Laboratory of Ecosystem Productivity

HEAD Vitaly G. TARASOV, Dr. Sci. Biol.

STAFF numbers 10, including 3 Drs. Sci., 4 Cand. Sci.

RESEARCH OBJECTIVES: Study of production and destruction of organic matter, including biogeochemical cycles of most important biogenic elements in coastal marine ecosystems and in zones of underwater hydrothermal activity in particular.

For several years, the Laboratory has been working on comparative anatomy. fine morphology, and taxonomy of the several less investigated taxa of marine invertebrates: Kinorhyncha, Priapulida, Loricifera, Nematomorpha (under leadership of Dr. Sci. A. Adrianov). Methods for study of exchange of oxygen, nitrogen and other biogenic elements on the bottom-water border have been developed. The oxygen cycles and some components of the nitrogen cycle have been investigated: nitrogen fixation, denitrification and nitrification in the surface layers of sea bottom deposits in different areas of the Pacific and Indian Oceans.

It has been found that the main source of biogenous elements in marine coastal waters are bottom sediments. Denitrification of bottom sediments in Vietnam coastal waters has been recognized as most important for nitrogen removal from ecosystem. Metals with variable valency have been shown to play an important role in biogeochemical processes in communities of soft bottom sediments in zones of shallow-water hydrothermal activity and in some coastal waters.

Specific marine ecosystems discovered in zones of shore volcanic activity in the western Pacific are presently under exploration. Biochemical processes in these systems characterized by extremely high rates of production of organic matter on the basis of photo- and chemosynthesis are determined by external flow ( underwater gasohydrothermal activity ) of some biogenic elements, reduced sulphur and metal compounds with changable valency. Biological communities of these areas have a high density of settlements and great biomasses of unicellular and multicellular organisms. Bacterial and algobacterial mats develop on the bottom around vents of hydrothermal solutions. New genera and species of bacteria have been identified in these ecosystems, including extremely thermophylic archebacteria, and several new invertebrate species. Biochemical peculiarities of metabolism have been revealed in some common invertebrate species, and some bivalve molluscs were found to have endosymbiotic bacteria.

Phone: 31-11-49