{"id":9426,"date":"2023-06-09T11:01:49","date_gmt":"2023-06-09T09:01:49","guid":{"rendered":"https:\/\/www.npkrka.hr\/?p=9426"},"modified":"2025-12-02T13:01:30","modified_gmt":"2025-12-02T12:01:30","slug":"utvrdivanje-stanja-invazivnih-vrsta-riba-na-sirem-podrucju-nacionalnog-parka-krka","status":"publish","type":"post","link":"https:\/\/npkrka.hr\/hr\/2023\/06\/09\/utvrdivanje-stanja-invazivnih-vrsta-riba-na-sirem-podrucju-nacionalnog-parka-krka\/","title":{"rendered":"Utvr\u0111ivanje stanja invazivnih vrsta riba na \u0161irem podru\u010dju Nacionalnog parka \u201eKrka\u201c"},"content":{"rendered":"

[hr]U 2022. i 2023. godini nastavljeno je istra\u017eivanje ihtiofaune rijeke Krke, s naglaskom na utvr\u0111ivanju stanja invazivnih vrsta riba na \u0161irem podru\u010dju Nacionalnog parka \u201eKrka\u201c<\/strong><\/p>\n

Invazivne vrste riba sve su ve\u0107i problem u vodotocima diljem svijeta. Zato su smanjenje utjecaja invazivnih vrsta sprje\u010davanjem njihova \u0161irenja i njihovo uklanjanje gdje god je to mogu\u0107e prioriteti za\u0161tite biolo\u0161ke raznolikosti u Europskoj uniji, pa tako i u Republici Hrvatskoj. Projektom kojemu je cilj borba protiv invazivnih vrsta utvr\u0111ene su smjernice, odnosno prijedlog mjera za smanjivanje brojnosti invazivnih vrsta i preporuke za njihovu provedbu.<\/p>\n

Radi utvr\u0111ivanja stanja invazivnih vrsta riba na podru\u010dju NP \u201eKrka\u201c provedeno je istra\u017eivanje alohtone (strane) invazivne i unesene slatkovodne ihtiofaune u rijeci Krki i njezinim pritocima.<\/p>\n

U 2022. i 2023. godini provedeno je pet terenskih istra\u017eivanja, u ukupnom trajanju od deset dana, u kojima je obavljeno uzorkovanje ihtiofaune. U istra\u017eivanju ihtiofaune primijenjeni su standardni postupak elektroribolova s obale ili iz \u010damca (aktivna metoda) i uzorkovanje u jezerima s pomo\u0107u standardiziranih jednostrukih najlonskih mre\u017ea \u201enordijskog\u201c tipa (pasivna metoda). Kao dopunska metoda kori\u0161tena je metoda postavljanja vr\u0161a. U istra\u017eivanju je zabilje\u017eeno dvadeset vrsta riba, s 10 546 jedinki raspore\u0111enih u \u0161esnaest porodica. U ukupnom uzorku najbrojnije su bile porodice Leuciscidae i Cyprinidae, svaka zastupljena trima vrstama, dok su ostale porodice bile zastupljene s po jednom vrstom. Od ukupnog broja zabilje\u017eenih vrsta, \u0161est je bilo alohtono: crni somi\u0107, babu\u0161ka, gambuzija, sun\u010danica, bezribica i bijeli amur. Deset vrsta riba pripadalo je zavi\u010dajnim (autohtonim ili doma\u0107im) vrstama: drlja, bijeli klen, rije\u010dna babica, zrmanjski klen, mrena, jegulja, visova\u010dki glavo\u010di\u0107, kolju\u0161ka, primorska pastrva i cipal. Ostale vrste (\u0161aran, \u0161tuka, linjak i grge\u010d) unesene su iz Dunavskog sliva.<\/p>\n

Od zabilje\u017eenih vrsta, najbrojnija je bila gambuzija (3 749 jedinke, 35,5 %), pa bezribica (2 728 jedinke, 25,8 %) i sun\u010danica (2 023 jedinke, 19,1 %), potom drlja (1 223 jedinke, 11,6 %). Te \u010detiri vrste \u010dine 92,1 % ukupne brojnosti jedinki, dok su ostale vrste zastupljene s manje od 2 %. Od svih lokacija na kojima je obavljeno uzorkovanje, daleko najve\u0107i broj ulovljenih jedinki alohtonih (stranih) i unesenih vrsta zabilje\u017een je u Carigradskoj dragi \u2013 pro\u0161irenju rijeke Krke kod manastira Krka, gdje je ulovljeno 7 660 stranih i 48 unesenih jedinki, potom na lokaciji \u201eKrka ispod Ro\u0161kog slapa\u201c, gdje je ulovljeno 1 295 stranih i 54 unesenih jedinki. Uzev\u0161i u obzir ukupan broj jedinki zabilje\u017eenih tijekom istra\u017eivanja u rijeci Krki i njenim pritocima, alohtone (strane) vrste bile su daleko najbrojnije, zabilje\u017eeno je 8 705 jedinki, dok su autohtone brojile 1 573, a unesene 268 jedinki.<\/p>\n

