It can be said that marine plankton has now entered the Anthropocene epoch.
It can be said that marine plankton has now entered the Anthropocene epoch. The researchers compared the compositions of fossil plankton (foraminifera) assemblages in sediments of the pre-industrial era with those of more recent times. The team has published their results in the journal Nature.
Planktonic foraminifera are microscopic organisms that live in the surface waters of the oceans. When they die their calcareous shells are deposited in the seafloor sediments. These fossil foraminifera document the species communities before humans began to alter the Earth's climate. In turn, information on the present-day state of planktonic foraminifera is revealed by samples collected in sediment traps over the past 50 years. By comparing the fossil and modern communities of foraminifera, researchers can determine to what extent the plankton assemblages have changed since the beginning of industrialization.
For their study, Dr. Lukas Jonkers and Prof. Michal Kucera of MARUM at the University of Bremen, and Prof. Helmut Hillebrand of the Institute for Chemistry and Biology of the Marine Environment (ICBM) at the University of Oldenburg, compared over 3,700 samples from pre-industrial sediments with samples from sediment traps that reflect the plankton status from 1978 to 2013. The scientists have concluded that the present-day species communities are systematically different from pre-industrial times. "The exciting result was that this difference is not accidental, rather it reflects a signal of global warming. Modern communities in areas that are becoming warmer are similar to pre-industrial communities from warmer regions, indicating that species communities have shifted their distribution in a direction consistent with temperature change," explains Lukas Jonkers.
Read more at MARUM
Photo: A sediment trap is retrieved from the sea. In these traps, particles are collected from the water column over an extended period of time, usually for one year. From the samples, scientists can learn when and where the various species live today. CREDIT: MARUM – Center for Marine Environmental Sciences, University of Bremen; C. Schmidt
