Archived Article

What the Maryland Department of Natural Resources
is doing to combat a dwindling population.

By Angel Bolinger and Steve Minkkinen

In a restoration effort, the Maryland Department of Natural Resources Fisheries Service (DNR), U.S. Fish and Wildlife Service (U.S. FWS), and Chesapeake Biological Laboratory (CBL) started working together to enhance the Chesapeake Bay sturgeon population. This effort began when U.S. FWS collected broodstock from the Hudson River in New York and artificially spawned them at the Lamar Hatchery in Pennsylvania. Some of these juveniles were transported to Maryland and raised in a State hatchery or at Potomac Electric Power Company. The remaining juveniles were transported from Lamar Hatchery to Maryland when they reached stocking size.

In 1996, three thousand sturgeons were stocked in the Nanticoke River. All stocked sturgeon were implanted with a coded wire tag behind the third dorsal scute. In larger sturgeon, a floy tag was inserted. A reward program was established in 1996, which offers money for a returned tag. Tag return reward programs provide important data such as movement patterns, growth, habitat, mortality, bycatch, and bycatch mortality. In this situation, tag returns would also inform managers on whether the Chesapeake Bay and its tributaries could provide suitable habitat, which would allow for feeding, growth, and survival. Recaptures from this effort indicate promising potential for hatchery restoration efforts.

Since stocking in 1996, the DNR, U.S. and FWS have been working with watermen to tag sturgeon caught in commercial fishing gear. Watermen receive a reward for each live wild sturgeon that the U.S. FWS tags and also for hatchery fish caught. This provides valuable information about sturgeon utilizing the Chesapeake Bay. Data indicates that although migratory sturgeon utilize the Bay to forage there is currently no natural reproducing population in Maryland's portion of the Bay.

In 1999, fisheries managers started making plans to develop its captive population for use as broodstock for a sturgeon stocking program in Maryland. This decision was based on tag returns, improvements in water quality and habitat data, and the reopening of over 300 miles of stream via the fish passage program. The program is based at the Manning Hatchery located in Cedarville. Guidelines from the Atlantic States Marine Fisheries Commission with regard to genetic diversity of hatchery fish will serve to guide development of a restoration program.

The Department recently obtained 20 wild sturgeon ranging in size from 18 inches to four feet from commercial watermen located anywhere from Eastern Bay south to Hooper's Island. These fish will be domesticated and added to the current population of 200 captive sturgeon. If these efforts prove successful, additional sturgeon will also be collected until we have suitable diversity in our captive population.

Back at the hatchery, pit tags were inserted into the third dorsal scute. Pit tags allow hatchery mangers to distinguish individual fish. The purpose of pit tags is akin to dog breeders using different colored collars on a litter of pups to tell them apart. DNA testing has been conducted on these fish to ensure genetic integrity for future breeding programs. When these fish reach sexual maturity, they will be used as brood stock. Females are typically mature at about six feet in length, which takes approximately 12 to 20 years. Males mature faster than females. They will reach sexual maturity when they measure approximately four feet, which takes about 8 to 10 years. The Department hopes to increase the growth rate and therefore sexual maturation by providing optimal growth conditions. Managers hope to start preliminary studies on the maturation of these fish during the next two years. Soon after this they will hope to spawn these fish for restoration efforts.

Collaboration with the United States Geological Survey in developing a generic database and with Center of Marine Biotechnology (COMB) in developing a captive breeding program for these fish, will help us develop the techniques to accomplish this.

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