Collaboration between state, federal and tribal entities protects public health, minimizes economic impacts, and may provide answers to why a massive West Coast algal bloom broke records this summer.Seabirds dot the surf and a placid mist rises from the sand as the sun warms the beach. There isn’t another human in sight — nothing but a pristine shoreline and the vast expanse of the ocean. Zach Forster stands on this narrow strip of Long Beach Peninsula, a northward jut of land where the Columbia River spills into the Pacific Ocean.
Forster, a scientific technician for Washington Department of Fish and Wildlife (WDFW), is responsible for collecting water and razor clam samples twice a week as part of the Olympic Region Harmful Algal Bloom Monitoring program (ORHAB). ORHAB is a collaborative effort between WDFW and a lengthy list of government agencies, private industries, and tribal entities.
This year, ORHAB and similar organizations along the West Coast faced a longer- and larger- than-usual harmful algal bloom (HAB). The bloom has lasted well into August, and it was worst along the California shore. During at least one point during the summer, the bloom stretched from Point Conception, California, to Homer, Alaska.
HABs are common in both marine and freshwater environments, though they each present different problems and are generally considered to have different causes. According to the Environmental Protection Agency, freshwater blooms like those commonly found in the Great Lakes “represent an ecological imbalance,” which can be brought on by things like nutrient runoff, sediment, weather, and circulation patterns. Marine HABs typically follow a seasonal cycle and are generated by a combination of factors including temperature, light, salinity, and water stratification.
What makes the blooms harmful differs from situation to situation. In the case of the West Coast bloom, it is the presence of domoic acid, a powerful biotoxin produced by the phytoplankton (or microalgae) Psuedo-nitzschia. There are seven different species of Psuedo-nitzschia common to the Pacific coast, all of which can produce domoic acid. When small finfish and shellfish consume the algae, the biotoxin gets passed up the food chain to large mammals and humans.
Domoic acid does not harm the razor clams or crabs that store the biotoxin in their tissues, but humans who consume the contaminated marine life can experience flu-like symptoms, as well as more serious conditions such as Amnesic Shellfish Poisoning, an illness that causes a permanent loss of short-term memory.
It is the job of Dan Ayres and Zach Forster to prevent this from happening along Washington state’s coastline. They work in close partnership with the state Department of Health to monitor for toxins, make beach and fishery closures, and issue warnings to the public.
Ayres is the coastal shellfish manager for WDFW. He joins Forster on this quarter-mile stretch of beach that is off-limits to recreational use and reserved for research. By closing off the beach, they’ve established a control area for studying razor clam population density and health. These factors will help them to predict how many clams may be available (and how many permits to issue) for recreational clam seasons. According to Ayres, a typical digging weekend will bring 10,000 visitors to the peninsula.
Forster stomps in a series of winding figure eights, causing the razor clams, burrowed two to three feet deep, to send a bubble of air up to the surface. The sand ripples with tiny holes indicating where these bubbles have risen – and where the scientists should dig.
Ayres takes a rounded spade with a long handle and digs straight down, then kneels to thrust his arm elbow-deep in the wet sand. He pulls out a flat, yellowish clam with a rubbery foot still wiggling out of the bottom of the critter’s shell.
Ayres and Forster collect a dozen samples and head back to the lab to process them. Forster checks his water samples under the microscope and estimates that the domoic acid count for this day’s collection (in August 2015) is higher than he expected to see, but still down from the height of the bloom, which reached 2 million cells per liter in May, at the peak of the bloom along the Washington coast.
“In 2001 and 2003, we had major coast-wide closures that lasted almost a year. The maximum cell counts of Pseudo-nitzschia were somewhere in the million to 500,000 cells a liter range. We blew that out of the water this year – our toxin concentrations were just through the roof,” says Forster.
To check today’s estimate, Forster moves to the lab where he employs an Enzyme-Linked Immunosorbent Assay (ELISA) method, which uses a competitive binding assay to measure domoic acid. He also is testing a new method, developed by Tom Stewart, the founder of Mercury Science Inc.
Stewart came from a medical diagnostics background and had training in electrochemistry. In the 1990s, he began to apply medical diagnostic technology to environmental pollutants, and modeled his first assay, to detect mercury in soil, after a home pregnancy test. “I just put one and one together,” Stewart says.
Stewart has now developed a field-usable immunoassay modeled on blood glucose sensors and modified to detect domoic acid. Stewart is field testing his assays around the country in labs like Zach Forster’s. “We want to be commercially available next year some time. They’re not for sale right now, but the feasibility of the prototypes has been very good, very promising,” says Stewart.
Stewart’s technology allows for immediate results out in the field without the financial overhead and days-long delay of sending samples off to another lab. “It’s going to be ready to be done on a beach, a boat, places that don’t have a robust lab and Department of Health system,” Forster says. This cheap, quick, and accurate turn-around time will make a huge difference during crab and razor clam seasons. When 10,000 recreational, commercial, and tribal diggers are harvesting razor clams at a time, undetected levels domoic acid could be a public health disaster.
Early detection and warning saves commercial harvesters and processors big money as well. Forster explains: “The commercial clam diggers could have dug all weekend, and then the processors would have bought the clams and been stuck with $10,000- 15,000 of clams that they would have been forced by the Department of Health to destroy.”
Forster says the diggers saved time and money by staying home, and the harvest will be available, in theory, the following season when the biotoxin is no longer present in the clam population. With enough time, the shellfish can filter domoic acid out of their systems. Add in the long-term damage from the public losing confidence in the safety of eating shellfish, and the benefits are easy to see.
Vera Trainer is the program manager for National Oceanic and Atmospheric Administration Northwest Fisheries Science Center Harmful Algal Bloom Program. Trainer says it’s important to emphasize that “commercially harvested fish and shellfish are safe. I know some people have been very concerned about this, but I think people should eat seafood with confidence.”
This summer’s HAB has led to closures of recreational and commercial shellfish harvesting in California, Oregon, and Washington. In Ayres’ territory, they lost roughly six days (or two weekends) of digging, which amounts to big losses in revenue for area businesses, which rely on the influx of visitors, along with the devastating losses to local tribes and subsistence fishermen. Ayres estimates the economic impact of these closures at about $9 million.
At this point, no one seems certain what has caused this bloom to grow so large and last so long, which has led many to ask: what makes this year different than others?
Trainer has been working with physical oceanographers and scientists collecting data from on board NOAA’s research vessel the Bell M. Shimada. The Shimada just wrapped the fourth and final leg of an ocean-surveying project collecting samples and attempting to map the algal boom.
“We’re definitely looking at the physics offshore, we’re getting data from moorings, we’re really trying to understand how this year differed from others,” says Trainer. “And then we’ll put that together with the measurements of toxins that we have from a variety of cruises.” She expects to see final reports in October.
Back on that pristine stretch of beach, Ayres talks about how much he looks forward to seeing everyone out digging again when this bloom subsides. “It’s so fun to work this beach on a day when people are successful, even if it’s stormy. You talk to group after group: they’re soaked, but say ‘We got ‘em. We’re going home – we’re going to have a clam feast!’ That’s something that’s hard to quantify.”