Fish Farmers' Noise Blasts Whales from B.C. Waters
SIMOON SOUND, British Columbia, Canada, November 7, 2001 (ENS) - Killer whales have fled the waters between Canada's west coast and northern Vancouver Island to avoid loud underwater sounds used by salmon farmers to keep seals away from their fish pens, a marine mammal research team has found.
Two British Columbia whale researchers, Alexandra Morton of Raincoast Research and Helena Symonds of OrcaLab, combined 16 years of data on the movements of killer whales, known as orcas, off northeastern Vancouver Island. Morton says her 13 years of data show a 67 percent decline in killer whale activity since acoustic harassment aimed at seals began.
Their study has been accepted for publication by the "Journal of Marine Science" issued by Denmark's International Council for Exploration of the Sea.
In 1993, salmon farmers began broadcasting a 195 decibel noise, which is as loud as a jet engine at take-off, in an attempt to keep harbor seals from attacking their slow swimming penned fish.
The acoustic harassment devices work by causing pain in the ears of the marine mammals. If they come too close, they are deafened.
"It was as if a door slammed in their face," said Morton of the orcas' reactions. "The salmon farmers were only concerned with seals, but it was the whales that left, immediately abandoning over 300 square kilometers (116 square miles) of territory, wherever salmon farms used acoustic harassment. Whales can not risk their hearing."
Whales rely on sound for their livelihood, vocalizing not only to communicate, but also to navigate, find food and mate.
Morton first alerted Fisheries and Oceans Canada (DFO), the agency responsible for the protection of marine mammals in Canadian waters, to the potential harm of these noisemaking devices. In response to her concerns, DFO conducted a controlled study measuring impact of the noisemakers on harbor porpoises. The results were the same, says Morton. "Harbor porpoise abundance declined precipitously" when the noise was played.
The DFO never published this study, but Morton says it confirmed what some fish farmers suspected, that the noisy devices, rather than deterring seals, actually attract them "in a dinner bell effect." The farmers claimed the devices are required by insurance companies.
"DFO continues to ignore even their own scientists to support the growth of the fish farm industry," said Morton, "While I know biologists of great integrity within DFO, I was horrified to find that DFO policymakers had no intention of protecting whales. There was nothing I could do to inspire them to uphold the Fisheries Act."
Under Canada's Fisheries Act, the disturbance of whales, dolphins and porpoises is specifically prohibited and offences carry a fine of $500,000 or a 24 month prison term.
"DFO's responsibilities were clear. Acoustic harassment devices contraven the Fisheries Act and should have been banned outright," said Morton.
The BCSFA points out that the aquaculture industry employs 3,000 people and eases the pressure of consumer appetite, conserving wild fish populations while satisfying the growing worldwide demand for high quality seafood.
The provincial Environmental Assessment Office produced a 1998 Salmon Aquaculture Review that noted the harmful effects of noise blasts on all marine mammals near fish farms. "Species occurring commonly in protected waters and potentially in the vicinity of fish farms with acoustic deterrent devices (ADDs), in addition to harbour porpoise, include Pacific white-sided dolphins, Dall's porpoise, killer whales, humpback whales, minke whales and gray whales," the review pointed out.
The noisy devices may not work to deter the targeted seals. The government review acknowledged that studies of seals' response to ADDs suggest that "they may eventually habituate to the sound or lose hearing sensitivity in the frequency range of the ADD signal."
After five continuous years of use, the farmers turned the devices near Morton's research station off for undisclosed reasons. Within two years some whale families began to return. "Our initial results were confirmed," said Morton. "But, resident pods with young babies have not returned. I suspect, the matriarchs still don't trust this place."
"It has been very sad to see the orcas turn away from inlets which once belonged to them," Morton mourned. "I made the Broughton Archipelago my research base 18 years ago because when I first arrived whales could make a living in these waters. I would not make that same choice today. The fish farms have interfered carelessly with the natural web of life in the Archipelago."
Letter from Morton to the Canadian Government
Visit OrcaLab at: http://www.orcalab.org/
Read the 1998 B.C. Salmon Aquaculture Review online.