Fauna of Free-Living Nematodes (Nematoda) of Sandy Beaches of Lake Baikal Splash Zone in Intense and Moderate Anthropogenic Influence Areas

Abstract

The qualitative and quantitative characteristics of the fauna of free-living nematodes in the splash zone of sandy beaches in two regions of southern Baikal (Listvenichny Bay, opposite Nerpinariy, and Bolshie Koty Bay in the Varnachka area) have been studied. The coastal zone and water area of Listvenichny Bay are under intense anthropogenic impact due to the continuous flow of tourists, as opposed to the beach of Bolshie Koty Bay, located 3 km north of the village and visited by fewer people. It is found that the species composition of nematodes of the first beach is poorer than that of the second one (18 and 29 species, respectively). The number of nematodes during the open-water period in the splash zone of the Varnachka gradually increases from June to October 2015 (11.7 times). During the same period, there is no regular growth in the population of the Nerpinariy station; moreover, in August there is a noticeable drop, with the initial (June) level recovered only by October. An analysis of abiotic factors has not revealed any significant reliable changes that explain such a sharp fall in the number of worms. At the same time, the largest anthropogenic load is in August due to the high and almost continuous flow of tourists in the village of Listvyanka.