By Taylor Schaefer, Staff Writer for Save The Water™ | December 14, 2015

The West Coast Faces Its Largest Algal Bloom

Unusually warm ocean waters triggered a massive harmful algal bloom (HAB), or “Red Tide,” along the U.S. West Coast in 2015. This outbreak released dangerous levels of domoic acid, forcing the closure of much of California’s crab fisheries.

Raphael M. Kudela, Ph.D., a phytoplankton expert at UC Santa Cruz, stated: “This year’s bloom was incredibly toxic and is the largest we’ve ever seen on the West Coast.”

Toxic Algae Are Increasing Worldwide

California isn’t alone. Globally, harmful algae events have surged in frequency, scale, and toxicity over the past several decades .

This particular outbreak was amplified by El Niño conditions, but human activities also play a major role. Pollutants such as sewage, pesticides, and fertilizers enrich coastal waters, creating the perfect breeding ground for HABs .

Why Domoic Acid Is Dangerous

At low levels, algal toxins cause minimal impact. But once concentrations climb and fish, shellfish, and plankton ingest them, the toxins accumulate in tissues and spread through the food chain .

Shellfish contaminated with domoic acid appear normal, but when consumed, the toxin travels directly to the human brain, disrupting nerve signal transmission . Stored in crab fat tissue, the toxin passes into crab meat, making it highly dangerous to consumers.

The World Health Organization estimates 50,000–500,000 poisoning cases annually from algal toxins . Effects on marine mammals and birds can be even more severe, leading to mass die-offs.

Possible Control Strategies

Scientists are testing several approaches:

• Sewage reduction programs – cutting nutrient pollution reduces bloom intensity .
• Mechanical control (clay flocculation) – dispersing clay particles binds algal cells and sinks them out of the water column .
• Biological control – using living organisms to target HABs. While promising, this raises concerns about introducing non-native or engineered species into fragile ecosystems  .

Each method presents regulatory, ecological, and funding challenges, making prevention more practical than large-scale mitigation.

Working Together Against Red Tide

The “red tide” problem will persist as natural drivers like El Niño combine with human-caused pollution. However, reducing chemical runoff and nutrient overloads can lessen HAB frequency and severity.

Save the Water™ conducts research to identify and remove harmful pollutants, with the goal of improving water quality and protecting human and ecosystem health. Through advanced testing, public education, and innovation, STW™ is helping communities tackle challenges like HABs and secure safe, sustainable water sources for future generations.

References

1. Andrew Steingrube. Nov 18, 2015. Algae Doom. Good Times. Link
2. DZ Wang. June 2008. Neurotoxins from Marine Dinoflagellates: A Brief Review. Marine Drugs, 6(2). Link
3. DM Anderson. July 2009. Approaches to Monitoring, Control and Management of Harmful Algal Blooms (HABs). Ocean Coast Manag, 52(7). Link
4. Austin Herbaugh. Dec 4, 2015. Toxic algae bloom closes commercial crab harvesting. The Orion. Link
5. Mario R. Sengco, et al. Jan 26, 2001. Removal of red- and brown-tide cells using clay flocculation. Marine Ecology Progress Series, 210:41–53. PDF
6. Donald M. Anderson, et al. Jan 2001. Monitoring and Management Strategies for Harmful Algal Blooms in Coastal Waters. Asia Pacific Economic Program/IOC. Link
7. HMT Hokkanen & JM Lynch. 1995. Biological Control: Benefits and Risks. Cambridge Univ. Press.

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