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One of the whales tested with satellite tagging. Satellite tracking and diving data show that the whales that were tested are doing well and have continued their migration.

For the first time, baleen whales have had their hearing tested: They can hear more than we think

The first successful hearing tests ever conducted on baleen whales took place in Lofoten in June. Researchers are surprised by how well the whales can hear the noise created by humans.

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Norwegian Defence Research Establishment

The international team or researchers collecting important measures of hearing in baleen whales have concluded their third field season in Norway. 

They now have data on the hearing abilities of two young female minke whales (Balaenoptera acutorostrata). 

Capable of hearing high frequencies

For the first whale, the team collected the first auditory brainstem response (ABR) in any minke whale. The procedure is similar to hearing tests regularly performed on newborn human babies.

For the second whale, the team collected both the ABR and information on the frequency range of hearing, i.e., the frequencies the whale can hear. 

The results were surprising. The researchers found that minke whales have a much higher frequency limit for hearing than previously assumed based on their ear anatomy and the frequencies at which they vocalise. 

Tested like dolphins

The non-invasive hearing tests were conducted in the same way as the tests regularly performed on dolphins and porpoises. Sensors were placed on the surface of the skin using suction cups that allowed the whale’s brainwaves to be recorded when it heard a sound played by the researchers. 

Satellite telemetry has shown that both whales have continued their normal behaviour following the studies.

After the hearing tests, the whales have shown normal behaviour. This whale swam almost 1,000 nautical miles, past Nordkapp, to grazing areas off the coast of Finnmark.

This year's experiments were concluded on June 30th. The researchers hope to collect data from more whales next summer. 

Saved from a painful death

The team was particularly pleased that they were able to assist the first whale, which had a fishing net entangled around its upper rostrum.

Remains of a fishing net had grown into the rostrum of one of the whales. The researchers managed to remove this before measuring the whale's hearing.

It was clear that the whale had been entangled for some time; tissue had grown around the netting, which was cutting into the animal’s rostrum. 

The team was able to successfully remove the entanglement. Without their intervention, the whale may not have survived.

About the project

The research effort, led by the National Marine Mammal Foundation (NMMF), the Norwegian Defence Research Establishment (FFI), and LKARTS-Norway, is an effort to acquire fundamental information necessary to establish scientifically based regulatory guidelines to better mitigate ocean noise exposure for baleen whales. 

The information will fill a knowledge gap that is critical to protecting all baleen whales from anthropogenic ocean noise. 

The research is funded by the Subcommittee on Ocean Science and Technology Interagency Task Force on Ocean Noise and Marine Life, which includes the Office of Naval Research, Bureau of Ocean Energy Management, National Oceanic and Atmospheric Administration’s National Marine Fisheries Service, US Navy Living Marine Resources, and the US Marine Mammal Commission.

More information about the project can be found here.



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