News & Events
Friday, June 5, 2009
The Noisy Sea
Underwater audio recordings are proving to be an important piece of evidence used in whale research by the Oceans Initiative Marine Wilderness Project at Tides Canada. Marine biologists Erin Ashe and Dr. Rob Williams (who popped out of meetings in Madeira, Portugal at the International Whaling Commission to write to us) explain Canada’s role in marine conservation and why recording sea sounds might prove a lifeline to whale survival.
"Canadians can be proud to celebrate World Oceans Day. Canada’s proposal to the 1992 Earth Summit in Rio provided an impetus for its enactment. Despite some failures along the way, Canada has made many marine conservation gains since 1992. In particular, the passing of the Species at Risk Act (SARA) created an obligation to initiate recovery plans for 16 threatened and endangered marine mammal populations in Canada
Killer whales are iconic in our area for a reason – they lead exceptional lives. Our populations of killer whales are among the best-studied whales on the planet. Every individual is known from long-term photo-identification studies conducted by Fisheries and Oceans Canada, and these whales are unique among mammals in that both sons and daughters stay with their mothers and families their entire lives. Their populations are small, and have undergone dramatic declines recently.
Killer whales need a quiet ocean to find food.
Canada’s recovery plan will require us to maintain the whales’ habitat to protect its acoustic attributes and prey species. Declining wild salmon stocks and increasing ocean noise conspire to make those basic needs difficult to meet.
In 2008, the Scientific Committee of the International Whaling Commission endorsed a goal of global action that will reduce the contributions of shipping to ambient noise energy in the 10-300 Hz band by 3dB in 10 years and by 10dB in 30 years relative to current levels.
Underwater microphones
Last year, Oceans Initiative and Pacific Wild, another project of Tides Canada, deployed underwater listening devices to collect information on how loud or quiet BC coastal waters are compared to the rest of the world, and whether certain areas get loud enough to disrupt the foraging or communication abilities of killer whales or other marine mammals. We plan to deploy two more hydrophones this summer, and hope that our work can provide a current acoustic baseline against which future industrial development applications, such as oil tanker traffic, can be evaluated.
Our long-term hope is that quiet areas can be identified, and then protected as acoustic refuges that are integrated into Canada’s National Marine Conservation Areas strategy. Our main interest is in conducting research on topics and species that are not yet on the conservation radar, like minke whales and Pacific white-sided dolphins, which are understudied.
A regional or global approach is required when working with highly mobile and migratory species like humpback whales, which cross international jurisdictions when they undertake one of the longest migrations of any mammal. During their migration from breeding grounds in Hawaii to their feeding grounds in BC and Alaska, humpback whales run a gauntlet of human-generated threats including floating plastic garbage, noise from marine traffic, entanglement in fishing gear, and ship strikes. Recently, a humpback whale was struck and killed by an oil tanker in Alaska, while another was successfully disentangled from fishing gear in inshore BC waters.
We all play a role
The threats that marine mammals face now are more subtle than harpoons; there are serious, but insidious threats to ocean habitat. All nations contribute to climate change; we all use the plastic and fishing gear that can entangle wildlife; and we all use the oil and goods that are shipped, noisily, across oceans, thereby putting marine mammals in danger. Together, we can work to understand these threats and to develop solutions necessary to protect our oceans and the whales that live in them."
Learn more about the Oceans Initiative Marine Wilderness Project:
Erin and Rob conduct research on marine wildlife in British Columbia (BC). They have studied baleen whales in the Antarctic and river dolphins in the Amazon, but work primarily in Pacific Canadian waters, namely, by surveying the animals and habitat between the waters surveyed by US Federal agencies in California, Oregon and Washington and Alaska. They partner on marine conservation projects with government agencies, non-government organizations and First Nations. Rob has been a member of the Scientific Committee of the International Whaling Commission since 2001.
