A new citizen science project invites volunteers to help study insect diversity in the Grand Canyon.
A shot of the south side of Glen Canyon Dam and the Colorado River. Every night when she’s on the water, Gibney Siemion, a river expedition guide in the Grand Canyon, crouches at the edge of the Colorado River right on the line where the sand turns from wet to dry. Her equipment is rudimentary: a jar of grain alcohol poured into a plastic Tupperware with a glowing bar of black light perched on its edge. But this is an effective insect trap. Siemion, and citizen scientists like her, are using these traps in a 240 mile experiment to understand how energy demand and dams on the Colorado River are washing away key insect species. “The flow of the Colorado River is extremely unnatural,” says Ted Kennedy, an ecologist with United States Geological Survey. As energy demands in the U.S. West peak and ebb over the course of a day or season, the amount of water flowing through a dam like Glen Canyon, just north of Grand Canyon, varies tremendously. All this regulation “could be limiting the diversity of insects that we have here,” Kennedy says. When the cities feeding off the Colorado River dams need less power, the water level in Glen Canyon drops. But during the daytime or peak summer months, more water plummets through the dam’s power turbines to meet electricity usage, and the flow in the river increases. This amounts to a kind of artificial tide creating fluctuations in water height as great as a meter (over 3 feet) in a day. As the river rises and falls, so does the number of insects that Siemion and her cohort of citizen scientists catch in their Tupperware.
Citizen and professional scientists inspecting a black light trap. Kennedy says the die-off is probably happening when the insects lay their eggs. Adult aquatic insects tend to lay their eggs just under the water surface, near the shore. “But the shoreline is constantly changing,” Kennedy says. “Twelve hours [after the egg-laying], the water level drops out and those eggs desiccate and dry out and are killed before they ever hatch.” In the summer, when temperatures can reach up to 130°F, the insect babies have no hope for survival under the sun. Aquatic insect species that lay their eggs only along the shorelines, like mayflies or caddis flies, are the ones that have vanished from Glen and Grand Canyon. Kennedy says showing the connection between the waning insect diversity and the flow of water coming out Glen Canyon Dam was difficult. To get at the issue, he and other professional scientists needed to more fully understand changes of the insects’ life cycles over months and across an immense section of the river. "It wasn’t going to cut it,” Kennedy says, “if it was just us out there collecting data once every three months.” Then he realized that guides like Siemion and hundreds of others are out on the river every day during the spring and summer. Kennedy and the U.S.G.S. Grand Canyon Monitoring and Research Center recruited a handful of river guides as well as boatloads of students from a non-profit program called Grand Canyon Youth to collect samples. And collect they did. Thousands of samples have been collected since the project launched in 2012. “The data that I’ve seen from this work are incredible,” says Wyatt Cross, an ecologist at Montana State University. “Their efforts contribute hugely to our understanding of aquatic invertebrates in Grand Canyon.” For river guides like Siemion, taking part in the research and learning the ecology helps her and her passengers develop a stronger connection with the canyons. “It’s a special thing,” she says. “It helps people to build a sense of place to understand some of the name of the species that call this landscape home and understand their natural history, their life cycle.” And Siemion says the work is making people more aware of the environmental impacts of the modern thirst for electricity. “This particular project – it gives us an even greater level of resolution and another example of just how damming this river has completely altered the flora and fauna.”
Image Credits: Christian Mehlfuhrer (top); David Heramimschuk (bottom).
The post originally appeared on the SciStarter blog.