The zooplankton of lake Skadar/Shkodra: Species diversity and abundance

Abstract

The most common groups of freshwater metazooplankton in Lake Skadar/Shkodra are rotifers, copepods, and cladoceran microcrustacean. Rotifers dominate in the zooplankton and consist of about 58% of the entire zooplankton species, while Copepoda and Cladocera are represented by 29 and 54 species, respectively. The copepod and cladoceran species found in the lake are common in the wider region with specific presences in different lake areas. The presence of rotifers in the plankton of Lake Skadar shows a clear difference in terms of both abundance and composition. During different periods of investigation, a clear similarity in the horizontal distribution of the zooplankton was revealed and it reflects the major water movements in Lake Skadar/Shkodra. The water movements and flow from the north to the south are sufficiently large and show only minor modifications due to the local winds. In a situation of limited investigation or vegetation influences (in the extensively developed northern and southeastern zones of the lake), it is apparent that the main drivers in determining the diversity and horizontal distribution of zooplankton in Lake Skadar/Shkodra have to be explained by the movement of the water masses, the influence of river inflows, differences in temperature values, the low nutrient content, and the differences in nutrient content.