Researchers find climate change impacts plankton – a key marine food source
A key type of zooplankton’s inability to adapt to climate change could have adverse implications for marine food chains across the world if a severe global warming event were to occur, researchers at Oxford University have found. Their study investigated how planktonic foraminifera adapted to changing climatic conditions over the last 700,000 years, or seven global ice ages – with results demonstrating that the species maintained a static thermal niche over the period. This meant that they would need to seek out suitable habitats or risk extinction if the climate change were sudden and dramatic. In comparison, zooplankton species with flexible niches would be able to adapt to such changing conditions. The scientists used an atmosphere-ocean global climate model to chart species’ occupied mean annual temperatures at both sea surface and the depth of their habitats. They were also able to use the fossil records of the foraminifera to build an accurate record of the species’ past distribution patterns. The species constructs “shells” of calcite that capture carbon and record an isotopic signature of past ocean conditions, accumulating in abundance over large areas of the seafloor.