Puget Sound Fact Book

Puget Sound is often referred to as the second largest estuary in the United States behind only Chesapeake Bay, but its overall size may be less important than its complexity. The place is defined by the mixing of saltwater from the ocean and freshwater from creeks and rivers that create an almost alchemical transformation of habitat. In this article, we look at the geologic forces that formed Puget Sound and made it the dynamic system that we understand today.   

This article provides a general overview of tidal patterns in Puget Sound. 

The diversity and complexity of estuarine ecosystems is vital to the overall health of Puget Sound. This summary fact sheet focuses on the current state of these ecosystems in Puget Sound—large river deltas, embayments, their interconnecting beaches, and rocky coasts—and the historical changes that have occurred since the development of the Puget Sound coastline. Additional emphasis is placed on the historical losses of tidal wetlands within these estuaries. 

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.

The boundaries of Puget Sound and the Salish Sea are not always consistently defined by scientists and government agencies. This article clarifies the distinctions between oceanographic and watershed-based definitions of these geographic areas. 

The health of an ecosystem is tied closely to the health of its food webs. This article provides an overview of the concept, origin, and characteristics of a food web and how predator and prey relationships are shaped in the Salish Sea.  

Land cover conversion through human development was listed as a leading cause of ecosystem decline in the 2014 Puget Sound Pressures Assessment, a document supported by the Environmental Protection Agency and prepared by more than 60 of the region's scientists. 

Runoff from rain and melting snow is one of the leading causes of pollution in Puget Sound. Here are selected facts related to stormwater, its prevalence, how it affects the Puget Sound ecosystem, and its environmental and economic impacts.

The Lower Duwamish Waterway in Puget Sound was designated a Superfund cleanup site in 2001. Its legacy of contamination predates World War II and the waterway continues to pollute Puget Sound through stormwater runoff.

Puget Sound is the second largest estuary in the contiguous United States. Today, we understand that estuaries — where freshwater and saltwater merge — are among the most productive places for life to exist.

The following fact sheet represents economic and environmental activities of major ports in the Puget Sound region. This is a living document and may be updated as new information becomes available.