Public Health Warning About Toxic Shellfish on the West Coast
In the last 48 hours, authorities have issued an urgent warning to residents and visitors along the West Coast: shellfish washed ashore may be contaminated with toxins produced by harmful algal blooms (HABs). Mass mortality events among shellfish and other marine life are often early indicators of a HAB, but the danger to people who handle or consume affected shellfish can be severe and immediate.
What Are Harmful Algal Blooms?
Harmful algal blooms occur when certain microscopic algae multiply rapidly in coastal waters. While not all blooms are dangerous, certain species produce potent toxins that can accumulate in shellfish such as mussels, clams, and oysters. When people eat contaminated shellfish, they may experience food-borne illness that ranges from mild to life-threatening. HABs can also affect fish and other marine life, leading to beach closures and economic disruption for coastal communities.
Health Risks and Symptoms
The toxins associated with HABs pose distinct health risks, depending on the toxin class. Shellfish poisoning can manifest in several syndromes:
- Paralytic shellfish poisoning (PSP) — neurologic symptoms such as tingling, numbness, dizziness, and in severe cases, difficulty breathing.
- Amnesic shellfish poisoning (ASP) — memory loss, confusion, vomiting, and severe gastrointestinal issues.
- Diarrhetic shellfish poisoning (DSP) — prolonged diarrhea and abdominal cramps; symptoms are usually gastro-intestinal.
- Neurotoxic shellfish poisoning (NSP) — a combination of neurological and gastrointestinal symptoms.
People who suspect shellfish exposure and experience tingling, numbness, or trouble breathing should seek urgent medical care. Young children, the elderly, and those with underlying health conditions are particularly at risk.
What to Do If You Find Shellfish on the Shore
Authorities urge caution with any shellfish found along beaches during HAB events. Do not harvest, collect, or consume shellfish that have washed ashore. When in doubt, assume the shellfish may be unsafe and keep a safe distance. Local health departments typically publish closures and advisories during HAB outbreaks, and it is essential to respect posted signs and official guidance.
What Residents Should Do Now
To minimize risk, follow these steps:
- Avoid harvesting or eating shellfish from beaches under HAB advisories. If you are unsure, do not consume the product.
- Report sick or deceased wildlife around the shore to local authorities; this can help determine the bloom’s location and intensity.
- Stay informed by monitoring official health department updates, beach closure notices, and HAB alerts from environmental agencies.
- If you suspect illness after shellfish exposure, contact healthcare providers and report possible HAB-related symptoms to public health officials.
How HABs Are Monitored and Addressed
Scientists use water testing, shellfish toxin screening, and satellite data to monitor HABs. When detected, agencies may close affected fisheries, issue public advisories, and implement warning signs at beaches. While blooms often subside, the toxins can persist and travel through the food chain, underscoring the need for ongoing vigilance even after visible algal activity declines.
Public Health Message
The health and safety of coastal communities depend on timely information and prudent actions. If you live along or visit the West Coast and encounter unusual beach conditions or mass animal die-offs, treat the area as hazardous and avoid contact with shellfish and other marine life from affected zones until authorities declare the area safe. This situation highlights the value of strong environmental monitoring and clear communication between scientists, public health officials, and residents to prevent preventable illnesses.
