The quest for the lost kelp forest

Background

The kelp forest is shrinking bit by bit, but why is it disappearing?

Few people know that the kelp forest stores essential oxygen just like the rainforest. We are entirely dependent on the kelp forests to be able to breathe and live.

However, in vast areas along the Norwegian coast, the kelp forests have disappeared, leaving barren “desert zones” where lush kelp once thrived.

A spiny invasion  

Looking down at the seabed, we can glimpse part of the reason for the kelp forest’s disappearance.

There, we find a species that has overtaken the kelp’s territory.

Where there was once kelp forest, the seabed is now covered with dense sea urchin populations.

“Sea urchins consume the kelp, and although sea urchins have a natural place in the ecosystem, in many areas they have overrun large stretches,” says senior researcher Philip James.

“When there are too many sea urchins, they don’t get enough food. They cluster together, and if we harvest them, they contain little nourishment because they haven’t eaten enough kelp,” James adds.

He emphasizes that sea urchins are not as malevolent as they might sound.
“But they become a problem when they occur in such large numbers,” he points out.

“Why have sea urchins begun consuming the kelp forest in such large numbers?
“We do not know for certain, but there are various theories”,

“One theory suggests that the reduction in predator fish species such as cod and wolffish has created favourable conditions for the sea urchins”, James concludes.

A new generation 

James and Bjørnsborg want to make the next generation aware of the consequences of the sea urchins’ greedy appetite.

They will visit primary schools in Tromsø to stimulate students’ curiosity about seaweed, kelp, sea urchins, and the fragile balance of the ocean’s ecosystem.

“Visiting students and inspiring curiosity about the research we conduct at Nofima is a fun way to share science,” says Bjørnsborg.

Objectives

To disseminate the concept of macroalgae forest restoration and restoration of the delicate balance between macroalgae forest and sea urchins in the Tromsø area to school groups in the area.

What we do

• Develop a school information and field day with touch tanks, photo boards, suitable age appropriate stories, show and tell quiz and a teacher information pack.
• Hold a series of field days at the shoreline around Tromsø for different schools and classes in 2025
• Send out a school information pack to schools that could not attend the field days and hold a final open field day in June 2026

Contacts