Temporal variations in vertical distribution and occurrence of marine cladocerans in an urbanized harbour, Dardanelles, Turkey

Cladoceran species abundance, occurrence, and distribution with respect to temperature, salinity, and chlorophyll-a concentration were investigated in an urbanized harbour located at Kepez, Dardanelles from April 2005 to April 2006. Field samplings were performed weekly and environmental parameters were measured in situ. The most common species of the five cladocerans recorded at the study site were Penilia avirostris with 49%, followed by Pleopsis polyphemoides, Pseudevadne tergestina, Evadne nordmanni, and E. spinifera, with 43%, 26%, 14%, and 2%, respectively. Although the cladocerans found at the study site are characteristics species of the Black Sea, the Sea of Marmara, and the northern Aegean Sea, their abundance, timing of occurrence, and maximum densities appear to have changed considerably in comparison with previous reports in the literature.