It's a way specific species are studied and tracked that gives a current picture of the state of our environment and what may be at risk.
The longest running contaminant monitoring program in the United States is a daily part of Mike McKay's environmental biology class at TSTC.
McKay has been a "mussel watch" volunteer for thirteen years, tracking the species at Hubbard Creek Lake.
As strange as it sounds, it's a tried-and-true way for researchers to assess water quality.
"Indicator species, especially freshwater mussels, since they're a siphon feeder, if there is pollution, salt, lack of water, any kind of thing that throws off the balance of the lake, the mussels will die," McKay explained.
Essentially, the indicator species provide a snapshot view of water quality -- and in the case of Lake Hubbard and many other Texas lakes, they also give a clearer picture of how devastating the drought has been, with rising salinity levels and the decline of mussels.
For students in McKay's class, mussels aren't the only species to "watch" out for -- they also track the threatened box turtles and the steady decline of the Texas horned lizard.
"Being a kid, you would walk outside and see two or three [horned lizards] and now, you hardly ever see one," said Joe Bryan, a student in McKay's class.
The information the students collect is gathered and sent off to Texas Parks and Wildlife researchers.
"We're the eyes for Texas Parks and Wildlife because they're not able to come and look everywhere, at all times," said another student, Nicholas Morris.
So whether it's through counting clams or tallying turtles, the project is a way to bridge the gap between the classroom and the real-life research the students will do for the rest of their lives.
The students were featured in Texas Nature Tracker magazine for their work.