Researchers puzzled by humpback 'whale wave' off B.C. coast
A new study of humpback whales off the northern BC coast has detected a previously undetected “wave” pattern in terms of their habitats. Researchers from the Gitga’at First Nation, the North Coast Cetacean Society, and the Scripps Institution of Oceanography and the University of California say the findings has implications for whale conservation and raises the effect of industrial use of the northern BC waterways. (FILES)
A decade-long study on humpback whales in B.C.’s north coast has found a previously undetected pattern of movement for humpbacks — a discovery researchers say has implications for whale conservation in light of potential industrial projects in the area.
Researchers surveyed humpback whales in the Kitimat fiord system between 2005 and 2014 and discovered the mammals move in a “wave” pattern from the outer channels in the spring inward into the fiords in the fall.
“The big question is why,” said Janie Wray, lead researcher at the North Coast Cetacean Society, which runs a research facility on Gil Island, south of Hartley Bay.
The pattern has not been recorded in other humpback whale populations in similar habitats, partly because few studies involve long-term monitoring.
The study also coincided with the return of the humpback whales in the area — a drastic increase from 42 in 2004 to well over 430 in 2016 — which made the pattern observable, added Wray.
Researchers used to think whale movements were based on the pursuit of food, but models have shown the “whale wave” is likely driven by other factors, such as social reasons or communication needs.
“We think there is a social component we don’t quite understand just yet,” said Wray. “It could be companionship. Given whales are really quite vocal creatures, it could be acoustics of a particular area.”
The study, published in the marine science journal Marine Ecology Progress Series, is a collaboration by researchers from the North Coast Cetacean Society, the Gitga’at First Nation, the Scripps Institution of Oceanography at the University of California, and the U.S. National Oceanic and Atmospheric Administration’s Southwest Fisheries Science Centre.
The study also found some humpbacks skip the usual migration to warmer waters near Hawaii in the winter, opting to remain in the protected channels year-round.
“We’re guess that maybe they’re not leaving because they don’t have to,” said Wray. “They probably think they’ve found paradise here … a safe place to feed and bring their calves.”
That could change if projects such as the proposed LNG Canada plant in Kitimat pushes through, bringing with it increased tanker traffic.
The study appears to indicate humpbacks develop behaviours coordinated to the specific oceanography of the fiord system, noted lead author Eric Keen from the Scripps Institution of Oceanography.
“We can’t expect these whales to simply pick up and go somewhere else if industrial activities, such as shipping lanes, disrupt continuity of critical habitats like the Douglas Channel fiord system,” he said.