Tests on Waterways Should Include Insects, say Scientistsby Lisa Stiffler
LAKE STEVENS -- Clear, cool water flows around fallen logs, tumbles over brown cobblestones. Mossy trees, sword ferns and yellowed grasses line the banks.
A prehistoric-looking great blue heron appears overhead, coasting lazily on a cushion of air.
Welcome to rural Snohomish County's Little Pilchuck Creek -- the epitome of a healthy stream.
But appearances can be deceiving, as scientists discovered when they put seemingly pristine Little Pilchuck under the microscope. They went beyond traditional environmental measures to scrutinize tiny insects.
The creek, they discovered, was on the brink of serious trouble.
Deadly pollution, experts say, can come in pulses that quickly fade away, skirting detection. Stormwater runoff can blast through, harming aquatic life before rapidly dissipating. Sometimes each little piece looks OK -- temperature, oxygen levels and bacteria -- but together they make an environment inhospitable for fish or birds.
That's why researchers at the University of Washington are urging the state Ecology Department to add studies of bugs, fish and algae to new, tougher water-quality standards that are awaiting approval.
"It gives you a way of measuring the real condition of the river," said James Karr, a professor in the UW Aquatic and Fishery Sciences Department. "The first thing you look at is the biology, because that's the only way to determine if it's broken or not."
Ecology officials admit the biological tests are "intriguing," but say a whole new category of standards would be a tough sell with the public. And it'd be challenging to use the tests to write pollution permits.
"I think it's like a 10-years-down-the-road thing," said Melissa Gildersleeve, a manager in Ecology's water-quality program. "Our big focus is to get these new rules approved and get things implemented."
The battle to establish new rules has been long and controversial. Farmers argued the rules were too "fish-centric." Environmentalists claimed they didn't go far enough.
The U.S. Environmental Protection Agency is expected to decide whether to approve the state's revised standards this year. They are used to identify creeks, rivers and lakes that are in poor shape, earning them a place on a list of polluted waters, as required by the federal Clean Water Act. "Impaired" waters get special limits on pollution from sources like industry and sewage-treatment facilities, and in stormwater runoff.
A number of states, including Ohio, Maine, North Carolina and Vermont, already include biological tests in their water-quality standards to define what's impaired.
"We just felt like it was a more holistic indicator of what is going on with water quality," said Michelle Woolfolk, an environmental supervisor with the Department of Environment and Natural Resources in Raleigh, N.C.
Since 1993, biological tests have been used by the Ecology Department for research, including measuring trends in stream health and examining human impact on water quality.
But it would be tricky, Ecology officials said, to translate something like the diversity of bug life in a creek into permits restricting what pollutants can be released by a sewage treatment plant, for example.
New tools for determining water quality are being tried out, said Rob Plotnikoff, fresh-water monitoring unit supervisor for the department. It takes time to incorporate new measures and to figure out how.
"It's not a process that can be frivolous in any way," Plotnikoff said. "It can influence the livelihood of many citizens in the state."
Numerous counties and cities are using the tests in their own evaluations.
For a given region, there is a diverse suite of life that's expected to thrive in a healthy stream. In a damaged stream, perhaps only one or two of the heartiest species will be found.
Taking a sample of insects in the fall indicates what the water quality has been "during the time those bugs have been alive," said Kit Paulsen, environmental scientist with Bellevue Utilities. "That's something that's really, really useful."
A flush of polluted stormwater could wash away and kill stream life. A survey of aquatic life could detect their absence, even months after the event. The tests also reveal more subtle problems caused by changes in water flow, erosion and plant life.
"Every urban stream we sample ends up on the (impaired waters) list because of aquatic life," said Leon Tsomides, a biologist with Maine's Department of Environmental Protection.
The water-quality standards awaiting a decision by the EPA don't require an examination of stream life. Instead, they measure physical traits, such as temperature, pollutants and dissolved oxygen. The only living thing that is tested for is bacteria, which relates more to human health than the vitality of a river or stream.
Calculating stream health by studying insects is relatively straightforward. A net with a square-framed opening is partially submerged in the rocky bed of a stream. Researchers dig through the rocks, dislodging bugs clinging to gravel and woody debris. The insects flow into the net. Then they're preserved in alcohol for analysis.
Under a microscope, scientists can identify tiny winged midges, caddis fly larvae ensconced in their cocoons of twigs and sand, and squishy mayflies. In healthy waters, there is a diversity of insect species and many of them. The presence of stoneflies, which need plenty of oxygen and cold water, also indicates good health, Karr said.
Biological tests are cheaper than tests for chemicals and pollutants, Paulsen said. Volunteers can be trained to collect insects, though professional biologists are best at the identifications.
The data is also a useful indicator of whether restoration efforts are working or not.
Millions of dollars are being spent in Washington to control pollution and restore streams, but "we've missed the diagnostic component," Karr said. "Why continue to waste money?"
After scrutinizing Little Pilchuck, the researchers found that the insect life wasn't the plentiful, diverse population found in healthier waters.
While not dire, taking the pulse of the bug world showed that the creek is at risk. More people, pavement and cars in fast-growing Snohomish County could tip the balance, leaving the creek unfit for salmon and other sensitive critters.
The tests are just a small step toward adequate protection of local waterways, supporters say.
Looking at stream biology won't fix everything, said Karr. "But at least we won't continue to make the same mistakes."
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