Throughout the year, curious nature lovers head
out to local streams with their smartphones to
take a close look at what’s living in the water.
With a drawstring backpack kit provided by the
Audubon Naturalist Society (ANS) in Chevy Chase,
volunteers can use a net, spoon, small white bucket
and magnifying box to scoop up samples from the
water. A Creek Critters app developed by the society
helps participants sort through bug types and
identify them by shape or the number of legs.
“People get really excited about being in the
stream and ;nding macroinvertebrates,” says
Gregg Trilling, Creek Critters’ program manager,
who helped ;eld-test the free downloadable app.
The idea came from an ANS supporter who was
interested in a modern, mobile way of testing
water quality and funded the project. An ANS
team worked with programmers to create the
app, which was introduced in 2015 and has been
re;ned each year since. It aims in part to promote
“This kind of tool is handy, and many
people ;nd it easier to use than other printed
identi;cation worksheets,” Trilling says.
The health of a stream can be determined by
how many creatures call it home, from dragon;y
larvae to hellgrammites to leeches and crane
;ies. App users’ reports on a stream’s health are
displayed on a map maintained by ANS. Generally,
less diversity in a stream indicates poor water
quality. Lisa Alexander, executive director of ANS,
says the small creatures living in the water are
good bioindicators because different bugs can
tolerate different levels of pollution.
“We call it a canary in the coal mine. These
interesting macroinvertebrates drop out when
the water becomes more polluted,” she says.
The organization’s hope is that the app will call
attention to the problem of stormwater runoff and
motivate people to take action.
Sarah Morse, executive director of the Little
Falls Watershed Alliance, a local environmental
group, says the app has been embraced at the
organization’s Creek Critter Days, held twice a year.
“Truly, people don’t know that anything lives in
the creek besides ;sh. When they use the app,
you hear people call out, ‘Wow!’ It’s this ‘aha!’”
Morse says. “For us, it’s building a new set of
enthusiasts for the stream and gets them to
see how what they do impacts what lives in the
Gregg Trilling of the Audubon
Naturalist Society helped
;eld-test the nonpro;t’s Creek
Critters app, which helps with
assessing water quality.