Stunned by an electric current shooting through the water, hundreds of tiny black-nosed dace turned belly up and floated to the surface.
Biologists, armed with electrodes, even ferreted a dozen or more eel out of the shadowy embankments of the Jabez Branch yesterday morning.
But the brook trout were no where to be found.
"If they were there, they would come zooming out and boink their nose right into the screen (of the electrode)," said Mark Staley, a conservation associate with the state Department of Natural Resources.
The Jabez -- a narrow, shallow stream at the headwaters of the Severn River -- is the last naturally occurring brook trout stream in the coastal plain from Southern Maryland to Harford County.
Four years ago, DNR biologists counted 24 brook trout in Jabez's Left Fork and 11 in the Right Fork. Last year, two adult males and a single infant trout remained.
Yesterday, there were none.
"Just because we found no trout does not mean the habitat is bad," said Lina Vlavianos, a Millersville resident who has become one of the Jabez' leading advocates. "It's an indication that something drastic took place, but it does not mean that the quality of the stream is permanently damaged."
The state discovered a self-sustaining trout population in Jabez in 1977, Staley said. The temperature-sensitive fish flourished particularly in the Left Fork, which is fed by cool underground springs and is well-shaded by thick brush, he said.
Then, in the mid-1980s, the numbers began to dwindle.
"We think that's because of the highways and warm water getting into the stream," Staley said.
DNR biologists are investigating theories that sediment from construction and storm water heated as it runs off new road asphalt are responsible. Trout cannot survive water temperatures above 70 degrees Fahrenheit. Sediment can bury and suffocate their egg nests.
The Left Fork flows at the base of the recently completed intersection of routes 32 and 3.
The plight of the Jabez has attracted increasing attention.
As Todd Heerd, a DNR conservation associate, strapped the Model 12 Electro-fisher -- a 44-pound backpack unit that powers two electrodes -- onto his back, a camera crew filmed a television documentary on citizen efforts to protect the stream.
Staley, Vlavianos and two newspaper reporters followed behind as Heerd waded into the stream, no more than 1 feet deep, sweeping the water with the electrodes. The backpack emitted a high-pitched hum.
Starting at an automated temperature-monitoring station, Heerd and Staley fought through thick underbrush to search 1,892 feet of the Right Fork and 1,100 feet of the Left Fork.
Dace, mud minnows and eel were stunned but unharmed. Vlavianos, who has joined similar DNR expeditions the last four years, reached into the water, pulled out an eel and measured it at 18 inches long.
"That's the biggest one we ever saw -- maybe he gobbled up all the trout," Vlavianos said in jest. "Oh wait, I can just see some developer using that as an excuse. 'It wasn't us, it was the eels.' " By itself the stream is unimpressive.
"Most people wouldn't look at this and say, 'Oh man, what a trout stream!' " Staley said.
But the Jabez is the last of its kind. And it gives scientists a chance to test strategies to combat the ill effects of development.
A $100,000 study of the effects of thermal pollution is under way. And the DNR has recently announced plans to purchase 100 acres located between the Left and Right Forks.
Melvin Beaven, DNR' regional fisheries biologist, led a second team yesterday from Severn Run upstream to Hog Farm Road. They didn't find any trout, but no trout were found along that section of the Jabez last year either, he said.
Beaven said he was particularly disturbed to find blue-green algae and bacterial slime festering in the lower Jabez, a sign of fertilizers and other polluting nutrients.
Still, Vlavianos and a number of DNR officials want to restock the Jabez with brook trout to see if they can survive.
"Right now, it didn't look good and it's getting worse each year," Beaven said. "But we're certainly not going to give it up."