Areas near Olympic National Park have been in the news in recent months for some pretty bizarre reasons. First it was those mythical vampires in nearby Forks, Washington, inspired by the best-selling Twilight books and movie. Now there's the following news headline: "Science Finds Swirling Vortex of Poison off Washington Coast."

A somewhat calmer—if less riveting—approach to the same story is entitled: "Scientists Discover 'Hot Spot' for Toxic Harmful Algal Blooms off Washington Coast." Either way, this is important stuff, but not a current crisis, for anyone who enjoys consuming shellfish—and that includes a lot of fans of clams from the Olympic Peninsula and anywhere else in the country.

A new study funded by NOAA and the National Science Foundation reveals that a part of the Strait of Juan de Fuca, which separates Washington State from Canada’s British Columbia, is a potential “hot spot” for toxic harmful algal blooms affecting the Washington and British Columbia coasts. Understanding where and how these blooms originate and move is critical for accurate forecasts that could provide early warning to protect human and ecosystem health, according to NOAA scientists.

Scientists concluded that under certain conditions, toxic algal cells from this offshore “initiation site” break off and are transported to nearshore areas, where they can trigger blooms that can ultimately force the closure of Washington state shellfish beds on beaches.

Algae blooms don't sound a major problem, but under the right—or perhaps wrong—set of conditions, they can affect a lot of people, including visitors to Olympic National Park who enjoy digging for clams.

According to the Washington Department of Fish and Wildlife (WDFW):

When the [clam] season is open, more than 30,000 clam diggers may descend on the Washington coast in a single weekend, filling beaches, restaurants and motels from Long Beach to Kalaloch. During nighttime openings in fall and winter, diggers' lanterns form twinkling constellations that stretch for miles along the shoreline.

For coastal communities, this influx of visitors generates more than $12 million per year in economic activity during winter and spring when business is otherwise slow.

All that activity can be halted by a microscopic algae, the diatom Pseudo-nitzschia.

Under conditions that are not fully understood, certain species of Pseudo-nitzschia can produce domoic acid, a marine toxin that can be harmful—and sometimes fatal—to humans, marine mammals and birds. Razor clams, which consume algae and concentrate domoic acid in their body tissue, can become a link in this toxic food chain. Although razor clams, themselves, are not affected by domoic acid, those clams imbued with the toxin can poison humans and other species who eat them.

Sometimes called "red tides," toxic algae blooms occur when environmental conditions spark a proliferation in cell growth, sometimes coloring the water with their pigment. The term is misleading, however, because toxic blooms actually come in a variety of colors - yellow, orange, brown, pink, red or translucent—and have little to do with the tides.

Moreover, not all colorful algal blooms are toxic. Noctiluca, which produces brilliant red streaks the color of tomato soup, has no known ill effects on humans. For these reasons, scientists generally use the term "harmful algal blooms"(HABs) to describe blooms that are toxic to humans, fish and other animals.

Domoic acid was first detected on the West Coast in 1991, when dozens of brown pelicans and cormorants were found dead or suffering unusual neurological symptoms in Monterey Bay, California. By October of that year, toxin levels were soaring from northern California to the north coast of Washington state, prompting coast-wide shellfish closures. Although no one died from the 1991 outbreak, 25 people in Washington became ill during the first recorded incidence of domoic acid poisoning on the West Coast.

This problem isn't limited to the Pacific Northwest. According to WDFW, these single-celled plants present a significant health risk in virtually every coastal area of the United States and around the world.

According to the National Centers for Disease Control, an average of 30 cases of HAB-related poisoning are reported in the United States each year. Although most victims survive, three deaths and 183 illnesses have been attributed to HABs in the four Pacific coast states (primarily Alaska) since 1980. Nationwide, economic losses resulting from fishing closures and other efforts to protect public health exceed $50 million per year.

Many scientists ... believe the problem is getting worse. In March 2003, Dr. Donald Anderson, a senior scientist at Woods Hole Oceanographic Institution in Massachusetts, told a congressional subcommittee ... "virtually every coastal state is now threatened by harmful or toxic algal species, whereas 30 years ago, the problem was much more scattered and sporadic.

The toxin can also affect other marine life popular with seafood lovers, including Dungeness crab. Biologists with WDFW and other agencies conduct regular testing prior to opening of each season in Washington State. Dangerous levels of domoic acid prompted closure of beaches in Washington to clam digging in 1991, 1998 and 2002.

Testing by state biologists haven't found any problems so far this year, although the popular Kalaloch Beach in Olympic National Park will remain closed to clam digging until further notice because clams in that area have not grown to harvestable size.

The state website has information about seasons, locations and regulations for razor clam diggers.