FISHERY MANAGEMENT IN THE DANUBE CATCHMENT AREA

Ribolovno gospodarenje Dunavom različito je u njegova tri područja. U gornjem toku prevladavaju problemi športskog ribolova i ekoloških rekonstrukcija, u srednjem im se toku u nekoj mjeri pridružuje i problematika komercijalnog ribolova, čija važnost dolazi do izražaja u donjem toku. Ove razlike nisu toliko posljedica veličine korita koliko ekonomske razvijenosti pojedinih država, njihova ribarskog zakonodavstva, te načina njegove provedbe. Mnoštvo pregrada u gornjem toku Dunava (29 u Njemačkoj, 9 u Austriji) bitno utječe na ihtiocenoze, a radikalan je primjer brana Gabčikovo na slovačko-mađarskoj granici, koja je ulov riba smanjila na četvrtinu. U donjem toku Dunava ulov je spao na trećinu, a i sastav je vrsta radikalno promijenjen u negativnom smjeru, s drastičnim padom udjela jesetrovki, štuka i linjaka. Uzrocima se smatraju gradnja brana, povećana koncentracija nutrijenata i teških kovina, krivolov i prelov. Nužne su bitne promjene u regulaciji komercijalnog ribolova. U srednjem toku, kamo pripada Hrvatska, također se uočava tendencija pada udjela bentofanih i fitofilnih vrsta riba. U tom je području zakonski predviđena koegzistencija športskog i komercijalnog ribolova, no prednost treba dati športskom ribolovu, a komercijalnom se, pod strogim nadzorom, može dopustiti izlov eventualno utvrđenog viška prirodnog prirasta. S obzirom na riblje migracije i političke granice u Podunavlju, radi uspješnog ribarskog gospodarenja, nužno je uspostaviti suradnju i koordinaciju sa susjednim državama.There are three successive regions of the Danube, each of which has to deal with its own problems in fisheries. Sport fishing and ecological recontruction problem matters predominate in the upper flow. These problems also characterize the middle flow, where to a certain extent, commercial fishery is coming into view, while the lower flow has to deal with commercial fishery problems to full extent. The difference is not so much due to the morphometry as to the development and state of the economy of the countries in the river basin, their legislation on fishery and the manner in which the legislation is applied. Numerous dams of the upper flow of the Danube (29 in Germany, 9 in Austria), influence significantly the ichthyocenoses. An extreme example of that is Gabčikovo dam at the Slovak-Hungarian border where fish catch decreased to one fourth. In the lower segment of the Danube fish catch falls down to one third and is followed, by a drastically negative change of fish species composition. The records show that highly valued species as sturgeons, pike and tench are in drastic decline over the last few years. The changes were caused by physical barriers, like dams and weirs, by water pollution, by increasing concentration of nutrients and heavy metals, by poaching and by overexploitation. For all those alarming reasons, some legal interventions in commercial fishery must be undertaken. In the middle flow, where the Danube flows through Croatian territory, there have also been declining trends of bentivore and phytophyl species respectively. The law supports the coexistence of sport and commercial fishery in this area and although sport fishing should be given the advantage, commercial fishing should be rigorously supervised and allowed only when there is a naturally produced surplus. Because of fish migrations and political frontiers of Danube area, it is essential that the neighboring countries coordinate their efforts in managing fisheries successfully