– There is one! – Oi-oi, shout the passengers in unison. The eyes are fixed on some furious splashes. Suddenly, a new silver and gold glittering giant soars above the waves and lands with a splash. Then one more. – The whole fish was in the air! – Fantastic! Great fun, says Christina Pehrson. Christina Pehrson (in the middle of the picture) is on a tuna safari on her 76th birthday. The trip is a gift from her daughters. Patrik Weiler has taken her daughter to see the tuna that have returned after 50 years. The lady in the tomato-soup-coloured south-west has one big smile. It’s her birthday today. The tuna safari was a gift from the daughters. She is among 20 passengers on the boat that slipped out of the harbor in Helsingborg at 5 p.m. Arranging safaris for tourists has become a million-dollar business in the areas around Øresund. This is a Danish boat from Helsingør looking for tuna jumps. Photo: Rolf Petter Olaisen / news In the waters outside, two Danish tourist boats are also out scouting for the giant fish. Fast fish in a busy sea For many decades they have not been seen. In the 1950s and 1960s, the several hundred-kilogram fish were virtually eradicated from Danish and Norwegian waters. But in recent years, they have flowed back to Øresund in ever greater numbers in late summer. There have never been more of them than this autumn. An estimate from the Øresund Aquarium says that between five and ten thousand of them have visited in search of food. The bluefin tuna are often called mackerel sturgeon in Norwegian. They have a top speed of 70 km/h and are an impressive sight when they shoot up from the depths, often with a fish in the mouth. – Yes, I got it, Patrik Weiler says happily. The passenger with the largest camera lens on board shows one of the flash shots: Tuna floating in front of Helsingborg’s seaside. In the mouth you can see what is probably a horn gill. Photo: Patrik Weiler In the picture, a power plug of a fish floats above the water against a background of Swedish high-rise buildings. Lured by the food Another person who is happy that the tuna is back is the head of the Øresund Aquarium, Jens Peder Jeppesen. The aquarium is located in Helsingør on the Danish side and is run by the University of Copenhagen. The marine biologist has this explanation for what happens in the strait outside. – It must be the colossal quantities of fish that we see out here such as herring, mackerel and anglerfish, he says. Jens Peder Jeppesen has been head of the Øresund Aquarium for over 25 years. The marine biologist is thrilled that the strait between Denmark and Sweden has such a vibrant wildlife. Photo: Rolf Petter Olaisen / news – If we get down to the bottom, there are a lot of cod here too. In smaller size. So it must be a hodgepodge of fish that attracts so many, he adds. The tuna is otherwise not the largest swimming creature that makes a pilgrimage to the area. Recently, a 15 meter long humpback whale appeared in the strait while they were out on a tuna safari. – It was a fantastic experience. Not an eye was dry then, says Jeppesen. Killer whales were also recently seen in the strait. Sperm whales too. The aquarium organizes boat trips where the public can see dolphins, porpoises, seals and tuna. They also have seabird safaris. Because even large flying fish eaters come to help themselves from the rich food platter. The Øresunda Aquarium’s own boat Planula on a tuna safari. Photo: Bettina Pedersen The secret in the depths The Øresund region is among the Nordic region’s most densely populated areas with over 2 million inhabitants. Photo: Rolf Petter Olaisen It may seem strange that such a densely populated area is an eldorado for marine species. The sea area is one of the busiest in the world. And quite without it being the intention, this may have been the very key to the rich marine life. The strait was so congested that the authorities decided in 1932 that fishing boats with trawlers should not have access. Due to the busy ship traffic in the Øresund, bottom trawling was prohibited. This has meant that the area is now more rich in fish than the surrounding areas. Photo: Rolf Petter Olaisen / news Trawling means that boats drag a net bag behind the boat. It is equipped with heavy trawl doors and drags along the bottom. The method is the preferred one almost everywhere. Except in Øresund, where the fishermen have to use other methods. – When an area is not scraped, the ecosystem gets a boost. And it all just works better. Right from the bottom level up to the very largest organisms. Like whales, says Jeppesen. The ban means that the soft seabed, which is full of small animals, including brush, is kept as an intact food dish for the fish. Illustration: Firskering Directorate Happy fisherman – Norwegian-made, says Søren Jacobsen proudly, patting the red-and-white schooner bobbing in the harbor in Helsingør. He has his fishing equipment in a large box in the middle of the boat. – The fish’s head gets stuck here, he says and shows one of the large meshes on the nylon net. In these gill nets, only fish of the right size should get stuck. Fisherman Søren Jacobsen fishes for different types of flounder. Photo: Rolf Petter Olaisen / news The fish that are bigger and the fish that are smaller do not enter his nets. They also do not damage the bottom. – What I notice as a professional fisherman is that there are many fish of many different species. It’s good business for me that life is what it is. So it is a good idea to introduce the trawl ban, says Jacobsen. He is the leader of the Danish association for gentle coastal fishing, which has just under 100 members. He earns his income by fishing various types of flounder such as turbot, plaice, sole and plaice. – I can make a living from it. I have a good business, he says slyly. – That is what is so unique, we have had this ban on trawling which means that we can harvest from nature and at the same time look after it, he adds. Norwegian fishermen skeptical The descriptions from the fishery-rich strait seem almost the opposite of the situation in the Oslofjord 60 miles further