Scientists need help to map problem algae. The filamentous algae float around as mats on the surface or lie like dense blankets on the seabed. Now we need help to map their extent.
“Lurv is the popular name for fine-filament algae. These grow quickly if the water is warm and has a lot of nutrients,” explains marine biologist Jonas Thormar.
Lurv has a bad reputation.
These algae can bloom quickly if given good conditions. They can grow loosely on the bottom, cover eel grass, be stuck on rocks, seaweed or kelp. They spread the word, if they get the chance.
And they compete with other species in the ecosystem – such as kelp and eelgrass.
“Filamentous algae can take the space and light from these important habitat types,” explains Thormar.
Kelp forests and eelgrass beds are both breeding grounds for fish and carbon stores – they are often referred to as our underwater rainforests.
Here you can see a little and a lot of litter in the same eelgrass bed at different times of the season:
Do you have “fur” in your backyard?
Although algae in the Oslofjord or Skagerrak tend to get the most attention, algae can occur throughout the country.
“The Norwegian coast is long, and there are large local variations. It is therefore far too expensive to carry out traditional monitoring of kelp. It is made even more difficult by the fact that the amount of kelp can increase dramatically in just a week or two, if conditions are favourable,” says the marine biologist.
And that’s where they come in – those who like to be outside, who walk along the beach, watch from a pier, paddle around in a small boat, or generally have their eyes on the sun.
To investigate the extent, the Institute of Marine Research and the Oslofjord Outdoor Council are inviting people to a ‘Litter Weekend’. We need DI’s help to map where you see – and where you don’t see – litter.
Lack of knowledge
The observations will help to map both local and regional variations, which will form the basis for a more comprehensive monitoring plan for 2026.
The focus should then be on seasonal variation – from the first bloom to how much the quantity varies throughout the season – and areas with particularly high abundance.
“Systematic monitoring of fur has not been carried out in Norway before. Therefore, there is little knowledge about changes over time,” concludes Thormar.
Soft fur around eelgrass at Bolærne.
Photograph credit: Jonas Thormar / Institute of Marine Research