North Sea Greater Silver Smelt Fisheries Management Plan

Background

Stock

Whilst this FMP covers the fishery in UK waters of ICES areas 4 and 2.a. ICES assesses greater silver smelt in areas 1, 2, 4 and 3.a. The stock unit was originally defined based on historical and present fishing patterns.

In the Norwegian Sea and North Sea-Skagerrak the distribution is continuous from the Skagerrak along the Norwegian Deep northwards along the Norwegian shelf to the entrance to the Barents Sea. Documented spawning areas are deep shelf troughs and upper slope waters off of mid-Norway and deeper parts of the Skagerrak, but it is likely that the species also spawns in deep Norwegian fjords. Studies of population genetics have not been conducted in the relevant areas.

GSS in UK waters of area 4 are at the southern end of the biological range and are only generally caught as bycatch. The principal targeted fishery is in Norwegian waters of area 2, further to the north.

GSS can reach a maximum length of around 60-70 cm, and form dense, demersal-associated schools, with distributions stretching from the Skagerrak to the Barents Sea. Adults generally reside deeper (>300m) than juveniles.

GSS is a deep-water schooling species that is caught by semi-pelagic and demersal fishing vessels. It is therefore more accurately described as a semi-pelagic, benthopelagic or bathypelagic species.

The species is an opportunistic predator that feeds largely on zooplankton and small marine species. Its diet commonly includes copepods, euphausiids, amphipods, mysid shrimps and small fish. Juveniles largely consume smaller planktonic organisms, while larger adults predate on larger crustaceans and other marine fish. Feeding behaviour may vary with depth, season and prey availability. (Bergstad, 1993; ICES 2024^[5]).

Within the marine food web, GSS are considered to occupy the mid-level as by feeding on planktonic crustaceans and small fish species this links the lower trophic levels to larger predators. Importantly North Sea GSS act as prey for commercially and ecologically important species, including larger fish (cod, saithe and ling) and marine mammals. Therefore, the intermediate position that GSS inhabits in the marine foodweb makes it an important link in the movement of energy through deep-sea ecosystems. (Bergstad, 1993; ICES 2024)

The stock is currently assessed as being fished within safe biological limits. The 2026 ICES advice^[6] indicated that fishing pressure on the stock is below F_MSY, and the stock size is above MSY B_trigger.

Location

This stock is found in ICES subareas 1, 2, and 4, and Division 3.a (Northeast Arctic, North Sea, Skagerrak and Kattegat). This FMP only applies to the UK waters of Subarea 4 (North Sea) and Division 2.a.

Fishery

The principal targeted GSS fishery is in Norwegian waters of Division 2.a where the species is caught as part of an industrial targeted fishery by EU vessels. In the North Sea (ICES Division 3.a and Subarea 4) GSS is primarily caught as bycatch in other fisheries. Trawl fisheries for other species along the Norwegian Deep in Division 4.a (northern North Sea) result in variable but sometimes significant landed bycatch of GSS.

GSS in UK waters of area 4 are at the southern end of the biological range and are only generally caught as bycatch.

Historically there was a targeted pelagic fishery for North Sea GSS in UK waters of ICES areas 4 and 2.a, however this hasn’t existed for a number of years.

There have been no substantial recorded catches of North Sea GSS by the UK fleet since 2015. The only recorded catch was 376 kg in 2022. This suggests that the stock is of minimal importance to the UK fleet . There are occasional bycatches from the UK’s demersal over 24 metres fleet, though these are small in number.