Surveying a lake's population of bass is entertaining work — if you don’t mind the dark, the bugs, the late hours, the risk of electric shock, or the things that go bump in the night.
State Game, Fish & Parks Department fisheries biologist Michelle Bucholz faced all those complications Thursday night as she carefully piloted an 18-foot aluminum boat around stumps and rocks and across the vaguely discernible surface of Sheridan Lake.
She was looking for bass, as well as a better understanding of the largemouth and smallmouth populations in the popular recreational lake. And because bass tend to avoid the nets that are effective with other fish species, Bucholz and her three fisheries interns had to take a more proactive approach.
"Nets just don't work very well with bass," Bucholz said. "That's why we're out here tonight, using this kind of equipment."
That equipment included electro-fishing gear that puts a charge in the water and momentarily stuns fish, which then come to the surface where they can be netted, measured, weighed and recorded. It's part of an annual survey of fish populations in area lakes that helps GF&P keep tabs on the health and abundance of game species and adjust management when needed.
It's especially important on lakes like Sheridan, where special restrictions require bass to be at least 15 inches long to be kept.
"If we didn't do the surveys, we wouldn't know how our regulations are doing, and there'd be no use in having them," said Gene Galinat, regional fisheries program manager for GF&P in Rapid City. "The surveys tell us how things are doing and whether we're doing the right things or need to change something."
Some fish species can easily be caught in nets placed in lakes. Bass are tougher. So fish crews often work at night, when the fish are in shallow water and easier to approach than during the day. The electric charge also is more effective in the shallows.
Thursday was a beautiful night to be out on Sheridan, with an almost-full moon slipping in and out of thin cloud formations that had suggested but failed to deliver evening showers.
The surface of the lake was just settling down from the jet skis and powerboats that roiled it up until sundown. That's when Bucholz and her crew — fisheries interns Brandon Vanderbush, Michael Undlin and Jeremy Kintz — motored into position along a bulrush-covered shoreline on the west side of Sheridan.
It was the first of six stretches of shallow water, typically two to six feet deep, that the crew would shock that night. Each spot was cluttered with snags and log and rocks just waiting to bump the hull, so Bucholz piloted the boat while the three interns stood near the front and wielded dip nets with 10-foot handles.
They used the nets to scoop up bass stunned by an electric field created in the water in front of the boat.
A pair of 9-foot booms hung clusters of cables into the water in front of the boat, serving as the anode to the electrically connected cathode of the boat. A "dead-man's switch" controlled by foot is one of the safety measures, to assure that if someone falls over the front, the electricity shuts off.
A beeper also sounds while the electricity is on to give further warning. Signs on the sides of the boat warn of potential electrical hazards.
The action begins immediately when the current is turned on. During the first run, stunned perch of various sizes suddenly shot up in clusters to the surface of the water illuminated by spotlights on the boat. So did bullheads, suckers and a bright red European rudd.
Bass were less common than perch, but soon began to skitter to the surface one or two at a time. They were quickly scooped up by the interns and placed in sorting tanks supplied with fresh water from the lake.
After two 10-minute runs, 41 bass were in the tanks. Bucholz steered the boat up to shore so the fish could be measured and weighed; scale samples were removed from a few.
They ranged in size from 3 inches to more than 16 inches, with the heaviest weighing about 2.5 pounds.
As with more conventional fishing, the big one got away Thursday night. A stout, partially immobilized largemouth barely slipped under the boat as Kintz swiped at it deeply with his net. The net got hung up on a underwater snag and broke at the handle.
"He lives in legend now," Kintz said of the big one.
The netted bass, however, will live on in the lake and in statistics. For the entire night, including six 10-minute fishing segments at routes used in the past, 101 bass were taken, recorded and released. The work is the most time-consuming of the evening's chores.
Taking 101 bass in six 10-minute passes indicates a strong population, Galinta said. Scale samples from some of the bass helps GF&P determine their age, which helps evaluate growth rates in the lakes.
All told, it's well worth the night shift. But it is less fun when the hours get long and late, the bugs get thick and the next day's responsibilities beckon.
"I've got two girls, and they'll be getting me up at 6 a.m.," Bucholz said as she motored the boat up to the north shore ramp shortly after 10 p.m.
After two sections of shoreline, the media was allowed to leave. But Bucholz and her crew faced additional hours of fish survey work, past midnight, back out in the darkness.
"Oh, if I was still single and didn't have kids, it would be more fun," she said.