Volunteers Bag Mussels and Deploy Cages

Project Metric

8,000Mussels bagged in 2021 See Our Impact

Mussel Watch is our short name for the research project carried out by the Washington Department of Fish and Wildlife (WDFW). They use mussels to determine the types and amounts of contaminants appearing at key nearshore locations across Puget Sound. This information is used in the Stormwater Action Monitoring (SAM) program to assess the impacts of stormwater runoff on the environment and evaluate stormwater management actions’ effectiveness.

Mussel Watch photo 1
Volunteers bagging mussels

Toxic contaminants enter Puget Sound from various pathways, including non-point sources such as stormwater runoff, groundwater release, air deposition, and point sources such as marinas, industrial, and wastewater treatment plant outfalls, and combined sewer overflows. Mussels are used for this type of monitoring because they are filter feeders and thus pick up whatever organic or inorganic chemicals are in the water. We provide the volunteers that make this project possible.

The monitoring for toxins was started in 2015/2016 after earlier pilot studies and is done every two years. There are several stages in this project, and our volunteers play a significant role in at least one of them, the initial bagging of mussels. Bagging is done at the Penn Cove Shellfish Farm in Coupeville in early Fall over 3-4 days in two shifts/day with 6-8 volunteers each shift. It takes a lot of people to produce the 500 bags of mussels needed, and SWS provides the vast majority of them. The work involves selecting healthy mussels of the right size and then placing them in plastic mesh bags with 20 mussels/bag in two compartments. After a rest period in Penn Cove to allow the mussels to recover, the bags of mussels are placed in special cages and deployed at the monitoring sites.

Mussel Watch photo 3
Mussel Watch photo 2

WDFW has chosen 95-100 monitoring sites around Puget Sound, including two on Whidbey Island (Polnell Point and Penn Cove) and one on north Camano Island (east of Maple Grove boat launch). Mussels cages are deployed at 0.0 foot tide, which only occurs at night during the months selected by Washington Department of Fish and Wildlife for testing using mussels. Deployment and retrieval after three months are carried out at night during minus tides in early November and late January. We have five teams in Island County to do this second stage of the project. After retrieval, the mussels are taken to WDFW laboratories for chemical analysis of the mussels. Since its inception, SWS has contributed volunteers to this project on the order of 20 – 40 every monitoring period.

WDFW to date has identified several major contaminants in the mussel tissues, including organic compounds, pesticides, and 7 metals. Compared to early data, it appears that concentrations of some organic chemicals and pesticides are increasing in the waters of Puget Sound in some locations. The State will use this information to implement actions designed to correct pollution problems in Puget Sound.

PDF of Mussel Watch presentation slides

Maple Grove Beach

A cage of 80 mussels (four strands of 20 each) is deployed at the 0.0 tide line in early November and retrieved in late January, then delivered to the lab for testing for toxic stormwater chemicals.

Metric: 2021

This is the first year this site has been part of the survey.

Penn Cove

Washington Department of Fish and Wildlife volunteers will place Pacific blue mussels (Mytilus trossulus), which absorb pollution as they filter-feed, in small cages at a number of intertidal locations in the greater Puget Sound.
Metric: 2

Months that the mussel cages sit on the bottom before volunteers retrieve them.

Possession Point

Washington Department of Fish and Wildlife partnered with Stormwater Action Monitoring (SAM) to evaluate the health of Puget Sound’s nearshore environments, using mussels as their study organisms.
Metric: 10

Number of years Sound Water Steward Volunteers have been helping with the Washington Department of Fish and Wildlife Toxics-focused Biological Observation System (T-Bios)

Polnell Point

The goal of this study is to evaluate the health of the nearshore environment in urban growth areas and determine whether conditions are getting better or worse over time.