After a 65-year absence, harbor porpoises are back in San Francisco Bay, providing scientists a unique view into their lives.
Marine biologists are studying some of San Francisco’s least-known residents from an unlikely laboratory: the Golden Gate Bridge. Through binoculars, Bill Keener suddenly spots a harbor porpoise, its dark gray dorsal fin appearing briefly before re-submerging. Keener predicts the porpoise’s course and, just as it surfaces again, photographs the animal before it disappears. “Got it,” he declares triumphantly.
This harbor porpoise is one of more than 600 that Keener and the other marine mammal scientists of Golden Gate Cetacean Research have recorded in the San Francisco Bay since 2008, compiling the world’s first photo catalog of wild harbor porpoises.
“What was known about harbor porpoises until now has mainly been from dead, dying or captive animals,” says Keener, “It’s an avocation rather than a vocation,” Szczepaniak says, grinning.
With financial support from the National Wildlife Federation and its donors, the researchers are taking advantage of unique circumstances that are bringing the behavior of these normally elusive animals to light. Because porpoises predictably gather in deep, turbulent waters near the Golden Gate at high tides, presumably following small fish that school there to eat accumulated plankton, the scientists closely observe and photograph the animals either from the bridge or a nearby shore without changing their behavior. “We are getting this wonderful, natural glimpse into their lives that no one has ever had before,” says Webber. This is remarkable given that just six years ago no porpoises were found in the bay.
Happy Humpday (^_^)