engleski

Biocenotical structure of benthic communities in the Ponikve accumulation (the island Krk)

During 1994 and 1995, seasonal and areal changes in biocenotical structure of benthic community in the accumulation Ponikve was investigated. The goal of research was to found out the level of trophy and the accumulation water quality. The water of the Ponikve reservoir is usable water for the inhabitants on the island Krk. Samples were taken by Peterson sampler. Microscopic analyses were done and benthic communities were identified to species level. Relative frequency of species and relative purity and loading was determined. Indicator species values, and index and degrees of a sample saprobity were done. Measured physical and chemical parameters in the accumulation do not indicate significant differences between investigated sites. Total number of 132 species were found (73 lower plants and 59 animal species). Bacillariophyceae were dominant in phytobenthic community, Ciliata in microzoobenthic, while among the macrozoobentic community Oligochaeta and Gastropoda were dominant. Maximal values of relative abundance in benthic community were mesaured in spring. Significant decrease of abundance was measured in summer and winter. Index of saprobity was from 1.6 to 2.1. According to hydrobiological and biocenotical investigation of benthic community, the Ponikve accumulation has mesotrophyc characteristics with tendency to eutrophycation, specially during the low water and higher water temperature.

microbenthos; macrobenthos; accumulation

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