Diversity of littoral zoobenthos in Lake Arakhley (Transbaikalia) during the arid phase

There is little data available on the zoobenthos of the Baikal region’s eastern periphery water bodies in low-water years. The taxonomic diversity of zoobenthos of the littoral zone of a deep lake (Arakhley, Transbaikalia) was studied in an extremely low-water year, 2017. The zoobenthos of the lake littoral zone was represented by 44 taxa. Chironomids accounted for 41% of the zoobenthos taxonomic diversity, 14% each – gastropods and leeches. The taxonomic diversity of the littoral zoobenthos in different parts of the lake varied from 19 to 24 taxa and averaged 22.3 ± 1.97 taxa. The relationship between taxonomic diversity and depth in Lake Arakhley is described by polynomial dependence. Deviations from the relationship identified at the periphery of vegetation thickets were due to the ecotone effect. Obtained data shows the state of zoobenthos taxonomic diversity under conditions of climate aridization and the reduction of littoral sandy habitats.

Littoral Zoobenthic Biomass in Lakes, and Its Relationship to Physical, Chemical, and Trophic Factors

The hypothesis that littoral morphometry exerts a strong effect on zoobenthic biomass was tested in Lake Memphremagog, Quebec–Vermont, by regression analysis of the relationship between littoral zoobenthic biomass and littoral slope, exposure (Lake area visible from sampling site), and trophic status (micrograms of chlorophyll a per litre). Eighty-one percent of the variance in Log littoral zoobenthic biomass (LZB) could be explained by[Formula: see text]When the predictions from this relationship were compared with littoral zoobenthos estimates from other lakes, residuals were positively correlated with the calcium concentration of the water (r = 0.41) and negatively correlated with the chloride concentration (r = −0.51). The regression equation obtained for all of the sites was[Formula: see text]and explained 80% of the variation in Log LZB. Sites situated within deltas from stream inflows did not differ significantly from these that did not (ANCOVA), indicating that coarse allochthonous input from these fluvial sources was not a major factor determining littoral zoobenthic biomass in these lakes.