Research Technical Report

Monitoring Beachcast Seabirds In Monterey Bay

Benson, S.R., A. DeVogelaere, and J.T. Harvey (1998)

Sanctuary Currents Symposium, March 1998

ABSTRACT

In May 1997, a monitoring study of beachcast birds and mammals was established in the Monterey Bay region. During weekly and monthly surveys, trained volunteers systematically searched 47km of sandy beaches along Monterey and Carmel Bays. The primary goal was to assess trends in the distribution and abundance of beachcast seabirds, and assist the Monterey Bay Sanctuary program with early detection of mortality events caused by natural and anthropogenic perturbations. Secondary objectives of the program were to determine the appropriate sampling frequency for beachcast monitoring, and assess the effects of time-of-day and tidal cycles on deposition rates. During the first six months of the program, the most common beachcast seabirds were Common Murre (Uria aalge) and Sooty Shearwater (Puffinus griseus). Two significant deposition events occurred: greater than 400 Common Murres were deposited along beaches in the southern half of the bay during late August (cause undetermined), and greater than 400 birds were impacted by a spill event in the northern half of the bay in October. Although designed largely to identify long-term patterns, this monitoring study has demonstrated its usefulness in resource management over a short six-month period.