Composition and seasonal distribution mesozooplankton in South Black Sea

In this study, composition and sesonal distribution of mesozooplankton is studied comperatively at a station off Trabzon between 1999-2006. Sampling is done perpendicularly by Kalchico type sampling net which has a 75 µm mesh size and 75cm diameter.19 zooplankton species have been identified during 1999-2006 period in South Black Sea region. Maximum abundancy rates for feeding zooplankton were 172.242 indv./ m2 in September 1999, 926.679 indv./m2 for August 2000, 938.544 indv./m2 for December 2001, 1.669.397 indv./m2 for February 2002, 666.822 indv./m2 for April 2005 and 488.749 indv./m2 for June 2006. During the entire research period some species from copepoda are represented by different maximum abundancy rates such as Acartia clausi 43.219 indv./m2 in August 2000, Calanus euxinus 52.690 indv./m2 in April 2001, Pseudocalanus elongatus 33.955 indv./m2 in April 2005, Oithona similis 50.008 indv./m2 in August 2001, Paracalanus parvus 25.918 indv./m2 in February 2002 and Centropages ponticus 9.306 indv./m2 in September 2006. Study area was dominated by Noctiluca scintillans in May 2006 and June 1999, 2005.Maximum rates for meroplankters were detected in September 1999, August 2000, December 2001, January 2002, April 2005 and June 2006. Bivalve larvaes showed the highest contribution to total meroplankters biomass except the year 1999. Oikopleura dioica (Appendicularia) maximum abundancy rates were found in December 1999, September 2000, October 2001, February 2002, April 2005 and June 2006. The maximum rate for Sagitta setosa (Chaetognatha) was noticed in August 2001.In a study carried out along the southern coast of the Black Sea between Akçakoca (Düzce)-Trabzon in fall season and represented by 10 stations, zooplankon abundancy has been found changing by water depth and increasing from western part toward to eastern part of the Black Sea.