Shellfish Beds
Area of harvestable shellfish beds

This indicator tracks changes in the classification of harvestable shellfish beds in Puget Sound. The Washington State Department of Health classifies 115 shellfish growing areas in Puget Sound to assure that harvested shellfish are safe to consume. The data collected for the classification process represent the conditions that dictate shellfish harvest, and their trends provide information on marine water quality in Puget Sound.

Area of harvestable shellfish beds
By: Classification change

Area (acres) of harvestable shellfish beds where the Washington Department of Health classification has changed. Upgrades in classification mean that water quality has improved, allowing for fewer restrictions on shellfish harvest. Downgrades mean there are either more restrictions on when shellfish may be harvested, or harvest is not allowed. 

Key Vital Sign Indicator Results

  • Commercial shellfish growing areas in Puget Sound cover roughly 260,000 acres. About 86% (224,600 acres) of this area is suitable for harvest.
  • In 2022 the Leadership Council approved a new target to achieve a net gain of at least 500 acres approved for shellfish harvesting every year, based on a three-year rolling average. The net change in harvestable shellfish beds in 2023 for all of Puget Sound was 432 acres. The three-year average (2021-2023) net change was -146 acres.
  • In 2023 improved water quality conditions in four growing areas resulted in classification upgrades across 476 acres. That same year, Washington Department of Health (DOH) needed to downgrade classifications in two growing areas. A total of 44 acres were downgraded resulting in more restrictions on shellfish harvest. For more information, see the Interpretation of Results section.
  • Since 2007 more acres of shellfish growing areas have been upgraded than downgraded. The positive trend reflects state, tribal, and local investments in effective pollution identification and correction programs. However, in both 2021 and 2022 more acres were downgraded than upgraded. This recent pattern is concerning and highlights the ongoing challenge to identify and correct nonpoint source pollution that impacts water quality in the nearshore.
  • The upgrades in growing area classifications since 2007 were dramatically offset by the 2011 downgrade of the Samish Bay shellfish growing area (4,037 acres). This downgrade impacted the overall net acreage gained and slowed progress toward the previous 2020 recovery target.

Contributing Partners


Achieve an annual net gain of at least 500 acres approved for shellfish harvesting, based on a three-year rolling average.

Target fact sheet

Memo to Science Panel with rationale

Data Source

Washington State Department of Health, Office of Environmental Health and Safety

Shellfish Growing Area Annual Reports

Vital Sign Indicator Reporter
Indicator Details
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