PILOT STUDY USING FORAMINIFERA TO ASSESS AND MONITOR THE HEALTH OF PUGET SOUND

This study reports on a preliminary investigation of foraminifera in two of the most highly degraded area of Puget Sound, Elliott Bay in Seattle and Commencement Bay in Tacoma, Washington, U.S.A. Foraminiferal samples and sediment quality data provided by NOAA and the Department of Ecology span the period from 1997 to 2010, allowing an assessment of foraminiferal populations over time correlated with their environmental parameters. The Puget Sound is a regional depression lying between the Olympic Mountains on the west and the Cascade Mountains on the east, and consists of four glacially-carved, fjord-type basins separated by relatively deep sills. Strong tidal flows combined with large fluvial run-off results in vigorous mixing in most of the Sound, although some parts experience periodic hypoxia events. Puget Sound is influenced heavily by run-off from watersheds on both the east and west sides, many of which flow through densely populated areas. Based on high chemical concentrations, responses to toxicity tests, and altered macrobenthos, 1% of Puget Sound sediment is considered significantly degraded, however, these conditions are concentrated in the urban waterways of Seattle, Tacoma, Everett, and Bremerton. In addition, recent studies indicate pH decreases due to ocean acidification and anthropogenically stimulated respiration processes may profoundly impact the Puget Sound ecosystem. Although foraminifera have been used successfully in pollution studies in numerous localities worldwide, they have not previously been employed in Puget Sound. Results of this study indicate foraminiferal populations display low diversity, populations dominated by pollution-tolerant species and, in many instances, a paucity of agglutinate taxa. In addition, there is a notable absence of Ammonia beccari, a species generally abundant in coastal waterways.