The sublittoral benthic fauna of the estuary and Firth of Forth, Scotland

SynopsisThe structure of the sublittoral benthic macro-invertebrate populations of the Forth estuary and firth, Scotland, is described, giving the species richness, abundance and biomass for the area from the freshwater tidal limit to the North Sea boundary. Eight faunal associations have been defined, which include classical Petersen communities in the marine area and transition associations within the estuary. The spatial distributions of the associations are predominantly the result of the physical environment, but superimposed on the effects of salinity, sediment type and bathymetry are the effects of urbanisation, industrialisation, dredging and spoil disposal and thermal discharges. The benthos of the major part of the firth has been little affected, although that of the peripheral and estuarine areas does show anthropogenic effects.The water column-benthos and fisheries-benthos interactions are also discussed. Elevated levels of nutrients in the water column may be the cause of enriched benthic populations in the firth and an assessment of the fish-benthos coupling indicates an estuarine functioning similar to other northwestern European areas.

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BIOLOGICAL MONITORING OF THE FORTIES OILFIELD (NORTH SEA)

International Oil Spill Conference Proceedings ◽

10.7901/2169-3358-1983-1-405 ◽

1983 ◽

Vol 1983 (1) ◽

pp. 405-414 ◽

Cited By ~ 5

Author(s):

J. P. Hartley ◽

J. Ferbrache

Keyword(s):

North Sea ◽

Biological Effects ◽

Monitoring Program ◽

Benthic Fauna ◽

Sediment Type ◽

The North ◽

Naturally Occurring ◽

The North Sea ◽

Similar Survey ◽

Benthic Sediments

ABSTRACT The Forties Oilfield (the largest in the U.K. sector of the North Sea) has been in production since September 1975. In June 1975, a quantitative survey of the benthic sediments and fauna over the area was made at the start of an environmental monitoring program for the field. The results of a repeat survey carried out after three years of production have been reported by Hartley.13 This paper presents data from a third similar survey in June 1981 and compares the findings with those of the earlier surveys. The benthic fauna of the Forties Field is rich and diverse and qualitatively corresponded well in 1981 to previous descriptions. Naturally occurring gradients in both the sediment type and fauna are a feature of this area. Changes in the densities of certain species were noted at some sites in 1981, including increases in certain opportunistic forms. Although no areas of biological effect could be delineated around the four production platforms, the industrial activity in the field may be implicated in the changes found at several stations. The hydrocarbon content of the sediments was low and, with one possible exception, did not appear related to the biological changes noted. The results to date suggest that offshore oilfields in deep water, developed using water-based drill fluids, present relatively few biological problems in the short term. Since no major biological effects have been found after six years of drilling and production, a reduced program of monitoring is recommended to maintain biological surveillance during the life of the field.

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Linked sediment and water-column methanotrophy at a man-made gas blowout in the North Sea: Implications for methane budgeting in seasonally stratified shallow seas

Limnology and Oceanography ◽

10.1002/lno.10388 ◽

2016 ◽

Vol 61 (S1) ◽

pp. S367-S386 ◽

Cited By ~ 18

Author(s):

Lea Steinle ◽

Mark Schmidt ◽

Lee Bryant ◽

Matthias Haeckel ◽

Peter Linke ◽

...

Keyword(s):

Water Column ◽

North Sea ◽

The North ◽

The North Sea ◽

Shallow Seas

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Metabolic alkalinity release from the Elbe estuary to the North Sea

10.5194/egusphere-egu21-8648 ◽

2021 ◽

Author(s):

Mona Norbisrath ◽

Jeannette Hansen ◽

Kirstin Dähnke ◽

Tina Sanders ◽

Justus E. E. van Beusekom ◽

...

Keyword(s):

Stable Isotopes ◽

Water Column ◽

Fresh Water ◽

North Sea ◽

Total Alkalinity ◽

Elbe Estuary ◽

Metabolic Processes ◽

The North ◽

Carbon Species ◽

The North Sea

The Elbe is the largest river entering the German Bight. Its estuary is a heavily used waterway connecting the sea to Germany&#8217;s biggest port in Hamburg. The Elbe navigation channel is continuously dredged, and agricultural fertilizer input from the catchment ensuing large phytoplankton blooms in the river Elbe exerts additional anthropogenic pressure. Biogeochemistry in the estuary is additionally governed by the North Sea and its strong tidal cycles, which ensure an exchange of fresh and marine waters.The aims were to quantify the release of the carbon species total alkalinity (TA) and dissolved inorganic carbon (DIC) along the Elbe estuary, and to estimate the contribution of aerobe and anaerobe metabolic processes. Therefore, we used water samples collected continuously during a cruise in June 2019, to measure TA and DIC, and the stable isotopes of nitrate. We applied mass balances, to characterize the metabolic activity and detect their effect on the carbon speciesThe Elbe estuary could be subdivided into two parts: 1) an outer marine driven part, which is dominated by conservative mixing, also visible in higher TA than DIC values, and 2) an inner fresh water part in which metabolic processes play an important role.We found a strong increase in TA and DIC (several hundred &#181;mol kg-1) in the Hamburg port area, with higher DIC than TA values. We unraveled the water column impacts of nitrification and denitrification on TA and DIC by analyzing the stable isotopes &#948;15N-NO3- and &#948;18O-NO3-, and identified water column nitrification as a dominant pelagic process in the port of Hamburg and in the fresh water part further downstream. Because nitrification cannot explain the significant increase of TA and DIC in the port region, anaerobic processes such as denitrification in the sediment also appear to play an important role.&#160;

