Microphones in bay could help right whales

BY ALISON AULD
Canadian Press
September 30/02

    HALIFAX - The sound rises up from the ocean floor like a deep, throaty groan.
   The calls, similar to the plaintive moans of an elephant, are the mysterious communications of the North Atlantic right whale and are becoming an increasingly important tool in trying to save the giant marine mammals.
    "You can use this data for monitoring when the animals arrive, when they leave, how they move on a day-to-day basis," says Chris Taggart, a fisheries oceanographer at Dalhousie University in Halifax.
   Mr. Taggart and a team of scientists are part of a growing research community that is using the whale's distinct calls to learn more about its social habits and to find ways to protect it from its biggest threats - ship strikes and fishing gear.
   Mr. Taggart's group placed an array of hydrophones, or . submersible microphones, on the bottom of the bay, where some of the world's 300 remaining right whales congregate every summer to feed on rich supplies of plankton.
   Scientists recorded sounds for about a week and are trying to isolate and identify them as right-whale calls. Once they do, they're hoping to have hydrophones continuously listen for the whales so they can alert ships passing through the busy channel.
   The information from permanent hydrophones would be almost instantly passed on to a central traffic-control station and then relayed to vessels, allowing them to reroute and steer clear of the animals.
   "Most of the information now used to have vessels avoid whales is based on either very intermittent airborne surveys and opportunistic ship observations," Mr. Taggart said after returning from the bay last week.
   "That's useless at night and in the fog and it's not real time. With acoustic monitoring, one could monitor continuously and you can use that information directly to alter ship traffic.
   "We're just trying to solve the problem."
   Every year, the right whale population is threatened as the slow-moving animals are struck and killed by vessels steaming through their habitats. Scientists say part of the problem is that there is no proof the whales know what a ship is and that it can harm them.
   It's just one of many mysteries surrounding the creature, whose communications are also being studied for their social meaning.
   Susan Parks, an American scientist working out of Lubek, Maine, has been collecting audio recordings of the whale for several weeks in the bay, hoping to learn more about an animal whose behaviour still puzzles experts.
   "They have a pretty diverse repertoire and it hasn't gotten the same attention as humpbacks because they don't really seem to produce a song," says Ms. Parks.
   Ms. Parks is analyzing the species by playing back their own calls to groups that congregate on the water's surface. In many cases, they are drawn to the sounds, indicating they might use them to attract other whales for socialization or mating purposes.
   What's unusual about the right whales is that it is usually the female who is making the calls and she is often the only one in a group of several males.

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