One day this winter Ron Wierenga ’93 and I drive out to Vancouver Lake. The road from downtown bends north and west, paralleling the Columbia River for several miles through an industrial district and past the port. Wierenga, who manages the clean water program for Clark County, points to a gray structure a few hundred yards to our left. “That’s a barge right there,” he says. “The Columbia River is just on the other side of that dike.” As we ease out of the city, the landscape flattens and opens up. A gaggle of cackling geese in a field ignores us as we drive by. As we get out to look over the lake, a man with a small black cockapoo climbs down from his pickup for a lunchtime walk.
There was a time when this spot would routinely go underwater. The Columbia would rise and flood its banks and pour into this area, says Wierenga. It would recharge the lake with fresh water, which would later flow back out to the Columbia through Lake River to the north.
But that was more than a century ago. The area was settled, the land was deeded to the port, and dikes were built. Then in the 1930s construction of the Bonneville Dam 40 miles upriver changed the way the Columbia behaved. For the lake, that meant an end to the regular flooding and cleansing.
Late last summer, Vancouver Lake was closed by the Clark County Health Department.
The lake may be picturesque, but at the time its waters had dangerous levels of E. coli and cyanobacteria (blue-green algae). Swimmers, waders, and wind surfers were banned for 30 days from the quiet, shallow water.
Other users—including walkers and birdwatchers—shied away as well.
The bell-shaped lake covers about 2,300 acres. It is about two miles wide, but only 15 feet in its deepest spots. The middle of the lake is less than four feet deep most of the time. Still, it has seven miles of shoreline as well as views of Mount Hood, Mount St. Helens, and Mount Adams.
On one side it is surrounded by fields, farms, and the Shillapoo Wildlife Recreation Area. That landscape has barely changed from the time of the city’s settlement. The other side is flanked by Fruit Valley, a neighborhood that sprouted during the ship building boom of World War II and today holds about 1,000 households.
The lake is home to several rowing teams and a 93-member sailing club. It is where beginning kayakers first hit the water, and children can learn to sail in little O’pen Bic boats.
For the resource that it is, though, the lake is pretty quiet. “From my perspective, it is underutilized considering its proximity to Vancouver and the size of the lake,” says Wierenga, who has a master’s in environmental science. “I think people are intimidated by the water quality problems. They really love the lake; they’re just afraid of the water.”
TROUBLED WATERS
About five years ago, the community grew concerned over algal blooms and the levels of possible toxins in the lake. They were worried about public health, and that their pets might become sick from drinking and playing in the water. The lake became a high-profile public issue and in 2004 a community partnership was formed to bring together the port, the city, and the county to manage activities around the lake, including guiding research and involving the public. As well, the U.S. Army Corps of Engineers, the state departments of Ecology, Fish & Wildlife, and Natural Resources, and nine citizens joined the group.
It wasn’t the first time someone tried to fix the lake. In the 1960s, a team led by Washington State University engineer William Funk studied it to see if changing the way water flowed through would clear up some of the blue-green algae problems. Vancouver Lake was one of Funk’s first projects in Washington, where he had been hired as a limnologist—“sort of a fresh water oceanographer.”
At the time the lake was extremely shallow and very stagnant, says Funk. “You couldn’t take a boat in.” The mud was so deep and viscous that one day when he waded in, his team had to pry him back out with a pair of oars.
To better understand the lake’s history, Funk visited with longtime locals, who told him they remembered when the lake had been at least 30 feet deep. “But it was pretty well down the tubes when we saw it,” he says. With massive “blue-greens,” it was perhaps the worst lake that he had ever seen. Much if its water was coming in from Salmon Creek where there was septic tank drainage. The high level of nutrients, shallow depth, and stagnant water made it an ideal home for algae blooms.
Funk’s crew, which included colleague Surinder Bhagat and several graduate students, spent July of 1967 on the lake in a boat they called “Big Red.” Their assignment was to take samples to assess water pollution and see if the lake could serve the community as a large water-based recreational site. Funk’s team also researched plans for dredging and flushing the water body. But the proposal made elected officials nervous. In addition to being intensive and expensive, “I thought there was a 70 percent chance it would work and a small percent chance there would be a disaster,” says Funk.
