The fish and shellfish resources in seas adjacent to the Outer Hebrides

SynopsisThe demersal fishery in Hebridean seas is based mainly on haddock, whiting and cod, mostly from local spawning grounds, with some recruitment from the North Sea. An important seasonal fishery for dogfish is based on a highly migratory stock. All these stocks are probably fully exploited.Herring spawning grounds occur west and north of Lewis, and larvae drift eastwards to nursery areas, mainly in the North Sea. Enhanced recruitment in the late 1960s and an increase in fishing effort produced a large increase in landings but these have subsequently declined. The west coast herring fishery is subject to quota regulations for conservation. There are also important exploitable stocks of mackerel and sprats. Since 1971 an industrial fishery for Norway pout has taken a few thousand tonnes per annum.Shellfishing by small boats goes with crofting. Since 1962 the number of larger boats has increased with full-time fishing, particularly for Norway lobsters and lobsters. Exploitation has been helped by processing and lobster-holding facilities. Scallops and periwinkles are also important commercially and there are good prospects for cultivating oysters and mussels.By far the largest underexploited fish stock is blue whiting, which migrates south to spawn in March-April on the continental slope in depths of over 400 m to the west of Scotland. The spawning stock in this area is estimated to be 5-15 million tonnes. Sandeels may also occur in commercial quantities in some areas.

Download Full-text

Predicting the effects of area closures and fishing effort restrictions on the production, biomass, and species richness of benthic invertebrate communities

ICES Journal of Marine Science ◽

10.1016/j.icesjms.2006.02.006 ◽

2006 ◽

Vol 63 (5) ◽

pp. 822-830 ◽

Cited By ~ 76

Author(s):

J.G. Hiddink ◽

T. Hutton ◽

S. Jennings ◽

M.J. Kaiser

Keyword(s):

Species Richness ◽

North Sea ◽

Fishery Management ◽

Benthic Communities ◽

Fishing Effort ◽

Management Actions ◽

The North ◽

The North Sea ◽

Effort Reduction ◽

Positive Effect

AbstractTo effectively implement an Ecosystem Approach to Fisheries (EAF), managers need to consider the effects of management actions on the fishery and the ecosystem. Methods for assessing the effects on target stocks are generally well developed, but methods for assessing the effects on other components and attributes of the ecosystem are not. Area closures and effort controls are widely used fishery management tools that affect the distribution of fishing effort and may therefore have consequences for a range of species and habitats. An approach is developed to predict the effects of area closures and effort control on the biomass, production, and species richness of benthic communities in the North Sea. The redistribution of beam trawling effort as a result of management action was modelled with a random utility model, assuming that fishers selected fishing grounds on the basis of their knowledge of past catch rates. The effects of trawling on benthic invertebrates were predicted using a size-based model that accounted for differences in habitat among fishing grounds. Our simulations demonstrated that closures of different sizes and in different locations could have positive or negative effects on benthic communities. These predicted effects resulted from the trade-off between recovery in the closed areas and additional trawling effects in the open areas that arose from displaced fishing activity. In the absence of effort controls, closure of lightly fished areas had the strongest positive effect on benthic communities. Effort reduction also had a positive effect. Therefore, area closures in lightly fished areas, coupled with effort reduction, are expected to minimize the effects of fishing on benthic communities. As it was not possible to access full international data for the North Sea beam trawl fleet, the results of the analyses are illustrative rather than complete. Nevertheless, what is demonstrated is an effective approach for assessing the environmental consequences of fishery management action that can be used to inform management decision-making as part of an EAF.

Download Full-text

Fishing effects in northeast Atlantic shelf seas: patterns in fishing effort, diversity and community structure. V. Changes in structure of the North Sea groundfish species assemblage between 1925 and 1996

Fisheries Research ◽

10.1016/s0165-7836(98)00210-0 ◽

1999 ◽

Vol 40 (2) ◽

pp. 153-183 ◽

Cited By ~ 56

Author(s):

Simon P.R Greenstreet ◽

Fiona E Spence ◽

Julie A McMillan

Keyword(s):

Community Structure ◽

North Sea ◽

Fishing Effort ◽

Species Assemblage ◽

Northeast Atlantic ◽

The North ◽

Shelf Seas ◽

The North Sea

Download Full-text

First record of the rare crab Asthenognathus atlanticus Monod, 1933 (Crustacea: Brachyura: Varunidae) in the North Sea

