Now, Rissa CS teamed up with local architects and Tromsø kommune to use the guano from kittiwakes and the shells of urchins as feed for local wildflower projects.

This is all part of Rissa CS’s plan to shift perceptions of these animals. Kittiwakes are often criticised for nesting in urban areas, while sea urchins – left to proliferate after their natural predators were overfished – are often blamed for devastating kelp forests.

The regeneration of northern Norway’s kelp forests is the ultimate goal of the Ocean Green project, which is working to restore the natural balance beneath the water through a radical reduction in urchin numbers. A byproduct of this goal is, of course, a multitude of urchins.

Ocean Green partners are exploring a number of ways in which harvested urchins can be put to use – and the partnership between Rissa CS and ViNN – Vejetasjon i Nord-Norge – a research and development project exploring the use of local, wild plants in urban areas is a perfect match.

A ViNN-ing combination

While Ocean Green works to develop its large-scale harvester, Ruché and a huge team of volunteers have removed more than 70,000 urchins by hand, with impressive results in kelp restoration. At the same time, Rissa CS leads another group of volunteers (The Kittiwalkers) to monitor Tromsø’s kittiwake hotels – artificial nesting structures designed to support the endangered black-legged kittiwake while reducing conflict with local residents. Sea urchins and seabirds’ guano are rich in nitrogen, phosphorus and calcium that plants need to grow.

When Ruché met landscape architect Mari Anneline Aston Bergset through colleagues involved in the kittiwake project, their overlap was obvious.
‘We realised that we had research interests,’ Bergset says. ‘Since we were working with plants, both guano and sea urchins could be interesting.’
Their initial conversations grew into a practical experiment in one of Tromsø’s central parks.

‘We established a series of planting plots,’ explains Ruché. ‘One receives sea urchins as a soil amendment, another receives kittiwake guano, a third combines both materials, while a fourth serves as a control. Nearby, another planting site sits directly beneath the kittiwake hotels, allowing birds to fertilise the soil naturally over time.’

The experiment explores a simple but important question: can locally sourced sea urchins and kittiwake guano replace imported fertilisers while helping plants grow healthier and more resilient? And, at the same time, can using these local resources contribute to nature conservation? Guano is exceptionally rich in nitrogen and phosphorus but is also acidic. Sea urchin shells contain high levels of calcium, which researchers believe may help buffer that acidity while making the nutrients more available to plants.

The midnight sun effect

In the far north of Norway, Bergset highlights a unique challenge in growing everything from ornamental plants to food – the very short growing season.
The Arctic north has months of darkness, but it also has the midnight sun. ‘The result is a very short window for growth,’ she explains, adding that ‘that window is 24/7’.

What this means is that preparing soil well at the start of this very active growing season is essential. ‘For these short months, the continuous daylight of the Arctic summer allows plants to grow around the clock. If the soil contains the right balance of nutrients from the outset, newly established plants may develop more quickly before becoming largely self-sustaining,’ says Bergset.

Changing perceptions, right on the high street

This collaboration between Rissa CS and Bergset’s isn’t just about finding new ways to feed soil but part of a wider project exploring new approaches to urban planting. Bergset talks of the traditional approach: where neatness is emphasized and the focus is often on imported ornamental species, grown using manufactured fertilisers, irrigation systems and continual maintenance.
Working with ecologists, Bergset and her team are exploring whether native vegetation, supported by locally available nutrients, could reduce both environmental impact and long-term costs – ultimately delivering healthier, better integrated ecosystems.

Like the kittiwakes or the sea urchins though, it seems local plants have something of a negative image. Bergset explains how the city planting project attracted criticism almost immediately.

‘The day after it was planted, there was a lady in the paper saying how upsetting it was to see all of these weeds in our main street,’ she recalls. ‘Even though we have signs explaining that the planting is part of a research project, many people only saw untidiness.

‘I definitely think that there’s a lot of outreach and communication needed to help people understanding why we’re doing this,’ Bergset continues. ‘That includes discussing and developing aesthetics and an understanding of – or appreciation of – wild plants in urban spaces.’
The planting trials are still in their early stages and it will take time before the data shows whether sea urchins and kittiwake guano offer measurable benefits for urban planting.

But the collaboration – and how visible it is to local people – serves another purpose: that conservation is not only about protecting nature but about changing how people see it.

‘As with local plants and birds, which are, by their nature more visible, it is really important that people better understand the reasons for kelp loss in northern Norway,’ stresses Ruché. ‘The green sea urchins itself is not the problem – and we are not trying to eradicate this native species. What we are trying to do at Rissa Citizen Science and through the Ocean Green project is to reduce numbers to allow a more natural balance that in turn allows kelp forests to regrow. The proliferation of sea urchins and the resulting urchin barrens are the result of historic overfishing of urchin predators, probably combined with other factors such as climate change.

‘We’ve seen through hand removal just how effective urchin reduction is in regenerative restoration. What we also need here is for these waters to be protected. We have to stop fishing urchin predators if we are going to have anything like a sustainable solution.’