Thank algae for oxygen

The oxygen in every other breath we take comes from the sea, and it is algae that we have to thank. Professor Angela Wulff has devoted her research career to these important marine species.

Half of the oxygen in the atmosphere comes from the sea, but it is not the visible macroalgae – such as seaweed – that are the biggest producers of oxygen. It is the microscopic phytoplankton that account for half of oxygen production.

“Most people think it’s the rain forest,” says Angela Wulff, a professor at the Department of Biological and Environmental Sciences. “But algae are incredibly important when it comes to our oxygen production.”

Algae are useful because they produce oxygen, and because they are the building blocks for the sea’s food web and are eaten by other species. But algae also have many other uses.
“There are a lot of things that we use algae for without realising it. For example, when you eat a cake or a pastry, it’s a product from algae that acts as a thickener to hold the vanilla sauce or the jam together.”

Angela Wulff

Angela Wulff

PROFESSOR WULFF WAS in the Antarctic recently with one of her doctoral students to study benthic diatoms – algae that live at the bottom of the sea – and to investigate their resistance to climate change.
“Diatoms are used as an abrasive agent in toothpaste, for example. There are a huge number of unused applications for diatoms.”

There was a focus on harmful algal blooms during the Harmful Algal Blooms and Climate Change conference at the Wallenberg Centre at the end of May. However, algal blooms are not always a bad thing, and are not always toxic.
“You could draw parallels with grass. If it wasn’t for grass, there are lots of animals that wouldn’t exist on land. And it’s the same with the sea: without algal blooms we wouldn’t have fish. But sometimes there’s too much of a good thing and a single species dominates. A bit like the way nettles grow next to outside toilets because they thrive on over-fertilisation.”

IN THE CASE OF HARMFUL algal blooms, there are too many algae and when they break down there is a lack of oxygen. In other words, the algae become toxic. At certain times, algal blooms are a worry along the east coast of Sweden, but they are a particularly big problem around the coasts of Africa, India, North America and South America.
“Algal blooms are an enormous problem there, and people even die as a result. We’re now experiencing ongoing climate change and acidification of the sea, and as researchers we want to study whether there’s something in this that could mean we see even more harmful algal blooms. We also want to find out whether toxic algae withstand temperature changes better than other algae.”