Spatio-temporal variability of zooplankton and zoobenthos as the elements of integrated zoocenosis in a marine lake (Crimea, Black Sea): What is a general pattern?

Abstract

The number of small lakes (<1 km2) on Earth is much greater than the total of all large lakes. Marine small saline lakes play an important environmental, social, and economic role but there is often a lack of studies within these environments. Changes are ongoing in many lakes due to natural and anthropogenic causes, and these changes can be dramatic in marine small saline lakes. The authors conducted a study of the spatio-temporal variability of zooplankton and zoobenthos in a small hypersaline Crimean lake of marine origin. The study was done at three lake sites during 3–5 periods in 2018. Animal composition and abundance were studied in plankton, floating filamentous green algae mats, and soft bottom. The temperature fluctuated between 10 and 28 °C, and salinity varied between 23 and 170 g L−1. 9 macrotaxa of animals were found in plankton, and 9 in the benthos. Harpacticoida dominated in 80% of cases, and Ostracoda in 20% of cases. The total abundance of zooplankton averaged 42.4 × 104 ind. m−3. The total abundance of zoobenthos was on average 9.2 × 105 ind. m−2 in mats, and in the soft bottom community on average 2.4 × 105 ind. m−2. There is a single differentiated integrated zoocenosis in the lake without division into separate zoocenoses of plankton, mat, and bottom. Comparison with data of 2004–2006 showed that despite the high level of variability of the components of the zoocenosis, there were no direct long-term changes within it.