<P> In ecology , primary production is the synthesis of organic compounds from atmospheric or aqueous carbon dioxide . It principally occurs through the process of photosynthesis , which uses light as its source of energy , but it also occurs through chemosynthesis , which uses the oxidation or reduction of inorganic chemical compounds as its source of energy . Almost all life on Earth relies directly or indirectly on primary production . The organisms responsible for primary production are known as primary producers or autotrophs , and form the base of the food chain . In terrestrial ecoregions , these are mainly plants , while in aquatic ecoregions algae predominate in this role . Ecologists distinguish primary production as either net or gross , the former accounting for losses to processes such as cellular respiration , the latter not . </P>
<P> In ecology , primary production is the synthesis of organic compounds from atmospheric or aqueous carbon dioxide . It principally occurs through the process of photosynthesis , which uses light as its source of energy , but it also occurs through chemosynthesis , which uses the oxidation or reduction of inorganic chemical compounds as its source of energy . Almost all life on Earth relies directly or indirectly on primary production . The organisms responsible for primary production are known as primary producers or autotrophs , and form the base of the food chain . In terrestrial ecoregions , these are mainly plants , while in aquatic ecoregions algae predominate in this role . Ecologists distinguish primary production as either net or gross , the former accounting for losses to processes such as cellular respiration , the latter not . </P>
where does most of the primary production occur in an ocean ecosystem
where does most of the primary production occur in an ocean ecosystem
algae
algae