Report of the Ad hoc Group on Mixed Fisheries in the North Sea (AGMIXNS)

The ICES’ Ad hoc Group on Mixed Fisheries Advice for the North Sea [AGMIXNS] (Chair: Carl O’Brien (UK and ICES)) met at ICES HQ, 3-4 November 2009 to further develop mixed fisheries advice for the North Sea. The investigations of this group built upon the work of the ICES’ Workshop on Mixed Fisheries Advice for the North Sea [WKMIXFISH] which met earlier in August this year.

The current report demonstrates the feasibility of producing results which are of practical use for mixed fisheries management advice; rather than being merely illus-trative. The species considered here as part of the demersal mixed fisheries of the North Sea are cod, haddock, whiting, saithe, plaice, sole and Nephrops norvegicus. All of these are now subject to multi-annual management plans apart from whiting and Nephrops.

The mixed fishery advice is based on the CFP TAC regime and amongst others, con-siders two scenarios as lower and upper boundaries of the range of possibilities:

i) fishing does effectively stop when the catch for the first quota species meets the upper limit corresponding to single stock exploitation bound-ary for agreed management plan or in relation to precautionary limits; and

ii) fishing stops when the last quota species is fully utilised with respect to the upper limit corresponding to single stock exploitation boundary for agreed management plan or in relation to precautionary limits.

As a cross check, the landings by national fleets were summed over nation for each scenario, and the share by country was compared with the initial proxy for relative stability used as input to the model. The results show that only minor deviations are observed across all scenarios, indicating that the approach used does not lead to vio-lation of the underlying hypothesis of relative stability in the TAC sharing (quotas) across nations.

The main finding from this study indicates the feasibility of ICES providing mixed fisheries advice from 2010 in the North Sea. However, this will be dependent upon an ICES’ data call for which AGMIXNS has provided a proposal and a rationale.

The format of a candidate template for mixed fisheries advice has been developed by AGMIXNS and presented in this report for ACOM’s consideration; together with a format for a candidate mixed fisheries annex that parallels the ICES’ single stock an-nex.

In the light of the data deficiency identified with respect to Nephrops stocks, the fig-ures presented in this report are merely indicative of the approach and should not be overly interpreted at present. As such the results presented in this report demonstrate the feasibility of the approach rather than their immediate application to next year’s advice. Further agreement on the presentation of scenarios is recommended.