How Big, How Blue, How Beautiful: seagrasses help fight climate change in Norway

Maria Potouroglou

By GRID-Arendal

September 13^th, 2017

Human activity releases 9.9 Gt of carbon every year. That’s 9,900,000,000 tonnes – equivalent to emissions from 2 billion passenger cars for one year. For perspective, there are just over a billion cars on the road in the world today.

What is the atmosphere doing with all of this carbon?

One fact about all that carbon pollution is that more than half - 57% - of it “disappears”. Terrestrial ecosystems sequester 2.6 Gt and another 2.2 Gt is absorbed by the oceans. So, if it wasn’t for the natural ecosystems doing something with that carbon, climate change would be happening more than twice as fast.

During the summer, an exciting fieldwork mission started with scientists from GRID-Arendal, Institute of Marine Research (IMR) and the University of Oslo collecting sediment cores from various sites within the Skagerrak coast in the southern part of the country. We joined forces with media experts to document the fieldwork and raise awareness of scientific seagrass research.

The coasts of Scandinavia and the Baltic Sea are key distribution areas for Zostera meadows, the most widely distributed seagrass in the Northern hemisphere. This region is estimated to support more than 6000 individual meadows covering at least 1500-2000 km2. That’s four times bigger than the combined seagrass area of western Europe.

While this region plays a key role in the coastal carbon dynamics, we lack estimates of the carbon storage potential of seagrasses in Norway. Nearly one-third of global seagrass area has disappeared over the last 100 years, this is equivalent to losing a seagrass bed of a football pitch size every half an hour, mainly due to industrial and agricultural run-off, coastal infrastructure development and dredging. Norway has lost 42% of the previously documented seagrass beds in the Atlantic coast, and the rate of global loss is accelerating. This decline could have severe consequences on the total capacity of seagrasses to sequester and store carbon in addition to the other ecosystem services that they provide such as essential fisheries habitat, filtering water and protecting shorelines from wave energy, thereby reducing disaster risk.

A newly developed project called “SEAME - Blue carbon stocks in seagrass meadows”, a core task under the Norwegian Blue Forests Network (NBFB), aims to fill a major gap in our knowledge about Norwegian seagrasses by providing estimates of the carbon storage capacity of Zostera.

Watch this space for more news on SEAME. Detailed reports are going to be available soon so that we answer questions such as:

How much carbon has been stored in seagrass meadows in Norway - How blue?
What’s the total carbon sink of seagrasses in Norway - How big?
And most importantly, so we can together explore the beauty of these extremely important habitats - How beautiful!