'Pingers' show promise to keep whales away from nets
Acoustical “pingers,” required in some Atlantic Coast fisheries to help porpoises stay out of driftnets, are getting strong reviews from salmon harvesters on both sides of the Gulf of Alaska along with almost desperate interest from others here trying to avoid costly whale encounters.
Federal officials in Alaska have raised the possibility that use of the herring-sized transmitters might amount to “harassment” under the Marine Mammal Protection Act. The Juneau-based distributors who use and sell them, backed by a Kodiak researcher, expressed confidence in their utility and legality.
A recent email from Garland Walker, an attorney in Juneau for the National Oceanic and Atmospheric Administration, stated, “Injury, intent to injure or doing something in negligent fashion that while not intended to injure a marine mammal, would in the view of a reasonably informed person would cause injury to a marine mammal, would be considered harassment.”
Walker, on annual leave, could not be reached for comment. Matt Brown, deputy chief of NOAA enforcement in Juneau, said June 7 that federal managers are planning to discuss the question.
“Some Protected Resources people had concerns,” Brown said of the NOAA division.
“Somebody could try to stretch it to harassment but they would really have to stretch it and in the court system, I would bet, you would very easily be able to defeat it,” said Kathy Hansen.
With her husband Ed, Hansen is a salmon driftnetter and owner of Kathy’s Net Loft and Gear Supply in Juneau, the exclusive Alaska distributor for Fumunda Marine “whale pincers.”
Neither the Hansens nor NOAA released the full email but Kathy Hansen said Walker didn’t say using pingers is illegal but left a question.
“He doesn’t write what people are actually looking for, which is that this is a legal item to use,” she said.
Pingers are pointy-ended tuboids, just over 6 inches long, that contain a small transmitter and lithium battery. When seawater completes the connection between contacts built into the polymer units they emit a mammal-specific signal every five seconds.
Pingers were first used more than a decade ago, attached along the top of shark nets along swimming beaches, to prevent dolphin entanglement.
Fumunda, headquartered in Sippy Down, Queensland, developed their use, at a lower frequency, for humpback whale avoidance in response to a population growing at ten percent annually, according to James Ross Turner, managing director of Fumunda Pingers Proprietary Ltd.
Unlike their large and small toothed cousins, humpbacks and other baleen whales hear sound much like humans and don’t use “sonar” to send out a signal that bounces off other creatures or things.
Tanglings and interactions off Australian beaches dropped from 14 in 2008 to one in 2010, Turner said.
Success Down Under allowed pingers to migrate to South African beaches where their use is on beach shark nets is also growing. Fumunda now operates in 26 countries and works with academic and government researchers in more than a dozen countries.
Although their first whale-related research use in North America was in a 1992 project to warn humpbacks away from buoy lines in the Newfoundland cod fishery, they didn’t reach Alaska until 2009 when Turner sent several to Kate Wynne, a University of Alaska Fairbanks professor researching marine mammals from Kodiak.
“The reaction, if I can call it that to the deployment of the pingers was pretty well immediate,” Turner said.
Alaska’s humpback whale population is growing at about 7 percent annually, and becoming an increasingly expensive problem for commercial harvesters.
Kathy Hansen, who is also executive director of the Southeast Alaska Fishermen’s Alliance, had been in touch with Wynne on possible solutions.
Wynne said a few Kodiak setnetters gave pingers a “test drive” in 2011 and reported great results.
“They had whales come within, what sounded like about 25 yards, and casually move around the end of the net. That’s why everyone got so excited about them.
“That’s why the word spread throughout the fleet, that these things seem to work very well.”
The Hansens reported similar results in more than a month of use last summer. Their whale encounters “dropped immensely,” said Ed Hansen, who suggested that “pinger” is a poor name.
When strung along a driftnet, they act more like a row of lighthouses warning a humpback that it is approaching a shoreline, he explained.
“It got to the point where, at times, when we would have run away from fishing an area because there were so many whales around, we just quit worrying about it and just continued to set our net, is how comfortable it started to make us feel,” Kathy Hansen said.
This year Wynne is measuring the “whale perspective” on pingers. She plans to attach temporary tags to whales to record the level of sound they receive from a pinger and track their movement.
“We’re hoping to be able to see if they actually are responding to our approach with the pinger at different distance,” Wynne said.
Pingers aren’t very loud. The 3 kilohertz whale pinger broadcasts at 135 decibels, and Wynne is concerned that their tone may be lost to whales amid general background noise, especially if it includes vessel engines.
Wynne also said she’s heard that a Petersburg seine skipper is working out a way to launch a pinger upstream from his net so that it drifts toward the purse and, hopefully, keeps whales away.
“I think it’s very doable,” Wynne said.
She was less optimistic about the Northern Southeast Regional Aquaculture Association’s ongoing use of pingers positioned on buoys along the shoreline near salmon smolt release sights.
Steve Reifenstuhl, NSRAA general manager, agreed but said he’s getting desperate.
“We’ve had tremendous problems with whale predation so we are looking at different strategies,” he said.
Over the last few years chum salmon returns to its Hidden Falls hatchery and a remote release site on nearby Takatz Bay have fallen dramatically. He thinks learned behavior by the Southeast panhandle’s growing whale population may be the reason.
“To think that they can come right back to Hidden Falls is pretty dead certain. I think that they remember feeding strategies and can even teach others,” Reifenstuhl said.
Results from the project weren’t yet available at that time, but the pessimistic outlook is a result of the subtly different use of pingers in this case.
NSRAA is using pingers to keep whales away from a known food source rather than the foreign object that is a net.
“That’s the huge difference, if there’s positive reinforcement. If there’s food on the other end, just alerting them could be worse,” Wynne said.
All of the operations have huge incentives to find a way to keep whales away. Fumunda whale pingers cost $150 each, and have a range of about 100 yards. Salmon driftnets are 200 or 300 six-foot fathoms long, depending on the fishery. That requires an investment of up to $1,200, plus replaceable batteries.
A new seine net can cost $138,000, according to Ed Hansen, while a new salmon driftnet can cost $5,800 and a whale can easily punch a $2,000 hole in a net that is salvageable.
“They’re all looking for some type of humane, or whatever you want to call it, legal, deterrent because these nets are so expensive,” Ed Hansen said.