B.C. has the opportunity to conserve “globally rare” quiet habitat for endangered and noise-sensitive whales and dolphins, but fast action is required, say the authors of a new study.

At least 20 liquefied natural gas plants are proposed for the B.C. coast, which could add thousands of tanker trips a year to coastal waters from Howe Sound to the Hecate Strait, the body of water between Haida Gwaii and the mainland near Kitimat and Prince Rupert.

But ocean noise from shipping and other marine traffic is disruptive to marine mammals — and likely many other species — causing the animals stress, disrupting navigation, feeding and their ability to detect predators over vast areas. Noise travels hundreds of times farther in water than air, according to the study published in Marine Pollution Bulletin.

“The science part is easy,” said lead author Rob Williams, a Pew Fellow in Marine Conservation, affiliated with University of St. Andrews and co-founder of Oceans Initiative. “The more we look at the problems caused by ocean noise on whales and fish, the more we find.”

The looming problem for marine animals in B.C. waters is that tanker traffic associated with port expansions and LNG projects promises to make a considerable din.

“The difficult is making policy and management and getting the ear of legislators,” said Williams. “The longer we wait the harder this gets.”

Williams cited the plight of southern resident killer whales, which are “just hanging on.”

“Every year we count and there might be 78 or 81 and we celebrate the birth of every calf,” he said.

The researchers mapped the areas of B.C.’s coast frequented most by Minke whales, orcas, white-sided dolphins porpoises and elephant seals among others and also identified areas with the most intense acoustic pollution.

“Marine animals, especially whales, depend on a naturally quiet ocean for survival, but humans are polluting major portions of the ocean with noise, said co-author Christopher Clark, a bioacoustics researcher at Cornell University. “We must make every effort to protect quiet ocean regions now, before they grow too noisy from the din of our activities.”

The good news is that many of the areas most densely populated by the study’s target species are relatively quiet and could be kept that way with minimal disruption to existing marine traffic, possibly by adding noise to the threats mitigated by existing Marine Protected Areas.

“When protecting highly mobile and migratory species that are poorly studied, it may make sense to focus on threats rather than the animals themselves,” said co-author Erin Ashe, a founder of Oceans Initative. “Shipping patterns decided by humans are often more predictable than the movements of whales and dolphins.”

The researchers have mapped important habitat for whales that are still quiet, mainly in coastal waters between the northern tip of Vancouver Island and Prince Rupert. Rather than focus on areas already subject to acoustic pollution, the researchers instead created “opportunity maps” of areas that can still be saved.

“If we think of quiet, wild oceans as a natural resource, we are lucky that Canada is blessed with globally rare pockets of acoustic wilderness,” said Williams. “It makes sense to talk about protecting acoustic sanctuaries before we lose them.”

rshore@vancouversun.com