Aggressive fish is spreading rapidly in the Baltic Sea – Expressen

It came from the sea in eastern Europe and western Asia.

Now, the round goby from the Black Sea up an aggressive and anti-social behavior, while it spreads quickly along the Gotland coast.

Now it turns out that the new fish threatens established species.

– It will probably have a negative impact on flounder, eelpout and others less, like fish, says Magnus Thorlacius, researchers at Umeå University, to P4 Gotland.

As late as in 1990 discovered the first round goby in the Baltic Sea, which in Polish waters.

Since then, it has multiplied rapidly and in 2010 appeared on the outside Visby, where it is now part of the common stock.

But the specimens of fish that has spread so far the north is now showing a slightly different behavior. A behavior that can be summarized as antisocial.

– When they think it’s getting crowded they go on. They are more risk averse, more active and they stay happy for themselves, rather than in a group. They are anti-social, so to speak, says Magnus Thorlacius to P4 Gotland.

“Required measures within a few years”

He announced in December his thesis on how the fish are now spreading in Baltic Sea.

The rapid proliferation should, in his view be an effect of the new behavior. When it becomes more round gobies in one place, they move on, everything to be by themselves.

Marcus Thorlacius says it only will take 3-5 years before it starts to spread in large quantities . If you want to prevent the further proliferation measures must be taken within a few years, writes P4 Gotland.

For the spread in question affects the other fish stocks in the Baltic Sea.

outcompete other fish

While larger fish serve to round goby is spreading further, because there will be more food for them, the risk smaller fish to disappear altogether.

According P4 Gotland is an aggressive fish you are dealing with, and it lives in the same place and eat the same food as several other fish.

– It will probably have a negative impact on flounder, eelpout and others less, like fish. But by fishing them intensively in the beginning you could slow down the spread, says Magnus Thorlacius.