Updated: Mar 16
Do you enjoy spending time at the beach, digging clams, learning new skills, and contributing your time to an important community project? The Skagit Conservation District is now seeking interested community volunteers (age 18 and up) to provide support in monitoring local recreational shellfish harvesting beaches. The goal of the Biotoxin Program is to protect humans from illness and death caused by eating shellfish contaminated with biotoxins.
Biotoxins are poisons that are produced by certain kinds of microscopic algae (a type of phytoplankton) that are naturally present in marine waters, but normally in amounts too small to be harmful. However, a combination of warm temperatures, sunlight, and nutrient-rich waters can cause rapid plankton reproduction, or "blooms." These blooms are commonly referred to as harmful algal blooms or "HABs" because of their potential to cause illness.
Molluscan shellfish (shellfish with hinged shells such as oysters, clams, and mussels) are filter feeders and ingest any particles, both good and bad, that's in the surrounding water. Algae is a food source for them, and HABs create a plentiful food supply. When shellfish eat toxin-producing algae, the toxin remains in their system; large amounts of algae means more toxin can concentrate in their tissue.
Biotoxins don't harm shellfish, but they can accumulate in shellfish to levels that can cause illness or death in humans and other mammals that eat them.
Cooking Does Not Destroy Biotoxins.
Cooking will kill the algae that produces the toxin, but the toxin itself is not affected by cooking and remains in the shellfish tissue. There is no antidote for biotoxin poisoning. Victims must wait for the toxins to naturally flush from their body. Life support systems such as respirators and oxygen are used in extreme cases to keep the victim alive and stable.
Harmful Algal Blooms Don't Always Color the Water
An area may be experiencing a massive bloom even though the water appears clear. A popular misconception surrounds the term "red tide." This term is commonly associated with PSP toxin, but algal blooms that color the water red are generally harmless to humans. Shellfish in both recreational and commercial harvest should be routinely tested for biotoxins known to be present in marine waters, such as Paralytic Shellfish Poison, Amnesic Shellfish Poison, and Diarrhetic Shellfish Poison.
When toxins are detected at dangerous levels, the harvest area must be closed.
The area must remain closed until lab results confirm that biotoxin concentrations have dropped to safe levels. When an area that is on or near a public beach is closed, a notification is sent to the local health department and a news release is issued about the closure. The closure information is also posted on the Washington State Department of Health’s website and included in the recorded hotline to let recreational harvesters know that shellfish in that area are not safe to eat.
Danger, Warning, or Closure Signs are placed on the beach, but they are often vandalized or stolen. Beachgoers should not count on warning signs to let them know if a beach is closed for harvest.
When the closure is in an area that is commercially harvested, all licensed companies harvesting in that area are notified to stop harvesting immediately. Any commercial product on the market that came from the closed area is also recalled.
Biotoxin Levels are Unpredictable