scholarly journals A reassessment of trends in the North Sea Large Fish Indicator and a re-evaluation of earlier conclusions

2012 ◽  
Vol 69 (2) ◽  
pp. 343-345 ◽  
Author(s):  
Simon P. R. Greenstreet ◽  
Stuart I. Rogers ◽  
Jake C. Rice ◽  
Gerjan J. Piet ◽  
Emma J. Guirey ◽  
...  
Keyword(s):  
North Sea ◽  
Previous Analysis ◽  
Fish Communities ◽  
Marine Science ◽  
Large Fish ◽  
The North ◽  
The North Sea ◽  
Corrected Data ◽  
Sea Fish

Abstract Greenstreet, S. P. R., Rogers, S. I., Rice, J. C., Piet, G. J., Guirey, E. J., Fraser, H. M., and Fryer, R. J. 2012. A reassessment of trends in the North Sea Large Fish Indicator and a re-evaluation of earlier conclusions. – ICES Journal of Marine Science, 69: 343–345. Previous analysis of the Large Fish Indicator, the basis for the North Sea “fish communities” EcoQO, suggested a strong recovery between 2001 and 2008. Discovery of a mistake in this earlier analysis now suggests that this recovery is not as strong as first thought, but reanalysis of the corrected data still supports the majority of conclusions drawn in the original paper.

scholarly journals A red herring from the Öresund (ICES40G2): the apparent recovery of the Large Fish Indicator (LFI) in the North Sea hides a non-trawled area

2013 ◽  
Vol 70 (6) ◽  
pp. 1081-1084 ◽  
Author(s):  
Andreas Sundelöf ◽  
Håkan Wennhage ◽  
Henrik Svedäng
Keyword(s):  
North Sea ◽  
Gadus Morhua ◽  
Marine Science ◽  
Large Fish ◽  
Marine Strategy Framework Directive ◽  
Important Species ◽  
The North ◽  
The North Sea ◽  
Technical Regulations

Abstract Sundelöf, A., Wennhage, H., and Svedäng, H. 2013. A red herring from the Öresund (ICES40G2): the apparent recovery of the Large Fish Indicator (LFI) in the North Sea hides a non-trawled area. – ICES Journal of Marine Science, 70: 1081–1084. As reported in a number of previous papers in this journal, the Large Fish Indicator (LFI) was developed for the North Sea. ICES Statistical Rectangle 40G2 was accidentally included in the North Sea calculations of LFI for 2004, 2007 and 2008. This inclusion significantly increased the LFI and was subsequently removed from the analysis. We identify and discuss three reasons to revisit rectangle 40G2 when considering LFI for the North Sea: (i) according to the Marine Strategy Framework Directive (MSFD), the area belongs to the North Sea, (ii) it is a geographically well-defined area where technical regulations have prevented the use of trawls since the 1930s, and (iii) there is evidence of a productive and rather closed cod (Gadus morhua) subpopulation unit in the area, which is an important species for the North Sea LFI.

scholarly journals Inferring the location and scale of mixing between habitat areas of lesser sandeel through information from the fishery

2010 ◽  
Vol 68 (1) ◽  
pp. 43-51 ◽  
Author(s):  
Henrik Jensen ◽  
Anna Rindorf ◽  
Peter J. Wright ◽  
Henrik Mosegaard
Keyword(s):  
North Sea ◽  
Large Scale ◽  
Pelagic Fish ◽  
Fishing Ground ◽  
Marine Science ◽  
Foraging Habitat ◽  
Small Pelagic Fish ◽  
The North ◽  
The North Sea

Abstract Jensen, H., Rindorf, A., Wright, P. J., and Mosegaard, H. 2011. Inferring the location and scale of mixing between habitat areas of lesser sandeel through information from the fishery. – ICES Journal of Marine Science, 68: 43–51. Sandeels are small pelagic fish that play an important role in the diet of a range of natural predators. Because of their limited capture by traditional survey gear, little is known about their large-scale distribution or the degree of mixing between habitat areas. Detailed information collected directly from the fishery was used to map fishing grounds, which were then assumed to reflect the foraging habitat of the species. Length distributions from individual hauls were used to assess differences in the distributions as a function of distance between samples. Sandeel foraging habitat covered some 5% of the total area of the North Sea. Mixing between neighbouring fishing grounds was too low to eliminate differences in length distributions at distances between grounds down to 5 km. Within fishing grounds, mixing was sufficient to eliminate differences in length distributions at scales <28 km but insufficient at greater distances. The lack of mixing between grounds may result in large differences in sandeel abundance among adjacent fishing grounds. Further, notable abundance at one end of an extensive fishing ground is not necessarily indicative of similar abundance at its other end.

