Single-stock exploitation boundaries


Exploitation boundaries in relation to precautionary considerations


ICES reiterates the previous advice that catches should not exceed 22 000 t, which corresponds to the lowest observed catch since 1980, taken in 2001. This catch level coincides with a time when survey abundance estimates derived from the major fishing grounds did not decrease.

There should be no directed fishery for demersal S. mentella in Subarea XIV until there are clear signs of improvement in the adult stock size of S. mentella in that area.

Management considerations


Sebastes mentella is a deep-sea species with late maturation and slow growth and is hence considered to be vulnerable to overexploitation. It can therefore only sustain low exploitation and management should be based on that consideration.

The advice for 2007 catch was 22 000 t, which corresponded to the lowest observed catch in Subarea V since 1980, taken in 2001 and 2004. The advised catch in 2007 and 2008 coincides with the only substantial increase in biomass indicated by the Icelandic groundfish survey (in 2001).

As this stock is at a low level, the fishable biomass of S. mentella in Subarea XIV is low, and the area is considered to be a nursery ground, ICES advises that there should be no direct fishery for S. mentella in Subarea XIV.

The present management scheme in Division Va sets a joint TAC for S. marinus and S. mentella on the shelf. This impedes direct management of each stock, and ICES repeats its advice that the two species should be managed separately.

From the German survey on the Greenland shelf there are indications of increase in biomass from 2003 and onwards. These fish will reach fishable size in the coming years. However, it is not clear whether these fish will recruit to the pelagic stock or to the demersal stock.

The stock structure of redfish S. mentella in Subareas V, VI, XII, and XIV, and in the NAFO Convention Area has been evaluated by ICES (2005). The outcome is not conclusive and supports different hypotheses (from a one-stock to a different multi-stock hypothesis). Consequently, and solely for practical reasons, the perception of the stock structure is unchanged in this report compared to the 2003 report. Additional information on stock structure has become available recently and ICES will evaluate this information in 2008.

Analysis of logbook information from 1991–2006 shows that the pelagic fishery east of the “redfish line” occurs in the same area as the bottom trawl fisheries, the two fisheries often coinciding seasonally and occurring within the same depth range. Analysis based on the same source indicates that annual catch with pelagic gear east of the “redfish line” has been decreasing over the period. The average annual pelagic catch was around 13 thousand tonnes in the period 1991–1998 (range: 4–25 thousand tonnes), but in more recent years the average annual catch has been less than 3 thousand tonnes (range: 0–8 thousand tonnes).

There are no explicit management objectives for this stock.