Sunfish: An alien species that has proliferated uncontrollably in Macedonian lakes

An increase in the number of sunfish (Lepomis gibbous), foreign species Coming from North America, it has been recorded in western and central lakes in recent years Macedonia.

Four out of ten fish in some of his ponds Florina It is the sunfish, which recent studies have shown is of concern for the future of the endemic species.

According to ichthyologist Thanasis Varveris, the imported species were first discovered in 1994 in Lake Kerkini, Lake Volvi and the artificial Lake Aoos. A little later it was found in Lake Kastoria, the artificial lake Polyphytos, two lakes of Prespa, Vegoritida and the smaller lakes Zazari, Heimatida and Petron.

As Mr Varveris explained to APE-MBE, the sunfish “competes with endemic species of lakes by consuming their eggs during the breeding season”.

From the fish fauna of the lakes, there are no predators that can threaten it, except for the gulian, which lives in the deeper parts of the lakes, and the sunfish lives on the surface.

“Many lakes and rivers in Europe face similar problems – and perhaps to a greater extent,” Mr Varveris said.

“Specific species adapt and survive even in alpine-type lakes where conditions are not favorable,” he added. How does he manage? It has a smaller growth size of 12 to 18 cm instead of 30 cm, but also has a shorter life cycle of two years than the usual six years.

Running away

But how did this fish reach Greek waters? Mr. Varveris says it spreads in two ways: from the enrichment of lakes, where sunfish are among the endemic species, and from the transfer of nets from lake to lake, where some sunfish eggs succeed and survive.

How to deal with its rapid population growth? Mr. Varveris notes that “the only solution is for it to be caught by fishermen and incorporated into the lake fish food value chain.”

According to the projected models, climate change along with the increase in lake water temperature is expected to create conditions that will lead to a significant expansion of the species’ presence zones by 2050 and at the same time an increase in its life cycle by 2050. two in six years.

In the context of the consultation on the “National List of Invasive Alien Species (Invasive Species)” of the Additional Western Chamber of Geotechnical Macedonia, KYA, in a letter to the Directorate of Natural Environment and Biodiversity Management of the Ministry of Environment and Energy, referring to the data of the study, “moderate” risk to the list of inland water fish It is requested to include specific species by indicating the category.

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