A microcosm system for the study of pollution effects in shallow, sandy, subtidal communities

The introduction of pollutants into the marine environment is inevitable, so an understanding of their effects is needed. Because shallow, coastal waters are at greatest risk and many of these shorelines are sandy, a test system for the shallow, sandy, subtidal environment is required. We developed a microcosm system for this purpose and tested it for three months to determine whether the benthic community remained healthy. Furthermore, because long-term effects on the environment occur primarily in the sediment, an experimental method for administering pollutants to the sediment is necessary. We administered a 1-mm layer of clean sand (simulating a technique of administering pollutants as a coating on sand) and tested the benthic community for artifactual effects of the sand itself. Fifteen metrics of community health, including the abundance of benthic microalgae, nematodes, and copepods, were measured. Most metrics were not significantly affected either by containment in the microcosms or by the addition of a 1-mm layer of clean sand. These microcosms are suitable as a test system for the shallow, sandy, subtidal environment.