CHECKUP ON THE LAKES
What the fish can tell us

Researchers are going electric to measure the health of the bass in the Butler Chain of Lakes -- a good measure of the overall state of the water.

Rich Mckay | Sentinel Staff Writer
Posted April 8, 2007

LAKE BUTLER -- A few yards off Egret Island, amid the cane grass and cypress stumps rising from the shallows, Dave Goodfred and Larry Mortland idle their boat engine and start coasting.

The pair are fishing for bass -- not with a topwater popper or spinner lure, or even a plain old worm.

"We're going electric," Mortland says. "Thirteen-point-five kilowatts."

The two anglers, researchers with the Florida Fish and Wildlife Conservation Commission, will shock their finned prey in the name of science, not sport.

The agency, along with Orange County's Environmental Protection Division, is conducting a three-month survey of the Butler Chain of Lakes' largemouth-bass population.

"Healthy fish will indicate that the lakes are healthy," said Sergio Duarte, a senior environmental specialist for the county.

They are looking for signs that the bass population is under stress, such as small, skinny fish with lesions or other indications of illness, said Goodfred, a commission researcher.

They will weigh and measure the fish on the boat and then toss them back.

The information they gather in the study, to finish at the end of the month, will then be compared with data from the last count on the 11-lake chain, in 1987.

"For 20 years, no one has looked at this with scientifically, statistically valid data," Goodfred said.

"This will tell us if anything's changed -- habitat, fish population, overfishing? We don't know."

Water quality is prized in this chain, and largemouth bass are its benchmark.

Bass typically feed by sight. So anything clouding the water affects their ability to hunt.

To measure that, the team first faces an age-old challenge: catching the fish. Mortland and Goodfred use their power to zap. The researchers built the electro-fisher themselves with a generator they bought at Lowe's and other equipment.

They lower the 15-foot fiberglass poles with metal hoops into the water and turn on the power. As the boat coasts through the rushes, hundreds of small, silverside minnows rise in all directions -- like popcorn in a hot pan.

A black water snake writhes near the shore. Pickerel bend back and forth in a C-shape. But Mortland and Goodfred stay focused, looking for any bass in the mix.

"You can pick them out easy," Mortland said. "You look for their white bellies and the red flare of their gills."

"Got one," Goodfred said as he hauled up a 6.2-pound bass that measured a hair more than 21 inches. "It's a beauty."

The female fish had no obvious signs of parasites or lesions.

"We're finding both lots of small fish as well as a good number of bigger fish," he said. "We're not done yet, but those are very favorable results. It means that there are enough of the small fries getting enough food to graduate into the bigger class."
The hunt goes on for several hours at locations selected by a computer and pinpointed by satellite coordinates so the study will be considered statistically valid.

Throughout the study, they expect to collect and assess about 1,000 fish. They will also interview local anglers to find out what they're seeing.

Bass are a longtime favorite for sport fishermen. The fish are voracious predators that readily strike at artificial lures, and they put up a good fight.

Some anglers already complain that speedboats and motor propellers chop up grasses that the bass need.

Tim Fey, a licensed fishing guide and owner of a business called bassfishingfl.com, said that unlike other lake chains in Florida, the Butler Chain remains "surprisingly healthy."

"I do 95 percent of my business on Butler, and now I'm running into guides who usually run on the Kissimmee [Chain]."

The lakes have been under stress from a growing amount of nutrients from human-driven sources, including fertilizers from lawns and golf courses and seeping septic systems.

Though there's an ongoing debate about how much development is too much, Fey said that he has noticed a change in the fish from 20 years ago.

"The fishing was better. More fish. Bigger fish," he said. "It's from the typical things: people. More of them. More and more houses."

Duarte said the county and the state can help the fish population by creating additional habitats, or restricting where and when people can fish.

The study will help show whether that's needed.

Other recommendations could range from limiting speedboats with motors that disturb habitat -- to doing nothing at all.

The data will be kept by the state and county and can be used for comparison to future studies.

"After we get the data, it will take some time to analyze it," he said.

Rich McKay can be reached at rmckay@orlandosentinel.com or 407-420-5470.
Copyright © 2007, Orlando Sentinel

Gathering stunned bass (JULIE FLETCHER, ORLANDO SENTINEL)
Mar 20, 2007

Weighing a large mouth bass (JULIE FLETCHER, ORLANDO SENTINEL)
Mar 20, 2007

GRAPHICS

Site of the study: Butler Chain of Lakes
Apr 8, 2007

HOW IT'S DONE: ELECTRO-FISHING

To check a lake's health, scientists study the fish in a unique way: zapping them with electricity from a 13.5-kilowatt generator and then catching them in a net. Twin 12-foot fiberglass poles are outfitted with 24-inch-wide metal hoops. Small probes fastened at the end of the hoops send an electric current into the water within a 10- to 15-foot radius.

Fish are stunned but not killed. They typically float belly-up toward the surface, and the researchers pull them out with a net. Most of the fish are released, but a handful are taken in a tank back to the lab to study.

The electric shocks can affect anything within the radius: birds, frogs, even humans.

"Yeah," Florida Fish and Wildlife Conservation Commission researcher Larry Mortland confessed sheepishly. "We dropped a net once, and I absent-mindedly reached for it."

"It won't kill you, but you'll go just like the fish: You'll flop around.''

And yes, he said, it sort of hurt.