Normally, we mostly present you animals threatened by climate change – but this time, we have some good news for you: Researchers recently found out that there is a way corals might actually survive the multiple threats of humanity. We actually give these small creatures a very hard live:  pollution, overfishing and last but not least climate change. The latter influences the reefs by ocean acidification and rising sea temperatures.

For a long time it was thought that those cnidaria folks won’t cope with those impact. But the new study gives a glimpse of hope: If we manage to lower CO2 emission under the current level and stop overfishing, then all reefs with more than 20 per cent coral cover will survive. That’s the only chance, the researchers figured out.

For their work they took into account models for climate change, ecosystem dynamics, and carbonate processes. That way they could show that fish colonies are crucial for corals to survive, as they eat away straggling algae on the reefs resulting in more space for corals to grow.

Remember our Facebook-series on animals threatened by climate change? Here is some good news: There are also a few species that benefit from climate change. One of these is a special kind of protozoa – so called Foraminifera. Not only that, the fact they are thriving on a warmer climate also benefits humans and the planet as a whole.

There are about 10.000 different species of Foraminifera, all of them covered with a lime shell. They live mainly along the coastlines of Somalia, Kenia, Tansania, Mosambique, South Africa, Namibia and Angola. Though some of them are really tiny – even smaller than a sand grain – they perform enormous tasks: “Foraminifera are ecosystem engineers,” says Martin Langer, Professor at the the Steinmann-Institut for geology, mineralogy and paleontology at the University of Bonn. “With their shells, these protozoa produce up to two kilograms of calcium carbonate per square meter of ocean floor. This often makes them – after corals – the most important producers of sediment in tropical reef areas.”

Foraminifera to replace corals

This becomes important in a warming world. Corals have trouble handling warmer and more acidic oceans: their skeletons dissolve, corals die. And with disappears the habitat they provide for small fish and other aquatic species. What’s more, as whole reefs disintegrate they can no longer stabilize and protect coastlines from flooding.

This is where the Foraminifera come in: It’s not only that more acidic oceans won’t harm their skeletons. They thrive on warm water of at least 14 degrees celsius. Plus, warmer water temperatures make them spread, the research team around Martin Langer now found out: If ocean temperatures rise by about 2.5 degrees Celsius on average until 2100, Foraminifera are predicted to expand their habitat by almost 300 kilometres in latitude towards the poles.

Hope from the past

Researchers hope Foraminifera might take over the protection task of corals by stabilizing coastlines with their limy skeletons. This hope is at least supported by history, says Langer: “The fossil record shows that whenever during the history of Earth the carbon dioxide content of the atmosphere was considerably higher and the oceans were clearly warmer, foraminifera were among the most frequently occurring carbonate producers in tropical oceans.”