Using sound to track the presence of North Atlantic right whales could help protect the critically endangered species from further deadly interactions with humans, new research finds.
Monitoring right whales’ distinctive calls with underwater microphones could help regulators to prevent them from coming into contact with fishing gear and large ships, two major causes of death for the protected animals, according to a recent scientific study that involved nearly 20 research organizations, including two in Maine.
This past year has been brutal for the North Atlantic right whale population. Eighteen of them — 4 percent of the estimated population of 450 — have been found dead off the East Coast and in Atlantic Canada. More than a dozen of the dead whales were found in Canada’s Gulf of St. Lawrence, which traditionally has not been considered part of the whales’ primary habitat, but rather within its occasional range.
None of the dead whales has been found in the Gulf Maine, but concerns about the amount of fishing gear in the gulf have led to increased regulation of Maine’s lobster fishery, forcing lobstermen to make expensive gear modifications to reduce the potential for whale entanglements. Last year’s right whale deaths prompted three environmental groups to sue the U.S. government last month over what they say are still-inadequate restrictions on lobster gear.
Right whale migration habits can be tracked with underwater microphones that record their location as they move back and forth along the eastern seaboard, researchers say. Recording their distinct calls can be more reliable than visual sightings because microphones can detect whales around the clock, regardless of whether they are submerged. Visual surveys, the traditional method for conducting population counts, frequently are limited by weather, daylight, and the whales’ proximity to the surface.
Underwater microphones off Cape Cod transmit data in real time about whales in the shipping channel leading to Boston, as opposed capturing and storing data that scientists retrieve later, according to Sean Hayes, the protected species branch chief for the National Oceanic and Atmospheric Administration in Woods Hole, Massachusetts.
Live monitoring can alert ships when to slow down to reduce the chance of striking a whale, but there is a catch to deploying underwater microphones that have this transmission capability, he said.
“It’s a very expensive piece of equipment,” Hayes said Tuesday of scientific buoys equipped with data transmitters. “They’re pretty costly to purchase and maintain.”
The cost of the underwater microphone technology is expected to drop in the next couple of years, he said. The added cost of having remote live access to the data — especially for buoys far enough from shore to require satellite uplinks rather than cell phone coverage — is likely to remain around roughly $100,000 per year, including maintenance costs.
Hayes said the idea of deploying more live data microphones has not been dismissed, given the urgency of the right whales’ situation, but finding money to fund the project faces an uphill battle as proposed budget cuts for NOAA and other federal agencies loom on the horizon.
Sean Todd, chair of marine sciences at College of the Atlantic in Bar Harbor and a collaborator on the study, said Wednesday that more live monitoring is urgently needed, especially in Canada, which has fewer protections for right whales.
“Whale migration is shifting so rapidly that it is difficult to place preventative measures within an effective time frame,” Todd said. “Hopefully, real-time acoustic monitoring and our improved knowledge of right whale movements will lead to fewer deaths in the future.”
He expressed frustration that NOAA is facing budget cuts, rather than getting more money to study climate change. The federal government in Canada, on the other hand, is taking the issue and the right whale crisis “quite seriously,” he added.
“There’s no doubt whatsoever climate change is happening,” Todd said. “It’s ridiculous this is a political debate.”
Even without the live transmission component, sound monitoring can provide regulators with important data when making long-term management decisions, according to Genevieve Davis, a NOAA researcher and lead author of the study. It can bring concentrations of whales to the attention of researchers before clusters of entanglements or ship strikes occur, as happened last summer with the snow crab fishery in the Gulf of St. Lawrence.
“Passive acoustic monitoring is a powerful, cost-effective, long-term monitoring tool that can give a better understanding of trends and reveal range expansion, decline, or distribution shifts in populations, as well as changes from year to year,” Davis said in a statement. “In an ocean where conditions are changing rapidly, adaptive management is needed to identify and protect areas that are crucial for this species.”
The collaborative study, published in Nature Scientific Reports, incorporated more than 35,000 days of data recorded from 2004 to 2014 by underwater microphones deployed from Canada to Florida, including off the coast of Maine. Erin Summers of Maine Department of Marine Resources also contributed to the study.
The study revealed that right whales are spending less time in the Bay of Fundy and in the northern Gulf of Maine, which is warming faster than 99 percent of the world’s oceans, but have been gathering in larger numbers in Cape Cod Bay.
Researchers have hypothesized that right whale migrations have been affected by climate change as the plankton they eat shifts northward to cooler waters.
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