Sand bank Koketrays - a Case Study on the Effect of Marine Protected Area Designation as a Key Approach to Black Sea Biodiversity and Habitats Conservation

Sand bank Koketrays is the second marine area declared 'protected' along the Bulgarian Black Sea coast in 2001. A comparative analysis between zoobenthic coenoses in Bourgas Bay and sand bank Koketrays, as the main prerequisite for the conservation of the sand bank as a protected area is discussed in the paper. Three periods in the evolution of macrozoobenthic community are outlined: the period when no local anthropogenic impact was registered (1990-1992), just after the performance of bottom trawling for Rapana venosa in 1999 (2000-2002) and a three years period later (2003-2006). An increasing of the opportunistic Polychaeta and Oligochaeta species in abundance is established between 2000-2002 (a total of 44% vs. 69%) and nearly 5 times decrease in abundance of the conservative mollusk species (42% vs. 9%). A positive tendency toward recovery of the ecological state of bottom invertebrate fauna after the announcement of the site as 'protected area' is established the participation of sensitive species (I EG) increases up to 27.7 % and the AMBI index reaches 2.18, which indicates a process of gradually improvement of zoobenthic coenosis ecological status.