Sampling Variation in Sandy Beach Littoral and Nearshore Meiofauna and Macrofauna.

摘要

This study evaluates sampling procedures and statistical methos for analysis of the fauna assoicated with high-energy sandy beaches. A intensive, one-season sampling of selected physical attributes and fauna of a relatively undistrubed beach site in central Monterey Bay, Calif., was used as a basis for this evaluation. Organisms were sorted and identified to the lowest possible taxonomic level and numerical abundances were computed. Existing techniques for quantitative sampling of macrofauna in the littoral zone are adequate for quantitative base-line studies, but many samples must be taken to ensure reasonable confidence limits on density estimates. It may not be practical to attempt density estimates of certain macrofaunal species, such as the mole crab which show extreme spatial heterogeneity. A procedure was devised for sampling surf-zone macrofauna using a suction dredge. Surf-zone fauna differs greatly from littoral macro-fauna and appears to be a separate ecological unit. Area sampling the surf zone is difficult due to surge, so a time-of-pumping standardization is recommended. Meiofauna shows distinct intertidal zonation patterns both in density and taxonomical composition. Considerable variation from one beach site to another can occur and this may be related to small changes in physical factors, especially interstitial space.