Good advice offered for those wanting to go in for sea urchins. It is evident that sea urchins are one of the world’s best paid seafood products. Senior Scientist Sten Siikavuopio at Nofima, who has engaged in research on sea urchins for nearly 15 years, said that the sea urchin has grazed down the kelp forest and has been a pest and a nuisance along large parts of the coast. Concurrently, it is gourmet food in Japan and France. His motivation has been to prepare for a new industry.
He has presented his doctoral thesis for the degree of Dr philos. at the University of Tromsø. The work comprises a total of 10 papers about the green sea urchin. This is the sea urchin species that is most abundant in Norwegian waters and the one with the greatest commercial value. The roe is the part of the sea urchin that is consumed.
According to the thesis over a period of many years, Siikavuopio has carried out research on which factors provide the greatest growth and also the best roe quality, including what it likes to eat, water temperatures, water quality and stocking density in the tanks. He said that the optimal water temperature for adult sea urchins lies between 10 and 12 degrees in summer and around eight degrees in winter.
The sea urchins, which have low oxygen consumption, are also extremely sensitive to oxygen content in the water. Consequently, the water needs to be replaced regularly. Sea urchins lack a heart and brain and their movement patterns are random, particularly when they are searching for food. This is important when it comes to the shape of the tanks. The sea urchins need vertical surfaces to attach themselves to.
Siikavuopio said that they have observed ‘behaviour of solidarity’ in the tanks. A short time after the feeding, the sea urchins had divided the feed amongst themselves. All of the sea urchins got food and that surprised us. He added that the technology is ready and a new feed is also commercially available. A couple of companies are doing sea urchin farming today and achieving good prices. We now need to upscale this to a larger industry in Norway.
