Rocky intertidal resources monitoring handbook Cabrillo National Monument Point Loma, San Diego, California

Engle, John; Davis, Gary

Describes rocky intertidal monitoring program background and methods: survey sites, target species, fixed plots and transects, scheduling, personnel, logistics, videoing, photoplot surveys, circular plot surveys, line intercept transect surveys, timed searched, visitor and bird census, data management. Includes maps. Long-term monitoring of biological resources and public use in rocky intertidal habitats at Cabrillo National Monument was initiated in 1990 in order to assess dynamic ecological conditions with respect to impacts from public visitation and other human activities in the San Diego metropolitan area. Public access to the monument's intertidal zone is restricted to a single point on the western coast of Point Loma approximately 800 m north of the tip of the peninsula (Figs. 1 & 2). From this point, visitors can explore about 1 km of open ocean shoreline without crossing deep channels that extend to the base of steep cliffs, or moving around the southern tip of the Point into San Diego Bay. This situation creates an apparent gradient of public use extending from the access location downcoast to the Point. The resource monitoring stations were stratified into 3 areas along this presumed human use gradient, with each area encompassing roughly 330 m of shoreline (Fig. 2). Each of the survey locations, designated Area I, Area II, and Area III (Figs. 1 & 2), have been monitored semi-annually (Spring and Fall) for the past 6 yr. Two sites north of the Monument, Navy North and South (Fig. 1), have been monitored in 1995 using the same techniques. A separate manual has been developed for the Navy sites. Continued monitoring of all 5 sites in future years is highly recommended. Biological surveys at these locations provide quantitative seasonal data for index species in fixed plots or transects, and qualitative inventory data for other plants and animals whenever possible. In addition, Cabrillo National Monument personnel collect data on prevailing sea/weather conditions and abundances of birds and visitors at the Monument sites whenever possible during daytime low tide periods. This handbook provides guidelines and specifies procedures for monitoring target species assemblages at Area I, Area II And Area III rocky intertidal sites at the Cabrillo National Monument, Point Loma, San Diego. The handbook will help survey teams prepare for surveys, locate the permanent study plots and standardize sampling procedures for future surveys at these sites, either for continued seasonal monitoring or for impact prevention or assessment studies should the need arise. Visitor and bird census methods and survey data management techniques also are described.

Rocky intertidal resources monitoring handbook Cabrillo National Monument Point Loma, San Diego, California

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