Adults squealed in delight at the creepy crawlies dancing around their plastic trays on Wednesday.
They counted out 25 of the first bugs they found from the spot on Left Hand Creek — mayflies, caddisflies, leeches, snails, dragonfly larvae and more.
The group of citizen scientists were assisting Can’d Aid, Trout Unlimited, Longmont and the Left Hand Watershed Center by collecting data on benthic macroinvertebrates, or aquatic animals without backbones that are large enough to see without a microscope.
“Citizen science means we take volunteers out of the community that may or may not be trained and we get to do some science that actually then goes into databases for us later or for scientific groups to use,” said Barb Sheedlo, president of the local chapter of Trout Unlimited, the St. Vrain Anglers.
Wednesday was the third year that scientists from Longmont and Trout Unlimited guided volunteers rallied by Can’d Aid through the data collection. Collecting the bugs and critters from the water of three tributaries to the St. Vrain Creek produces data about their relative health.
“It’s another line of evidence that’s used to monitor water quality and understand based on the populations of benthic macroinvertebrate how the river might be changing in the relative sense,” Barabara Luneau, a member of Trout Unlimited, explained.
The three sites were all around Longmont, including a spot on Lefthand Creek just off of Emery Street and Main. One volunteer strapped on waders and made her way across a riffle in the water, using a net to catch the bugs being distrubed by her shuffling.
Another volunteer collected rocks, using river water to rinse off the bugs on the bottom. The river life was then spread out on white trays as four volunteers collected 25 samples each for a total of 100 macroinvertebrates.
The citizen scientists sorted through the creatures to identify what was what. This data provides an understanding of what bugs are most common in a body of water, which in turn indicates the overall river health.
Luneau explained that macroinvertebrates provide a longer term idea of river health compared to using a sensor to read present conditions in the water. The repetitive data will also build a baseline of information to help with comparison over the years.
“No matter what the events are that happen in the river, those insects are going to be subject to that,” she said.
There is special interest in the Longmont tributaries because the St. Vrain Creek has a large population of small fish species that are of special interest to the state’s conservation efforts. Understanding how these streams are impacted by water quality events through the presence of macroinvertebrates could help land and wildlife managers see if the tributaries could be sustainable habitat for fish nurseries.
Left Hand Watershed Center Program Associate Maria Pezza explained that the data collected Wednesday is part of a network of watershed data throughout the county.
“We compile data that the city, the county, various municipalities and nonprofits are collecting and we bring it all together and report out on it as a resource for land managers to look at and say is our watershed healthy? Is it not?” Pezza said. “And what can we do to make it more healthy now?”
Scott Severs, senior wildlife technician for Longmont, said the city uses the data to make decisions about its environmental impacts, like understanding how water treatment is changing stream quality or what they can do to improve aquatic diversity.
“Right now the city is looking at possibly, sort of on a wishlist, of removing some barriers to fish movement,” he said. “We have to also make sure that if we remove those barriers, can we also have the food resources for those fish in those stretches?”
Getting more people interested in their watershed is also important to the project. With more than 20 citizen scientists of all ages helping to better understand the creeks running through Longmont, event organizers emphasized the importance of understanding the water where one lives.
“One of our big goals in setting this program up … is to create that community engagement with our watershed,” Luneau said.