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Modelling water column processes in the North Sea

Philosophical Transactions of the Royal Society of London Series A Physical and Engineering Sciences ◽

10.1098/rsta.1993.0062 ◽

1993 ◽

Vol 343 (1669) ◽

pp. 509-517 ◽

Cited By ~ 6

Keyword(s):

Water Column ◽

North Sea ◽

Process Water ◽

Phytoplankton Dynamics ◽

Annual Cycles ◽

The North ◽

Field Investigations ◽

Southern Central ◽

The North Sea ◽

Northern North Sea

In the North Sea advective transports are not negligible. Nevertheless, physical properties like sea surface temperature (SST) can be hindcasted with sufficient precision by vertical process water column models. Annual cycles of SST in the southern, central, and northern North Sea can be simulated using physical upper layer models with relatively small RMS errors. For the Fladenground Experiment (FLEX’76) in the northern North Sea the RMS error is less 0.3 °C for the 2 months of the experiment. This justifies the initial use, at least, of vertical process water column models in simulations for investigating transfer processes in the planktonic ecosystem. Experiments have shown that the simulated entrainment velocities at the bottom of the mixed layer during summer are critically dependent on the resolution of the forcing variables. The effects of this resolution on the annual phytoplankton dynamics will be discussed. Phytoplankton dynamics are strongly influenced by those of the zooplankton, and vice versa. Several field investigations have shown that, seemingly, phytoplankton cannot sustain the observed stock of zooplankton in the northern North Sea: there exists a gap between the abundance of phytoplankton and the need for it to maintain the zooplankton. Revisiting FLEX’76, the simulations with water column models of increasing complexity concerning detritus suggest that pelagic detritus can fill the gap in food availability for the zooplankton. If it is assumed that the zooplankton feeds also on detritus, the zooplankton experiences no food shortage.

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Water circulation in the Firth of Forth, Scotland

Proceedings of the Royal Society of Edinburgh Section B Biological Sciences ◽

10.1017/s0269727000006734 ◽

1987 ◽

Vol 93 (3-4) ◽

pp. 273-284 ◽

Cited By ~ 1

Author(s):

P. P. G. Dyke

Keyword(s):

General Circulation ◽

Bottom Topography ◽

Circulation Pattern ◽

Theoretical Models ◽

The North ◽

Open Sea ◽

River Outflow ◽

The North Sea ◽

Firth Of Forth ◽

Wind Driven Currents

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.

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Vertical distribution of pre-settled sandeel (Ammodytes marinus) in the North Sea in relation to size and environmental variables

ICES Journal of Marine Science ◽

10.1016/s1054-3139(03)00150-4 ◽

2003 ◽

Vol 60 (6) ◽

pp. 1342-1351 ◽

Cited By ~ 14

Author(s):

Henrik Jensen ◽

Peter J Wright ◽

Peter Munk

Keyword(s):

Vertical Distribution ◽

Water Column ◽

North Sea ◽

Distribution Patterns ◽

Food Concentration ◽

The North ◽

Vertical Distributions ◽

The North Sea ◽

Drift Trajectory ◽

Vertical Positioning

Abstract Vertical distribution patterns of larval and juvenile sandeels were investigated at four locations in the North Sea. Sandeels between 6 and 65 mm were found to depths of 80 m, with vertical distributions dependent on both length and environmental factors. At one location with a stratified water column, the highest densities were found during the day in midwater where food concentration was also highest. In areas without marked vertical hydrographic gradients, larvae were relatively more abundant in surface waters during the day. At all locations, larvae of all sizes were generally more homogeneously distributed in the water column during night than during day. The extent of vertical migration, as measured by the standard deviation of the mean depth, increased generally with length. Gear avoidance was evident for larvae ≥20 mm. Catch efficiency generally depended on both length class and surface light intensity. A simulated drift pattern of larvae, based on ADCP current measurements from two locations, predicts that the horizontal drift trajectory would only be affected slightly by the vertical positioning of the larvae in the water column during the time of sampling. The implication of vertical migrations for dispersal of larvae away from the spawning grounds is discussed.

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