For the past three summers, a Norwegian-American research team has visited Lofoten to measure what minke whales hear. The aim has been to get closer to the answer to one of the sea’s mysteries. What sounds can whales actually perceive? The project is controversial, because the whales are captured and confined in an area, where they are exposed to sound signals. According to the critics, this causes unnecessary stress and strain on the animals. This year, for the first time, the researchers managed to test the hearing of two minke whales. A few days ago, two young minke whales were captured, tested, satellite tagged and released. The data will be used in the work to regulate man-made noise in the sea. The researchers are surprised by the results they can already tell about. This is how the researchers measure the whale’s hearing: The minke whale comes to the coast of Nordland in May. The animals move into Vesterålen, before swimming out along the Lofoten wall on their way up into the Barents Sea to graze. This is where the scientists will catch the whales. The natural conditions outside Stamsund and Henningsvær will help the researchers catch the whales. Here the whale walks close to land and navigates between islets and reefs on its way to the Barents Sea. The researchers will draw a seine between islets. When the whales swim into the area, they will close the groove again, like a pool. The method they will use to test the whales’ hearing is the same type of technology used on infants. Electrodes with a suction cup are attached to the whales’ necks. They are then exposed to different sequences of sound. The signals sent between the ear and the brain will give the researchers an indication of which sounds the whales hear. The researchers will monitor the animals’ health throughout the test. By stimulating the different frequencies, the researchers can see how little sound is needed before the whale perceives it. The researchers will mark the whales so that they can be observed when they are released into the wild. Perceive more noise than thought Bald whales hear more than we think, is the main conclusion. – The results are sensational. The minke whale had a much higher frequency limit for hearing than we have previously assumed based on the ear anatomy and the frequencies in the sounds they make. That’s what Dr. Petter Kvadsheim from the Norwegian Defense Research Institute (FFI) says. Researcher Petter Kvadsheim at the Norwegian Defense Research Institute (FFI) Photo: Privat He says that in the first instance we were able to test the method with electrodes that sit on the whale’s skin. And it was especially for the high pitches that they were surprised. – This means that they perceive more of the man-made noise than we previously assumed. What we have found may have consequences both for the defense and others who engage in noisy activity. Over 62,000 signatures and more than 50 researchers worldwide believed that both animal and human lives could be put at risk if the project was allowed to continue. Since then, several Norwegian whale researchers have come out and said that they support this research. Minke whale got stuck and drowned Earlier this summer, it was known that a whale had got stuck in the barrier and drowned. The whale was not part of the project, but had become stuck in the barrier that the researchers had left outside. The project was temporarily stopped. Have you taken the criticism seriously? – Ever since we started planning this, we have had a thorough process with the authorities who grant permission for this. And we are very concerned about animal welfare, says Kvadsheim to news. However, he completely rejects that the research is unnecessary. – What we do not take into account is the part of the criticism that is about the fact that this is unnecessary research and that we know what we need to know. Because it’s wrong. This is knowledge we did not have before. The natural conditions outside Stamsund and Henningsvær are the area they have selected for the research. Here the whale walks close to land and navigates between islets and reefs on its way to the Barents Sea. Photo: The Norwegian Defense Research Institute news has tried to get a comment from some of the whale researchers who have been critical of the project, without success. WWF: Need more research on this Head of the ocean team in the WWF World Wide Fund for Nature, Fredrik Myhre, believes that more research needs to be done on hearing in whales. It is important to find out how the animals are affected by man-made noise. – Noise from, for example, petroleum activity, shipping and sea wind affects wildlife differently and, if not done correctly, can pose a serious threat to various species, including whales. He says it is important that research is carried out in as gentle a manner as possible and with minimal risk. He believes that noise today is taken far too little into account in the management of our marine areas. – The government needs to do something about that, says Myhre. Marine biologist Fredrik Myhre, head of the ocean team at WWF World Wide Fund for Nature Photo: Geir Barstein / WWF World Wide Fund for Nature Costs NOK 25 million The Norwegian-American project is 4 years old and costs NOK 25 million. The study to map the baleen whales’ hearing is led by the National Marine Mammal Foundation (NMMF) and the Norwegian Defense Research Institute (FFI). The client is the US authorities. But what they find will certainly benefit the Norwegian authorities, explains Kvadsheim. According to the plan, the study of what minke whales can hear is to be completed next summer. – We have made great progress this year. We will return and complete our studies next year. This is how they proceeded to test the hearing of the two minke whales. In the first whale, the team measured auditory brainstem response. This test method is also used on humans, to see if our brain registers a sound. – This was an important step in finding suitable settings for future hearing tests, says Dr. Dorian Houser from the National Marine Mammal Foundation. In the second whale, the team took it a step further and collected both ABR and hearing frequency range information. The research project to map the hearing of baleen whales is led by the National Marine Mammal Foundation (NMMF) and the Norwegian Defense Research Institute (FFI) on behalf of the US authorities. The aim is to gather basic information that is necessary to establish scientifically based guidelines for noise exposure of baleen whales.
ttn-69
– They hear more than we think – news Nordland
