Features of the Species and Spatial Structure of Macrobenthos in the Green Cape Lagoon (Kandalaksha Bay, White Sea).

Abstract—Features of the species and spatial structure of sublittoral macrobenthic communities in a lagoon ecosystem of Green Cape (White Sea) have been studied. Thirty-one invertebrate species and three species of sea grasses and algae (Zostera marina, Cladophora sericea, and Fucus vesiculosus) were found in the sublittoral zone of the surveyed lagoon. The data on the species composition, diversity, and spatial structure of macrobenthos communities indicate the predominance of littoral brackish water and marine euryhaline macrobenthos species (Hydrobia ulvae, Tubificoides benedii, Chironomus salinarius, and Macoma balthica) in the coastal region of the lagoon, marine littoral and sublittoral euryhaline species (mainly polychaetes Heteromastus filiformis, Polydora ciliata, and Capitella capitata) in the central deeper region, and marine sublittoral less euryhaline species (Pontoporeia femorata, Anonyx nugans, Nereimyra punctata, Terebellides stroemi, Astarte montagui, Micronephthys minuta, and Atylus carinatus) at the outlet of the lagoon. The ecosystem of the Green Cape lagoon belongs to lagoons heavily separated from the sea with depleted specific fauna (many littoral species) and largely influenced by the carbon load and salinity. The reduced connectivity of the lagoon with the sea due to the continued rise of the White Sea coast (4 mm per year in this area) will contribute to a decrease in the species diversity and the dominance of a few small eurytopic invertebrate species resistant to organic load, oxygen deficiency, and desalination. [ABSTRACT FROM AUTHOR]