Ocean life in a big plastic tube
The mesocosms are impressive pieces of equipment. It’s only when you see them up close and with people beside them that you realise how big they are and what a logistical challenge it is to get them up here to the Arctic and deployed in the Kongsfjord.
Professor Ulf Riebesell has been explaining to me exactly how they work.
He arrived two days ago and it’s “all systems go“, now that the season has started and the fjord is more or less ice free – at least at the point chosen here. There are nine separate “tubes“, which will be lowered from the Esperanza once everything is ready, each to contain their own little mini-cosmos of ocean life. The ocean absorbs around 30% of the CO2 we emit – good to buffer climate change, says Ulf, but bad for the creatures in the ocean that rely on calcium to form their shells or skeletons.
Co2 reacts with water and forms carbonic acid which makes oceans slowly more acidic. Lab experiments show that some organisms have a hard time, especially calcifying organisms, which need calcium to form their shells and skeletons.
On a global scale, this has implications for example for coral reefs, with their huge biodiversity, importance for coastal protection, the food supply and also for tourism. Calcifying organisms are everywhere, Ulf stresses, many organisms in ocean depend on forming calcium carbonate and are crucial links in the food webs. Scientists here will be looking particularly at a type of snail,the pteropod up to 1 cm in length, which, as our Professor puts it, have transformed their feet into wings. They’re also knows as butterflies of the sea.
They’re a key link in the food web between algae and higher trophic forms like whales etc. But they form their shells from material very susceptible to acidification. The scientists want to see what happens if they are affected by acidification, and what that would mean for the food web.
The Greenpeace boat has also transported loads of equipment the scientists will need to collect and test the samples in the Ny Alesund marine lab.
The Arctic, says Ulf, is the place to be to study ocean acidification. Cold waters take up more gas than warm. The polar oceans are close to the stage where water becomes corrosive for organisms depending on calcification. In 20-30 years some parts of Arctic will be completely corrosive for many organisms. Now that’s a scary thought.
And while there’s a lot of debate going on about what extent of climate change will have what effect – with ocean acidification, there’s no debate, Ulf says. It’s a chemical process and it’s easy to model how acidification will increase with certain levels of CO2 emissions. The big unknown is how it will affect marine life. And that’s the point of the giant test-tubes in this Arctic fjord. Unlike a lab experiment, which will look at individual organisms, the scientists here are looking at whole communities of life-forms. A daunting task – with potentially devastating results. We need to do something to reduce the CO2 emissions very, very soon, says the Kiel professor.
