An American shad, second from bottom-center, swims past a fish-counting window at Conowingo Dam in Darlington, Md., on May 8, 2015. A worker holds counters in both hands—one for gizzard shad and one for American shad.
by Will Parson
April 26, 2016
Though they spend most of their lives at sea, American shad are nonetheless dependent on the tributaries of the Chesapeake Bay every spring. They are the largest of five species of river herring that swim upstream to spawn in freshwater, a fact that once made them easy pickings for nearby residents. Native Americans and European colonists—tipped off to the shad’s return by the blooming of the aptly-named shadbush—would use baskets, nets and traps to catch the fish.
But population growth put more pressure on the species, and the construction of dams and other structures blocked migrations to shad habitat. The 1980s and 90s saw the closure of commercial shad fisheries in Maryland and Virginia.
Fisheries biologist Chris Avalos from Normandeau Associates Environmental Consultants watches a hopper bucket raise roughly 3,500 fish—mostly gizzard shad—at Conowingo Dam's east fish lift in Cecil County, Md., on May 8, 2015. Fish passage facilities at four hydroelectric dams on the lower Susquehanna River allow American shad to spawn upstream.
Gizzard shad are released from the hopper at the top of the east fish lift at Conowingo Dam.
To see the efforts of shad restoration today, one can simply follow the shad as they make the same upstream migration they always have. First efforts tap into the same seasonal migration. Adult shad are caught just before spawning, and their fertilized eggs are sent to hatcheries to help restock tributaries. Some dams have been removed, while others, like Conowingo Dam on the Susquehanna River, have implemented fish lifts or other measures to allow shad and other anadromous species to pass. Between 1989 and 2015, more than 3,300 miles of fish passage were opened in the Chesapeake Bay watershed.
By 2014, shad numbers in some tributaries had improved significantly. Shad were above targets in the Potomac and Rappahannock rivers, though they were less established in the lower James and York and negligible in the upper James and Susquehanna.
Jim Davis, operator of the west fish lift at Conowingo Dam, pulls up an American shad in a holding tank. The west lift is primarily used for research purposes.
A crew from Maryland Department of Natural Resources catches shad for the American Shad Study at Conowingo Dam in Darlington, Md., on May 8, 2015. The entrance to the east fish lift is visible in the background.
A worker from Virginia Department of Game and Inland Fisheries squeezes unfertilized eggs from a female shad caught on the Potomac River near Dogue Creek on April 12, 2012. (Photo by Steve Droter/Chesapeake Bay Program)
Fisheries Biologist Joshua Tryninewski walks among tanks holding juvenile American shad at the Van Dyke Research Station for Anadromous Fishes in Port Royal, Pa., on May 18, 2015. Since 1976 the Pennsylvania Fish and Boat Commission has operated the seasonal station to help restore shad to the Susquehanna River Basin.
American shad larvae start to hatch from eggs collected from the Potomac River at Van Dyke Research Station for Anadromous Fishes in Port Royal, Pa., on May 18, 2015. The station held roughly 2.2 million American shad fry in 2015, which was down from the year before, according to Fisheries Biologist Joshua Tryninewski. The station can hold roughly 10–20 million fry.
Hatching larvae fall from a container holding eggs into a larger holding tank at Van Dyke Research Station for Anadromous Fishes in Port Royal, Pa., on May 18, 2015. "They're pretty delicate fish," said Fisheries Biologist Joshua Tryninewski, who manages the station.
At about 20 days old, American shad fry are roughly two centimeters long at Van Dyke Research Station for Anadromous Fishes in Port Royal, Pa., on May 18, 2015.
American shad from the Van Dyke Research Station for Anadromous Fishes in Port Royal, Pa., are released nearby into the Juniata River. The hope is that the shad will grow up and return to the Juniata River to spawn on their own.
To view more photos, visit the Chesapeake Bay Program’s Flickr page
Photos and text by Will Parson
About Will Parson - Will produces digital stories for the Chesapeake Bay Program. He studied ecology and evolution at University of California, San Diego. He reported on water and the environment as a graduate student at Ohio University's School of Visual Communication, and worked at newspapers in New England before landing in Maryland.