Oceanological and Hydrobiological Studies ◽

10.2478/oandhs-2021-0030 ◽

2021 ◽

Vol 50 (3) ◽

pp. 352-358

Author(s):

Marco Faasse ◽

Hendrik Gheerardyn ◽

Rob Witbaard ◽

Joël Cuperus

Keyword(s):

North Sea ◽

First Record ◽

Western Mediterranean ◽

Distribution Range ◽

Marine Waters ◽

The West ◽

The North ◽

The North Sea ◽

Northward Expansion ◽

First Time

Abstract Several species new to the area were collected while monitoring Dutch marine waters using a dredge. The varunid crab Asthenognathus atlanticus Monod, 1933 was recorded for the first time in the North Sea. Until 2008, this relatively rare crab was known from the west coast of Africa and the western Mediterranean to northern Brittany in the north. In recent years, its distribution range has expanded, as indicated by records from the Bay of the Seine and the area around Dieppe-Le Tréport. Our finding from Brown Bank (southern North Sea) indicates a further, northward expansion of its distribution range. We list the hosts with which the crab is associated. Earlier arguments for climate change as an explanation for the northward range expansion are supported.

Download Full-text

Why do jellyfish bloom in Norwegian waters and what can be done to recover the ecosystems in the North Sea and on the Norwegian coast?

10.7287/peerj.preprints.2842v1 ◽

2017 ◽

Author(s):

Johannes Hamre

Keyword(s):

North Sea ◽

West Coast ◽

Trophic Levels ◽

The West ◽

Fish Stocks ◽

Norwegian Coast ◽

The North ◽

Key Species ◽

Wide Range ◽

The North Sea

The ecosystems with their relationships between fish species and stocks, have been established by evolution for millions of years, but during the last 50 years, the ecosystems in the North Sea and along the Norwegian coast have been changed fundamentally by fisheries. The North Sea mackerel stock has been depleted and its feeding grounds have been invaded by the Western mackerel which spawns west of Ireland. This stock is now very rich in numbers and occupies the North Sea, the Norwegian Sea and the western Barents Sea. If the trend continues, mackerel may outcompete many of the other fish stocks in the area. Traditionally and until the beginning of the 1970s, there was a large stock of sandeel spawning in the North Sea and on the Norwegian coast. Sandeel juveniles was an important food source for a wide range of species, including sea mammals and birds. The fact that this stock has also been overfished, may explain many changes observed in the ecosystem on the west coast of Norway, for example a large reduction in the populations of sea birds. There are several instances where ecosystems shift to sustain jellyfish blooms in response to depletion of forage fish stocks. This was registered in Namibia in the 1990’s, where the pilchard stock was decimated and the biomass of jellyfish soon became overwhelming. On the west-coast of Norway, there are now frequent blooms of jellyfish, yet another indication that a controlling factor is missing in the system, in this case sandeel, which is a key species in the transfer of nutrients from zooplankton to higher trophic levels in the area. In this paper, I give a description of the situation and some suggested measures that should be taken in fisheries management.

Download Full-text

Recent Foraminifera from the North Sea (Forties and Ekofisk areas) and the continental shelf west of Scotland

Journal of Micropalaeontology ◽

10.1144/jm.4.2.117 ◽

1985 ◽

Vol 4 (2) ◽

pp. 117-125 ◽

Cited By ~ 23

Author(s):

John W. Murray

Keyword(s):

Continental Shelf ◽

North Sea ◽

Standing Crop ◽

High Energy ◽

The West ◽

The North ◽

Energy Environment ◽

Bottom Waters ◽

The North Sea ◽

Northern North Sea

Abstract. The regions studied are all of mid continental shelf depth (70–145 m) and have bottom waters of normal marine salinity. The North Sea has lower bottom water temperatures than those to the west of Scotland. However, the major difference between the two regions is one of tidal and/or wave energy: the northern North Sea is a low energy environment of muddy sand deposition whereas the sampled part of the continental shelf west and north of Scotland is a moderate to high energy environment of medium to coarse biogenic carbonate sedimentation.The physical differences between the two main areas are reflected in the living and dead foraminiferal assemblages. The northern North Sea is a region of free-living species whereas the continental shelf west of Scotland has immobile and mobile attached species living on firm substrates. The northern North Sea is very fertile and has high standing crop values.The dead assemblages are small in size and very abundant. To the west of Scotland the sea is less fertile, standing crop values are low, the dead assemblages are moderate to large in size and reasonably abundant due to the slow rate of dilution by sediment.

