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CS 4: Background

The OSPAR (Quality Status Report 2000) considered Bay of Biscay and North Iberian Coast region being a subtropical/boreal bio-geographical transition zone within Region IV. This area is of particular importance due to the nature of the transition zone: southern species at the northern edge of their ranges and northern species at the southern edge of their ranges inhabit the same area (Gomes et al., 2001). This greatly enhances the importance of this area because species in the limits of their distribution may react faster to climate/density changes (Lawton, 2000). In addition, the topographical diversity is reflected in the ecological richness of the region, which includes a wide range of fish species, many of these of commercial interest (Sánchez and Olaso, 2004).

Hake, anchovy and tuna are presently the most important commercial fish species in the Bay of Biscay area. Tuna being a large scale migratory species, hake and anchovy can also be considered the main fisheries restricted to the Bay of Biscay ecosystem (considering the ecosystem itself and the human communities using them). Thus, the proposed study includes ICES (International Council for the Exploration of the Sea) fishing areas VIIIa, VIIIb, VIIId and VIIIc and the demersal/pelagic interrelated fish communities, considering hake and anchovy as key species of the area.

The European hake (Merluccius merluccius L.) is a commercially exploited top predator gadoid species in the Bay of Biscay area. It is a demersal species mainly found between 70-370 m depth, but it also occurs in inshore waters (30 m) and to depths of 1000 m (Cohen et al., 1990). Within this geographical area ICES recognizes the existence of two stocks, the so-called northern (ICES Division IIIa, Subareas II, IV, VI and VII and Divisions VIIIa,b,d) and southern stock (ICES Divisions VIIIc and IXa) (ICES, 2005a). The northern stock of European hake in the Bay of Biscay (Div. VIIIa,b,d) is one of the main commercial species for Spanish and French fleets and it has been commercially exploited since the 18th century (Casey & Pereiro, 1995), with annual catches ranging from 42 000 to 96 000 tonnes during the period 1961-2003 (ICES, 2005a). In 2003, the value of the northern hake TAC was estimated at around 90 M€.

The population size of northern European hake precipitously declined during the late 1990s and the present level is considered to be only 50 % of the level of the 1970s. Based on the most recent assessment of this species, the northern stock is likely to be at a reduced reproductive capacity and at risk of being harvested unsustainably (ICES, 2005a). The stock is outside the safe biological limits and at the beginning of the 1990s the spawning biomass had decreased below the precautionary approach level (BPA = 140 000 tones), and has remained at that level. Fishing mortality has been above FPA between 1987 and 2000, has then declined during recent years and is estimated to be above FPA in 2003. Due to the critical state of the population and in order to recover it an Emergency Plan was introduced in June 2001 (see Council Regulation Nº1162/2001) and, finally, a Recovery Plan was implemented for the northern stock of European hake in 2004 under the EC Reg. No 811/2004.

Therefore, the current management objectives of this stock are those explicitly established in the EC Reg. No 811/2004. The objective of the Northern hake stock recovery plan is to increase the level of spawning biomass of this stock to values equal or greater than 140 000 tons (BPA) in two consecutive years (EC No 811/2004). Once the target level has been achieved the Commission will introduce follow up management measures replacing the recovery plan. The short term predictions carried out during the last assessment showed that this level could be reached in 2006 with the current management measures. Thus, Northern hake in the Bay of Biscay is proposed as a Case Study due to their socio-economical importance for the Spanish and French fishing Industry, its biological status and because of the especial measures applied during the last few years in its management. Also, it is interesting as a CS to evaluate the possible level of compliance of such plans and its influence on the consequent success of the Recovery Plan.

Several fleet segments focus its activities on Northern hake and most of them caught hake in mixed fisheries. Among other species in the catch we found megrim, monkfish, nephrops, blue whiting, and horse mackerel. They are also of great economical importance and are being routinely assessed by ICES Working Groups. The northern hake population, as the majority of the UE stocks, is managed by TAC and quota regulations. In addition to this, the following technical measures are in place: minimum mesh size in some areas for some gears, and minimum length in landings (EC No 850/1998).

The Southern hake population has showed a similar trend to that of Northern hake. The population size of Southern European hake dramatically declined during the late 1980s and is presently at its lowest historic levels. Fishing mortality has been well above the Fpa and has been around Flim for most of the time series. Based on the most recent assessment of this stock, Southern hake is considered to suffer a reduced reproductive capacity and to be at risk of being harvested unsustainably (ICES, 2005a). Due to the critical state of the population, ACFM advised that “in the absence of an agreed recovery plan, no catch should be taken from this stock in 2005. A recovery plan should be implemented as a prerequisite to reopening the fishery. The recovery plan should include monitoring the development of the stock, clearly stating specified reopening criteria, and monitoring the fishery when it is reopened???. Currently, a recovery plan for this stock is under development.

A specificity of hake, in contrast to the other gadoid considered in this project, cod, is that adult hake lives and spawns in the shelf edge, whereas juvenile recruitment occurs in specific areas on the continental shelf (Ibaibarriaga et al., submitted; ??lvarez et al., 2004), which in turn make it also a good candidate for the CS. Commercial fish hake prey species in the whole area are: Anchovy, Sardine, Blue whiting, Horse mackerel and Mackerel (Gonzalez et al., 1985; Pereda and Olaso, 1990; Guichet, 1995; Cabral and Murta, 2002; Hill et al., 2003).

Anchovy, a potential prey of hake, is another very important fishery in the Bay of Biscay, both in economic and social terms. Anchovy is a short-life span pelagic fish species with large inter annual variation in recruitment which likely is greatly influenced by environmental factors. The population numbers, and fishery, depends largely on the incoming year class; and thus, the stock is in a state of potential collapse because is based mostly on recruitment. In addition, anchovy population seems to have suffered important long-term changes in the distribution of the stock. Therefore, anchovy of Bay of Biscay is proposed as the second key species due to its importance (both in the ecosystem and commercial) and its biological/characteristics.

Based on the most recent estimates of SSB and fishing mortality, ICES classifies the anchovy stock as being at risk of reduced reproductive capacity and as being harvested sustainable (ICES 2005b). The stock is very low in relation to the levels observed throughout the 1990s and this is mostly due to poor 2001-2003 year classes. In June 2005, and in response to a special request, ICES, based on preliminary information, considered that strong management measures are required for anchovy, in order to protect the remaining stock, i.e. that the fishery be closed immediately, and remains until there is reliable fishery-independent evidence of a strong year class recruiting to the stock.

The fishery of anchovy is carried out by Spanish purse seine fleet and the French trawl fleet (Uriarte et al., 1996). The Spanish purse seines operated mainly in spring, while the French trawlers operate in the centre/south of Bay of Biscay from the beginning of the year till April and in the north of the Bay of Biscay in August/September (ICES, 2005b). Thus, there is a clear geographical and time separation between both fleets.
Anchovy fishery is regulated by quota regulation. In addition to that, ICES (ICES, 2005b) recommends measures to protect juveniles, in order to allow a large part of the recruiting year class to spawn. Among these measures ICES include closures of key nursery areas and economic incentives with the purpose to diminish the catch of recruiting fish.

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