Primary production of coral ecosystems in the Vietnamese coastal and adjacent marine waters

Coral reef ecosystems in coastal waters and islands of Vietnam have high primary production. Average gross primary production (GPP) in coral reef waters was 0.39 g C m−2 day−1. GPP of corals ranged from 3.12 to 4.37 g C m−2 day−1. GPP of benthic microalgae in coral reefs ranged from 2 to 10 g C m−2 day−1. GPP of macro-algae was 2.34 g C m−2 day−1. Therefore, the total of GPP of whole coral reef ecosystems could reach 7.85 to 17.10 g C m−2 day−1. Almost all values of the ratio of photosynthesis to respiration in the water bodies are higher than 1, which means these regions are autotrophic systems. Wire variation of GPP in coral reefs was contributed by species abundance of coral and organisms, nutrient supports and environmental characteristics of coral ecosystems. Coral reefs play an important ecological role of biogeochemical cycling of nutrients in waters around the reefs. These results contribute valuable information for the protection, conservation and sustainable exploitation of the natural resources in coral reef ecosystems in Vietnam.