Scientists and fishery managers on the West Coast are stepping up their efforts to track the harmful algae blooms that close coastal fisheries, endanger human health and are increasing worldwide.
Algae blooms are critical for ocean production, and most are not harmful, but some of them produce toxins that accumulate in razor clams and other shellfish and poison those who consume them. Others can also choke out marine life by depleting oxygen supplies, creating underwater "dead zones."
To protect people from ingesting toxins after a bloom, managers in Oregon, Washington and California are forced to close clam, oyster and mussel beds to commercial and recreational harvests that are extremely valuable to coastal economies.
One bloom in 2002-03 caused razor clam and Dungeness crab closures in Washington that resulted in losses of more than $10 million, and a closure of the razor clam fishery in Clatsop County cost local communities an estimated $4.8 million. Toxic algae also have been blamed for 14,000 sick or dead seals, sea lions, sea otters, dolphins, birds and gray whales along the West Coast.
This week, 80 leading scientists, managers and industry representatives gathered for the first time for a West Coast Harmful Algal Bloom Summit in Portland. At a public session at the downtown Marriott Hotel Thursday, leaders presented their plans for a regional monitoring network that will employ new technologies to identify and forecast dangerous algae blooms.
The plans include installing remote-controlled sensors in the ocean to test for toxins coastwide and deliver instant alerts to managers on land. The new testing methods could give managers earlier notice of harmful blooms, more precise forecasts of their specific locations and speedier decision-making in closing coastal fisheries.
The algae Pseudo-nitzschia, shown here under the microscope, produces domoic acid, which is responsible for amnesic shellfish poisoning. The Environmental Protection Agency estimates harmful algal blooms costs the U.S. economy $40 million every year.
Photo by Submitted photo
There is growing evidence that humans could be influencing blooms through sewage and fertilizer releases, climate change or by transporting algae species from one area to another. But despite a growing awareness of the impacts of harmful algae, experts know little about what causes specific blooms to occur and how to predict where they are headed.
Long-term, the coastwide network of testing could help determine what is causing the detected increase in harmful algal blooms, which scientists say might be tied to climate change, cyclical El Niño events, an increase in monitoring or transport of algae through ship ballast water.
A natural process
Peter Strutton, an oceanographer with Oregon State University and organizer of the summit, said algae, or phytoplankton, blooms are normal ocean phenomena occurring along the West Coast after spring and summer winds bring cold, deep, nutrient-rich water to the surface of the ocean in a process called upwelling. When the nutrient-loaded water is exposed to sunlight, the phytoplankton bloom. The tiny plants are a source of food for zooplankton and other marine creatures, which are eaten by larger animals in the food chain.
But certain species of phytoplankton have the ability to produce toxins that can be harmful to humans. One called Pseudo-nitzschia produces domoic acid, which accumulates in the tissues of razor clams, mussels and oysters and causes a syndrome known as amnesic shellfish poisoning in humans. Another species, Alexandrium, produces saxitoxin, which can lead to paralytic shellfish poisoning if ingested.
Alexandrium catenella, shown here under the microscope, produces a suite of toxins responsible for paralytic shellfish poisoning symptoms. It is one of six groups of harmful algae that have a strong presence on the West Coast and threaten human and marine environmental health as well as coastal economies.
Photo by Photo courtesy of Northwest Fisheries Science Center
Other types of harmful algal blooms in the region, while not harmful to humans, can cause fish kills or harm the environment through excessive growth.
Not all phytoplankton blooms are toxic, though, and Strutton said even the species that are potentially toxic don't always produce toxins.
"We're not sure what causes phytoplankton to suddenly become toxic," said Strutton. "Some scientists believe it may be stress from a lack of nutrients. But one thing that is critical is to develop a coordinated approach to monitoring, responding to, and forecast these blooms."
Algae 'don't respect state borders'
Robert Magnien, director of the National Oceanic and Atmospheric Administration's Center for Sponsored Coastal Ocean Research, said the entire coast needs better alert and response systems to manage the growing threat of harmful algal blooms, which pose a risk to human health, disrupt fisheries and coastal economies and "don't respect state borders."
Algal blooms can slash income for the West Coast aquaculture industry, valued at $100 million, the Dungeness crab fishery, worth between $25 million and $45 million to the crab boats alone, and the $13 million razor clam fishery, said Dan Ayres, a biologist for the Washington Department of Fish and Wildlife.
The earlier scientists can detect an oncoming bloom and the better they can predict where it is going, the better everyone can plan around it to "realize economic value while providing maximum safety," said Ayres.
Taking the ocean's pulse
The trick to predicting the movement of the blooms will be getting data from the ocean, which is "almost as difficult as getting information from Mars," said Strutton. A network of regional observing systems could employ new technology such as underwater moorings and robotic vehicles to "take the pulse of the ocean."
Managers could receive the data by cell phone or through the Internet and, using computer models, "we can predict where the harmful algal bloom will go in the next few days and provide important information to protect human health and well-being of coastal economies," he said.
The traditional testing for toxins on the beach can take between one and three days to produce results from the lab, said Raphael Kudela, associate professor of ocean sciences at the University of California-Santa Cruz.
"Some new technology allowed us to speed this up and do it at the beach - in 20 to 30 minutes - telling you whether or not there are toxins in there," said Kudela. "We need to get into the ocean to get that information farther off shore."
The razor clam fishery in Clatsop County alone has an average value between $7 million and $8 million, said Matt Hunter, shellfish manager for Oregon Department of Fish and Wildlife in Astoria.
In addition to speeding up managers' decisions about when fisheries need to close, earlier detection of harmful algae could allow shellfish growers to harvest their crops before a bloom affects their aquaculture operations, Hunter said.
He said it might also help animal rescue operations decode marine animals strandings on shore, some of which are caused when animals eat fish guts that contain accumulated toxins from algae blooms.