By-catch means that besides targeted fish species unselective commercial fishing gears catch also other species. In short, there are two types of victims in the passive fishing gears (i.e. gill and trap nets) of the fishermen working on the Baltic Sea. These are marine mammals: ringed and grey seals and water birds, first of all diving ducks.
Some birds, e.g. long-tailed ducks, are rather abundant, which might mean that the problem is not that serious. However, some others, like e.g. Steller’s eider are very rare and fully protected. Since the populations of such species are small and unfortunately permanently declining each such by-caught bird is a small tragedy.
Both of the seal-species, grey seal and ringed seal, are protected in most of the Baltic Sea countries. While the grey seal population shows now some signs of growth, the ringed seal is still rare. Moreover, very mild winters have seriously impacted the reproduction possibilities. Ringed seals can give birth only on ice, which has become a scarcity. Additional fishing mortality can be critical.
What is by-catch?
How to cope with the by-catch problem?
Bycaught stellers eider, highly endangered bird species
Bycaught large male grey seal