One of the unfortunate side effects of the commercial fishing is by-catch of bird and mammal species. Alternative fishing gears can be used to reduce this danger to birds and seals. What kind of fishing gears could it be? And are they any better than traditional fishing gears?
Long-lines look just like its name implies. It’s a long line with many hooks. This gear sinks to the bottom where the target fish (cod usually) are dwelling. These species are usually caught with big-mesh sized gill nets. But big-mesh sized gill nets are especially dangerous to the diving birds due to entanglement, whereas practically no by-catch of birds is possible with long-lines. Although seals sometimes take fishes from the lines together with hooks, the cost of repair is way less expensive than repairing or even replacing gill nets after seals visit. The long-lines are easy to set and their efficiency while catching cod is similar to the gill nets.
Fishermen usually use small-mesh sized nets while catching herring and smelt. Even if small-mesh sized nets are not that dangerous, the big number of these gears in use still mean remarkable cumulative bird mortality. Fishing with herring trap-nets gives less or no mammal or bird by-catch, since the trap-nets are partly open above. These alternative trap-nets can provide large quantity of fish, far more than using gill nets. However, trap-nets are bigger making them expensive and quite hard to take out of the water, therefore there is a permanent danger of storms which may completely destroy the expensive gears. Operating of herring traps is tricky business if the users are not experienced.
Since herring trap net is targeting almost all fish, it is not selective gear. So, by-catch of fish bellow commercial size limit can be rather big. Still, it is not a big problem, because catch remains alive in the trap-net and can be released. Beside herring, the gear catches other commercial fish species rather effectively, so it could be used for almost all year round. Seals might attack gears seeking fish, but the damage made to the trap-net usually is smaller than made to the gill nets.
In traditional fykes, seals can easily swim into the fish bag and damage the catch from inside, or tear holes in the fish bag from outside damaging the fishing gear and releasing all the catch. "Seal-safe” fyke nets (catching many different fish species) are different from traditional fyke because they can tolerate the attacks of seals in search of food and prevent them from entering.
How are seal-safe fyke nets made? The traditional rather weak construction material in fish containing part of the fyke (“fish bag”) is changed with very strong seal-safe netting (“Dyneema”). Strong grid (steel or strong netting) is placed in the mouth of the gear (“funnel”). This saves seals, because often seals cannot find their way back from gear and drown. Since seal-safe fyke nets can sustain the seal attacks, fishermen have their catches untouched. At the same time fishing with traditional old fykes is in many areas already almost impossible due to the increased number of grey seals.
So the economic performance of the new seal-safe fykes is much better.
Which fishing gears would you choose – traditional or alternative?
Alternative fishing gears
Project's main site -
Seal-safe fyke nets (Photo: Markus Vetemaa)
New net material versus old that got overgrown - both were thrown in the sea at the same time (Photo: Markus Vetemaa)