scholarly journals Tunny Investigations made in the North Sea on Col. E. T. Peel's Yacht, “St. George,” Summer, 1933. Part I. Biometric Data

1934 ◽  
Vol 19 (2) ◽  
pp. 503-522 ◽  
Author(s):  
F. S. Russell
Keyword(s):  
North Sea ◽  
South Coast ◽  
Body Proportions ◽  
The South ◽  
Biometric Data ◽  
The North ◽  
The North Sea ◽  
Sea Fish ◽  
Made In

1. Details are given of the types of hooks lost in tunny in the North Sea in the summer of 1933.2. Data are given on the measurements made on thirty-two large migrating fish caught in the North Sea in August and September, 1933.3. In certain body proportions the tunny measured differ from those in the G4 Group (200 to 260 cm. in length) given by Heldt for fish from Tunis and by Frade for fish from Algarve on the south coast of Portugal, while in some characters they resemble the Tunis fish and in others the Algarve fish, but all the North Sea fish were between 232 and 271 cm. in length.4. It was found that there was a tendency for fish with short second dorsal fins to have short first dorsal, anal, and caudal fins, and for those with long second dorsals to have these other three fins long.5. Measurements were made to supply data on the condition of the fish.

scholarly journals Long-term effects of an offshore wind farm in the North Sea on fish communities

2015 ◽  
Vol 528 ◽  
pp. 257-265 ◽  
Author(s):  
C Stenberg ◽  
JG Støttrup ◽  
M van Deurs ◽  
CW Berg ◽  
GE Dinesen ◽  
...  
Keyword(s):  
North Sea ◽  
Wind Farm ◽  
Fish Communities ◽  
Offshore Wind ◽  
Offshore Wind Farm ◽  
Long Term Effects ◽  
The North ◽  
The North Sea

scholarly journals Modelling the direct impact of bottom trawling on the North Sea fish community to derive estimates of fishing mortality for non-target fish species

2009 ◽  
Vol 66 (9) ◽  
pp. 1985-1998 ◽  
Author(s):  
G. J. Piet ◽  
R. van Hal ◽  
S. P. R. Greenstreet
Keyword(s):  
North Sea ◽  
Fish Species ◽  
Fish Community ◽  
Direct Impact ◽  
Fishing Mortality ◽  
Bottom Trawling ◽  
The North ◽  
Target Fish ◽  
The North Sea ◽  
Sea Fish

Abstract Piet, G. J., van Hal, R., and Greenstreet, S. P. R. 2009. Modelling the direct impact of bottom trawling on the North Sea fish community to derive estimates of fishing mortality for non-target fish species. – ICES Journal of Marine Science, 66: 1985–1998. This study introduces a spatially explicit model that combines abundance data for all the main fish species in the demersal North Sea fish community with international effort data and estimates of gear-, species-, and size-dependent catch efficiency to determine the mortality of non-target fish species caused by bottom trawl fisheries and its spatial variation. Where necessary information was lacking, assumptions were made, and a sensitivity analysis performed to examine the impact of these issues on model results. Model outcomes were validated using international landings and discard data for five target species: cod, haddock, whiting, sole, and plaice. This showed that depending on its configuration, the model could reproduce recorded landings and discards of these species reasonably well. This suggests that the model could be used to simulate rates of fishing mortality for non-target fish species, for which few data are currently available. Sensitivity analyses revealed that model outcomes were most strongly influenced by the estimates of gear catch efficiency and the extent to which the distributions of fishing effort and each species overlapped. Better data for these processes would enhance the contribution that this type of model could make in supporting an ecosystem approach to fisheries management.

scholarly journals Ecotypes as a concept for exploring responses to climate change in fish assemblages

2010 ◽  
Vol 68 (3) ◽  
pp. 580-591 ◽  
Author(s):  
Georg H. Engelhard ◽  
Jim R. Ellis ◽  
Mark R. Payne ◽  
Remment ter Hofstede ◽  
John K. Pinnegar
Keyword(s):  
Climate Change ◽  
North Sea ◽  
Trophic Level ◽  
Fish Assemblages ◽  
Environmental Drivers ◽  
Trawl Survey ◽  
The North ◽  
The North Sea ◽  
Increasing Trends ◽  
Sea Fish

