E. Petrova*, S. Stoykov
Institute of Fish Resources, 9000 Varna, Bulgaria
(Manuscript received 30 August 2017; accepted for publication 6 November 2017)
Abstract. The aim of this paper is to establish the biodiversity status of the macrozoobenthos in some protected marine areas (NATURA 2000) along the Bulgarian Black Sea coast. The observation stations in the period 2010-2012 were within the frames of the following habitats: 1160 – Large shallow inlets and bays; 1110 – Sandbanks, slightly covered by seawater and Sublittoral mussel banks on sediment. In general, the data shows steady state compared to the 1980s, except for the area near Kamchia River, characterized by low biodiversity due to water pollution from the river inflow (with contaminants from agricultural and industrial sources in the upper river stream) and less salinity leading to marine mussel species reduction. In the border area, near the Emona zone, the black mussel catches varied between 160-600 kg in 2005, while only single specimens were detected in 2013. In the same field, the yield of Rapana venosa was within the limits of 5-40 kg in 2005 and between 80-160 kg in 2013. The established variability showed a dynamic balance between Mytilus galloprovicialis and Rapana venosa that pose a challenge for future stock of the black mussel and point the need of regular monitoring.