GOLDEN GATE CETACEAN RESEARCH
Field Studies of Porpoises, Dolphins & Whales
in San Francisco Bay and on the Coast of Northern California
Harbor porpoises (Phocoena phocoena) have returned to San Francisco Bay after an absence of approximately 65 years. Their recent foraging in the Bay may be an indicator of the health of the ecosystem.
We have begun a multi-year assessment to document this population’s abundance and distribution, as well as to examine site fidelity, habitat use and reproductive timing, among other parameters.
While the basic biology of the harbor porpoise is well known (mostly through the examination of strandings), relatively little work has been done on free-ranging behavior. Since our study’s inception in September 2009, observations have been conducted primarily from Cavallo Point, Marin County, and from the pedestrian walkway of the Golden Gate Bridge, resulting in an image database of recognizable animals. This is the most comprehensive photo-identification effort undertaken for this species.
With the issuance of the federal permit to approach the porpoises by boat, we are now able to add more detailed images to the database. We hope to answer several critical questions over time, such as whether the porpoises give birth annually or every other year, and the reasons for the species range reestablishment.
This research is authorized by a Letter of Confirmation issued by the National Marine Fisheries Service.
Project Leader: William Keener
Harbor porpoise entering San Francisco Bay