ABIOTIC FEATURES OF CAPE ECOSYSTEMS OF THE NORTHWESTERN PART OF THE BLACK SEA

Abstract

The information on the formation, transformation and abiotic features of rocky capes in the northwestern part of the Black Sea (NWBS) poor with hard substrata was analyzed and summarized. Studies of cape ecosystems (CE) – solid substrates, hydrodynamics, water environment quality, were conducted in 1991–2021 in the sea region of Odessa. Literature sources have not previously considered capes as a special type of ecosystems. According to current consensus, rocky capes are components of the global coastal-shelf biotope of the periphytal. In the NWBS they are formed in the «land – sea – atmosphere» contact zone during the process of transgression, landsliding and erosion of soft soils. Rocky capes act as skeleton for the coastline, protecting the sandy banks of estuaries and beaches from erosion during the longshore migration of sediments. CE are in dynamic relationship with the loose bottom soils adjacent to them and are characterized by the greatest biotope diversity among all coastal ecosystems. CE are characterized by the stability (decades, centuries) of large fractions, the variability (weeks, months) of loose deposits and the high dynamics (hours, days) of the water mass. Capes are under the influence of winds, waves and currents, all of which provide ventilation of their ecosystems. They also prevent the accumulation of metabolites, the contamination of the entire water column with H2S and the development of acute hypoxia. Finally, they create favorable conditions for hydrobionts from different systematic groups in terms of temperature, salinity, dissolved O2 content and pH value. In cases of H2S release into coastal shallow waters, CE become a refuge for the hydrobionts inhabiting adjacent ecosystems. Overall, CE play an extremely important role in the preservation of biota and therefore require special protection measures.