When you think of cave creatures, shrimp probably don’t come to mind. But, there’s a species of shrimp only found in Kentucky Caves. That shrimp has a turbulent conservation legacy that continues today and it relates to the quality of the water we drink.
Mammoth Cave specialist Rick Toomey bounces a beam from his high-powered flashlight over a clear underground pool. We found it after tracking about three miles underground from the cave entrance.
“This is where the scientist in the 1880s first found the shrimp and described it to the world,” he says.
Ecologist Kurt Helf responds by shouting across the cave pool: “We’re standing in history!”
Kentucky Cave Shrimp, which are only found in the Mammoth Cave area, are a curiosity; according to Helf and Toomey, most people are surprised to find out such a species exists. When you think of cave creatures, things like bats and salamanders may come to mind — translucent one-inch shrimp, not so much.
“And they are difficult to find,” Toomey says. “They are somewhat transparent, and you are trying to find them in a large, dark stream.”
They’re also the subject of research that could help us better understand how healthy the water we drink really is.
The species has a fascinating conservation history that extends into present day.
In the 1970s, the shrimp was declared extinct. There had been no sightings for years, and there is one dominant theory to explain why.
“Through the ’50s, the ’60s, early ’70s in the United States, water quality was very bad in many, many rivers,” Toomey says.
This included the rivers that ultimately feed the underground waterways of Mammoth Cave.
The Clean Water Act, which addressed growing concern about water pollution, was amended in 1972. Seven years later in 1979, a cave scientist found something interesting: one freshly dead Kentucky cave shrimp.
Soon after, another scientist found three live shrimp.
The species has recovered into the thousands. But they are still considered an endangered species.
Helf says there’s still so much we don’t know about the Kentucky Cave Shrimp; scientists need more information before they can help them.
“While there has been a lot written about them, I’m not certain some of these things are known to our satisfaction,” Helf says. “For instance, what is their preferred habitat? We’ve seen them in large cave rivers, slower-flowing streams, but the place they’ve been most abundant is these pools.”
To find out the answer to this question, Helf says the parks system has developed new monitoring protocols to tally the cave shrimp population. Often, that involves a researcher doing exactly what we are doing today — going deep into the cave streams with bright lights and taking a look at the habitat.
“We’re not only monitoring the organisms themselves, the cave shrimp, we’re also monitoring the water quality,” Helf says. “We’re deploying small sensors in the water to look at flooding in their habitat. We’re also monitoring water temperature.”
Once there’s more data on their numbers and patterns, scientists will have a better idea of how to make sure the species survives.
But why spend so much on such a small species that most people will never know exists? Toomey and Helf say there are two answers.
“One of the practical reasons we care about the cave shrimp is that the cave shrimp is responding to the water quality, and that’s the water we’re drinking,” Toomey says. “If we protect the water we are drinking and don’t actively go in and hurt the shrimp, they’re going to be just fine.”
And one that’s a little more emotional.
“If these animals disappear, the caves lose something of their mystery,” Helf says. “It fires the imagination to know these animals are there, that they exist in this dark habitat — but how cool is that?”