world's oceans are absorbing large amounts of carbon dioxide (CO2), which
is increasing their acidity and threatening the survival of many marine species,
especially calcifying organisms including corals, shellfish and phytoplankton.
According to a research presented at a symposium organized by UNESCO's Intergovernmental Oceanographic Commission and the International Council for Science's Committee on Oceanic Research (SCOR), this in turn could disrupt marine food chains and alter ocean bio-geochemistry in ways that are not yet understood or predictable.
A report on the meeting's conclusions says that the ocean is one of the Earth's largest natural reservoirs of carbon and each year absorbs approximately one third of the carbon dioxide emitted by human activities.
The absorption of carbon dioxide by the oceans is considered a beneficial process that reduces the concentration of CO2 but there is growing concern over the price of this service.
The researchers said that calcifying organisms, including plankton and corals, and also non-calcifying organisms, would be unable to grow and reproduce effectively at higher CO2 and lower pH levels.
Rising temperatures combined with elevated CO2 and decreasing pH pose a serious threat to coral reefs, possibly leading to the elimination of some reefs by the end of this century.
The report signals the need for further research and identifies research priorities, in a bid to increase understanding of the changes taking place and their consequences, and to allow for more informed policy decisions in this area.