Physical environment

Overview

The Puget Sound ecosystem is shaped by its physical environment. This article looks at Puget Sound's geologic history as well as dynamic factors such as the flow of its rivers and currents.

Puget Sound basins. The oceanographer’s definition of Puget Sound is limited to the following marine basins: Hood Canal, Main Basin (Admiralty Inlet and the Central Basin), South Basin, and Whidbey Basin. Map: Kris Symer. Data source: WDFW.

Related Articles

After a wet winter/spring transition it has been noticeably drier, warmer and sunnier. River flows are near normal levels and in Puget Sound and coastal bays salinity is increasing above normal. The spring bloom is developing but not very pronounced, yet, Noctiluca is already visible in southern Hood Canal. Suspended sediment near rivers and creeks, failing bluffs, and shellfish activities are frequent. Capturing herring spawning from the plane is informative; pilots share their observations.

The Salish Sea Model is a computer model used to predict spatial and temporal patterns related to water circulation in the Salish Sea. It was developed at the United States Department of Energy's Pacific Northwest National Laboratory with funding from the Environmental Protection Agency. It is housed at the University of Washington Center for Urban Waters which is affiliated with the Encyclopedia of Puget Sound.  

We are in a weakening La Niña, coastal downwelling has lessened and we are getting out of a cold and wet stretch, hurray. In March, rivers have almost returned to normal and carry clear water. It’s a good time to go diving if you don’t mind cold water. The productive season has only started in some places and patches of jellyfish are visible. Have a look at this edition and marvel about the secrets of the dead, or mysterious sediment clouds and the oil sheen spotted near Lummi Bay.

A 2021 article in the journal JGR Oceans describes circulation and mixing in the Salish Sea. The findings are based on simulations produced by the LiveOcean computer model.

Rivers are flowing higher than normal since 2020. Winter weather has been warmer and wetter. In marine waters, temperatures have become too cool for Northern Pacific anchovies to tolerate in North Sound. From patches of jellyfish and snow geese, to sediment and early blooms, there is more happening in the winter than you might expect. Puget Sound has many species worth showcasing such as the heart crab – a shy critter that wears its heart on its shell.

A new report from the Puget Sound Ecosystem Monitoring Program details the effects of a changing climate on Puget Sound in 2019, and documents how these changes moved through the ecosystem to affect marine life and seafood consumers.