Restoring kelp forests together: a community impact report.

Between April 2024 and May 2026, Rissa Citizen Science organized 23 kelp forest restoration events across three sites, engaging nearly 500 volunteers. These “Kelpers” have contributed both on land and in the sea, carrying out simple citizen science activities and reducing urchin densities to create conditions for seaweeds and kelp to recover. Time to reflect on this journey and share some of the results!

Kelpers at Sørsjetéen, May 2026.

Since the first sea urchin removal event in April 2024, community support and impact have exceeded all expectations. Together, volunteers have removed nearly 100,000 sea urchins at Telegrafbukta, Sørsjetéen and Øksfjord. As a result, kelp forests are recovering, creating nursery habitats for fish and bringing back biodiversity. This achievement has only been possible thanks to the dedication and enthusiasm of the volunteers.

To everyone who has dived, done citizen science, made waffles or stopped by to cheer us on, and to our partners, truly, thank you!

Kelpers in Telegrafbukta in Febreuary 2026.

Three kelp forest restoration sites

• Sørsjetéen is where the restoration journey began. Since then, seaweeds and kelp have successfully recolonized the entire 200-meter jetty. The site has now entered a maintenance phase, to allow this underwater jungle to mature.
  

• Telegrafbukta became the second restoration site, with volunteers beginning removing sea urchins in June 2025. The restoration site covers approximately 2,000 square metres, and around one-third of the area is restored to date. This site requires most of our attention.
  

• Øksfjord is located about six hours from Tromsø by car and eight hours by boat. During two restoration weekends in October 2025 and May 2026, volunteers worked together to restore approximately 150 metres of coastline. We would like to continue our collaboration with Lopphavet Marine Protected Area and keep restoring this site with the local commmunity.

The kelp forest restoration site in Øksfjord in October 2025.

Documenting the restoration effort

Rissa Citizen Science has documented the restoration efforts since the first sea urchin removal event, keeping track of metrics such as:

• Number of events,

• Number of sea urchins removed,

• Number of participants on land and in the sea,

• Time spent in the sea removing urchins.

We would like to share some of theses metrics to show our appreciation and transparency with how the kelp forest restoration has progressed over the last two years. We are reporting mainly about Sørsjetéen and Telegrafbukta, two sites where restoration started respectively in October 2023 and June 2025.

Figure 1: Participation to the kelp restoration events at Sørsjetéen and Telegrafbukta since the creation of Rissa Citizen Science.

The last two years have seen growing support, with some seasonal fluctuations. In total, nearly 500 volunteers joined the 21events organized at Sørsjetéen and Telegrafbukta (plus 2 at the Øksfjord site).

Figure 2: Number of sea urchins removed since the creation of Rissa Citizen Science.

Sea urchin removal has reached staggeringly high counts over the duration of this kelp forest restoration grass-roots initiative. Between Sørsjetéen, Telegrafbukta and the most recent trip to Øksfjord, a current total of 98085 sea urchins have been removed from all sites! This is an incredible figure and a testament to what can be accomplished through teamwork and continual effort. We have documented an average of 2698 and 2790 urchins removed per event for Sørsjetéen and Telegrafbukta, respectively. Huge thank you to our scuba and free divers, who have made for a very effective urchin barren clean-up crew!

Figure 3: Time in the sea restoring kelp forests since the creation of Rissa Citizen Science.

Scuba and free divers have been hard at work removing urchins and spent many hours in Tromsø’s coastal Arctic waters. Between Sørsjetéen, Telegrafbukta and Øksfjord, a total of 20336 minutes have been spent clearing out urchin barrens in preparation for kelp resettlement. That’s roughly 339 hours or 14 straight days of diving action! This time has been distributed with an average of 501 and 586 minutes of diving time per event at Sørsjetéen and Telegrafbukta, respectively.

Figure 4: Diameter and mass of the urchins sampled during the kelp restoration events since the creation of Rissa Citizen Science.

Figure 5: Mean mass of sampled sea urchins at Sæørsjetéen and Telegrafbukta since the cretaion of Rissa Citizen Science.

While the divers are at work, a sample of sea urchins is brought to the surface, where a team of citizen scientists count, weigh and measure the diameter of each urchin. This element is part of a research goal to evaluate how urchins respond to the recolonization by seaweeds at each site. The average mass of randomly sampled sea urchins has been 47,4 g at Sørsjetéen (n=339) and 15,6 g for Telegrafbukta (n=876). The average diameter has been 56,2 mm at Sørsjetéen, and 31,3 mm at Telegrafbukta. More work is being done to theorize influences on average mass differences between sites, so stay tuned!

Kelpers measuring the mass and the diameter of sea urchins sampled during the kelp forest restoration events in Telegrafbukta and Sørsjetéen.

The Urchin Density Challenge

Thanks to our talented app developer, Philip Redecker, volunteers around the world can contribute to the project through the Urchin Density Challenge, counting sea urchins and helping us track changes in urchin density at the Telegrafbukta site.

Between the launch of the app in November 2025 and May 2026, over 250 users worldwide have counted around 5,000 frames and 53,000 urchins.

Here you can see photographs taken during the 14 restoration events held at Telegrafbukta between 17 May 2025 and 3 May 2026.

Frame used for the Urchin Density Challenge.

Community-driven kelp restoration

Local restoration efforts are critical to reviving kelp forests around Tromsø. Each diver, citizen scientist, and waffle maker bring ecosystem balance closer to reality.

Sharing these results is our way of thanking the volunteers and community members who make this work possible. Every sea urchin removed and every minute spent at the events contributes to the recovery of kelp forests. We look forward to building on this momentum and expanding our impact in the years ahead.

Thank you again to all of those who have volunteered in the kelp reforestation events!

Sign up now to the next event!

Kelpers at Telegrafbukta, 23 August 2025.

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• Rissa Citizen Science efforts to restore kelp forests with volunteers is supported in part by the Ocean Green project, led by Ava Ocean, with science partners NIBIO (Norwegian institute for bioeconomy), NIVA (Norwegian institute for water research) and Akvaplan-niva. The industry partners are Across Nature and Hofseth Biocare. OceanGreen is funded by the Green Platform (Norwegian Research Council and Innovation Norway). 20 Knop helps with dissemination.

• The Arctic University of Norway is our partner for the Telegrafbukta restoration site.

• Finally, a special thanks to SUT, the student diving club in Tromsø, for their continued collaboration. Their support makes it possible for volunteers to participate in kelp forest restoration by providing affordable access to diving equipment.