Introduced to the Black Sea from the Far East several years ago, the Korean perch has successfully adapted and has already spread to the Sea of Marmara and possibly the Mediterranean Sea, scientists warn.
Its appearance could seriously change the ecosystems of these waters, including leading to a decrease in the number of local species, ichthyologists say.
The Korean perch was first registered in the Black Sea in 2013. According to previous observations, the species did not reach large numbers and did not pose a threat to local ecosystems. However, scientists have recently conducted a new study that gives different results.
It is believed that this fish could pose a threat to the local ichthyofauna, as it spreads rapidly, competes with local inhabitants for food and consumes coastal species. This could significantly affect the structure of the ecosystem - affecting both fish and benthos. The ratio of different species and taxonomic groups is likely to change soon, as well as the relationships between species. Biodiversity usually decreases with each invasion, scientists note.
It is believed that the young perch most likely arrived in the Black Sea on ships carrying oysters from the Far East for local farms - something that has already happened. Given the favorable conditions created for the mollusks during transportation, they could help the perch survive.
According to the samples collected in the Black Sea, the perch grows faster than in the Far East, and the average size of the fish is larger, their numbers are increasing and they generally feel comfortable here.
Although the salinity of the Black Sea is lower than in the Far East, and should be on the edge of the optimum for them, some adaptations have apparently occurred, which remains to be studied.
The range of the perch is also expanding. It continues to spread - it was already registered in the Sea of Marmara a few months ago. It has probably already spread to the Mediterranean Sea, where it would not be difficult to penetrate. it would be easy for it to penetrate there from the Sea of Marmara. In addition, the salinity there is higher and more suitable for it.