Endangered Right Whale Breeding Ground amid Shipping Lane Surveyed with Acoustic Monitoring Devices

A new report from Syracuse University details mating habits in an endangered North Atlantic right whale breeding ground off the Nova Scotia coast that's right in the middle of a heavily trafficked shipping lane.

Writing in the journal PLOS One, the researchers, report on the use of remote acoustic monitoring that enabled them to pinpoint the right whale breeding ground in the Roseway Basin.

"Remote acoustic monitoring is an important tool for understanding patterns in animal communication, and studies on the seasonality of context-specific acoustic signals allow inferences to be made about the behavior and habitat use of certain species," said study author Susan Parks, a behavioral ecology, acoustic communication and marine science expert at Syarcuse. "Our results support the hypothesis that the North Atlantic right whale's breeding season occurs mostly from August to November and that this basin is a widely used habitat area."

Parks and her collaborators, doctoral students Leanna Matthews and Jessica McCordic, report that 30 percent of North Atlantic right whales use the Roseway Basin throughout the year.

With only 400-500 individuals in existence, the Roseway Basin, which is part of a larger geological formation called the Scotian Shelf, is an essential meeting ground for endangered right whales.

Both the US and Canadian governments have taken steps to restrict shipping activity in the Roseway Basin, and the new research will enable lawmakers to make more informed decisions on how to regulate shipping traffic through or around the breeding ground.

The researchers used remote acoustic monitoring to monitor male whale breeding activities.

"Part of the answer lies in a loud 'gunshot' sound, made by the male whale," said Matthews, the article's lead author. "We're not exactly sure what the gunshot is, but we think it may be a male-to-male antagonistic signal or an advertisement to females. During a two-year period, we used non-invasive acoustic monitoring to analyze gunshots at two locations on the Scotian Shelf. The resultant data has provided tremendous insights into the whales' feeding and mating habits."

The analysis of this gunshot sound revealed it occurred mainly in the autumn months and mostly at night. In a news release, study co-author McCordic said the observed seasonal increase in gunshot sound production is consistent with the current understanding of the right whale breeding season.

"Our results demonstrate that detection of gunshots with remote acoustic monitoring can be a reliable way to track shifts in distribution and changes in acoustic behavior, including possible mating activities," she said. "It also provides a better understanding of right whale behavior and what needs to be done with future conservation efforts."