scholarly journals The Ecospace model applied to the North Sea: Evaluating spatial predictions with fish biomass and fishing effort data

2015 ◽  
Vol 300 ◽  
pp. 50-60 ◽  
Author(s):  
Giovanni Romagnoni ◽  
Steven Mackinson ◽  
Jiang Hong ◽  
Anne Maria Eikeset
Keyword(s):  
North Sea ◽  
Fishing Effort ◽  
Fish Biomass ◽  
The North ◽  
The North Sea

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

2006 ◽  
Vol 63 (5) ◽  
pp. 822-830 ◽  
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.

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

1979 ◽  
Vol 77 ◽  
pp. 479-494
Author(s):  
R. S. Bailey ◽  
J. R. G. Hislop ◽  
J. Mason
Keyword(s):  
North Sea ◽  
Fishing Effort ◽  
Fish Stock ◽  
Full Time ◽  
The West ◽  
Spawning Grounds ◽  
The North ◽  
Outer Hebrides ◽  
The North Sea ◽  
Fish And Shellfish

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.

scholarly journals Changes in the North Sea fish community: evidence of indirect effects of fishing?

2005 ◽  
Vol 62 (2) ◽  
pp. 177-188 ◽  
Author(s):  
Niels Daan ◽  
Henrik Gislason ◽  
John G. Pope ◽  
Jake C. Rice
Keyword(s):  
North Sea ◽  
Indirect Effects ◽  
Fish Community ◽  
Fishing Effort ◽  
Time Lags ◽  
The North ◽  
Exploitation Rate ◽  
The North Sea ◽  
Sea Fish

Abstract We investigate changes in the North Sea fish community with particular reference to possible indirect effects of fishing, mediated through the ecosystem. In the past, long-term changes in the slope of size spectra of research vessel catches have been related to changes in fishing effort, but such changes may simply reflect the cumulative, direct effects of fishing through selective removal of large individuals. If there is resilience in a fish community towards fishing, we may expect increases in specific components, for instance as a consequence of an associated reduction in predation and/or competition. We show on the basis of three long-term trawl surveys that abundance of small fish (all species) as well as abundance of demersal species with a low maximum length (Lmax) have steadily and significantly increased in absolute numbers over large parts of the North Sea during the last 30 years. Taking average fishing mortality of assessed commercial species as an index of exploitation rate of the fish community, it appears that fishing effort reached its maximum in the mid-1980s and has declined slightly since. If the observed changes in the community are caused by indirect effects of fishing, there must be a considerable delay in response time, because the observed changes generally proceed up to recent years, although both size and Lmax spectra suggest some levelling off, or even recovery in one of the surveys. Indeed, significant correlations between all community metrics and exploitation rate were obtained only if time lags ≥6 years were introduced.

scholarly journals Using MPAs to address regional-scale ecological objectives in the North Sea: modelling the effects of fishing effort displacement

2009 ◽  
Vol 66 (1) ◽  
pp. 90-100 ◽  
Author(s):  
Simon P. R. Greenstreet ◽  
Helen M. Fraser ◽  
Gerjan J. Piet
Keyword(s):  
Species Diversity ◽  
North Sea ◽  
Benthic Invertebrates ◽  
Regional Scale ◽  
Fishing Effort ◽  
Fishing Mortality ◽  
Total Allowable Catch ◽  
The North ◽  
The North Sea ◽  
Ecological Objectives

Abstract Greenstreet, S. P. R., Fraser, H. M., and Piet, G. J. 2009. Using MPAs to address regional-scale ecological objectives in the North Sea: modelling the effects of fishing effort displacement. – ICES Journal of Marine Science, 66: 90–100. The use of Marine Protected Areas (MPAs) to address regional-scale objectives as part of an ecosystem approach to management in the North Sea is examined. Ensuring that displacement of fishing activity does not negate the ecological benefits gained from MPAs is a major concern. Two scenarios are considered: using MPAs to safeguard important areas for groundfish species diversity and using them to reduce fishing impacts on benthic invertebrates. Appropriate MPAs were identified using benthic invertebrate and fish abundance data. Fishing effort redistribution was modelled using international landings and fishing effort data. Closing 7.7% of the North Sea to protect groundfish species diversity increased the fishing impact on benthic invertebrates. Closing 7.3% of the North Sea specifically to protect benthic invertebrates reduced fishing mortality by just 1.7–3.8%, but when combined with appropriate reductions in total allowable catch (TAC), 16.2–17.4% reductions in fishing mortality were achieved. MPAs on their own are unlikely to achieve significant regional-scale ecosystem benefits, because local gains are largely negated by fishing effort displacement into the remainder of the North Sea. However, in combination with appropriate TAC reductions, the effectiveness of MPAs may be enhanced.

scholarly journals Competitive interactions between two fishing fleets in the North Sea

2016 ◽  
Vol 73 (6) ◽  
pp. 1485-1493 ◽  
Author(s):  
Klaas Sys ◽  
Jan Jaap Poos ◽  
Jef Van Meensel ◽  
Hans Polet ◽  
Jeroen Buysse
Keyword(s):  
North Sea ◽  
Mixed Model ◽  
Fishing Effort ◽  
Competitive Interactions ◽  
Southern Bight ◽  
The North ◽  
Solea Solea ◽  
The North Sea ◽  
Fishing Fleets ◽  
Logbook Data

Abstract We examine whether the landing rates of Belgian beam trawlers in the Southern Bight of the North Sea were affected through competitive interactions with the Dutch beam trawler fleet and whether the development of a pulse trawler fleet has altered competitive interactions between both fleets. Effects of competition were investigated through a natural experiment based on the different weekly exploitation patterns of both fleets. Logbook data were used to fit a generalized additive mixed model for the daily landing rates of the target species sole (Solea solea) and plaice (Pleuronectes platessa). Results showed that landing rates of sole by the Belgian beam trawlers (>221 kW) from 2006 to 2013 were lower during weekdays than during weekends when the Dutch trawler fleet is in harbour, while no such an effect was found for plaice. After the development of a pulse trawler fleet in 2011, the negative weekday effect in the sole landing rates was much more pronounced in 2012 and 2013. This increased loss of efficiency during weekdays, as a result of increased competition with the Dutch trawler fleet, coincided with a reallocation of fishing effort by the Belgian beam trawler fleet.

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