The round goby is a newcomer to Finland and the whole of the Baltic Sea, but nowadays it spreads in large numbers. The first sighting of the round goby in the Baltic Sea was made in 1990 in Gdansk Bay in Poland, and it may have found its way there in the ballast water on ocean liners. The round goby originates from the Caspian Sea and Black Sea area. In 2005, this fish was found for the first time in Finnish waters. On that occasion, one individual grabbed an ice fisherman’s hook in the Finnish archipelago. We had to wait four years for the next sightings of this invasive species, but then in May 2009 several individuals were caught in Helsinki.
The round goby is a demersal fish that can grow up to 15-25 cm in length. Even though the round goby tastes good, the spread of it is not regarded as a good thing. This is because it is an efficient conqueror of areas and it competes successfully with flatfish, amongst others, for molluscs and benthos.