New York officials in May plan to release several dozen large Atlantic sturgeon into the Hudson River, a move that some biologists hope is a prelude to an eventual release in the Bay within the next few years.
The release was proposed by New York and U.S. Fish and Wildlife Service who hope the tagged, hatchery-reared sturgeon will provide new information about the habitat use, movement and post-release behavior of the fish.
The release was approved in March by Atlantic States Marine Fisheries Commission, a panel of fishery officials from East Coast states and federal agencies that is responsible for managing migratory fish stocks.
The Hudson release is the first along the Atlantic Coast since 1996, when the Maryland Department of Natural Resources turned more than 3,200 fish loose into the Nanticoke River.
“Not a heck of a lot has gone on in the interim,” said Steve Minkkinen, who was with the DNR and helped to plan the 1996 release and now heads the U.S. Fish and Wildlife Service’s Maryland Fisheries Resource Office.
The stocked fish are descendants of Hudson River fish that were captured and taken to the USF&WS’s Northeast Fishery Center in Lamar, PA, during the 1990s. Biologists at the center used the fish to perfect hatchery spawning techniques for sturgeon, and eventually produced thousands of young fish.
Some of those were released in the Hudson in 1994, and in the Nanticoke two years later. But the hatchery was left with about 600 fish, some of which are now 4-feet long, putting the hatchery in the unique position of being overpopulated with some of the rarest fish along the East Coast.
The Hudson plan, which will relieve space pressure at the hatchery, calls for releasing 25 radio-tagged fish in May, and another 325 tagged fish later in the year. The hatchery will keep about 135 fish for further spawning studies.
Because the fish are so large, predation is not expected to be a problem as is often the case with other hatchery-reared fish.
One thing that remains unclear is whether hatchery sturgeon—especially large ones—will return to their native river to spawn, as do wild sturgeon. Because some of the Lamar fish are 10 years old and will mature within the next few years, the release could shed light on that issue.
“We don’t know when these fish imprint to their home water,” said Andy Kahnle, a biologist with the New York Department of Environmental Conservation. “Salmon imprint at the larval stage. We have no clue when it occurs in sturgeon.
“These fish were spawned from Hudson parents and were hatched in a hatchery in the Susquehanna drainage. I don’t have any idea where they will return to spawn. That question is on the table.”
The Hudson is home to the largest remaining Atlantic sturgeon stock on the U.S. East Coast. Kahnle said it’s estimated that the Hudson stock includes 200–300 females and 500–600 males in its spawning population, and they produce between 5,000–8,000 fish a year.
About 17,000–20,000 immature Hudson fish are estimated to be living along the Atlantic Coast. “We may be seeing a rebounding of the Hudson stock, but it will take a while,” Kahnle said.
Kahnle said the rebound appears to stem from an Atlantic States Marine Fisheries Commission action in 1998 which mandated an unprecedented almost 40-year moratorium on catching sturgeon to give the population a chance to recover.
But that did not address all of the problems. Between 1988 and 2000, an average of 1,400 sturgeon a year were killed in bycatch off the Atlantic Coast. “That’s a lot of bodies given the low coastwide abundance of this species,” Kahnle said. Bycatch losses have declined in recent years as restrictions were placed on some of the most harmful fisheries.