As the region's population grows, scientists say we can expect to see increasing amounts of nitrogen and other elements flowing into Puget Sound. Known as “nutrients” these elements are naturally occurring and even necessary for life, but officials worry that nutrients from wastewater and other human sources are tipping the balance. That could mean big problems for fish and other marine life, gradually depleting the water of oxygen and altering the food web.

A regional sewage-treatment system in Thurston County has helped contain  low-oxygen problems in Budd Inlet as the population continues to grow. The system cleans up some of the effluent for replenishing groundwater supplies.

High amounts of elements such as nitrogen can cause blooms of phytoplankton that sometimes trigger perturbations throughout the food web. This occurs most often in the spring and summer after the long, dark, cloudy days of winter begin to fade.

The amount of oxygen in the Salish Sea is dependent on water circulation which distributes chemical elements such as nitrogen through the system.

Under the federal Clean Water Act, states are required to assess the quality of their surface waters and compile a list of polluted water bodies. The law mandates cleanup plans to address pollution and other water-quality problems. This article describes how this process works in Washington state for dissolved oxygen. 

The Salish Sea Model is used to predict spatial and temporal patterns in the Salish Sea related to factors such as phytoplankton, nutrients and Dissolved Oxygen. It is a collaborative effort between the Pacific Northwest National Lab, the Washington State Department of Ecology and U.S. Environmental Protection Agency.

The Puget Sound Ecosystem Monitoring Program (PSEMP) is an independent program established by state and federal statute to monitor environmental conditions in Puget Sound. 

The Puget Sound Ecosystem Monitoring Program released its fifth annual Marine Waters Overview this week. The report provides an assessment of marine conditions for the year 2015 and includes updates on water quality as well as status reports for select plankton, seabirds, fish and marine mammals.

An algal bloom is a rapid increase or accumulation in the population of algae in a water system. While most are innocuous, there are a small number of algae species that produce harmful toxins to humans and animals.

Decaying organic matter plays an important role in marine ecosystems. 

A report from NOAA and the Puget Sound Ecosystem Monitoring Program provides an overview of 2014 marine water quality and conditions in Puget Sound from comprehensive monitoring and observing programs.

The Puget Sound Update is a technical report that integrates results of PSAMP and other scientific activities in Puget Sound focused on marine life and nearshore habitat, marine and freshwater quality, and toxic contamination.

A report from the Puget Sound Ecosystem Monitoring Program provides an overview of 2013 marine water quality and conditions in Puget Sound from comprehensive monitoring and observing programs.

The Puget Sound Model was designed and built in the early 1950s at the University of Washington School of Oceanography as a research and teaching tool for understanding Puget Sound circulation patterns. The following text was written by Puget Sound Model co-creator John H. Lincoln (1915-2001) and is provided courtesy of the University of Washington School of Oceanography. 

The Puget Sound Marine Waters 2012 Overview from the Puget Sound Ecosystem Monitoring Program synthesizes conditions measured in 2012 and has been expanded to include observations on seabirds that rely on marine waters. Read an excerpt below, or download the full report.

Once a month, Washington State Department of Ecology marine scientists take to the air to obtain high-resolution aerial photo observations and gather water data at the agency's monitoring stations and via state ferry transects. This provides a visual picture of the health of Puget Sound, which they call Eyes Over Puget Sound or EOPS.

There are at least 28 species of rockfish in the Salish Sea, but their populations have declined in the past several decades. The proceedings from a 2011 rockfish recovery workshop in Seattle are now available.

An independent review conducted by the Puget Sound Institute (PSI) is featured in findings by the Environmental Protection Agency and the Washington State Department of Ecology that there is currently “no compelling evidence” that humans are the cause for recent trends in declines in dissolved oxygen in Hood Canal.

The Puget Sound Marine Waters 2011 report is now available. The report was produced by the Puget Sound Ecosystem Monitoring Program and assesses the condition and quality of the waters of Puget Sound.