Use of benthic foraminifera as environmental indicators in Budd Inlet, Puget Sound

Abstract

The pollution of coastal and estuarine environments is of growing concern as it potentially threatens ecosystems, economies, and the public health of people living in these areas. Budd Inlet’s circulation is relatively fast compared to similar inlets within Puget Sound, but it is still marked by water quality issues as a result of wastewater, lumber, and aquaculture pollution discharge. Foraminifera are frequently used in environmental studies to determine past and present parameters such as changes in temperature, pH, sea level, salinity, and the availability of dissolved oxygen. This thesis seeks to further investigate foraminifera population dynamics within Budd Inlet and the potential impact of point and nonpoint source pollution on their ecosystem. Investigation of Budd Inlet population showed a dominance of Ammonia beccarii at all sites, and a high number of tests with abnormal growth patterns. A selection of these abnormal tests were examined with SEM and MicroCT analysis. Ecology results showed that foraminifera populations decreased from the south to north of the inlet in correlation with C/N ratios, while the proportion of abnormal to normal tests increased. Finally, this thesis examined the fidelity of two sample processing methods and confirmed a <10% difference in the number of foraminifera acquired with traditional sieving and picking compared to the SPT floating method.