American shad run was low but stocking efforts were up
American eel numbers at Conowingo Dam were double over last year, the previous best catch.
Biologists say this spring’s shad run remained at relatively low levels, though they also reported a robust season for stocking hatchery-reared fish in tributaries around the watershed.
They also reported strong numbers of American eels at the Conowingo Dam on the Susquehanna River and the launch of a river herring stocking effort on the Patapsco River. American shad, as well as eels and river herring, are near record low levels along the East Coast.
For shad, long a restoration priority in the Bay watershed, the news was especially bad on the Susquehanna River, where only 12,733 American shad were lifted over the fish elevator at Conowingo, located just 10 miles upstream from the Bay. That was, by far, the worst number reported at the dam since 1997, when the multimillion dollar fish lift became the primary means for moving fish upriver.
Just 202 American shad made it past all four hydroelectric dams on the lower Susquehanna, making it the fourth- worst year since all of the lifts became operational in 2000.
Mike Hendricks, a fisheries biologist with the Pennsylvania Fish and Boat Commission, said slightly higher than average river flows during part of the spawning run may have affected the numbers passed at Conowingo.
“But,” he added, “we didn’t expect them to be one half of what they’ve been running the last couple of years, which is what they were, so I’m not sure what to make of that.”
Hendricks said the fish lift seemed to be operating well, but “the fish weren’t there. The anglers didn’t seem to be catching a lot. There was no evidence there were a lot of fish there.”
Normally, long and cool conditions that persist much of spring are thought to bode well for shad runs.
Jim Cummins, a fisheries biologist with the Interstate Commission on the Potomac River Basin, said his surveys on the river caught 15.4 shad per net, compared with a long-term average of 21.
But Cummins called it a “strange year,” adding that the long cool spring may have delayed the shad run, as some fish were still arriving in the river when the survey finished.
In Virginia, Brian Watkins, a scientist with the Virginia Institute of Marine Science’s Anadromous Fish Program, said the overall index of spawning female shad was “status quo” with numbers ticking down a bit on the James, remaining low in the York system, but rising a bit on the
“There’s no real change on the rivers,” he said. “The numbers are fairly low. But the Rappahannock does show some promise because it is in a little bit of an up trend from the past few years.”
Likewise, said Chuck Stence, a fisheries biologist with the Maryland Department of Natural Resources, “It doesn’t seem like it was as strong as it was the year before.” His crews had difficulty catching enough adults to produce eggs for hatcheries until the last few days of their collection efforts.
Indeed, biologists reported a solid year for stocking shad larvae in tributaries around the Bay. Around the region, they reported stocking more than 16 million hatchery-reared shad.
≈ The Pennsylvania Fish and Boat Commission released a total of 2.36 million fry in four Susquehanna tributaries.
≈ The Maryland Department of Natural Resources released 3.1 million larvae and about 450,000 older shad in the Choptank River, and 200,000 larvae and 95,000 juveniles in the Patapsco River.
≈ The Virginia Department of Game and Inland Fisheries released 4.82 million shad larvae in the James River; 4.33 million in the Rappahannock; and 400,000 in the Potomac River
≈ In Delaware, the Division of Fish and Wildlife released 558,000 shad in the Nanticoke and its tributaries.
Also, the Pamunkey and Mattaponi Indian tribes stocked smaller numbers in the Pamunkey and Mattaponi rivers. The 16 million is a bit less than what was routinely stocked a decade ago when numbers across the watershed
frequently passed 20 million a year. But efforts have been scaled back a bit in the James River, and the Susquehanna program lost the Hudson River as a source for its eggs. Nonetheless, it was still better than many recent years, when the total had hovered just a little more than 10 million.
This year also saw the expansion of stocking efforts in the highly urbanized Patapsco River watershed, funded as part of the mitigation for a dredging project.
This project is unique because it not only stocked American shad and its smaller cousin, the hickory shad, but also alewife and blueback herring.
It’s the only effort in the region that stocks alewife and bluebacks, which collectively are referred to as river herring. Once the most abundant anadromous fish in the region — some estimates place their spring spawning runs up Bay tributaries in the billions — they are now at historic lows all along the East Coast.
The DNR this year stocked 717,000 alewife, and 277,000 blueback herring — the first of a three-year stocking effort.
“If we see some good indicators out of this stocking work we are doing, it is something we could expand to our other projects,” said Brian Richardson, a fisheries biologist with the Maryland DNR.
Shad and river herring are anadromous fish that spend most of their lives swimming along the coast but return to their native rivers to spawn. Once their numbers were staggering — stories from colonial times tell of migrations so dense that fish would be crushed by wagons crossing streams.
Decades of overfishing, dam construction, habitat destruction and pollution have reduced their numbers to a fraction of historic levels. Efforts around the Bay have sought to rebuild populations through stocking, the removal of dams and construction of other fish passages, and improved water quality, but populations have remained low.
Shad and river herring might get a boost, though, from an action by the Mid-Atlantic Fishery Management Council, which set its first-ever limit on of alosine species — American shad, hickory shad, blueback herring and alewife — that can be caught by trawl netters fishing for mackerel. The council regulates fisheries that operate in federal waters, those more than three miles offshore, from North Carolina to New York, where anecdotal evidence has suggested that potentially large numbers of herring and shad were being caught as accidental bycatch.
“I think that’s long overdue and I’m glad to hear it is finally coming about,” Cummins said. “We’re all concerned that the bycatch issue, or some other issue while they are out to sea,
might be limiting their returns. It always makes us nervous when we aren’t getting the numbers back that we expect.”
Meanwhile, although shad numbers were low on the Susquehanna, an ongoing effort to capture American eels below the Conowingo and transport them upstream had its best year since collection efforts began in 2008.
Through mid-August, nearly 290,000 small eels had been captured below the dam, according the U.S. Fish and Wildlife Service Maryland Fisheries Resource Office. That was more than double the 135,478 collected last year, the previous best catch.
Unlike shad and river herring which spawn in the rivers and live in the oceans, eels spawn in the Sargasso Sea in the mid-Atlantic but live most of their lives in rivers and coastal waters.
- Category: Fisheries
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