Scouting for Sea Sounds
A Listening Trip with Seaflow
A low, eerie moaning drifted across the docks in San Francisco's Gashouse Cove, followed by a burst of loud crackling. I walked through the entry to Fort Mason and found a group of about 50 people, bundled in jackets and woolly hats, huddled around a tape recorder. It was cold here in the early-morning fog, and we expected that soon we would be much colder, as we headed out the Golden Gate toward the Farallon Islands aboard Captain Joe Nazar's catamaran Kitty Kat.
Along the way we hoped to see many kinds of wildlife, but first we were getting to listen to some sounds from under the water: recordings of whales, snapping shrimp, and noise from ships' propellers played for us by Roger Bland, professor of physics and astronomy at San Francisco State University and an expert in underwater acoustics. Bland would be riding along with us to make more recordings, and to allow passengers to listen in on passing ships and other underwater noise. (No whale songs, though--their low-frequency vocalizations must be converted to a higher pitch before humans can hear them.)
This late-September voyage was one of five special trips in 2008 arranged by Seaflow, a nonprofit organization dedicated to protecting marine life from ocean noise pollution, and the SF Bay Whale Watching company. In addition to looking for wildlife, passengers on these trips learned about the dangers that vessel traffic poses to marine animals within the Gulf of the Farallones National Marine Sanctuary, from oil spills and collisions to the noise pollution that may disrupt the animals' ability to communicate (see Chronic Ocean Noise). On each trip, Seaflow staff also collected data on the ships they encountered, recording the size, speed, location, name, and nationality, obtained through the ships' electronic identification system. Jackie Dragon, the group's campaigns director, told me that they have found that many ships are violating the (voluntary) speed limits in the Sanctuary, and that they don't always stay within the designated shipping lanes, cutting corners to make better time.
Aboard the Kitty Kat, we spotted a container ship just outside the Golden Gate, the first of many we would see that day. Bland dropped his hydrophone, an underwater microphone, over the side, but the ship was too far away and the wave churn too loud for us to hear its propeller. Nazar tried to get us closer to the huge vessel, but it picked up speed and was soon far out to sea. Not long after, we saw our first humpback whale, and turned to the day's main business: enjoying the abundant wildlife above and below the waves.
As we motored toward the Farallons, the sun emerged from the fog and schools of dolphins leapt alongside our bow. Jellies drifted by. We saw pairs of humpbacks, and even a small pod of five or six whales, and Bland was able to make some new recordings. Naturalist Melinda Nakagawa helped us identify birds, including cormorants, phalaropes, and sooty shearwaters. Up close, the rocky, desolate-appearing Farallons were bustling with activity, pelicans and murres crowding the rocks, the waters just offshore swirling with fat, sleek sea lions. In spring and summer, when more than 400,000 seabirds may nest here, the stench and noise can be overpowering. This late in the year the smell was quite faint, a blessing for those in our group with queasy stomachs.
Also aboard was French entrepreneur Pierre Lavagne, and along the way he demonstrated an instrument he invented, the Shelltone, which you can blow into to make sounds that he said are "inspired by the ocean and by whale songs." The idea came to Lavagne on a beach one day, and he spent the next two years working with acoustic engineers and musicians to design and build the instrument. Made of molded plastic in the form of a conch shell, it produced a sound like a moose in pain. I asked what he planned to do with it. "You tell me!" he replied.
As we headed for home, exhausted but exhilarated, two container ships loomed out of the fog still hanging over the Golden Gate. We were running late, though, and there was no time to stop and listen.
The next Vessel Watch whale watching trips are scheduled from September through November 2009 and will be run by Pacific Environment (http://www.vesselwatchproject.org/).