New research on Narwhals in the sound of the Nunavut eclipse suggests that animals can be more sensitive to shipping noise of what scientists previously believed, and that they change their behavior when ships are close.
The study, published earlier this month in Nature magazine, says that Narwhal Stop Echolocating and will vacate an area when exposed to the noise of the low ship. It also says that marine mammals are sensitive to sounds more than 20 kilometers away.
“It seemed to be a fact understood before our investigation that Narwhal was only affected in a short distance, but when you talk to the hunters and the elderly, that has not been the case,” said Alex Ootowak, a researcher at Pond Inlet, Nunavut and one of the co -authors of the study. It is with the North Oceans acoustic monitoring program.
The study supports the observations of the hunters around mining projects in the region, such as the Nanisivik mine now closed, and their belief that the Narval are more sensitive to shipping noise than existing marine noise guidelines recognized, Ootowak said.
“People seem to appreciate that our research is demonstrating what is a long time understood and known here,” Ootoowak said.
The investigation will be used to evaluate and mitigate the impacts of the shipment of mines, cruises and yachts trying to enter the passage of the Northwest, he said.
During the last decade, Oceans North partnered with the Pond Inlet (MHTO) and the Institution of Oceanography Institution Scripps based in California to study how to react the narval to send the narval to send noise in the sound of Eclipse, near the pond entrance, where they return every summer to feed in deep and abundant waters.
According to the new study, Narval numbers in the sound of eclipse in summer seem to have decreased by approximately 90 percent in the last two decades, about 20,200 animals estimated in 2004 to 2,081 animals in 2021.
Ootowak calls change throughout the “sad” years. When he was a teenager, his father took him to long trips to hunt and live on earth. The waters were so abundant that the dream would be a problem.
“You are constantly hunting and observing and enjoying the views of hundreds and hundreds of Narval,” he said.
“I want later generations to see what I saw,” he said.
The researchers also claim that between 2015 and 2019, there was a 384 percent increase in the number of boats that travel through the sound of the eclipse, with 80 percent of those ships connected to the regional mining activity, and the other 20 percent to tourism.
Inuit’s hunters in the region were the first to notice the changes in the behavior of the Narval Surface and the population number as the first mineral shipments left the Mary River mine in Baffinland in 2015, said Kristin Westdal, scientific director of Oceans North and another of the co -authors of the report.
She said that Narwhal was spending less time by diving, a generally indicative behavior of food and changing the direction of travel when they meet a ship. Data can help answer the question of how much noise is too much for animals, he said.
“It is interesting and also alarming when you can identify that position in which animals stop talking or disappear about that habitat,” he said.
The research will report the Interim Management Plan for the Nacional Marine conservation area Tallurutiup Imanga, as well as in future protected areas, according to Westdal. She said it will also be used by the Nunavut Impact Review Board when projects such as Mary River Mine are sought.
Study echolocation
The researchers used Narval Ecolocation clicks and satellite data to measure the distance of the ships of their recorders. They analyzed how Narwhal responded to the sound of the ships that passed through the area.
“These ecolocation clicks are associated with important functions such as food search, find food or navigate,” said Joshua Jones, a project scientist who supervises research with Oceans North and MHTO.
Previous studies found impacts within the 10 kilometers of the ships and the “strong avoidance” between the narval of the areas within a kilometer of ships that pass, according to the study.
New research suggests that the nose are even more sensitive to sound than other species with which they have been compared, such as murderous whales or dolphins, and show behavioral changes when ships are less than 20 kilometers, Jones said.
The noses are noise sensitive below 1 kHz, said Jack Ewing, staff research associate at the Oceanography Institution Scripps of the University of California in San Diego and another of the co -authors of the report. That is a lower launch than previous investigations have suggested that the animals were sesstive.
Narkwals also reacts to broadband sound pressure levels well below 120 dB, Ewing said.
“These sound levels are relevant to evaluate noise impacts in the future,” said Ewing.