Download Full-text

Report on the Surface Collections made by Mr. W. T. Grenfell in the North Sea and West of Scotland

Journal of the Marine Biological Association of the United Kingdom ◽

10.1017/s0025315400057842 ◽

1890 ◽

Vol 1 (4) ◽

pp. 376-381 ◽

Cited By ~ 1

Author(s):

Gilbert C. Bourne

Keyword(s):

Sulphuric Acid ◽

North Sea ◽

Deep Sea ◽

Early Spring ◽

The Other ◽

The West ◽

The North ◽

The North Sea

Mr. Wilfrid Grenfell, the Superintendent of the Mission to Deep Sea Fishermen, has most kindly arranged to carry on a series of observations on the pelagic fauna and the fishes of the seas traversed by the Mission boats in the course of their work. The following report gives an account of the pelagic fauna collected in the North Sea during the early spring, and in the west of Scotland and Kinsale Harbour during the summer. The collections were preserved in picro-sulphuric acid and spirit, and were forwarded to Plymouth for examination. Owing to pressure of work, and to my leaving Plymouth somewhat unexpectedly, I have not been able to make a thorough investigation of all the collections, but have worked out the Copepoda with care, and have confined myself to short notes on the other species.

Download Full-text

Monopseudocuma a new genus from the North East Atlantic and redescription of Pseudocuma gilsoni Bacescu, 1950 (Cumacea: Pseudocumatidae)

Zootaxa ◽

10.11646/zootaxa.1203.1.2 ◽

2006 ◽

Vol 1203 (1) ◽

pp. 39

Author(s):

ALISON M. MCCARTHY ◽

SARAH GERKEN ◽

DAVID MCGRATH ◽

GRACE P. MCCORMACK

Keyword(s):

North Sea ◽

West Coast ◽

New Genus ◽

East Atlantic ◽

The West ◽

The Past ◽

North East ◽

The North ◽

The North Sea

The validity of Pseudocuma gilsoni B|cescu 1950 has been questioned in the past. The recent discovery of material in Irish waters, and in the North Sea, confirms the presence of the species in the North East Atlantic and provides the opportunity to present a full redescription. A new genus, Monopseudocuma, is erected to accommodate the species. A neotype is designated from the West coast of Ireland.

Download Full-text

THE WEST COAST OF THE NORTH SEA

How the Old World Ended ◽

10.2307/j.ctvrdf252.9 ◽

2020 ◽

pp. 62-78

Keyword(s):

North Sea ◽

West Coast ◽

The West ◽

The North ◽

The North Sea

Download Full-text

Combined analyses reveal environmentally driven changes in the North Sea ecosystem and raise questions regarding what makes an ecosystem model’s performance credible?

Canadian Journal of Fisheries and Aquatic Sciences ◽

10.1139/cjfas-2013-0173 ◽

2014 ◽

Vol 71 (1) ◽

pp. 31-46 ◽

Cited By ~ 19

Author(s):

Steven Mackinson

Keyword(s):

Primary Production ◽

North Sea ◽

Ecosystem Model ◽

Ecosystem Approach ◽

Trophic Levels ◽

Fish Stock ◽

Supporting Evidence ◽

Sea Temperature ◽

The North ◽

The North Sea

When an ecosystem model of the North Sea is calibrated to data from multiple trophic levels, the model estimated the primary production required to support the food web correlates temporally with observed changes in sea temperature and nutrient levels, supporting evidence from empirical analyses. However, a different result is given from an alternative calibration using fish stock data only. The inference taken from the emergent primary production – temperature relationship and empirical data are that, on balance, there is stronger overall evidence to support the calibration constrained at multiple trophic levels. Two important implications of the findings are (i) that the relative importance of fishing and environmental effects is likely to be interpreted differently depending on the calibration approach and (ii) the contrasting model calibrations would give different responses to fishing policies. It raises questions regarding how to judge the performance (and credibility) of an ecosystem model and the critical importance of conducting empirical and modelling analyses in parallel. Adopting a combined approach to ecosystem modelling is an important step in the pursuit of operational and defensible tools to support the ecosystem approach to management.

Download Full-text