Invazivne vrste jedna su od najve\u0107ih prijetnji nativnoj zajednici riba u sustavu rijeke Krke. Danas su u Krki prisutne, uz autohtone vrste, i unesene vrste riba, od kojih su neke stvorile stabilne i vrlo guste populacije, tako da na nekim mjestima dominiraju u ihtiocenozi, ugro\u017eavaju\u0107i pritom populacije nativnih vrsta. Najgu\u0161\u0107e su populacije sun\u010danice, \u0161tuke, grge\u010da i crnog somi\u0107a. Sun\u010danica, crni somi\u0107 i gambuzija nalaze se na popisu invazivnih stranih vrsta<\/a> koje izazivaju zabrinutost u Europskoj uniji, a\u017euriranom 2022. Njihov je utjecaj na autohtonu ihtiofaunu vi\u0161estruk. Odrasle jedinke pojedinih stranih vrsta, posebice \u0161tuke i grge\u010da, hrane se prije svega mla\u0111im autohtonim vrstama, smanjuju\u0107i tako njihovu reproduktivnu uspje\u0161nost. K tomu, strane vrste uzrokuju kompeticiju za hranu i pogodna stani\u0161ta, a mijenjaju i stani\u0161ne uvjete. U tom je pogledu osobito opasna \u0161tuka zbog velike gusto\u0107e njezinih populacija.[\/hr]<\/p>\n

[en]
\nDetermining the status of invasive fish species in the Krka National Park area<\/strong>
\nIn 2022 and 2023, research of the ichthyofauna of the Krka River continued, with an emphasis on establishing the status of invasive fish species in Krka National Park<\/strong><\/p>\n

Invasive fish species are an increasing problem in watercourses around the world. The impacts of these invasive species can be reduced by preventing their spread and removing individuals wherever possible, and this is a priority in biodiversity conservation in the European Union, including the Republic of Croatia. This most recent project aimed at combatting invasive species has established guidelines and proposed measures to reduce the abundance of invasive species, with recommendations for implementing these measures.<\/p>\n

In order to establish the status of invasive fish species in the area of Krka National Park, research was conducted on the allochthonous (alien) invasive and introduced freshwater ichthyofauna in the Krka River and its tributaries.<\/p>\n

In 2022 and 2023, five field surveys over a total of 10 days were conducted to sample the ichthyofauna. Standard collection methods were used to research the fish fauna, including electrofishing from shore or boat (active method) and sampling in the lake-like sections of the river using standardised single Nordic type fish nets (passive method). Fish traps were also set as an additional method. In the research, 20 fish species were sampled, with a total of 10,546 individuals belonging to 16 families. The most common families were the Leuciscidae and Cyprinidae, each represented by three species, while all other families were represented by a single species. Of the total 20 species recorded, six were alien: black bullhead, Prussian carp, eastern mosquitofish, pumpkinseed, topmouth gudgeon, and grass carp. Ten species are considered native fauna (autochthonous): Dalmatian rudd, Italian chub, freshwater blenny, Zrmanja chub, barbel, eel, Visovac goby, threespine stickleback, Adriatic trout, and flathead mullet. The remaining species (carp, pike, tench and perch) have been translocated from the Danube Basin.<\/p>\n

Of the recorded species, the most abundant was the eastern mosquitofish (3749 individuals, 35.5%) followed by the topmouth gudgeon (2728 individuals, 25.8%), pumpkinseed (2023 individuals, 19.1%) and Dalmatian rudd (1223 individuals, 11.6%). These four species together accounted for 92.1% of all fish individuals caught, while other species together accounted for less than 2% of the total sample. Of all locations where sampling was performed, the highest number of alien and translocated species by far was recorded at Carigradska Draga \u2013 the lake-like expansion of the Krka River near the Krka Monastery, where 7660 alien and 48 translocated individuals were caught, followed by the location \u201cKrka under Ro\u0161ki Slap\u201d, where 1295 alien and 54 translocated individuals were caught. Taking into account the total number of individuals recorded during the research in the Krka River and its tributaries, the alien species were far more abundant, with 8705 individuals caught, compared to 1573 native individuals and 268 translocated individuals.<\/p>\n

Invasive species are one of the greatest threats to the native fish community in the Krka River system. Today, both alien and introduced fish species are present in the Krka, and some have established stable and very dense populations where they dominate the fish community, in turn endangering the populations of native species. The densest populations are those of the pumpkinseed, pike, perch and black bullhead. Pumpkinseed, black bullhead and eastern mosquitofish are all included on the list<\/a> of invasive alien species of concern in the European Union, which was updated in 2022. Their impact on the native fish fauna is many-fold. Adult individuals of these alien species, especially pike and perch, feed on young individuals of the native species, thereby reducing their reproductive success. Further, alien species create competition for food resources and suitable shelter, while also changing the habitat conditions. In that sense, the pike is a particularly grave threat due to the high density of its population.<\/p>\n

 <\/p>\n

 <\/p>\n

 
\n[\/en]<\/p>\n","protected":false},"excerpt":{"rendered":"

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