north. There it is the lack of fish that everyone is talking about. Large fish species are gone or in the process of disappearing, such as the local coastal cod. Scientists have warned of the danger of an ecological collapse. The eelgrass beds where the cod will grow up are often covered in slimy fur. The harmful algae get nourishment from the treatment plants and agriculture on land. Mostly it is shrimp that is trawled for. The fishermen’s organization warns against drawing strong conclusions about trawling from the example south of Sweden. – Our colleagues in Denmark and Sweden paint a different picture of the situation, says Alessandro Astroza, who is head of the department for southern Norway’s fishermen’s association. There are more reasons than a lack of trawling that cause fish to migrate to Øresund, believes department head Alessandro Astroza of the Fishermen’s Association in Southern Norway. He is also concerned that there are many reasons why the Oslo Fjord is struggling, and that not only fishing must be held responsible. Photo: Rolf Petter Olaisen / news – It is more the natural conditions with good water flow and sea depths of 10-20-30 meters that are very beneficial for the fish and biodiversity there, he says. According to what Astroza hears, cod is also struggling in Øresund, in the same way as other parts of the Kattegat and Skagerrak. The boss at the Øresund Aquarium has to admit that there is a shortage of large cod in the Øresund, but says there is a lot of cod in younger year classes. When it comes to the point about the ocean currents, Jeppesen gives the Norwegian fishermen the right that there are favorable conditions. Nevertheless, he will maintain that bottom trawling is the most important factor. – If bottom trawling had been allowed out here, Øresund would have been as dead as Lillebælt, he claims. In the neighboring Kattegat area too, according to Jeppesen, the fish are almost dead. Green eel grass beds – You must go faster! Cathrine Jensen, waves to the young people on the beach who are pulling on a rope. She herself stands with water up to her stomach in her green waders. She is employed at the Øresund Aquarium and will teach the visiting class about all the species that live in the sea outside. At the end of the rope is a fine mesh net which is pulled through the plant-covered bottom in fairly shallow water. Pupils from Rungsted grammar school learn about how much life there is in the depths of Øresund. A fine-mesh net is drawn over an eelgrass meadow at Kronborg Castle. Cathrine Jensen drags the net the last bit into the ground. Inside the aquarium, the students must count how many specimens of each fish species were hiding in the eel grass. The students’ tally shows that there were many hundreds of small fish in the eel grass. The contents are emptied into a white plastic tub which is transported into the aquarium. The third-graders from Rungsted gymnasium have their hands full counting all the small fish and putting the sums up on a board. – If we look in the aquariums, we can see that there are a lot of different fish. We have a nice biodiversity in Øresund, says Cathrine, who is one of the aquarium’s dissemination guides. A total of 155 fish species have been registered in the strait outside the aquarium, which is more than in other Danish waters. – Øresund gives hope, ocean researcher believes For ocean researcher Even Moland, Øresund is inspiring. Even Moland at the Institute of Marine Research is one of the researchers who has recommended that parts of the Oslo Fjord must be given peace for both trawling and other fishing for a period. Photo: Rolf Petter Olaisen / news – That you can have such a rich marine area in an area that is so densely populated and urbanised, it gives hope, says the marine biologist who works at the Institute of Marine Research. Restrictions on trawling are precisely a measure that both several Norwegian researchers and the Norwegian Environment Agency recommend being introduced in the Oslo Fjord. – If we are going to give the fishing community and the ecosystem in the Oslo Fjord a chance, then it is obvious to have larger trawl-free areas where the benthic community and the ecosystem can recover. – This combined with a network of zero-fishing areas where all fish are allowed to remain larger, older and more numerous, says Moland. Not much research has been done on how it will turn out. Nor how long it may take for species to return to the bottom and bodies of water. But it is permissible to dream that small and large fish can return to the Oslo Fjord from time to time. And perhaps also the super-fast giant that lures Swedes and Danes out on safari. The super-fast giants that appear in Øresund were also once regular guests in Ytre Oslofjord. It is not inconceivable that they can return if the right measures are taken, according to marine researchers. Photo: Bettina Pedersen – If we take the right measures to make the Oslo Fjord rich in fish, then we must not ignore the fact that the tuna will also search into the Oslo Fjord to find food, confirms Moland. – But it depends on the means and how long they are allowed to work, and how effective they are, he adds. The Danish marine biologist Jens Peder Jeppesen is also optimistic on behalf of the Oslofjord. – I am convinced that if you stop bottom trawling in the Oslo Fjord, you will get everything back, both cod and all the others. I have no doubt about that, he says. The speed can reach 70 km/h to 80 km/h when they are hunting for food. Photo: Bettina Pedersen The best gift In Helsingborg, a boat docks after a two-hour safari in Øresund. Christina Pehrson, two daughters and grandchildren rise ashore. Everyone is satisfied that they got to experience a lively Øresund and also got to see tuna jumping on their birthday. – It was the best I could get, says the newly 76-year-old. Christina Pehrson had a great time with jumping tuna on her birthday. Photo: Rolf Petter Olaisen / news
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Here, the sea is full of fish – due to the ban on trawling, says marine biologist – Stor-Oslo
