They call themselves kelp keepers. Surrounded on all sides by their round, spiky opponents. In the middle of a sea urchin desert. Once this was a lush, blue and green underwater kelp forest. But billions of sea urchins have invaded the seabed in northern Norway. They have grazed away the kelp forest. Among other things, because humans have overfished cod and catfish, the sea urchins’ natural predators. So the kelp keeper takes up the hammer and goes to work. The underwater desert For the kelp forest’s distress, it is both a forgotten crisis and a golden opportunity for the environment, climate and business, according to a new collaboration that is being launched today. – The Norwegian underwater desert is almost the size of the total built-up areas on land in Norway, says Joakim Hauge, head of the Environmental Foundation Bellona’s bio-programme. The sea urchins have grazed away a lot of kelp. Photo: Kevin Sempé They are behind the new initiative Nomare, together with the voluntary organization Tarevoktere and the business players Urchinomics and IFF. The aim is to find ways to restore and protect kelp forests on a large scale. Several methods are now being tested in an area of 3,000 square meters outside Tromsø. In addition to hammers, they use traps and industrial suction of sea urchins. If one succeeds in turning the desert into a kelp forest again, it could, among other things, store tons of climate-damaging CO₂, increase biodiversity and protect the coast from erosion, estimates the Norwegian Institute for Water Research (Niva). Exactly how much CO₂ kelp can store is still uncertain, according to the Institute of Marine Research. There are several different calculations. Nomare points to Niva, which estimates that: 12 million tonnes of CO₂ can be sequestered in living biomass 1.2 million tonnes of CO₂ can be annually stored long-term through dead kelp that falls to the seabed Nomare hopes that companies can also profit, for example by harvesting sea urchins and further processing the offal . The aim is to bring back the lush kelp forest. Photo: Jonas Thormar / Institute of Marine Research Climate crisis, good and bad The sea urchins are slowly moving away from the area themselves, says Kjell Magnus Norderhaug, who researches kelp forests at the Institute of Marine Research. The sea is getting warmer due to climate change, and this sea urchin is a cold water species. Nevertheless, it is a good idea to remove them as Nomare is planning, he believes. With kelp forests, other species also return. Photo: Jonas Thormar / Institute of Marine Research – Most of the grazed area is still there, and it has been there for over five decades. – If you remove sea urchins, the kelp forest will likely return. And then gradually the other species that belong there come after. But there are many sea urchins to remove if this is to have any effect, he adds. At the same time, climate change poses a major threat to kelp further south. Much sugar kelp forest in the Skagerrak has been lost due to increasingly frequent and intensive heat waves in the sea, explains Norderhaug. Kelp forests are threatened by more than just sea urchins. Photo: Jonas Thormar / Marine Research Institute – In the south, the temperature is so high that it is close to the tolerance limit for sugar kelp. When there are heat waves, it easily falls over. And because these heat waves come more often, the sugar kelp does not have time to recover before the next heat wave. This is more difficult to solve than sea urchins, he says. In the short term, measures to improve water quality can help during heat waves. – But more long-term measures are needed to limit emissions of CO₂ into the atmosphere.
ttn-69
To fight the sea urchins – news Norway – Overview of news from different parts of the country
