Catch control

In purse seine fishing it is difficult to assess the catch before it is crowded on side of the fishing vessel. Releasing fish after crowding has received increased focus in recent years, as research has shown that crowded fish that are released have a low survival rate.

Therefore it is vital for fisheries management and for the sustainability of the industry to have tools available that allow early assessment of the catch. As long as it is unknown how much fish is released it is difficult to determine the impact of purse seine fishing and thus determine how much fish should be caught each year.

Researchers at IMR have now solved this challenge. They have invented a cannon sampler that makes it possible to assess the fish in the seine before the fish is crowded. The sampler, which is developed in close cooperation with Norwegian seine fishermen, can give a representative sample of the school of fish, hereby revealing the fish size, species and quality. This can contribute to less dead fish being dumped. It also increases the profitability of seine fishing, as there are great price differences between smaller and larger fish.

The project has international potential, as the world’s purse seine fleet is large. Purse seiners catch 30 million tons of fish every year. There are also strict rules against releasing fish abroad. In Peru, the world’s largest seine fishery, it is illegal to release fish, and if the catch contains undersized fish it results in high fines and closure of fishing grounds.

This technology has both an economic and an environmental aspect. The latter has been acknowledged by the World Wild Fund for Nature (WWF). Senior Engineer Jostein Saltskår (IMR), Senior Researcher Bjørnar Isaksen (IMR) and senior Researcher Kurt Hansen (SINTEF Fisheries and Aquaculture in Hirtshals) recently won the WWF ”International Smart Gear Competition 2014” for the invention. It is the first time that Norwegians have won the international environmental competition.

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