so much to sea

Mackerel & Herring

Shetland's location at the centre of the North Sea and Atlantic Ocean's rich pelagic fishing grounds makes it the ideal port of call for boats keen to land their catch as quickly as possible at the peak of freshness.

Shetland Catch, a state-of-the-art pelagic factory, has excellent landing facilities and rapid processing, and supplies the finest herring and mackerel to markets across the UK, Europe, Russia, Japan, and Africa.

Herring and mackerel fillets are sold to the UK's supermarkets and smokehouses. And in Shetland, the plentiful supply has led to the production of delicious, added-value delicacies such as kippers, smoked mackerel, mackerel pates, marinated herring, and award-winning canned products.

Pelagic fish are the athletes of the sea. They live near the surface and are migratory fish, swimming together in shoals. The main species caught by the Shetland fleet follow a migratory path and include: MACKEREL and HERRING.


  • Pelagic fish – caught inshore on lines in the summer months and  seasonally caught by the pelagic fleet from October - November and January - February
  • A beautiful fish, with stunning green black tiger stripes
  • Designed for speed and distance, they follow an annual migratory path in search for food
  • Require a constant flow of water across the gills which means they have to swim constantly
  • No swim bladder, which means they can change depth quickly
  • In winter months they almost stop feeding

Did you know? Female mackerel produce 200,000 to 450,000 eggs which are 0.9 to 1.4mm in diameter.


  • Pelagic fish – caught using purse, trawl or drift nets in Shetland waters.
  • Spawn in the late summer
  • Migratory fish that moves in huge schools or shoals
  • Can live for up to 16 years
  • Very rich in oils, especially Vitamin D

Did you know? Herring means ‘army’ in Old Norse – which would go some way to explaining the way that these fish are constantly on the move


  • Highly efficient pelagic trawlers locate shoals using sonar and echo sounders
  • Some vessels use automatic jigging lines to obtain a guide to fish size, before shooting
  • Trawl net is shot away and towed
  • Sophisticated sensors determine approximately how much fish is in the net
  • Fish are pumped onboard via a pipe which is inserted into the net. During this operation, samples are taken by the crew to determine the fish size, so that the electronic sales process can begin
  • Fish are stored in large tanks in the hold and chilled using refrigerated seawater
  • The fish are landed by pump onto the processing factory (in Shetland, landings are made to Shetland Catch in Lerwick)
  • At the processor, the fish are graded and either left whole or filleted, frozen, packed and shipped to customer specifications.