Norway has big plans for offshore wind, which will, among other things, require ashore cables through the sea. But new research shows that haddock larvae are disturbed by magnetic fields from undersea power cables (external link). Ultimately, that can spill over into the fishcakes on the dinner table. There is because haddock is a widely used fish. Swim more slowly in the magnetic field Many organisms in the sea can use magnetic fields to move and orient themselves. More and more submarine cables are now being laid to transport electricity. Researchers from the Norwegian Institute of Marine Research are concerned that it will affect the fish’s ability to find their way around. That is why they have researched exactly this. They have looked at how baby haddock, also called haddock larvae, swim when exposed to magnetic fields. The researchers have looked at how the haddock larvae are affected by magnetic fields. They cannot therefore say anything about how adult haddock react to the power cables. Photo: Erling Svensen / Norwegian Institute of Marine Research – The magnetic field had a remarkable effect on the haddock larvae. It reduced their swimming ability by more than half, says postdoctoral fellow Alessandro Cresci at the Institute of Marine Research. – We were quite surprised by the extent. The Marine Research Institute is the only research center in the world that has researched how the early life cycles of fish are affected by magnetic fields, according to Cresci. Haddock is a common bycatch. This means that fishing boats that fish for cod can have haddock in the catch, and deliver the fish to the fish reception centres. Photo: Allan Klo / news – Much more development of offshore wind is planned along the Norwegian coast. Many turbines with large electrical output will be installed, says the researcher. To provide an answer to how the power cables affect the fish larvae, they have carried out several experiments. In the laboratory at Austevoll Research Station, they recreated the magnetic fields with the same intensity as that created by the cables. The researchers saw no pattern in the larvae swimming to or from the cables. They just swam slower. – They are probably very sensitive to changes in magnetic fields. Can affect fish food producers The Insula group is probably the company in Norway that uses the most haddock fillets for processing ready-to-consume products. The CEO of Insula Norway, Sigvald Rist, says that they have an annual consumption equivalent to around 6,000 tonnes of round haddock. In addition, there is the volume that goes to fillet products that are exported as industrial semi-finished products and whole fresh fish. CEO of Insula Norway, Sigvald Rist is concerned that new technological projects will put haddock at risk. Photo: Beth Mørch Pettersen / news – Human influence on the resources in the sea is very scary, and directly irresponsible to allow knowingly and willingly, says Rist. Insula has whitefish farms in Vardø, Båtsfjord and Havøysund in Finnmark. There, they buy fish directly from fishermen, and further process it, for example, into fresh fillet products. Insula has around 200 employees in its facilities in Finnmark, and 150 employees at Insula’s factory in Leknes in Lofoten. Photo: Beth Mørch Pettersen / news At Insula’s factory at Leknes in Lofoten, haddock fillet is the main ingredient in a number of fish food products, such as fish cakes, fish burgers, fish pudding and fish balls. – The population of coastal Norway, and the entire nation, has enjoyed the sustainable harvesting of the sea’s resources for many generations, says Rist. – We must by all means not let new technological projects destroy this. The fishcake producer Sjøfisk under Insula mainly uses haddock in its fishcakes. Photo: Kari Skeie / news I don’t think it affects the cod Bjarte Bogstad researches cod at the Institute of Marine Research. He says that haddock fry are generally closer to the seabed than cod fry. – So such effects will mean less for cod, even if the effect on cod larvae should be the same as on haddock larvae. Bjarte Bogstad, demersal fish researcher at the Institute of Marine Research, says he does not think cod larvae will be affected by magnetic fields from power cables in the sea. Photo: The Bogstad Marine Research Institute has no information on whether there should be a difference between cod and haddock in this context. Nevertheless, he points out that Cresci’s study has not taken into account that the haddock larvae are usually larger when they reach the seabed than the larvae that Cresci has researched. Since it is not known whether the effect depends on the size of the larvae, it may be that they will tolerate the magnetic fields better when they get bigger. According to Cresci, offshore wind turbines will need a network of cables. This will make the magnetic field larger. Cresci and his research team have only researched the magnetic field at one current-carrying cable. The effect of the magnetic field is reduced quite quickly when you move away from the power cable, says Cresci from the Institute of Marine Research. But he says that with offshore wind there will be a whole network of cables of several hundred square kilometres. This will make the magnetic field stronger. In addition, the larvae are less able to swim than adult fish and have difficulty avoiding the cables. To research the impact of sound from turbines The magnetic field itself is not the only problem, the sound can also disturb the fish, according to the researchers from the Institute of Marine Research. – The sound from the turbines is continuous and has a very low frequency. Very little is known about how this sound will affect the fish larvae, says Cresci. It remains for the researchers to find out whether the sound of offshore wind turbines will attract or repel fish fry and fish larvae. The sound created by the turbines can reach far away from where the sound is created.
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