Biological overview
Appearance & anatomy: Pollack (aka lyr) is a streamlined gadid with a dark green-brown back, paler flanks, a clearly pale lateral line arched over the pectoral fin, and a slightly protruding lower jaw. [1]
Size & lifespan: Commonly 40–80 cm in inshore catches; large adults can exceed 1 m. Longevity varies by area but individuals routinely reach 10+ years in northern waters. [2]
Habitat & distribution: A cool-temperate shelf and slope species distributed from the Barents and Norwegian seas, through the North Sea and Skagerrak, to the Celtic Seas and Bay of Biscay. Juveniles use coastal habitats (rocky reefs, kelp beds, bays); older fish range widely over banks, shelf edges and slope, from nearshore to a few hundred meters depths. [2]
Feeding & diet: Juveniles take zooplankton and small crustaceans; sub-adults/adults switch to forage fishes (e.g., herring, sandeel, sprat) and larger invertebrates, often hunting mid-water in schools. [2]
Reproduction & early life stage: Spawning late winter–spring over banks and shelf edges; eggs/larvae are pelagic before juveniles recruit to coastal nursery grounds. [1]
Juvenile vs. adult — the coastal-offshore shift
- Similar to saithe, pollack shows a pronounced ontogenetic habitat shift: 0+ to ~2-yr fish aggregate in coastal fjords/kelp beds (dense schools, mid-water feeding), while sub-adults/adults use banks and shelf-edge habitats and migrate between feeding and spawning grounds. [2] This underlies the common pattern of smaller fish inshore and larger fish deeper/offshore in Norwegian waters.
Fishery
In the North Sea, Skagerrak & Kattegat, pollack is not targeted; it is taken solely as bycatch in demersal fleets. In 2020 the catch mix was ~69% otter trawl, 21% gillnet, 5% seine, 2% longline, 3% other (ICES estimate). Recreational catches occur and may be substantial, but cannot be quantified for this area. [3]
Stock status & management
- Management: The EU North Sea multi-annual plan (MAP) applies to bycatches of this stock; when FMSY ranges aren’t available, fishing opportunities follow “best available scientific advice,” i.e., the ICES precautionary approach for category-5 stocks (data-limited stocks where no analytical assessment is possible).
- Stock assessment: A complete stock assessment for this stock is not performed. Scientific advice is prepared by ICES-WGNSSK (North Sea & Skagerrak demersal working group) based on commercial landings and discards for Subarea 4 & Division 3.a. [3]
- Last advice (2021) : Applying the precautionary approach, ICES advises catches in 2022–2024 should be no more than 1,828 t. (This is based on the 2018–2020 average catch reduced by a precautionary buffer, with discards estimated at ~0.49%.). [3]
Fishing tips
- Same spots, same styles: Fishing for pollack is much like fishing for saithe.
- Expect big fish on topwater: when you’re fishing on medium-size saithe busting bait at the surface, it is not uncommon for larger pollack to crash topwater baits right in the mix.