Current Stocks Status
Here we provide a brief summary of the current scientific assessment of the main stocks of interest to Scottish fishermen as provided by the International Council for the Exploration of the Sea (ICES) at the end of June 2014
In 2014 the European Commission informed that fish stocks in the North and West of Europe are recovering and that more and more stocks are now being assessed. Overfishing of stocks had fallen by 50% since 2009 and many continue to improve and are fished within sustainable limits.
North Sea Cod
Although Spawning Stock Biomass continues to rise (from a low base) and fishing pressure continues to fall the overall picture in relation to reference points remains similar to 2013 due to previous overestimation of SSB and underestimation of fishing mortality. Recruitment of juveniles remains low due to natural factors. Increase in the size of the cod stock is particularly noticeable in the northern part of the North Sea. The introduction of real-time closures, closed-circuit TV and fully documented fisheries (FDF) is expected to have contributed to the reduction of cod mortality and has seen the discard rate reduced by 50% since 2008.
North Sea Haddock (now Northern Shelf Stock)
ICES now assess haddock on the basis of a Northern Shelf stock (North Sea, Skagerrak and West of Scotland) and have provided advice equating to an 8% increase of TAC across the area. Fishing pressure is at an historical low and Spawning Stock Biomass is moderate and above precautionary limits. Recruitment of juveniles is characterized by occasional large year classes but is currently low due to natural factors.
North Sea Whiting
While fishing mortality has been declining in recent years the Spawning Stock Biomass has not shown signs of increase. Long run of medium to low recruitment of juveniles but most recent year shows improvement. It should be noted that stock size for whiting is more driven by natural mortality that fishing effort.
Northern Shelf Saithe
Spawning Stock Biomass is falling. Fishing pressure is falling and remains at maximum sustainable yield level. Recruitment of juveniles fluctuating around a low level but most recent year shows improvement.
Spawning Stock Biomass has been increasing since 1998 and has been very high in recent years. Fishing mortality has decreased significantly over the last 10 years and recruitment in recent years has been relatively high.
North Sea Plaice
Spawning Stock Biomass is at a record high level. Fishing pressure is at an all time low and recruitment of juveniles remains stable.
North Sea Megrim
Fishing pressure is at a low level and Spawning Stock Biomass is increasing. With no new data available for 2014 that changes ICES perception of the stock, advice is for same catch as current year (combined with West of Scotland).
North Sea Herring
Fishing pressure remains below the recommended level. North Sea herring stock abundance has continued to fluctuate at a relatively high level in the last few years but recruitment, while stable, is regarded as weak.
North Sea Nephrops (langoustines)
Although ICES advises that management of Nephrops should be implemented at Functional Unit level, mechanism is not in place to apply this. The 2013 TV survey shows varying levels of increase in stock abundance in Fladen, Firth of Forth and Moray Firth areas and a reduction in the Farn Deeps area. The remaining areas were assessed on the basis of the data limited stocks procedures. Advice for all areas results in an overall 12% increase in landings for North Sea Functional Units combined.
West of Scotland Cod
Spawning Stock Biomass is very low and fishing pressure remains high. ICES advises on the basis of the Maximum sustainable Yield approach that there should be no directed fisheries and that bycatch and discards should be minimised. ICES notes that discard estimates are based primarily on relatively low sampling by Marine Scotland Science but a parallel programme organized by the Scottish Fishermen’s Federation indicates lower discard rates. Efforts are being made to amalgamate the two schemes in order to improve the accuracy and precision of discard estimates used in the assessment process. ICES noted, that the contribution of seal predation to total cod mortality may impair the ability of the cod stock to recover.
West of Scotland Haddock
See comment above relating to Northern Shelf haddock stock assessment. Discussions still to take place on the allocation of the TAC across the new area.
West of Scotland Whiting
Spawning Stock Biomass continues to increase slowly but is below precautionary limits. Fishing pressure is at a historic low level. Recent recruitment shows an increasing trend. Introduction of selectivity measures in the nephrops fishery is expected to reduce discarding of whiting but has yet to be evaluated by ICES. The inclusion of SFF data may improve the accuracy and precision of discard estimates used in the assessment.
West of Scotland Megrim
Fishing pressure is at a low level and Spawning Stock Biomass increasing. With no new data available for 2014 that changes ICES perception of the stock, advice is for same catch as current year (combined with North Sea).
West of Scotland Herring
Spawning Stock Biomass is fluctuating at level just above the trigger point for adopting the precautionary approach with continued low recruitment. Fishing mortality remains stable at a low level. Advice for 2015 is for a 19% decrease in landings.
West of Scotland Nephrops (langoustines)
Advice for West of Scotland is delayed until after the 2014 Underwater TV Survey.
North-east Atlantic Mackerel
Fishing mortality is below management trigger points and SSB is maintained at long term high levels. Incoming year classes appear to be around or above recent averages.