The biological distribution of Hake (Merluccius merluccius) has changed in recent years, and Scottish whitefish fishermen are catching larger quantities of hake in most waters around Scotland, and particularly in the North Sea.
This change has occurred rapidly, in 2005 the Scottish fleet landed just over 1500 tonnes of hake into Scotland, this volume had risen sharply to 5700 tonnes in 2009 and in 2010 4,972 tonnes were landed with a first sale value of £9.0 million. From a relatively low value and low volume fishery, this species has become a very important commercial fishery in a short space in time. It is now the 6th most valuable species to the whole of the Scottish fishing industry.
European hake (Merluccius merluccius) is widely distributed around the NE Atlantic, and can be found from Norway to Mauritania. There are two distinct stock components to this species, the Northern stock and the Southern stock. The northern stock is considered to be migratory and widely distributed. European hake from the Northern stock spawn between February and July along the shelf edge, from the northern Bay of Biscay to south and west of Ireland. Juveniles move to shallow areas after they become demersal dwelling, in the main nursery areas in the Bay of Biscay and south of Ireland
Juvenile hake tend to feed on planktonic crustaceans, whereas adult hake feed on blue whiting, gadoid fish and small pelagic species. During the day the fish are found close to the seabed, but move up into the water column during the night.
Hake are a medium to large size demersal species which can grow to a maximum size of 140cm and weigh up to 15Kg.
In 2008 ICES classed the northern stock as being at full reproductive capacity and being harvested sustainably. The spawning stock biomass (SSB) was estimated to be about 140,000 tonnes, and fishing mortality to be on target. Recruitment was variable for this species but had been relatively stable. However, ICES benchmarked this stock in 2010 and some major revisions were made. A new assessment model was used, discard data was incorporated, and adjustments for faster growth rate and higher natural mortality were made.
As a result, the assessment is found to be limited in its ability to precisely estimate current stock abundance and mortality, and as such the assessment is indicative of trends only. The spawning biomass has been increasing in recent years and there are indications that fishing mortality has been decreasing. Recruitment fluctuations appear to be without any substantial trend.
This stock was benchmarked in 2010 and was carried out using a length-based model (without age data, as no age-reading criterion exists at present). In 2011 the assessment time period was modelled back to 1978. This has provided a better perspective of the historical development of the stock and has improved the quality of the assessment, meaning the uncertainty of SSB and F estimates are lower. The spawning stock biomass (SSB) has been increasing since 1998 and is estimated to be at a record high in 2011 of 131,000 tonnes. Fishing mortality has been decreasing in recent years, but is still above FMSY. After several high recruitments in 2006 to 2008, the last two recruitments are estimated to be low.
From: ICES Advice June 2011.
The EU agreed a recovery plan for this species in 2004, which aimed to increase the stock to over 140,000 tonnes. A level of fishing mortality was set, and a 15% constraint to changes in TAC's was agreed unless the stock fell below 100,000 tonnes. The actual EC recovery plan was not evaluated by ICES.
In 2009, a long-term management plan was put forward by the EU, the aim of which was to reach maximum sustainable yield (MSY). However, ICES evaluated the MSY value proposed for this plan and found it to be inappropriate.
At the December 2011 meeting in Brussels, the Council of Ministers of the EU set the Total Allowable Catches for hake as follows:
West of Scotland
and North Sea 53,653 5,550
None at present.