The Urchin Density Challenge gets a fresh upgrade!

The Urchin Density Challenge just rose to a whole new level! With the latest update, counting urchins becomes easier and more rewarding.

A Kelper at the Telegrafbukta site with the first-generation frame.

With the Urchin Density Challenge, those who can’t physically join our kelp forest restoration events can still contribute to the effort. How? Very simple! By counting sea urchins inside a 50/50 cm frame.

These counts help track the changes in urchin density inside and outside the restoration sites: a very important step to document the effects of the restoration.

We explained why counting urchins is important in this previous article (The Urchin Density Challenge has begun) .

The 50/50 cm frame used for the Urchin Density Challenge.

Since the launch of the Urchin Density Challenge in November 2025, over 250 users worldwide have counted about 5,000 frames and 53,000 urchins. Philip Redecker, the brilliant architect of the app said it himself: it’s pretty cool. Philip has now transformed the app with major upgrades, making the experience more intuitive and enjoyable.

Philip Redecker, the brain behind the Rissa Citizen Science app.

Our partner, Ocean Green, describes the Urchin Density Challenge as the gamification of science. For us, the Challenge is a way to engage more people in nature conservation and build a global community of ocean advocates.

Kelpers in Tromsø, May 2026

Tap and submit

With this latest update, you can now zoom in onto the frame, tap onto the urchins that you see (a number will pop up), and submit your count. Et voilà! The next frame will appear, and just so you know: you will never run out of frames. 25 new frames are photographed at every restoration event and uploaded into the app the same day. So far, 350 frames have been uploaded, and each frame can be counted an infinite number of times. The more counts, the more accurate they are. At least that is what we assume. Iona Wallis is soon starting her Masters thesis at UiT the Arctic University of Norway to confirm this hypothesis. Meanwhile, tap and submit!

Kelper in Øksfjord, by Ismaele Tortella.

Score!

What kind of an urchin counter are you? You can now answer that important existential question. Depending on your level of dedication, these are the achievements you can reach:

• Dedicated Counter: 50 frame counts.

• Century Club: 100 frame counts.

• Expert Contributor: 500 frame counts.

• Master Counter: 1000 frame counts.

And consistency pays off too!

Surely, you can reach a streak of 7 days to be a Week Warrior, but can you also make it to 30 days in a row to deserve the prestigious title of Month Warrior?

So far, only one person reached all the possible achievements. Since participation is anonymous, we don’t know who that person is. If you are this person, and you are reading these lines, please reach out to us. We would like to send you a little gift as a token of our gratitude :)

Last but not least, your ranking will show in the top right corner, although from 11 on, it will only say 11+. After all, not everyone is aiming for excellence, and every single frame count counts!

Install the app:

 Apple Store

Google Play

and start counting urchins! 

Kelper in Telegrafbukta, by Ann Cools.

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• The Urchin Density Challenge app is partly funded by the Ocean Green project, which aims at scaling up the restoration of kelp forest in Norway. Ava Ocean leads the project, while the science partners are NIBIO (Norwegian institute for bioeconomy), NIVA (Norwegian institute for water research) and Akvaplan-niva. The commercial 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.

• Iona Wallis will do her Maters thesis under the supervision of Andreas Altenburger and Marius Møller, at UiT The Arctic University of Norway.

• Without Philip Redecker, the Urchin Density Challenge would still be a promising idea. The Rissa Citizen Science’s app is also used by the Kittiwalkers to monitor the nests of the endangered kittiwake in Tromsø. Another one of Philip Redecker’s genius creation!