community exhibiting the normal low number/high diversity characteristics of many unimpacted communities in the North Sea. In general, seasonal differences in mean concentrations of lead, copper and zinc in sediments were small and within the limits of statistical variation. The concentrations of mercury and cadmium were mainly low and close to the detection limits of the analytical methods employed. The monitoring data from Bell Rock and St Abb's Head demonstrate that the dumping operation has had little effect on the benthic environment and that the macrobenthos showed no signs of stress due to the addition of sewage sludge.

Preliminary investigation of the heavy metal content of Capitella capitata (polychaete, annelid) from Largo Bay, Firth of Forth and Garroch Head sludge dump site, Firth of Clyde

Preliminary investigation of the heavy metal content of <i>Capitella capitata</i> (polychaete, annelid) from Largo Bay, Firth of Forth and Garroch Head sludge dump site, Firth of Clyde

Aspects of the molluscan fauna of the rocky shores of the Firth of Forth and Forth estuary, Scotland

SynopsisMolluscan species diversity decreased westward from the North Sea into the Forth with decreasing diversity of habitats, decreasing algae and increasing turbidity of water. Species diversity varied little from year to year or seasonally at individual sites. Adult Littorina littorea in particular were larger at lower than at higher shore levels, and larger in the outer than the inner firth or estuary, while Nucella lapillus adults were of more uniform size throughout the area.Population parameters and reproductive output of L. littorea and L. saxatilis in the estuary varied without strict relation to mere position between open firth and up-estuary sites. On the other hand, shells of L. saxatilis became progressively wider, breeding seasons of L. littorea were longer and less defined, breeding in L. saxatilis became more sharply seasonal and eggs of L. saxatilis had greater weight, calorific value and inorganic content at up-estuary sites. L. littoreashowed two-weekly peaks in spawning on spring tides while L. saxatilis showed monthly peaks in release of young near times of full moon.Comparison of fresh material and stranded shells with material from beach deposits up to 5500′ years old indicates changes in populations with changes in climate about 550 BC. Size of Littorina spp. continued to decrease while numbers of Mytilus edulis increased greatly near the onset of the industrial revolution.