Biodiversity : Biological diversity is a measure of the relative diversity among organisms present in different ecosystems. Diversity is the absolute number of species in an assemblage, community or sample.

Chemosynthesis : The synthesis of organic compounds using chemical energy derived from the oxidation of simple inorganic substrates.

Community :  An integrated group of species inhabiting a given area; the organisms within a community influence one another’s distribution, abundance, and evolution.

Ecosystem : A community of organisms and their physical environment interacting as an ecological unit ; the entire biological and physical content of a biotope.

Fluid seepage or cold seep : Area of the ocean floor where methane and other hydrocarbon-rich seepages occur.

Heterotrophic : Obtaining nourishment from exogenous organic material; used of organisms unable to synthesize organic compounds from inorganic substrates.

Hydrothermal vents :  Submerged earth form consisting of a vent of hot, mineral-rich waters on the ocean floor; generally located on or near spreading oceanic ridges or on the continental margins of subduction trenches (back arc basin).

Photosynthesis : The biochemical process that utilizes radiant energy from sunlight to synthesize carbohydrates from carbon dioxide and water in the presence of chlorophyll.

Seamount : An elevated area of limited extent rising 1000m or more from the surrounding ocean floor.

Species diversity :  The number and variety of species found in a given area in a region.

All English definitions were pulled from the Harrap's dictionary and the "dictionary of ecology, evolution and systematics" by R.J. Lincoln et al., Cambridge Univ. Press, 1982.