04-15-2008, 12:51 AM
American shad, once an important commercial and recreational fishery, declined sharply in the late 20th century. However, this trend may be reversing, thanks efforts of the North Carolina Wildlife Resources Commission and the U.S. Fish and Wildlife Service.
Since 1998, the two agencies have worked together to restore depleted populations of American shad along the Atlantic Coast by stocking more than 8 million "marked" shad fry in the Roanoke River as part of the Roanoke River American Shad Restoration Program.
So far, Commission biologists have captured more than 50 3- to 4-inch, hatchery-origin juveniles in the lower Roanoke River, as well as three adult fish with hatchery marks upstream on the spawning grounds.
The appearance of these adult fish indicates that the propagation program is working and that some of the fish are surviving four to five years in the ocean and then returning to where they were stocked.
"The marked adult fish that we collected in 2005 and 2006 are the first hatchery-reared fish that have survived to spawning age that we've documented." says Pete Kornegay, coastal region fisheries supervisor with the Commission.
Currently, only four rivers in North Carolina still support adequate stocks of American shad: the Cape Fear, Neuse, Tar, and Chowan rivers. Because of this, these rivers provide the brood fish used for fry production in the restoration program.
In the early days of the restoration program, collecting and fertilizing American shad eggs met with limited success. In 1999, however, the Commission's Watha State Fish Hatchery in Pender County and the Service's Edenton National Fish Hatchery developed improved hormone injection and tank spawning techniques that significantly increased fry production.
Before the fry are stocked, hatchery personnel immerse the young fish in water that contains a small amount of oxytetracycline (OTC), an antibiotic that stains the ear bone. Fry stocked below the Roanoke Rapids Dam in Halifax County are treated once to give a single mark on their otoliths while fry stocked above the dams are treated twice to give a double mark.
In addition to helping biologists distinguish fry from wild fish, this marking protocol helps them determine where the juveniles and adults they collect were stocked originally.
"Our collection of juveniles with a double OTC mark indicates that fry can survive their passage through the hydroelectric turbines of three dams," Kornegay says.
While overharvesting and habitat degradation have had a devastating impact on American shad populations coastwide, the construction of a series of dams along the Roanoke River has harmed the fish as well. For this reason, Dominion North Carolina Power, which owns two of the dams, has agreed to a long-term, well-funded mitigative program as a condition of its Federal Energy Regulatory Commission hydropower license.
Included in this program are measures to improve fry production as well as monitor fry stocking success upstream and downstream of the dams.
Because dams prevent fish from migrating upriver to spawn, the power giant is also assessing the feasibility of providing upstream passage facilities through a capture-tag-and-release program it started this spring. Dominion personnel, working with N.C. State University researchers, are capturing American shad, fitting them with radio transmitter tags and releasing the tagged fish in upstream reservoirs.
If the shad continue migrating to the next upstream dam (as they have in other states), it may suggest that these fish could be successful in migrating on their own to reach historic spawning areas upstream of the dams if a fish ladder, elevator or some other fish passage mechanism were provided.
Restoration of the Roanoke River's American shad population isn't just about having more shad to catch.
"Like its cousins the hickory shad and river herring, the masses of juvenile American shad produced each spring provide much needed food for other game and commercial fish species, many of which eventually end up on our plates," Kornegay says. "The importance of restoring the Roanoke River's American shad population cannot be overstated.
"We are hoping that the work we're doing here in North Carolina will eventually have a positive, coastwide impact on a host of popular fish."
For information on fishing in North Carolina's public, inland waters, visit the fishing page.
Since 1998, the two agencies have worked together to restore depleted populations of American shad along the Atlantic Coast by stocking more than 8 million "marked" shad fry in the Roanoke River as part of the Roanoke River American Shad Restoration Program.
So far, Commission biologists have captured more than 50 3- to 4-inch, hatchery-origin juveniles in the lower Roanoke River, as well as three adult fish with hatchery marks upstream on the spawning grounds.
The appearance of these adult fish indicates that the propagation program is working and that some of the fish are surviving four to five years in the ocean and then returning to where they were stocked.
"The marked adult fish that we collected in 2005 and 2006 are the first hatchery-reared fish that have survived to spawning age that we've documented." says Pete Kornegay, coastal region fisheries supervisor with the Commission.
Currently, only four rivers in North Carolina still support adequate stocks of American shad: the Cape Fear, Neuse, Tar, and Chowan rivers. Because of this, these rivers provide the brood fish used for fry production in the restoration program.
In the early days of the restoration program, collecting and fertilizing American shad eggs met with limited success. In 1999, however, the Commission's Watha State Fish Hatchery in Pender County and the Service's Edenton National Fish Hatchery developed improved hormone injection and tank spawning techniques that significantly increased fry production.
Before the fry are stocked, hatchery personnel immerse the young fish in water that contains a small amount of oxytetracycline (OTC), an antibiotic that stains the ear bone. Fry stocked below the Roanoke Rapids Dam in Halifax County are treated once to give a single mark on their otoliths while fry stocked above the dams are treated twice to give a double mark.
In addition to helping biologists distinguish fry from wild fish, this marking protocol helps them determine where the juveniles and adults they collect were stocked originally.
"Our collection of juveniles with a double OTC mark indicates that fry can survive their passage through the hydroelectric turbines of three dams," Kornegay says.
While overharvesting and habitat degradation have had a devastating impact on American shad populations coastwide, the construction of a series of dams along the Roanoke River has harmed the fish as well. For this reason, Dominion North Carolina Power, which owns two of the dams, has agreed to a long-term, well-funded mitigative program as a condition of its Federal Energy Regulatory Commission hydropower license.
Included in this program are measures to improve fry production as well as monitor fry stocking success upstream and downstream of the dams.
Because dams prevent fish from migrating upriver to spawn, the power giant is also assessing the feasibility of providing upstream passage facilities through a capture-tag-and-release program it started this spring. Dominion personnel, working with N.C. State University researchers, are capturing American shad, fitting them with radio transmitter tags and releasing the tagged fish in upstream reservoirs.
If the shad continue migrating to the next upstream dam (as they have in other states), it may suggest that these fish could be successful in migrating on their own to reach historic spawning areas upstream of the dams if a fish ladder, elevator or some other fish passage mechanism were provided.
Restoration of the Roanoke River's American shad population isn't just about having more shad to catch.
"Like its cousins the hickory shad and river herring, the masses of juvenile American shad produced each spring provide much needed food for other game and commercial fish species, many of which eventually end up on our plates," Kornegay says. "The importance of restoring the Roanoke River's American shad population cannot be overstated.
"We are hoping that the work we're doing here in North Carolina will eventually have a positive, coastwide impact on a host of popular fish."
For information on fishing in North Carolina's public, inland waters, visit the fishing page.