Seasonal Distribution of Nektobenthos in Varna Bay (Black Sea)

ABSTRACT

The nektobenthos is of great importance for the ecosystem functioning and demersal fish existence, but is poorly studied along the Bulgarian Black Sea coast. For this reason, investigations of nektobenthos in Varna Bay were carried out during the period 2007–2008. Materials from the water layer 20 cm over the sea bottom were collected. The main groups of nektobenthos and their seasonal distribution were studied. It was established that in spring period predominate larval stages of decapoda, and fish eggs and larvae. Relatively high temperatures in spring, improvement of hydrochemical situation and decreasing of phytoplankton blooms present favorable conditions for development of this group. In summer and autumn seasons appear representatives of zoobenthos (Isopoda, Mysida and other). Different zooplankton taxa were available over all investigated period, but are considered as a temporary component.

Keywords:

• Black Sea
• nektobenthos
• seasonal distribution