Researchers from Nova Scotia’s Dalhousie University write in the journal Nature that the number of phytoplankton has plummeted globally over the last century as the climate has warmed.
They say the rate of loss has increased in recent years. The microscopic plants are not only key to the oceanic food chain, but they are also responsible for producing half of Earth’s atmospheric oxygen.
The Dalhousie team says it believes there has been an approximate 40 percent decline in phytoplankton numbers since 1950, which can be linked to rising sea surface temperatures and changing oceanographic conditions.
They found that most of the decline occurred in polar and tropical regions, as well as in the open oceans, where most phytoplankton production occurs.