CAPE ECOSYSTEMS OF THE NORTHWESTERN PART OF THE BLACK SEA AS NATURAL RESERVES FOR MARINE COASTAL FISH

Abstract

The research paper examines the role of capes in the conservation of coastal ichthyofauna in the northwestern part of the Black Sea. The study spans from the Danube Delta to Cape Tarkhankut (Crimea). Particular attention was paid to the capes located near the megacity of Odessa – Velikyi and Malyi Fontan, Lanzheron and Odessa Pivnichnyi capes. The research incorporates archived data from the Institute of Marine Biology of the National Academy of Sciences of Ukraine, alongside literature sources and original field research conducted from May to October over the period 1981–2021.
Using a landscape-biotope approach, largely similar coastal ecosystems can be identified and grouped as follows: 1 – capes, 2 – sandy bays, 3 – sandy spits of estuaries, 4 – estuaries and lagoons, 5 – river mouths. Cape ecosystems stand out due to the accumulation of large fragments of stones that extend from the shore to depths of 8–10 meters, rising above the bottom and surrounded by soft sediments. The hard substates of the capes provide settlements for macrophyte algae, bivalves and multi-species biocenosis. Bottom and near bottom-pelagic fish also find favorable conditions for survival and reproduction in the cape ecosystems owing to active hydrodynamics, presence of hard substrates and food resources. In total, 120 fish species have been recorded in the capes ecosystems, of which 18 are semianadromous and river fish species, and 7 anadromous species. Eastern Atlantic-Mediterranean species and Ponto-Caspian relics composed the basis of the ichthyofauna. There are also two introduced species: the mullet Liza haematocheilus (Temminсk et Schlegel, 1845) and the common sunfish Lepomis gibbosus (Linnaeus, 1758). Among the fish recorded in the ecosystems of capes in the northwestern part of the Black Sea, 75 species are listed in various protected (red) domestic and international lists, including 48, 52, 42, and 41 species in the ecosystems of capes Burnas, Velikyi Fontan, Adzhiyask, and Tarkhankut, respectively. Owing to the abiotic conditions, the capes ecosystem of the northwestern part of the Black Sea become reserves for hydrobionts inhabiting neighboring ecosystems during storms, in cases of acute hypoxia following release of hydrogen sulfide in coastal shallow waters, and other negative phenomena. Although the capes in the southwestern part of the Black Sea form separate enclaves and occupy up to 10 % of the coastal zone areas of the seabed, they play an essential role in conservation of biota and require special protection.