The influence of human-driven climate change on the composition of the world’s marine plankton is described in Nature. Modern communities of foraminifera - a type of hard-shelled plankton that survives well in sediments - are shown to differ from those from the pre-industrial era, which began approximately 170 years ago. The findings reveal that marine plankton communities are changing in response to global warming.

Marine ecosystems are changing in response to climate change, but the scale of this change is hard to determine because scientists lack a comparative baseline from pre-industrial times. Sediment cores, which contain the remains of organisms from pre-industrial times, offer a way to resolve this problem.

Lukas Jonkers and colleagues studied planktonic foraminifera, a diverse group of marine zooplankton that is found all over the world. The team compared the foraminifera found in the pre-industrial levels of globally distributed sediment cores at more than 3,500 sites with those from recent sediment trap samples (from 1978 to 2013). They found that modern communities differ markedly from their pre-industrial counterparts; the amount of change correlates with the degree of temperature change, and the direction of change is consistent with the global pattern of sea-surface temperature warming seen in historical times.

The results raise concerns over the functioning of marine ecosystems, and the reliability of the services that these ecosystems deliver to society, the authors conclude.