His study and recommendations eventually succeeded, though it took close to 20 years to complete. In the 1980s, the U.S. Army Corps of Engineers dredged the lake and massed up the sediment in the middle to form what is now called Turtle Island. Then, at the spot where the lake is closest to the Columbia River, the Corps dug a canal about 4,000 meters long and installed tidal gates at one end. The nearly $20 million effort linked the Columbia to the lake. When the ocean tide is high and the river is up, water flushes down the canal and into the lake. Then it flows around the lake and then out to Lake River, which feeds back into the Columbia downriver as it heads toward the Pacific Ocean.
Funk went on to help clean up of a number of other Washington waterways, including Liberty Lake, Newman Lake, and Lake Roosevelt. He was also director of the State of Washington Water Resource Center housed at WSU in Pullman. As for Vancouver Lake, the project was right for the time, says Funk. But in the ensuing years the population of Vancouver has nearly quadrupled to 160,000, farming has faded, and the lake may be facing a whole new source of problems. The dredging and digging of a flushing canal “did improve it some, but it definitely didn’t solve the issue,” says Wierenga.
SMALL SOLUTIONS
Recently, the local agencies turned again to Washington State University for help. This time it came through two newly-arrived scientists at WSU Vancouver: ocean biologist Steve Bollens and his wife, biologist Gretchen Rollwagen-Bollens.
While Funk had urged a large-scale solution of dredging and flushing the lake, Bollens and Rollwagen-Bollens are working on the much smaller scale of microorganisms. These single-celled and multi-cellular invertebrates are another piece of the mystery of why the water clouds over with cyanobacteria each summer. Normally they eat the blue-greens, but for a time each year they’re not able to keep them in check.
Local volunteers had already started sampling the water for algae and toxins, but no one to that point had looked at the zooplankton, the microscopic underwater “grazers” (as Rollwagen-Bollens calls them) who eat algae and bacteria and in turn become food for fish.
Blue-green algae is a particularly tricky problem, she says. It’s not really an algae, but a bacteria. While it is an aquatic organism and it does photosynthesize, it lacks a nucleus. And it can be toxic to people and animals, particularly when a number of them get together and form colonies that become strands and tangles of the bacteria linked together. Given the right amount of warmth and nutrients, these colonies bloom and form a thick mat on the lake’s surface, blocking the sun for other organisms. And as they die and decay, they leech the oxygen from the water.
“The county was really interested in knowing what causes these blooms,” says Rollwagen-Bollens. “One, there are lots of nutrients in the water. That’s no mystery.” But there are also the predators to consider. “We need to know what’s going on with the grazers.”
Now in their third year of sampling, the WSU scientists have found that different kinds of cyanobacteria have dominated the lake in different years. There’s Anabaena, Aphanizomenon, and Microcystis, “or Annie, Fannie, and Mike,” as the aquatic biologists like to call them, says Rollwagen-Bollens. They may sound cute, but they’re nasty. “Mike is probably the most toxic,” she says. This particular bacteria can form a toxin that triggers liver failure.
So the scientists and their graduate students have been sampling from the lake and watching the movement, behavior, and diets of the plankton that normally feast on the algae and bacteria. “It turns out, at least in Vancouver Lake, a couple weeks prior to the bloom, the microzooplankton seem to be almost exclusively grazing on taxa other than cyanobacteria,” says Rollwagen-Bollens. That leaves the door open for the blue-greens to colonize. Once they’re in strand form, they’re more difficult for the small plankton to eat.
“We’re still analyzing the larger grazers, but they seem to be playing a role here as well,” says Rollwagen-Bollens. It’s important to know the biological interactions in the lake so that perhaps something can be done to encourage or discourage certain behaviors.
“The sad fact is Vancouver Lake is not unique,” says Rollwagen Bollens. “But what we learn in Vancouver Lake is going to help us understand shallow, warm-temperature lakes even more.”
“Having a research site in one’s own back yard is a good way to put it,” says Steve Bollens. “It’s really valuable for training graduate students as well as undergraduates.” They’re regularly at the lake collecting samples. They’re also running well-controlled experiments back on campus with types of grazer populations in the laboratories. While the case is very local, and a good example of how WSU is fulfilling its land grant mission by serving a Washington community, the problems of this lake are concerns in lakes throughout the Northwest, says Bollens, “and even more significantly, really occurring in temperate or mid-latitude regions around the globe.”