long-term monitoring photo plot surveys of rocky intertidal ecosystems

The Baseline surveys of rocky intertidal ecosystems (SC) project includes both Long-Term Monitoring and Biodiversity Surveys done in the SouthCoast of California. Long-Term Monitoring Surveys use fixed plots to document changes in percent cover, or abundance of targeted species or species assemblages. This fixed-plot approach allows the dynamics of rocky intertidal species to be monitored with reasonable sampling effort and provides sufficient statistical power to detect changes over space or time. Biodiversity Surveys provide detailed information about biodiversity and community structure. These surveys were designed to measure diversity and abundance of algae and invertebrates found within rocky intertidal communities on the western coast of temperate North America. This metadata record documents the Long-Term Monitoring Photo Plot Surveys. Photoplots are used to monitor abundance of organisms within target assemblages. In general, 5 replicate plots (50 x 75 cm) are placed in a stratified random manner throughout the target species' zone of maximum abundance. Plots are photographed in the field, and are scored for percent cover using a grid of 100 points either in the field or in the lab from photos. A species, higher taxon, or substrate located below each of the 100 points is identified and recorded. Layering is not scored separately, so the total cover is 100 percent. Long-Term Monitoring Surveys are comprised of one or more of the following procedures: 1) Photoplots used to monitor percent cover in assemblages such as barnacles, mussels, and rockweed, as well as small, mobile species such as snails and hermit crabs, 2) Line transects used to estimate cover of surfgrass, kelps and other algae not well-sampled by photoplots. 3) Irregular plots used for counts and sizes of large, mobile species such as seastars and limpets. Long-Term Monitoring Surveys are done throughout the year at sites ranging from Alaska to Southern California.