Like many Pennsylvania impoundments, Lake Wilhelm in Mercer County has too many gizzard shad. Whether unintentionally introduced via anglers' minnow buckets or through misguided attempts to improve the bass fishery with the unauthorized stocking of forage fish, it was a tragic mistake.
The shad now constitute a huge percentage of the lake's biomass. They compete with bluegill and bass fry for zooplankton, challenge other panfish for smaller minnows, and transfer nutrients from the fertile bottom to algae blooms.
Ironically, Lake Wilhem bass are statistically larger than before the shad explosion, but they're so full of shad they're rarely hungry enough to take an angler's bait.
"On May 15, I went out electro-shocking with Fish and Boat biologists and found some really huge bass -- one well over 4 pounds," said Goddard State Park manager Bill Wasser. "One bass actually burped up a partially digested gizzard shad 5-6 inches long. There's your problem right there."
With bass season opening statewide June 15, the park held an educational meeting May 24 to share information with anglers about the lake's gizzard shad. Fish and Boat Commission biologists said the best remedy continues to be increasing the predator-to-prey ratio.
Last year the agency increased its Wilhelm stockings of walleye fingerlings from 17,000 to 34,000 per year.
A shad problem at nearby Conneaut Lake was reversed through similar predator stockings, and other regional lakes including Pymatuning and Shanango are coping with shad.
"We've kicked around some other ideas," said Wasser, although no additional actions are in the works.
Those include increased stockings of predator fingerlings, paid for with grants acquired by the Friends of Goddard State Park group, and raising the bass size limit or implementing Big Bass regulations, which would increase the size of Lake Wilhelm bass and their capacity to eat shad.
Wasser said he's even scoured the Internet, researching methods used by other states to reverse growing shad populations.
"Right now education is important," he said. "We want our anglers to know that catch-and-release is a good thing to increase the predator population, and dumping minnie buckets in the lake is never good."
Get Out Festival
Visit with outdoors editor John Hayes when he hosts the Post-Gazette Family Fishing Tent 11 a.m.-4 p.m. Saturday at the Get Out Festival at Moraine State Park, Butler County.
The event includes paddling, boat rides and other outdoor activities.
Cross Creek detour
Highway construction beginning Monday will force a detour to Cross Creek County Park.
From westbound Route 50 and its juncture with Route 18, continue one-eighth mile on Route 50, right onto Skyline Drive, three-quarters of a mile left onto Serenety Farm Road, at second stop sign straight onto Atlasburg Road and continue 1 1/2 miles to the park entrance.
For details, call Cross Creek Bait and Tackle Shop at 724-356-2285.