Macroinvertebrates of inlets and outlets of the Tatra Mountain lakes (Slovakia)

The composition of invertebrates of inlets and outlets of selected West Tatra and High Tatra lakes (Slovakia, 49 degrees 10' N, 20 degrees 00' E) was analyzed. Twenty-seven sampling sites representing 11 inlets and 16 outlets of 19 mountain lakes were investigated. In total, 10,692 aquatic invertebrates from 27 samples were sorted, 7,314 from inlets and 3,378 from outlets. Altogether, 110 zoobenthic taxa (81 in inlets and 85 in outlets) belonging to 12 higher taxonomic groups were identified. The most constant benthic groups found both in inlets and outlets, at more than half of all sites, were Oligochaeta (93% of all sites), Chironomidae (78%), Trichoptera (63%), Plecoptera (59%) and Turbellaria (56%). The most abundant groups were Chironomidae (4,697 ind.), Oligochaeta (2,473 ind.) and Turbellaria (2,236 ind.). No statistically significant differences were found between the benthic communities of inlets and outlets. On the contrary, significant differences (P < 0.05) were found in some parameters of benthic communities of inlets situated in different altitudes (< 1800 m a.s.l., 1800-2000 m a.s.l., > 2000 m a.s.l), outlets of different altitudes, and finally, outlets of lakes with different areas (< 5 ha and > 5 ha). Cluster analysis relatively clearly separated outlets of subalpine lakes from the alpine lakes. Also, outlets of lakes with the lowest pH were separated from the other sites. In the case of inlets, West Tatra sites were separated from the High Tatra sites.