Modern biologists catch and study fish much the same way they did centuries ago: by shoving their hands, or a net, into the water and pulling fish out. But safely catching slippery fish can be tricky, which makes one piece of gear invaluable: electro-backpacks.
WNPR met up with some biologists in Southbury to learn more about that equipment -- and how counting and studying fish is vital to understanding river ecology.
Tim Wildman was dressed to fish, but his getup made for a passable Comic-Con-take on a Ghostbuster costume. On his feet were big rubber boots. On his face, cool sunglasses. And on his back, was something huge -- a pack connected to two long poles -- filled with wires, switches, and a large battery.
"It's kinda heavy," said Wildman, a fisheries biologist with the Connecticut Department of Energy and Environmental Protection. "Ninety degrees out. Full sun. You sweat a lot."
As we stood on the banks of the Pomperaug River at Audubon Connecticut's Center in Southbury, he described something called an "electrobackpack." It's a tool biologists use to stun and net fish.
"It's run off of a 24-volt battery and you've got certain settings that you can adjust the frequency, the hertz, and the voltage," Wildman said.
That energy flows through two-hand held probes, which beep as Wildman dips them into the water, producing an electrical current that stuns fish, and makes them a lot easier for biologists to net.
"That immobilizes them enough so that we can collect them -- put them in a bucket and do what we need to do with the sample," Wildman said.
Samples gathered via electrofishing counts are important because these catches give biologists a better sense of fish populations. How many there are -- and where they're living in the river. Wildman worked with Steve Gephard, a supervising fisheries biologist at DEEP, who said that information can inform habitat conservation efforts.
Gephard was running the whole show -- and he had a lot to coordinate. As Tim Wildman walked his electrobackpack through the shallow parts of the river and stuns fish, a trailing crew of netters scooped up the animals and quickly dumped them into water-filled buckets, which got carried over to Gephard for identification.
Gephard eyeballed the fish's overall body shape to determine its species and quickly pops it onto a wooden ruler to get its length. He barked the data, species names and length in millimeters to a nearby worker who jotted all the information down. The whole process is efficient and full of lots of commentary.
"Now, this is another pumpkinseed, but for those of you that don't know pumpkin seeds check this baby out, look at that pretty fish. Mmm. Beautiful," said Gephard, as he held up the Pumpkinseed, the one sunfish native to Connecticut.
Glinting in the sun, its blue and orange stripes are gorgeous. Gephard admired the creature for a second before getting a measurement and gently tossing the fish back into the stream. He reached for another fish floating in the bucket.
"Here's a small mouth bass for you. One of the larger predators of the stream," Gephard said. "You can see greenish sides. Sharp dorsal fin on the top. Soft dorsal fin on the bottom ... I'll throw him in and he'll go belly-up for a second, but pretty soon he'll start swimming around again."
Which raises the question: Does electrofishing hurt the fish?
Gephard said it's impossible to know for sure, but he's seen fish get brutalized by predators, losing pieces of their jaw -- and still being able to feed. "While I accept the fact that we're not able to fully appreciate the pain that other species like fish endure ... the fact that we can take these fish out of electrofishing, throw them in and they swim right off and then, sometimes, we see them feeding within the hour, it sort of implies to me that the discomfort that the fish is experiencing is not excessive."
When the day wrapped up, Gephard and his team counted over 180 fish. They even spotted two American eels. In case you're curious, the most common fish at this day and spot was the white sucker. The least common? Rock bass.
