With our changing climate, protecting all impacted organisms on Earth is a huge priority. The planet has gone through previous cycles of heating and cooling, and looking at these periods can give us clues about what may happen. An international team of researchers has done just that, by studying previously overlooked “ghost” plankton fossils.

The extraordinary fossils, housed in the Swedish Natural History Museum, come from single-celled sea plankton called coccolithophores. These creatures are extremely important in today’s ocean ecosystems, supporting marine food webs and locking carbon away in seafloor sediments.

“The preservation of these ghost nannofossils is truly remarkable. The ghost fossils are extremely small ‒ their length is approximately five-thousandths of a millimeter, 15 times narrower than the width of a human hair! ‒ but the detail of the original plates is still perfectly visible, pressed into the surfaces of ancient organic matter, even though the plates themselves have dissolved away,” explained co-author Professor Paul Bown from UCL.

The high abundance of these coccolithophores reveals that they were more resilient to past climate change events than theorized. It was previously thought that these microscopic communities completely collapsed, however, their abundance in number and species variety revealed otherwise.

“The ghost fossils show that nannoplankton was abundant, diverse, and thriving during past warming events in the Jurassic and Cretaceous, where previous records have assumed that plankton collapsed due to ocean acidification,” explained Professor Richard Twitchett, who was involved in the research. “These fossils are rewriting our understanding of how the calcareous nannoplankton respond to warming events.”

The study gives clues into how plankton may react to our current changing climate at present. The more information we know about how the world will respond, the more prepared we can be to preserve life going forward.

Source study: Science – Global record of “ghost” nannofossils reveals plankton resilience to high CO2 and warming