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Gianna Gruen | Ideas

Limy stars to save coastlines in a warming world

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.

Living Sands: Starsand Foraminifera from the Great Barrier Reef (C) Martin Langer/Uni Bonn

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.

Fossil remnants of giant Foraminifera from South Germany: Prolific producers of carbonate from the past. (C) Martin Langer/Uni Bonn

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.”


February 7, 2013



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sumisom | Ideas

Dire Straits for Coral Reefs

It's no secret that coral reefs around the world are under threat because of climate change. Coral reefs represent some of our most important natural resources, providing livelihood, food and protection for marine biodiversity. And now environmentalists say 75% of our existing coral reefs are in the danger zone.


According to a report called "Reefs at Risk Revisited," overfishing, warmer waters and pollution are among the biggest culprits endangering reefs today. Also, pwards of 500 million depend on reefs for sustenance and income. And it's only going to get worse in the next 20 to 50 years.


So what can we do? Cutting down on water consumption and pollution will in turn slash our CO2 emissions, which is a big plus. But also support reef-friendly businesses whether you're fishing, boating or snorkeling! And raising awareness is also key. Here's one way to spread the word: send coral reef e-cards from The Nature Conservancy!


February 23, 2011



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