scholarly journals Indicator-based status assessment of commercial fish species in the North Sea according to the EU Marine Strategy Framework Directive (MSFD)

2013 ◽  
Vol 70 (3) ◽  
pp. 694-706 ◽  
Author(s):  
Wolfgang Nikolaus Probst ◽  
Matthias Kloppmann ◽  
Gerd Kraus

Abstract Probst, W. N., Kloppmann, M., and Kraus, G. Indicator-based status assessment of commercial fish species in the North Sea according to the EU Marine Strategy Framework Directive (MSFD). – ICES Journal of Marine Science, 70: 694–706. The EU Marine Strategy Framework Directive (MSFD) is structured into eleven descriptors of good environmental status (GES). For each descriptor the current status of the marine environment should be assessed against its GES using ecosystem criteria and indicators. Within Descriptor 3 (D3) the MSFD addresses the status of exploited fish stocks according to three criteria (exploitation rate, stock size and size structure). This study performed an MSFD-compliant assessment of exploited fish stocks in the North Sea by aggregating data from analytical stock assessments and scientific research surveys to calculate indicator metrics for each criterion within each stock time-series. A stock achieved GES, when each indicator for each criterion had a good status. Of 43 assessed fish stock suggested by the EU Data Collection Framework, 63% (27) achieved GES. Though the MSFD explicitly demands that all exploited fish stocks achieve GES, this demand may be challenged by reality, because the status of exploited stocks depends not only on fishing impacts, but also on environmental conditions and ecological interactions. Therefore an alternative approach based on binomial distributions is presented to define limits for GES at the descriptor level. The implications and pitfalls of the applied assessment methods are discussed.

2018 ◽  
Vol 142 ◽  
pp. 132-146 ◽  
Author(s):  
Jacqueline D. Eggleton ◽  
Jochen Depestele ◽  
Andrew J. Kenny ◽  
Stefan G. Bolam ◽  
Clement Garcia

2020 ◽  
Vol 77 (5) ◽  
pp. 1772-1786 ◽  
Author(s):  
A D Rijnsdorp ◽  
J G Hiddink ◽  
P D van Denderen ◽  
N T Hintzen ◽  
O R Eigaard ◽  
...  

Abstract Fisheries using bottom trawls are the most widespread source of anthropogenic physical disturbance to seafloor habitats. To mitigate such disturbances, the development of fisheries-, conservation-, and ecosystem-based management strategies requires the assessment of the impact of bottom trawling on the state of benthic biota. We explore a quantitative and mechanistic framework to assess trawling impact. Pressure and impact indicators that provide a continuous pressure–response curve are estimated at a spatial resolution of 1 × 1 min latitude and longitude (∼2 km2) using three methods: L1 estimates the proportion of the community with a life span exceeding the time interval between trawling events; L2 estimates the decrease in median longevity in response to trawling; and population dynamic (PD) estimates the decrease in biomass in response to trawling and the recovery time. Although impact scores are correlated, PD has the best performance over a broad range of trawling intensities. Using the framework in a trawling impact assessment of ten métiers in the North Sea shows that muddy habitats are impacted the most and coarse habitats are impacted the least. Otter trawling for crustaceans has the highest impact, followed by otter trawling for demersal fish and beam trawling for flatfish and flyshooting. Beam trawling for brown shrimps, otter trawling for industrial fish, and dredging for molluscs have the lowest impact. Trawling is highly aggregated in core fishing grounds where the status of the seafloor is low but the catch per unit of effort (CPUE) per unit of impact is high, in contrast to peripheral grounds, where CPUE per unit of impact is low.


Author(s):  
J.W. Horwood ◽  
R.S. Millner

Large catches of sole (Solea solea) were made in early 1996 from the south-western North Sea. Sole suffer physiological damage in waters below 3–4 C. In February 1996 cold water of 3–4 C unusually extended from the Continental coast onto the Dogger Bank. It is likely that the increased catches were due to the consequential distribution and behaviour of the sole, making them more susceptible to capture.Exceptionally large catches of mature sole (Solea solea (L.)) were made in February 1996 by Lowestoft fishermen from the south-western North Sea. Surprisingly this was not welcome. The UK allocation of the North Sea sole is -4 % of the EU Total Allowable Catch (TAC), and fishermen are restricted nationally, and by the fishing companies, to a tightly managed ration. The Lowestoft Journal (8 March 1996) reported the suspension of a local fishing skipper for not throwing back 5000 kg of sole caught in the Silver Pits. We will show that the abnormal catches were due to exceptionally cold waters.Sole in the North Sea are at the northern extremity of their range, with sole seldom living in waters below 5°C (Horwood, 1993). In fact, North Sea sole were successfully introduced into Lake Quarun, Egypt, where they lived in temperatures in excess of 30°C (El-Zarka, 1965). Young sole migrate from their shallow inshore nursery grounds, such as the Waddensea, as winter approaches (Creutzberg & Fonds, 1971).


Hydrobiologia ◽  
2011 ◽  
Vol 670 (1) ◽  
pp. 23-34 ◽  
Author(s):  
Iñigo Martinez ◽  
Emma G. Jones ◽  
Sarah L. Davie ◽  
Francis C. Neat ◽  
Ben D. Wigham ◽  
...  

1969 ◽  
Vol 23 ◽  
pp. 33-36
Author(s):  
Jørn Bo Jensen ◽  
Sara Borre ◽  
Jørgen O. Leth ◽  
Zyad Al-Hamdani ◽  
Laura G. Addington

In the summer of 2010, the Geological Survey of Denmark and Greenland (GEUS) mapped the potential raw materials and substrate types, over large parts of the Danish economic sector of the North Sea, in cooperation with Orbicon A/S. The mapping was carried out for the Danish Nature Agency; it is part of the general mapping of raw material resources within the territories of the Danish state and forms part of the input for the implementation of the European Union’s Marine Strategy Framework Directive. The purpose was (1) to provide an overview of the distribution, volume and composition of available raw materials and (2) to identify, describe and map the distribution of the dominant marine bottom types.


2017 ◽  
Author(s):  
Johannes Hamre

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.


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