When Randy Musseau stood in a conference room in Halifax this week to teach the navy’s basic course in the field of passive acoustics, he had an unusual group of pupils: marine scientists who are among the first-ever civilian students to learn the military’s techniques for listening to the ocean.
The participants will use what they learn to better understand the effects of human activities on whales – information they can, in turn, share with the military to help protect the marine mammals.
“In my unit alone, we’ve been studying passive acoustics for 50 years,” said Mr. Musseau, training officer from the highly secure Trinity naval intelligence unit. “There are noises out there that we can classify immediately.”
The course is a modified version of the military’s basic passive acoustic analysis course, with classified material removed. Hansen Johnson, a marine bioacoustics researcher at Dalhousie University and one of the participants in the class, said the knowledge exchange will be a two-way street.
“They know a lot about ship noise; we don’t know a lot about ship noise,” he said. “We know a lot about biological noise; they don’t know a lot about biological noise.”
The students in the course are learning to classify ships based on the sounds they produce, which may help them understand the link between whale behaviour and ship noise. Disturbance, however, is hard to definitively measure, or tell apart from natural behaviour; it gets more obvious when the noise is added on purpose.
Learning how to mitigate harm to whales has taken on new urgency for the navy since environmental groups successfully sued the U.S. Navy over its sonar use in whale habitat.
The Canadian Armed Forces has a mandate to avoid harm to threatened wildlife, such as the critically endangered northern right whales that breed off the coast of Nova Scotia, as well as other endangered species such as blue and fin whales. The West Coast, meanwhile, is home to orcas, humpbacks, grey whales and other cetacean species. But with current technology and capacity, it’s difficult to even know where the whales are, much less whether human activities are harming them.
“I think we’re as well-informed as we can be,” said Danielle Smith, an environment officer based in Esquimalt.
Ms. Smith said navy ships operating on the coast do as much as possible to be aware of where whales are, including collaborating with whale-monitoring organizations and listening for whale sounds, and go as far as shutting down training operations to avoid harming whales – but real-time monitoring is extremely tricky. She believes more collaboration with outsiders is a critical step to help protect these species.
“I’ve spent about 10 years looking for a way to share some of that data,” she said. “We may be able to provide information that [other groups] don’t have the resources to provide.”
Water transmits sound about four times more efficiently than air does, meaning the tankers, bulk carriers, container ships and naval ships are making a racket underwater, and a good naval intelligence officer can tell them apart just by looking at the signature they make.
But ships also disturb whales with the noise they generate as they move through the water, like a convoy of trucks driving past a group of friends trying to have a conversation.
There is compelling evidence that sonar (the use of blasts of sound for finding submarines and ships) could disturb, disorient and even kill whales. Mass stranding events are thought to be related to sonar, which can travel hundreds of kilometers at high enough power to change whales’ behaviour with deadly consequences. Currently the navy restricts its use of particular sonar in areas known to be critical whale habitat, but knowing what areas are important for whales presents its own problems.
Some of these same underwater surveillance techniques can be used to help find them. Whales use species-specific sounds to communicate, hunt, find mates, and navigate. That means by listening carefully (like the navy listens for ships and subs), researchers can find and identify whales down to the species – if they know how and where to look. That’s where the new course comes in.
“They’re going to learn about better and faster and easier and more accurate ways of detecting and often identifying whale sounds in acoustic records,” said Chris Taggart, a professor at Dalhousie University’s Fisheries Oceanography laboratory, who has sent graduate students to the course.
Dr. Taggart is involved with the Marine Environmental Observation Prediction and Response Network’s (MEOPAR) WHaLE project, which uses unmanned submersible gliders to detect whale sounds and relay their locations to researchers onshore. The project hopes to eventually be able to automatically send out alerts to ships that are approaching whales, which can then slow down or change course to avoid collisions or disturbance.
Although sending students to the military for training may seem like an odd proposition for an academic, Dr. Taggart has been pushing for this kind of collaboration for years. He is known for working with industry to drastically reduce the risk of ship strikes on northern right whales by slightly altering shipping lanes.
“We’re not activists,” he said. “You’ve got to work with people to get stuff to work, and the navy wants to know more about whales and where they are so they can modify the things they do so they don’t hurt the whales.”
A formal agreement is being drawn up between the navy and MEOPAR to share the information both parties collect in order to benefit whale conservation work.
“We want to work with them because they’ve got acoustic smarts,” Dr. Taggart said.Report Typo/Error
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