A Temporal and Spatial Analysis of Dissolved Oxygen in Possession Sound, WA

Jasmin Graner, Marina McLeod, Ocean Research College Academy (ORCA), Everett Community College, 2000 Tower St., Everett, WA 98201

Hypoxia is conventionally defined as dissolved oxygen (DO) values below 2 mg/L; however, Vaquer-Sunyer (2008) found that 61.43% of marine species experience substantial mortality at DO levels of 4.6 mg/L or below. Hypoxic events have increased since the 1970s in shallow coastal and estuarine areas to the point where DO has arguably changed more drastically than other environmental variables of importance to these ecosystems. Studies have found that the main drivers of the increasing frequency of hypoxic events are eutrophication as a result of nutrient loading and increasing water temperatures due to climate change. Puget Sound in Washington State is particularly susceptible to hypoxia because the geological features of its basin restrict water circulation and the Sound receives a high influx of nutrients from rivers and anthropogenic activity. Studies have reported hypoxia in regions of Puget Sound: Sisters Point, Lynch Cove, and Hood Canal. This study examined DO data in Possession Sound, an inlet of Puget Sound where the Snohomish River empties, to contribute to the growing understanding of hypoxia in Puget Sound, particularly in an estuarine environment. DO data was analyzed along with salinity, water temperature, pH, and chlorophyll data to determine if hypoxia has occurred in Possession Sound and to assess the likelihood of future events. These data were collected by Ocean Research College Academy (ORCA) at six sites in Possession Sound from 2016 to present using an Exo Sonde instrument which allows for vertical analysis of DO in the water column. Preliminary results show that potentially toxic concentrations of DO occurred at depth during the winter months with a minimum value of 4.08 mg/L.

Additional Abstract Information

Presenter: Jasmin Graner

Institution: Everett Community College

Type: Poster

Subject: Environmental Science & Sustainability

Status: Approved

Time and Location

Session: Poster 7
Date/Time: Tue 3:30pm-4:30pm
Session Number: 5011