ices north sea herring 2023 2024

ICES has announced its advice for autumn spawning herring in the North Sea, Skagerrak and Kattegat, eastern English Channel

The International Council for the Exploration of the Seas (ICES) has announced its advice for autumn spawning herring in the Subarea 4 and divisions 3.a and 7.d, autumn spawners (North Sea, Skagerrak and Kattegat, eastern English Channel).

The ICES advice on fishing opportunities for 2024 is that when MSY is applied, catches should be no more than 532,166 tonnes.

It also advises that Catches of Western Baltic Spring-Spawning (WBSS) herring in the fishery for North Sea autumn-spawning herring in the east of 4.a and 4.b should be kept as low as possible.

Regarding the conservation aspect, ICES advises that no activities on spawning habitats should be allowed unless the effects of these activities have been assessed and shown not to be detrimental.

ICES’ research has shown that fishing pressure on the stock is blow FMSY and the spawning stock is above MSY Btrigger, Bpa and Blim.

The basis for the 28.3% increase of catch advice is threefold. First, the SSB in 2022 is estimated to be 32.5% larger than that predicted in the previous advice. Second, the recruitment in 2022 (2021-year class) is now estimated to be 87.3% larger than that estimated in the previous advice. The contribution of this year class to the SSB in the advice year is 32.6%. Third, the SSB in the advice year is forecast to be above MSY Btrigger, leading to a fishing advice in 2024 at FMSY rather than below FMSY (as was the situation in 2023).

 

Issues relevant for the advice

On the fishing opportunities

Signs of strong incoming recruitment

It is estimated that the recruitment for the stock was low over the period 2015– 2021. In contrast, the 2022 recruitment (2021-year class) is substantially higher, following IBTS-Q1 and IBTS-Q3 survey results. The newly built time-series on sampling late herring larvae in April suggests a strong contribution of the later spawned component in the southern North Sea (including the Downs component) to the overall recruitment.

SSB increase. An overall increase of stock level is estimated for 2022. It is expected that the strong 2022 recruitment (2021-year class) will contribute positively to SSB levels from 2024 onwards (32.6%).

Several spawning components of herring where protection measures should be continued. North Sea autumn spawners (NSAS) have several spawning components, including the Downs herring that spawns in divisions 4.c and 7.d. These components are fished on individual spawning grounds and in a mixed-component fishery in the central and northern North Sea. To help protect the Downs component, sub-TACs have been set for divisions 4.c and 7.d. A long-term management plan should be developed to ensure the maximum productivity of the stock and protect all components.

Fleet definition as used in the advice. When addressing NSAS catch options, catch by the A-, B-, C-, and D-fleets in Subarea 4 and divisions 3.a and 7.d have to be considered all at once. The input catch data are disaggregated in these different fleets based on assumptions that deviate from the definition of those fleets for management purposes (based on TAC settings). In the context of this advice, the fleets are currently described as follows:

Fleet A:  Directed fishery for herring for human consumption in the North Sea and Division 7.d but includes herring bycatches in the Norwegian industrial fishery. The catch of herring is almost exclusively NSAS herring, with some catches of WBSS herring in the eastern part of Subarea 4.

Fleet B: Bycatch industrial fleet of EU nations targeting sprat, Norway pout, and sandeel, operating in the North Sea. The catch of herring is assumed to be exclusively NSAS herring.

Fleet C:  Directed fishery for herring for human consumption in Kattegat and Skagerrak (Division 3.a). This fleet also includes catches from the Swedish D-fleet until 2021.  The catch of herring consists of a mixture of NSAS and WBSS herring.

Fleet D: Bycatch of herring in Kattegat and Skagerrak (Division 3.a) in the Danish and, from 2022, the Swedish small-meshed industrial fleet for sprat, Norway pout, and sandeel. The catch of herring consists of a mixture of NSAS and WBSS herring.

Interarea flexibility. Interarea transfers from Division 3.a to the North Sea have resulted in an increase in catches of NSAS and a decline in catches of WBSS. The transfer for 2023 is not yet known. The implications of the transfer may not be fullyaccounted for in the headline ICES MSY advice for 2024.

Catches of WBSS herring in eastern parts of 4a and 4b requires new management measures. ICES advises zero catches for WBSS herring. The catches of WBSS in the North Sea in recent years have been substantial (estimated at 5,236 tonnes based on the average over the 2020–2022 period). The catches of WBSS in 2023 are expected to continue to be larger in the North Sea than in subdivisions 20–24. Without additional area and seasonal restrictions on the herring fishery in the North Sea in 2024, catches of WBSS in the North Sea will be unavoidable, delaying the recovery of the WBSS stock.

On the conservation aspects

No activities that have a negative impact on spawning habitats should be allowed. Activities that might have a negative impact on the spawning habitat of herring (e.g. extraction of gravel, building of wind farms) should not occur unless the effects of these activities have been assessed and shown to be non-detrimental. Gravel substratum is an essential habitat for herring spawning in autumn.

At present, ICES is not fully able to quantify the level and relative impact of cumulative non-fisheries anthropogenic factors on the reproductive capacity of the stock. ICES is aware that there are non-fisheries anthropogenic impacts (e.g. spawning habitat degradation) that may decrease the early life-stage survival of herring.

Follow The Fishing Daily