Professor Bobbi Peckarsky, right, and Robert Allan Klumb, a graduate student in natural resources, examine insect life netted in Cayuga Inlet during biomonitoring of the stream, Nov. 18. Robert Barker/University Photography
On Wednesday, Nov. 18, nine volunteers headed by Entomology Professor Bobbi Peckarsky trooped out to the headwaters of Cayuga Inlet in West Danby, the site of a 7,000 gallon diesel spill caused by a train derailment on Nov. 3, 1997. The inlet, one of the premier fishing streams in the area, is home to naturally-breeding populations of rainbow trout, and thousands died after the spill.
The volunteers were there for the third in a series of "biomonitoring" sample-taking sessions. Biomonitoring is a method used by stream ecologists to gauge the well-being of marine life.
"Most people know about chemical pollutants in streams," Peckarsky said. "Not only that, they worry about them. And they know that if you've got trout in your stream it's probably OK. But fish populations aren't the only indicators of stream vitality. The best way to monitor the condition of a stream is to monitor the quality and quantity of its insect life."
Wearing waterproof waders and carrying long-handled kick nets, Peckarsky and her crew -- a mix of graduate and undergraduate students as well as community members -- fanned out along the creek below the spill site. Six people were chosen to be samplers. Each one had exactly 60 seconds. The task: to scuffle across the stream, kicking up insect larvae -- along with leaves, twigs, and pebbles -- into their nets. Then, chilly as it was, they were to empty their catch into pans of icy stream water, sort through the debris by hand and drop the larvae into wide-mouthed jars full of alcohol.
What next? Why, go upstream of the spill into uncontaminated waters and do it again; and yet again, at two sets of reference sites 4.5 and 10 kilometers downstream. For comparative purposes, the reference sites were chosen to pair the inlet with an uncontaminated major tributary.
This is getting to be old hat for a couple members of the crew. Last year, when they first did it -- two weeks after the spill -- the upstream and tributary sites were full of a rich variety of insect life. But below the spill, the stream smelled like a filling station. The volunteers netted only a scanty assortment of bugs. Most were elmids, or riffle beetles, a petro-tolerant order, and certainly not world-class fish food. The inlet reference sites were no better.
Even in February, when Peckarsky's undergraduate Aquatic Invertebrates class sampled the sites, the results were much the same. "Larvae drift downstream all winter long," said volunteer David Lytle, the teaching assistant for the class. "If the stream could have recovered in that amount of time, it would have."
The Aquatic Invertebrates class was last year's workhorse on this project. The 16 members spent half their lab sessions sorting through the soggy mass of leaf fragments that inevitably ended up in the jars, and they identified every bug they found. Volunteer Alison Mclennan, now a senior in entomology and an undergraduate teaching assistant for last spring's class, worked through the summer to finish the project, even taking samples home with her to identify.
"Since ninth grade, I've been fascinated by this stuff," said Mclennan. "I can't seem to keep away from it. While I was in high school, I helped monitor and restore a small polluted river in my town. Biomonitoring streams provides me with material that is interesting and challenging. It gives me a greater sense of the environment, what the components are and how they interact. It's a method I can use to contribute to knowledge and conservation of the environment."
Naturally, Peckarsky was impressed. "The most important thing I can do as an educator today is to train tomorrow's decision-makers in how to do rigorous, responsible environmental impact assessment," she said.
This time around, the spill site initially looked much better. Peckarsky's net came out teeming with larvae. Other samples, though perhaps not as productive, still indicated that the inlet had recovered considerably.
But 4.5 kilometers downstream, things were different. To all appearances, the creek was just as damaged as before. "We don't know why. We'll measure possible factors, like residues of petrochemicals in sediments, with the Stream Ecology class this coming spring," said Peckarsky. "But all conclusions are tentative until we are able to analyze the samples in comparison to those taken from the reference sites. The answers are still in the jars."
A summary report from last year's effort has been distributed to the New York State Department of Environmental Conservation, the U.S. Fish and Wildlife Service, Cornell's Center for the Environment, the media and other interested people on campus and in Ithaca.
| Cornell Chronicle Front Page | | Table of Contents | | Cornell News Service Home Page |