More Than 500,000 Shad Larvae Released into Brandywine Creek for Restoration Effort
Late Tuesday evening, the DNREC Division of Fish and Wildlife released more than 500,000 hickory shad larvae or “fry” into the lower Brandywine Creek as part of an ongoing effort to restore a once-abundant species.
“There was no time to even announce the stocking,” said Craig Shirey, a Fisheries program manager for the Division. “We received a call from hatchery personnel with the State of Maryland DNR Fisheries that they had a good batch of fry that needed to be stocked, and asked if we were interested. We jumped at the opportunity!”
From historical accounts, shad were once abundant throughout the Brandywine but the construction of dams has blocked fish from reaching their normal spawning grounds. Within Delaware’s 12-mile section of the river, there are 11 dams.
“This is just part of what is needed to restore both species of shad and other anadromous fish to the Brandywine. You have to give the fish the right amount of habitat and you need a sufficient number of spawning adults to create juveniles that will ‘imprint’ on the stream and return when they mature,” Shirey said.
A partnership of federal, state, city, non-governmental organizations and private industry has formed in an effort to restore these important species to the Brandywine. Restoration activities will include dam removal, opening up existing dam breaches, fish ladders and other fish passage options.
Dam removal is the only certain way to allow for both stream habitat restoration and complete fish passage. With every dam left in place, the chances of a successful restoration effort become less and less. Some streams have had successful restoration programs with one or two dams, none with more than three.
“We have reports of both American shad and hickory shad being caught by anglers in the lower Brandywine but without more spawning habitat we don’t think the population will ever be significant. The clock is ticking,” Shirey said.
Hickory shad are a slightly smaller cousin to the more popular American shad. They reach about 3 pounds in weight and are becoming increasingly popular as sport fish. This stocking follows on the heels of some American shad larvae that were stocked in 2007.
The Maryland hatchery system collects spawning adults in the lower Susquehanna River and transports them to their facility on the western shore. After the eggs hatch, the larvae are briefly immersed into a treated tank to receive a tetracycline mark. The mark appears on bony structures of the fish which they will carry for the rest of their lives.
Researchers can examine the otoliths, or “ear bones,” from shad in the future and tell if they were hatchery-reared or from natural spawning. This particular batch of larvae were several days old and about to run out of food supplied by their yolk sac. They needed to be either fed something like brine shrimp or released into the wild to feed on their own.
“Right now they don’t look like much – sort of like a half-inch piece of hair with eyeballs. But they grow quickly and by the end of the summer they will be about 5 inches long,” Shirey added. “And when these shad fry mature in three to five years and come back to the Brandywine, hopefully they will be able to move upstream and spawn.”