Why We Sometimes Do Not Harvest
Learn · Common Questions · Regulation and Oversight
Why Sometimes We Don't Harvest
Oysters are a living food. Harvest decisions are governed by environmental conditions, not inventory or demand. When conditions introduce risk to public health or product quality, harvesting stops.
Orientation
Temporary harvest pauses are not failures. They are a feature of a system designed to protect consumers and preserve long-term trust in shellfish as a safe, healthy food.
Primary reasons harvesting may pause
Certain naturally occurring algae can produce toxins that accumulate in shellfish. When detected, harvesting stops immediately.
- PSP (Paralytic Shellfish Poisoning): Caused by saxitoxins.
- DSP (Diarrhetic Shellfish Poisoning): Caused by okadaic acid and related toxins.
High air temperatures increase the risk of bacterial growth, including vibrio species. During extreme heat, harvests are paused or restricted to protect food safety.
Significant rain events can introduce bacteria, nutrients, and contaminants into growing areas. Monitoring data following rainfall determines whether harvesting can continue.
Changes in salinity, turbidity, or bacterial indicators can trigger temporary closures until conditions return to safe levels.
How these risks are monitored
Harvest decisions are made using a combination of state monitoring programs and on-site observation. We work closely with Washington State agencies that test water and shellfish tissue regularly throughout the year.
- Routine testing for marine biotoxins.
- Continuous water quality classification and review.
- Heat index and time-to-temperature rules.
- Rainfall and runoff-triggered sampling protocols.
What happens when harvesting stops
When conditions trigger a pause, oysters remain in the water. They continue to filter, feed, and grow. Harvest resumes only after monitoring confirms conditions are safe. There is no acceleration, workaround, or override.
Why this matters
Temporary closures protect consumers first. They also protect trust in shellfish as a category. The discipline to stop harvesting when conditions demand it is foundational to responsible aquaculture.
About the author
Antony Barran
Founder of Willapa Wild and steward of Oysterville Sea Farms. Writing from direct experience operating under Washington’s shellfish monitoring system.
- Shellfish harvesting stops when environmental risk increases.
- Harmful algae blooms are naturally occurring and closely monitored.
- Heat and runoff directly affect food safety.
- Monitoring data, not demand, determines harvest decisions.
- Harvest pauses protect public health and long-term trust.
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