engleski

Distribution, abundance, and condition of the European Eel from several rivers of Adriatic basin in Croatia

Distribution, abundance and condition of the European Eel population, Anguilla anguilla have been investigated in the short Croatian karstic rivers, Žrnovnica and Jadro, for four years. The study was conducted at three locations the first year and at two locations the next three years. Annual data from the Cetina River (at three locations), the Lateralni and Main channel of the Vrana Lake (at one location) are also included in this study. The total of 382 specimens was caught by an electric gear. Physical and chemical characteristics of water and biotic variables were performed in order to assess the possible eel distribution, abundance and condition. Principal component analysis (PCA) was used to explain relationship between abiotic and biotic habitat variables and eel length distribution. Length distribution changed in space from dominance of small eels (< 250 mm) closer to the sea, to larger eels in the upper reaches of the river. High conductivity was noted at the Lateralni and Main channel where mostly large specimens inhabit the area. In the Jadro and Žrnovnica, eels inhabit the entire watercourse while in the Cetina only the middle and lower parts are inhabited. Low b values of length weight relationship indicate poor body condition at the most of the investigated sites (b=2.050 – 2.778). Condition factor varies between 0.17-0.35. CPUE (g 100 m-1) of the Jadro and Žrnovnica rivers decline every year but eels are still observed there as well as in the Cetina River and both investigated channels.

Distribution; condition; European Eel; PCA; Croatia

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