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Stepanyan O. Macro water plant of the Black sea Abkhazian shelf / annotation

Stepanyan Oleg – candidate of biology, deputy of the chairman of Southern scientific center of Russian Academy of Science. Rostov-on-Don, Russian Federation.

Last great algological researches on Abkhazia shelf were conducted in 1960-1970s. In connection with USSR disintegration, war conflict, maritime scientific researches in this region were not realized more than 20 years. In July 2010 South scientific centre RAS for the first time conducted the complex ecosystem researches in the contemporary history of Republic of Abkhazia, the modern estimation of phytobentos condition was one of the challenges. Phytobentos sample taking is conducted in the littoral zone of Abkhazian shelf at the depth of 50m in the borders of work territory. At the row of stations with depths from 10 to 50m sea bottom dredgings were conducted with drag, bottom silt probes were selected with bottom-grab Van Veen, a part of the material was collected at breakwaters. Macro water plants in the soil probes, collected with bottom-grab Van Veen were absent. Drag is appeared to be the most efficient, in the result of several dredging in the point with coordinates of 43º08`09" n.l. and 40º24`09" e.l. with deepness of 34 m, water plants, attached to small boulders, with total mass to 0,5 kg were raised. Among macro water plants the representatives of red water plants – Ceramium, Polysiphonia and brown – Cystosira, Dilophys predominated. Green water plants in the deep-water probes were not detected. At the same time predominance of the green and red water plants is detected in the littoral zone in fouling hydrotechnic construction (breakwaters) communities. Earlier A.A. Kalugina-Gutnik showed that water plants species composition is poor, because of loose grounds domination – just 113 of species or 38,7% from the general numerical strength of macro water plants of the Black sea, at that the leading position is taken by red and brown water plants. In the course of researches 33 water plant species were detected, from them green water plants – 11, red – 14, brown – 8. The conclusion of A.A. Kalugina-Gutnik about thickets water plants absence at the great part of Abkhazian shelf is actual nowadays. It is interesting to note that earlier for Abkhazian shelf water plants of Cystosira kind were not mentioned. The finding of Cystosira crinita testifies about widening of its areal resettlement in the south-east part of the sea. The researches were conducted in the summer period and that is why the represent-atives of the winter-spring algal flora (Bangia, Urospora, Pylaiella, Ectocarpus and others). typical for adjoining area of Big Sochi were not detected. In the same time 13 species of brown and red water plants are detected, earlier not mentioned in the south-east part of the Balck sea, but usual in the water area of Big Sochi. Steady tendency of green water plants increase is marked for Russian part of the Black sea waters. For Abkhazian shelf this tendency is not so expressed, and insignificant presence of green and red water plants of polysaprobic group testifies about small limnetic flowing and minor removal of biogenic elements. In the last decade for Russian part of the Black sea waters narrowing of water plants areal to 5-15 м, practically algal ring at the solid understratum deeper 20m absented or significantly fragmented. Detection of water plant communities in the waters of Abkhazia at the depth of 40 м, testifies about absence of negative phenomena that probably connected with more favourable ecological atmosphere. Regionalization of the Black sea littoral part and revelation of 14 flora regions were conducted by A.A. Kalugina-Gutnik. Such extraction preserves actuality and corresponds to the modern phyto-geographical regionalization. The new phyto-geographical region is separated in the work of V.N. Nikitina and O.A. Lisovskaya for the south-east part of the Black sea – “continental slope of the north-west part of Colchis coast”, apparently such separation is rightful and the borders of phyto-geographical region are necessary to be enlarged, including Abkhazia shelf in it.

Key words: macro water plants, Abkhazia, Abkhazian shelf, seaside zone, fragmentation.

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