CANARIES IN THE COAL MINE: BENTHIC FORAMINIFERA IN THE ASSESSMENT OF PUGET SOUND, WASHINGTON STATE, BENTHIC ENVIRONMENTS

Benthic foraminifera have been widely used in monitoring marine ecosystems, particularly in polluted estuaries; in Puget Sound, however, their use is relatively new. Puget Sound is the second-largest estuary in the US, with an area of 2642 km². Industrialization in the Sound began in the late 19^th century and continues today, leaving a legacy of pollution resulting from logging, paper production, shipping, military activities, numerous light and heavy industries and agriculture. Using sediment samples collected by the Washington Department of Ecology, the Burke Museum Foram Research Project assesses foraminiferal assemblage characteristics to evaluate the health of benthic ecosystems and monitor the impacts of mitigation efforts. In addition to assemblage composition, density and diversity characteristics of each sample, we measure the dissolution effects observed in calcareous taxa. This particular study reports on results seen in four of the most anthropogenically-impacted embayments in the Sound: Commencement, Elliott and Bellingham bays and Sinclair/Dyes inlets over a temporal range from 1974 to 2014. Pollution remediation efforts started at different times in each of these, but have generally been ongoing since the late 1990s, thus our study includes data from pre- and post-mitigation measures. In general, results are not encouraging. Although Department of Ecology studies indicate the chemical conditions in the Sound have improved and are now within limits deemed to be acceptable, benthic foraminiferal assemblages tell a different story. While some improvement has been seen in Elliot and Commencement bays, Bellingham Bay and Sinclair/Dyes inlets have suffered a near-collapse in foraminifera in recent sampling cycles. This has been mirrored by the macro-benthos studied by Ecology biologists. Foraminiferal dissolution also shows increases, and in Bellingham Bay, many stations have either become barren or no longer have any calcareous foraminifera. Thus, benthic foraminifera are acting as canaries in the coal mine, telling us there is still something seriously wrong with the environment, and spurring us to find a parameter or combination of parameters that more realistically measures the state of the ecosystem.