DISTRIBUTION OF FORAMINIFERA IN THE NISQUALLY DELTA AREA OF THE SOUTHERN PUGET SOUND

The Puget Sound is the southern portion of the Salish Sea, a complex fjord system located in Washington State, USA, and British Columbia, Canada. Puget Sound is regularly flushed with normal marine waters because of a significant tidal flux. Over the last 150 years the entire Puget Sound system has been subjected to significant anthropogenic impacts. The Puget Sound region continues to have rapid population growth and is home to 6 million people. The combination of rapid growth and a history of anthropogenic impacts highlight the need for the development of biologic models to track the health of the Sound. Foraminifera have shown promise as indicators of environmental status of estuarine waters. Unfortunately, there are few published studies of foraminiferal distribution in the southern portion of the Puget Sound.

A set of 51 grab samples were collected near the Nisqually River delta by Robert Harmon (Shoreline Community College) in 1982. Oceanographic setting range from tidal channels within the Nisqually delta to open inlets. Depths range from 1 to >100 meters. Sediment composition is dominated by fine sand with coarser clastics in shallow near shore water. Close to the Nisqually River delta mud is comprises a significant portion of the sediment. Some samples contain significant amounts of plant material. Of the 52 samples 43 contain at least a limited Foraminiferal fauna. Of these samples 7 contained 1-116 specimens. The remaining samples contained sufficient foraminifera to conduct 300+ counts. The most common species are Elphidium excavatum, Buccella frigida, Elphidiella hannai, Eggerella advena, and Lagenammina arenulata.(check this) The Foraminifera distribution in these samples provides a baseline for mapping faunal changes in future sampling in this area of the Puget Sound.