Warmer ocean produces more marine toxins

With a growing prospect for an even warmer ocean, it’s important to thoroughly monitor and study the formation of poisonous algae

Interstate and interagency cooperation becoming increasingly vital.

Oregon and Washington differ in their approaches to managing razor clams but share a vexing problem with marine toxins that some fear will increasingly put human health at risk.

Pacific County, Wash., beaches were closed to clam harvests for three out of four previously scheduled days last week because of elevated levels of domoic acid, which can cause Amnesic Shellfish Poisoning in humans.

Domoic acid was unknown on the Pacific Northwest Coastline until the early 1990s, but now routinely shows up in samples — usually below the hazard threshold of 20 parts per million. Three people died and many became ill on Prince Edward Island in eastern Canada when it first showed up there in 1987. More often, it results in lesser neurological problems. It’s bad for seabirds and a real-life mass poisoning that caused birds to behave strangely is thought to have inspired Alfred Hitchcock’s movie, The Birds. See tinyurl.com/ktvw52n for more information.

Last week’s closure was the first for domoic acid in more than a decade, but it isn’t the only illness caused by toxin chemicals contained in the marine algae that serves as food for clams, crab and other commercially important species. In 2010, local clam seasons truncated due to paralytic shellfish poisoning (PSP), also known as red tide. This resulted in cancellation of a set of recreational digging dates. That was the first PSP closure since 1993.

A 2009 study of toxic-algae impacts by the University of Washington found that the 2008 razor clam season in Pacific and Grays Harbor counties generated $12.6 million in local economic activity. A single scheduled clam season opening on the Long Beach Peninsula can pump $1.2 million into area businesses, the study found.

Exactly comparable data is hard to figure for Clatsop County, since Oregon allows clamming for long stretches of time — unless they must be closed due to toxin concerns. Clamming no doubt contributes in large measure to the popularity of the North Coast as a prime recreational area.

Around the world, harmful algal blooms are an issue of increasing concern. Poorly understood, they are blamed on everything from changes in ocean upwelling patterns to runoff of fertilizers and other chemicals. Last week’s problem in Washington is believed to have originated in a pool of warm seawater off Clatsop County. Oregon officials planned to conduct tests of clams from Clatsop beaches to see if they, too, are above safe domoic acid levels.

Warmer water along the Pacific Coast is credited with producing pleasant winter weather the past two years, with a dawning possibility for another such year ahead, with a strong El Niño forming in the central Pacific, the warmest since 1991. An Australian newspaper reported on May 8, “Some models generated by the U.S. National Oceanic and Atmospheric Administration and not widely seen are pointing to ‘humungous anomalies’ of as much as 5 degrees by October-November for parts of the eastern Pacific.” Anything like this surge in ocean heat is likely to produce many side effects — including more toxic algae blooms.

It is clear that Oregon and Washington should continue working with universities, NOAA and other agencies in an effort to better understand these runaway algal blooms and the problems they cause.


View original article at: Editorial: Warmer ocean produces more marine toxins



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