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Tidal marsh at the Nisqually National Wildlife Refuge in Puget Sound. Photo courtesy of USFWS.

Survey looks at public knowledge of estuaries

About 75 percent of Puget Sound area residents surveyed did not correctly identify Puget Sound as an estuary, according to findings published this month in the journal Ecological Restoration. The survey was commissioned by the University of Washington Puget Sound Institute and conducted by the Washington Department of Fish and Wildlife.

“An estuary is a partially enclosed, coastal water body where freshwater from rivers and streams mixes with salt water from the ocean.” – U.S. Environmental Protection Agency

Think of it as Puget Sound’s secret recipe. Fill a large glacier-carved basin with salt water from the ocean. Add fresh water from some adjoining rivers. Stir vigorously.

The combination is as simple as it is transformative. It is what defines Puget Sound as an estuary. Without this mixing, Puget Sound would look vastly different — from the species that live in it to the way its currents move. 

A map of Puget Sound used in the survey. The map was intentionally designed to lack detail for research purposes. The design was based on previously conducted geographic literacy research (Roper Public Affairs 2006, Council on Foreign Relations and National Geographic Society 2016).

Salmon in particular depend on estuaries. When anadromous fish such as Chinook, coho, and steelhead gradually move from the rivers and streams where they are born, estuaries provide a waypoint. They are places where juvenile salmon can mature and grow as they get ready to venture into the open ocean. As such, restoring these salmon “nurseries” has become a centerpiece of Puget Sound recovery efforts.

Despite the ecological importance of estuaries, however, a new survey commissioned by the Puget Sound Institute and conducted by the Washington Department of Fish and Wildlife (WDFW) suggests that many area residents have a limited grasp of the word ‘estuary’ and generally don’t associate the term with Puget Sound.

The survey was conducted by WDFW social scientist Dr. David Trimbach to gauge the public’s geographic literacy about Puget Sound restoration efforts. The findings were published this month in the journal Ecological Restoration.

“When framing these challenges and potential restoration solutions, Puget Sound tends to be framed as an estuary in restoration research, outreach, education, and communications,” Trimbach and his co-author Rebecca Niggemann of WDFW wrote in the article. “However, it is not known whether ‘estuary’ is a commonly recognizable or understood term among Puget Sound residents.”


The survey was addressed to 407 Puget Sound residents through a Qualtrics research panel and had a margin of error of 5 percent. It found that about 75 percent of the respondents did not correctly identify Puget Sound as an estuary. About 65 percent of those surveyed said they had previously heard of an estuary but only about 40 percent were able to identify that an estuary is a “waterbody where fresh and salt water mix.”

Example survey question

Which of the following descriptions best defines the body of water outlined in the previous question (map question)?
Response OptionsResponses (%)
A large artificial reservoir3.9%
A large freshwater lake6.6%
A complex river system20.1%
An estuary24.3%
The ocean30.7%
I don’t know14.3%

Geographic literacy question #3 from the survey (n=407).

A potential communication mismatch

This disconnect between public knowledge and Puget Sound’s classification as an estuary could create challenges when trying to share information about Puget Sound recovery efforts, the authors wrote. “Place and place-based knowledge are one set of inputs that inform restoration,” according to the article. “If geographic literacy incongruencies exist (e.g., use of competing or varying place names or use of varying place-based attributes), then a form of communication mismatch…may emerge.” 

While knowledge of the word estuary was mixed, respondents did make the connection between estuaries and natural systems even if they did not always understand the word’s definition. When asked if humans, animals, and plants used estuaries, more than 70 percent strongly agreed. Respondents also had “a high level of familiarity with Puget Sound as a commonly used toponym or place name,” according to the paper, and 73 percent of those surveyed were able to identify Puget Sound on a map.  

More about estuaries

While Puget Sound is itself an estuary, it also includes within it many types of smaller estuaries, from mudflats to salt marshes to tidal forests and embayments. These smaller estuaries are often the focus of ecosystem recovery efforts and are addressed in the Puget Sound Partnership’s Estuaries ‘Vital Sign.’ More information about the different types of estuaries in our region is available in the Encyclopedia of Puget Sound.