Volunteers for Islands Oil Spill Association (IOSA) have regularly been practicing maneuvers in the event of an oil spill in the San Juan Islands, but their latest endeavor targeted our beloved Southern Resident orcas as well.
With the islands being so remote, it would take precious hours before rescue crews could arrive here to control or contain any spilled toxin and mitigate damage to the environment and wildlife. Think of the devastation caused by the Exxon Valdez in Prince William Sound in 1989, and you have an inkling of what could happen here.
The IOSA drills include rescue of oiled wildlife from beaches, and setting long flotation devices known as “boom” in designated areas to cordon off oil and channel it to collection points.
Recently the volunteers worked on a new drill, which included not only setting boom, but gave attention to directing killer whales away from the spill, similar to herding them.
The procedure was done successfully in Barnes Lake, Alaska, where killer whales somehow wound up in a lake and were starving. Experts surmised they were chasing salmon upriver and got caught in the lake when the tide went down, and were either too scared or uncertain to go back down the river on the next high tide. The concept to get them out was relatively simple, but the timing of the execution was critical.
In both the Alaska project and the March IOSA drill, volunteers in small boats strung out across the designated channel. On each boat they rigged long hollow steel pipes (Oikami pipes) hanging down into the water from the sides of the boats. Similar to tubular wind chimes, the pipes make a resonating sound when banged on with a metal object such as a hammer; this sound is amplified through the water, and the semi-circle configuration of the boats creates almost a sound curtain across the pass. As the whales enter the area, the boats gradually close the circle tighter, leaving an opening for the whales to turn around and head out. Though the sound is very unlikely to do physical harm to the whales, they don’t like it, so they move away from the sound; in the event of an oil spill, they would essentially be herded away from the area coated by deadly oil on the surface of the water.
That’s the theory. It worked in the case in Alaska; whether it would work here, we hope we never have to find out. But interestingly, the volunteers learned there’s more to it than just banging on some old pipes. The sounds were monitored by hydrophone so they tried chiming the pipes at distances from 100 to 800 yards from the hydrophone to determine the strength of the sounds. They tried them with the pipes empty (normal) and then flooded. They tried to synchronize the banging to increase the signal strength, but found without more advanced technology that would be impossible. They also discovered that eye protection is needed for all crew as chards of metal flew off the pipes when they were banged on the top. Likewise, banging on the rim distorted the rim and “shredded” the top of the pipe, requiring that they later be filed down to avoid sharp or rough edges that might cut volunteers on future drills. The pipes needed to be weighted on the bottom so they will stay in place and chime properly when the vessel is underway and the “sound curtain” is being tightened or re-directed.
The hydrophone crew posted a brief recording of the exercise, so curious whale lovers can hear what it sounds like, though of course, we’ll never know what it sounds like to an orca.
Who could have imagined that such a simple-sounding exercise could be so intricate? We are grateful to all the staff and volunteers of IOSA, Soundwatch, and agency reps/marine mammal researchers who participated in the drill, and continue their vigilance for the safety of the magnificent killer whales who grace these waters.