Redfish (Sebastes mentella and Sebastes norvegicus)

Fish species
Typography
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For more than a decade, recruitment failure has been observed in Barents Sea redfish stocks (Figure 4.3.42); but signs of improvement have been observed recently. With this understanding, it is important that juvenile age groups are given the strongest protection from being caught as bycatch in any fishery, e.g., shrimp fisheries in the Barents Sea and Svalbard area where significant numbers of young redfish often occur (Figure 4.3.43).  This will ensure that the recruiting year classes can contribute as much as possible to stock rebuilding (ICES AFWG, 2014).

Deep-Sea Redfish (Sebastes mentella)

It is likely that only year classes prior to 1995 will contribute significantly to the spawning stock in the coming years, because subsequent year classes (1996-2003) were extremely poor. Several years with management measures to ensure protection and growth of year-classes subsequent to 2003 may have caused the higher abundance and biomass recently observed along the continental slope and in pelagic waters of the Norwegian Sea. These year classes need to be protected as they offer an opportunity to increase future spawning stock size.

Since the 1990s, the fishery for deep-sea redfish (S. Mentella) in the Barents Sea has been restricted to by-catches in demersal fisheries. A new directed pelagic fishery for this species in international waters of the Norwegian Sea has developed since 2004. This fishery increased to record levels in 2006 with a total catch of 33,000 tonnes, the highest level since 1991. Since then this fishery has decreased, and the total landings of S. mentella in Subareas I and II during 2012-2013 (demersal and pelagic catches) were around 10,000 tonnes. For many years no directed fishery has been advised for this stock. ICES decided to give advice on catch levels in 2013, after a new assessment model was accepted in 2012. The advice given for 2014 was 24,000 tonnes (ICES AFWG, 2014).

Figure 4.3.42. Results from the statistical catch-at-age model showing the development of total biomass (‘000s), spawning stock biomass and recruitment at age 2 for the period 1992-2012, for S. mentella in subareas I and II.Figure 4.3.42. Results from the statistical catch-at-age model showing the development of total biomass (‘000s), spawning stock biomass and recruitment at age 2 for the period 1992-2012, for S. mentella in subareas I and II.

Figure 4.3.43. Distribution of deep-sear redfish in August-October 2013.Figure 4.3.43. Distribution of deep-sear redfish in August-October 2013.

Golden Redfish (Sebastes norvegicus)

In the absence of defined reference points, the status of the stock cannot be fully evaluated. Year classes during the last decade have been very weak, and biomass of the mature component of the stock is less than 20,000 tonnes (Figure 4.3.44). The ICES assessment shows a substantial reduction in abundance, and indicates that presently the stock level is historically low and in very poor condition.  Given the slow growth and low productivity of this species, this situation is not expected to improve within the near future (ICES AFWG, 2014).

More stringent protective measures should be implemented, such as no directed fishing and extension of the limited fishing moratorium that was implemented for this stock, as well as a further improvement of trawl bycatch regulations. It is also of vital importance that the juvenile age groups are given the strongest protection from being caught as bycatch in any fishery, e.g. the shrimp fisheries in the coastal areas as well as in the Barents Sea and Svalbard area and pelagic trawl fisheries for herring and blue whiting in the Norwegian Sea. This will ensure that recruiting year classes can contribute as much as possible to slowing stock decline. Golden redfish is currently also being caught in a directed fisheries for demersal species. Better statistics on this bycatch, and regulations to prevent this from continuing, are needed. The catches were around 7,000 tonnes in 2004-2010, but declined slightly to below 6,000 tonnes in 2011-2012. These catch levels seem to contribute to a continued decline in this stock (ICES AFWG, 2014).

Figure 4.3.44. Sebastes norvegicus. Mature stock biomass (in thousand tonnes). Bold line – 2013 assessment, dotted line – 2012 assessment. Figure 4.3.44. Sebastes norvegicus. Mature stock biomass (in thousand tonnes). Bold line – 2013 assessment, dotted line – 2012 assessment.