Abstract Engelhard, G. H., Ellis, J. R., Payne, M. R., ter Hofstede, R., and Pinnegar, J. K. 2011. Ecotypes as a concept for exploring responses to climate change in fish assemblages. – ICES Journal of Marine Science, 68: . How do species-rich fish assemblages respond to climate change or to other anthropogenic or environmental drivers? To explore this, a categorization concept is presented whereby species are assigned with respect to six ecotype classifications, according to biogeography, horizontal and vertical habitat preference, trophic guild, trophic level, or body size. These classification schemes are termed ecotypology, and the system is applied to fish in the North Sea using International Bottom Trawl Survey data. Over the period 1977–2008, there were changes in the North Sea fish community that can be related to fish ecotypes. Broadly speaking, there were steady increases in abundance of species that were either Lusitanian, small-bodied, or low-/mid-trophic-level ecotypes, and generally declining or only marginally increasing trends of most Boreal, large-bodied, or high-trophic-level ecotypes or combinations of them. The post-1989 warm biological regime appears to have favoured pelagic species more than demersal species. These community-level patterns agree with the expected responses of ecotypes to climate change and also with anticipated vulnerability to fishing pressure.

scholarly journals Development of the large fish indicator and associated target for a Northeast Atlantic fish community

2014 ◽  
Vol 71 (9) ◽  
pp. 2403-2415 ◽  
Author(s):  
Larissa Modica ◽  
Francisco Velasco ◽  
Izaskun Preciado ◽  
Maria Soto ◽  
Simon P. R. Greenstreet
Keyword(s):  
North Sea ◽  
Fish Community ◽  
Ecosystem Approach ◽  
Time Lags ◽  
Bay Of Biscay ◽  
Large Fish ◽  
Biodiversity Indicator ◽  
Eu Member States ◽  
The North ◽  
The North Sea

AbstractThe large fish indicator (LFI) was developed to support the North Sea fish community Ecological Quality Objective (EcoQO) pilot study, intended to establish an operational ecosystem approach to management. Subsequently, procedures established in the North Sea were applied to the Celtic Sea to derive an LFI and target specific to this region. The Marine Strategy Framework Directive (MSFD) requires EU Member States sharing marine regions to cooperate using the Regional Seas Conventions, and using indicators already adopted by them. The MSFD explicitly suggests the LFI as a foodweb indicator, but it could equally well be used to monitor biodiversity. Here, we apply the established rationale to develop an LFI and target specific to the southern Bay of Biscay. Despite declining in the 1990s, the LFI subsequently recovered to near original values in 2008. Previously, relationships between the LFI and fishing pressure have involved lengthy time-lags. We observe a similar relationship, but with shorter lag. The nature of the larger species responsible for much of the change in the LFI may explain this difference, and might also suggest that, in the Bay of Biscay, the LFI is more appropriately used as a biodiversity indicator, rather than a foodweb indicator.

scholarly journals Development of the EcoQO for the North Sea fish community

2010 ◽  
Vol 68 (1) ◽  
pp. 1-11 ◽  
Author(s):  
Simon P. R. Greenstreet ◽  
Stuart I. Rogers ◽  
Jake C. Rice ◽  
Gerjan J. Piet ◽  
Emma J. Guirey ◽  
...  
Keyword(s):  
North Sea ◽  
Fish Community ◽  
Environmental Influence ◽  
Fish Stock ◽  
Fishing Pressure ◽  
Stock Management ◽  
The North ◽  
A Value ◽  
The North Sea ◽  
Sea Fish

Abstract Greenstreet, S. P. R., Rogers, S. I., Rice, J. C., Piet, G. J., Guirey, E. J., Fraser, H. M., and Fryer, R. J. 2011. Development of the EcoQO for the North Sea fish community. – ICES Journal of Marine Science, 68: 1–11. Development of the Ecological Quality Objective (EcoQO) for the North Sea demersal fish community is described. Size-based metrics were identified as the most effective indicators of the state of the community, but such metrics are also sensitive to environmental influence. Redefining the large fish indicator (LFI) produced a metric more sensitive to fishing-induced change and therefore more useful to managers. Fish stocks were thought to be exploited at a sustainable rate in the early 1980s, so in a process echoing the precautionary approach to fish stock management, this was considered the reference period for the LFI, suggesting a value of 0.3 as the appropriate EcoQO. The LFI declined from around 0.3 in 1983 to 0.05 in 2001, followed by a recovery to 0.22 in 2008. However, analyses of the longer-term groundfish survey data suggest that, even were fishing pressure to be reduced to early 20th century levels, the LFI would be unlikely to rise much above a value of 0.3. The response of the LFI to variation in fishing pressure suggested a more complex relationship than anticipated, underscoring the need for operational theoretical size-resolved multispecies fish community models to support management towards broader ecosystem objectives.

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