MORPHOGENETIC DEVELOPMENT AND FORMATION OF REPRODUCTIVE ORGANS IN THE BROWN ALGA, FUCUS DISTICHUS, UNDER DIFFERENT GROWTH CONDITIONS OF THE AVACHA BAY (SOUTH-EASTERN KAMCHATKA)

Brown alga Fucus distichus is one of the widespread, eurybiont species and is a promising object for commercial and sanitary mariculture. This determines the interest in studying its development under different growing condi-tions. In this paper, we discuss the morphogenetic development of F. distichus labeled samples in different areas of the Avacha Bay: Zavoiko Bay and Seroglazka Bay, from May to August. The bays differ significantly in the level of anthropogenic pollution and hydrodynamic load and, to a lesser extent, in the temperature regime and pH level of coastal waters. During observations, which began in May and ended in August, the total height and length of branches of different orders were measured and the state of fertility was determined in the studied samples. During the research period, the morphometric processing of labeled samples was carried out 4 times in Zavoiko Bay and 6 times – in Seroglazka Bay. The study results showed that anthropogenic pollution has the greatest im-pact on the development of the studied species. In Seroglazka Bay, where the berths of 2 large fishing enterprises are located and also household and industrial discharge from 12 city sewers occurs, F. distichus formed only 3 dichotomous branches from May 29 to August 12, and the fertility stage was absent. In Zavoiko Bay, which is widely open to tidal currents and does not have sewage discharge, F. distichus formed 6 dichotomous branches and all the terminal branches were at different stages of fertility. Based on the obtained data, we concluded that Fucus can be used for biomonitoring of the ecological state in the coastal areas.