TAXONOMIC COMPOSITION AND STRUCTURE OF MACROZOOBENTHOS IN LAKES OF DIFFERENT TYPES IN THE GREEN BELT OF FENNOSCANDIA (THE MURMANSK REGION)

Abstract

A description of macrozoobenthos in different types of water bodies located in the Northwest of the Murmansk Region within the Green Belt of Fennoscandia is presented. Surveys revealed 70 taxa of aquatic invertebrates in the lakes. 89 % of all the identified systematic groups belonged to the type Arthropoda. A majority of insects were chiron-omids (Chironomidae). Most of the identified taxa can be characterized as eurytopic species with high ecological plasticity, which resulted in a high level of similarity between the benthic fauna of the lakes in the background and the impact zones. Among the 70 identified taxonomic groups, 39 taxa were present in both zones. The zoobenthos structure of the littoral and pelagic areas of the studied lakes is similar, but the composition of the dominant groups was highly variable in both the background and the impact zones. Bivalvia (6-32 % of the total biomass), Chironomidae (29-81 %) and Oligochaeta (5-40 %) dominated in pelagic areas. Chironomidae (24-61 %), Trichoptera (18-53 %) and Gastropodae (3-23 %) dominated in the littoral zone on stony substrates. The abundance and biomass of the benthic fauna of the investigated lakes varied widely: 190-1937 ind./m2 and 0.2-9.7 g/m2 in pelagic zones and 968-4982 ind./m2 and 4.8-24.9 g/m2 in the littoral zone.

Keywords

• lakes
• benthic fauna
• taxonomic diversity
• abundance
• biomass
• anthropogenic pollution