Shellfish Harvesting Restricted in Oregon Due to Historic Paralytic Shellfish Toxin Levels
Health and wildlife officials in Oregon have taken precautionary measures by closing shellfish harvesting along large stretches of the state’s coastline. The decision arises from alarming levels of paralytic shellfish toxin (PST), a potent neurotoxin found in specific types of algae. The closure, which impacts both recreational and commercial harvesting, covers approximately 250 miles of shoreline, stretching from the California border to Cape Lookout in Tillamook County.
The closure began in early June 2024 after tests revealed record PST concentrations from various locations along the coast. In one sample taken at Seal Rock, PST levels soared above 14,000 micrograms per 100 grams of tissue, a striking figure that exceeds the federal safety threshold by more than 75 times. Matthew Hunter, the shellfish program manager for the Oregon Department of Fish and Wildlife (ODFW), remarked, “These are the highest levels we’ve ever recorded in Oregon. Testing results in some areas are off the charts. It’s a serious public health concern.”
The source of this heightened toxicity appears to be a widespread algal bloom involving Alexandrium, a type of microscopic algae known for producing PST. Climatic factors such as warmer ocean temperatures and low water circulation can lead to rapid growth in these algae, creating conditions ripe for harmful algal blooms (HABs). Marine experts note that recent shifts in sea surface temperatures and currents have likely contributed to this disturbing trend.
Individuals consuming contaminated shellfish risk experiencing paralytic shellfish poisoning (PSP), a potentially fatal condition characterized by symptoms like tingling lips, numbness, and dizziness. Dr. Emilio DeBess, a public health veterinarian with the Oregon Health Authority, emphasized the urgency of the situation, stating, “Symptoms can appear within minutes or a few hours of consumption. Immediate medical attention is critical. There is no antidote—only supportive care.”
The current restrictions do not stem from reports of illnesses or fatalities related to PST. Nonetheless, authorities strongly advise against harvesting or consuming shellfish from affected regions until further notice. Regular testing continues, with health officials monitoring PST levels weekly along the coastline.
This incident stands out not only for the unprecedented levels of PST found but also for its broad geographic reach. Previous PST closures in Oregon have typically affected specific areas or types of shellfish. The last significant outbreak occurred in 1992, resulting in temporary shutdowns of several areas. In contrast, the current closure encompasses more than half of Oregon’s 360-mile coastline and nearly all shellfish species.
The ramifications for coastal communities are significant, particularly for towns like Newport, Astoria, and Coos Bay, where local economies rely heavily on shellfish harvesting. Commercial shellfish harvesting alone generates millions each year, with recreational activities bringing in thousands of visitors during peak summer months. Angela Kimball, who manages a bait and tackle shop near Lincoln City, expressed concern over the timing, noting, “It’s our peak season. We depend on shellfish festivals, clammers—families come from all over. Now everyone’s calling to cancel.”
According to the Pacific Coast Shellfish Growers Association, Oregon’s shellfish industry contributes approximately $270 million to the state’s economy and supports over 3,200 jobs. As harvesting is suspended, local businesses are already facing economic challenges, with potential disruptions to supply chains and seasonal hiring on the line.
Federal oversight of PST is managed by the U.S. Food and Drug Administration (FDA), while state agencies routinely conduct sampling during high-risk periods. As harmful algal blooms become more frequent across U.S. coastlines, NOAA has bolstered its investment in programs that monitor and forecast these blooms. A 2023 report indicated that the frequency and severity of harmful algal blooms have escalated over the past 30 years, linked to issues such as coastal eutrophication and long-term climate changes.
Oregon is not alone in grappling with these issues. Recent years have seen similar PST closures in states like Washington, California, Maine, and Alaska. Events that were once rare are beginning to occur annually in some regions, prompting experts to re-evaluate long-term coastal management approaches. Dr. Vera Trainer, a NOAA marine biologist, pointed out, “What was once rare is becoming routine. Our coastal waters are responding to global changes in ways that directly affect human and ecosystem health.”
As of June 10, 2024, the closure zone prohibits harvesting along the entire Oregon coast south of Cape Lookout. Compounding the situation is an ongoing long-term harvesting ban on razor clams due to another outbreak of domoic acid, further straining the local shellfish market.
In response to this crisis, ODFW and OHA have intensified toxin monitoring efforts and are collaborating with NOAA and local laboratories to investigate the causes of the bloom. Officials warn that closures could extend for weeks or even months, depending on future toxin levels and environmental conditions.
The National Shellfish Sanitation Program dictates strict protocols for testing and reopening affected regions. Before resuming harvesting, areas must report two consecutive weeks of safe test results, and current PST levels suggest this process may take considerable time.
Local lawmakers are advocating for enhanced federal resources to bolster monitoring and response measures regarding harmful algal blooms. Some scientists recommend improving coordination across West Coast states to better track the movement of algal blooms and predict their risks. Oregon is participating in collaborative efforts such as the West Coast Ocean Data Portal, aimed at enhancing data sharing and response effectiveness.
The message from health and fishery officials is unambiguous: steer clear of harvesting and consuming shellfish from impacted regions. With rising summer temperatures fostering the continued presence of harmful algal blooms, ongoing vigilance is essential. Hunter reaffirmed the gravity of the situation, stating, “We understand the disruption to traditions and livelihoods. But the stakes are high. One bad meal can be fatal.”
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