MACROINVERTEBRATES COMPOSITION IN THE BLIZNEC STREAM, SECOND AND THIRD MAKSIMIR LAKE

Abstract

Dvogodišnjim istraživanjem u proljetnom razdoblju praćen je kvalitativni i kvantitativni sastav makroskopskih beskralježnjaka u Drugom i Trećem maksimirskom jezeru te u potoku Bliznecu. U godini 2002. i 2003. Gastropoda po brojnosti i biomasi prevladavaju na svim trima lokacijama. U Drugom maksimirskom jezeru povremeno se jače razvijaju Gastropoda, Bivalvia, Diptera i Crustacea. U Trećem maksimirskom jezeru dominantni su Gastropoda (od 1,484 do 2,506 g m–2) dok su Crustacea, Oligochaeta i Hirudinea prisutni u značajnoj biomasi. Potok Bliznec kvantitativno je najbogatiji vrstama, pri čemu prevladava Gastropoda (od 0,568 do 3,026 g m–2), a jači je razvoj prisutan i kod Trichoptera, Crustacea, Diptera, Heteroptera i Bivalvia (Tablice 2 i 3). Biološkom metodom bodovanja utvrđeno je da se kvaliteta vode potoka Blizneca kreće u rasponu od onečišćenih do vrlo onečišćenih voda.Qualitative and quantitative macroinvertebrates in spring period was investigated during two years in the first and second Maksimir Lake and Bliznec stream. The domination of Gastropoda was outstanding at these three investigated sites. From time to time stronger development of Gastropoda, Bivalvia, Diptera and Crustacea was noted at the second Maksimir Lake. Gastropoda was dominant at the third Maksimir Lake (from 1.484 to 2.506 g m–2) while Crustacea, Oligochaeta and Hirudinea made important biomass. Species density in the Bliznec stream was quantitative higher than the one at other stations. The dominant group was Gastropoda (from 0.568 to 3.026 g m–2) and there was higher development of Trichoptera, Crustacea, Diptera, Heteroptera and Bivalvia (Table 3 and 4). Bliznec stream water quality, observed by biological method given by Kerovec, ranged from polluted to highly polluted