(full paper is archived in the Miller Library)
Title: Spatial variation in reproduction of the acorn barnacle, Balanus glandula, and its implications for marine reserves
Student Author(s): Chaplin, Becky
Faculty Advisor(s): Denny, Mark
%E Somero, George
Location: Final Papers Biology 175H
Date: June 2001
Abstract: Understanding source-sink dynamics is critical to successful design of marine reserves. Determining what conditions optimize the production and quality of larvae is a crucial step in identifying optimal source habitat. Water temperature may be an important factor to consider since it influences reproduction and growth in many marine species. During spring upwelling, water temperatures within Monterey Bay, California are generally 2º to 3º C warmer than at nearby open coast sites. Egg size and allocation to reproduction (reproductive effort) were measured in the acorn barnacle Balanus glandula collected from 3 populations within Monterey Bay and 3 open coast populations outside of the bay. Additional collections were made in Southern California and Oregon to test for a latitudinal gradient in embryo size. Egg size did not vary between Southern California and Oregon barnacles. Within Central California, however, eggs were roughly 10% larger at the colder open coast sites than within Monterey Bay. Differences in reproductive effort were not correlated with habitat type (bay vs. open coast); rather, the three northernmost sites had lower reproductive effort than the three southernmost sites. Further study quantifying food availability and barnacle growth rates are needed. However, this study suggests that substantial variation may exist in the quantity and quality of barnacle larvae produced by closely spaced sites. Such variation should be considered when siting marine reserves.