2007 Status Review of Atlantic sturgeon - National Marine Fisheries ...

and Wicomico/Pocomoke rivers (S. Minkkinen, USFWS, Pers. Comm. 2006). Prior to 1890,
when a sturgeon fishery began, Secor (2002), using U.S. Fish Commission landings, estimated
approximately 20,000 adult females inhabited the Chesapeake Bay and its tributaries.
For the past several decades, state fishery agencies and research facilities operating in the
Chesapeake Bay have conducted extensive finfish sampling surveys in the mainstem Bay and all
major tributaries. These surveys occurred in all seasons and were conducted using many gear
types, including trawls, seines, and gill nets. While no surveys were directed at sturgeon,
incidental captures were recorded. These data supplement reports of sturgeon captures from
commercial fishers using gill nets, pound nets, and fyke nets with occasional visual observations
of large sturgeon, including carcasses found on beaches during the summer.
A mixed stock analysis, performed from nDNA microsatellite markers, indicated that the
Chesapeake Bay population was comprised of three main stocks: 1) Hudson River (23-30%), 2)
Chesapeake Bay (0-35%), and 3) Delaware River (17-27%) (King et al. 2001). The contribution
of fish with Chesapeake Bay origin fish, which had not been identified in previous genetic
studies, indicates the likely existence of a reproducing population within the Bay. This is further
supported and substantiated by the capture of young juveniles at the mouth of the James River
and two YOY Atlantic sturgeon captured in the river in 2002 and 2004 (Florida Museum of
Natural History 2004, A. Spells, USFWS, Pers. Comm. 2006).
Several sturgeon sightings were made by commercial fishers and researchers between 1978 and
1987 near the Susquehanna River mouth. A deep hole (19 m) on the Susquehanna River near
Perryville, MD also supported a limited sturgeon fishery (R. St. Pierre, USFWS retired, Pers.
Comm. 1998). Maryland DNR personnel reported a large mature female Atlantic sturgeon in the
Potomac in 1970 and another in the Nanticoke River in 1972 (H. Speir, Maryland DNR, Pers.
Comm. 1998).
A Virginia Institute of Marine Science (VIMS) trawl survey was initiated in 1955 to investigate
finfish dynamics within the Chesapeake Bay; the survey was standardized in 1979. Since 1955,
40 Atlantic sturgeon have been captured, 16 of which were captured since 1990, and two of these
collections may have been YOY based on size. No fish were captured between 1990 and 1996;
however, seven were captured in 1998. In subsequent years, catch declined ranging between
zero and three fish per year. Similarly, American shad monitoring programs (independent stake
gill net survey) also recorded a spike in Atlantic sturgeon bycatch that peaked in 1998 (N = 34;
27 from James River) and declined dramatically in later years to only one to three sturgeon being
captured in each year from 2002-2004 (Figure 9). These observations could be biased by
stocking 3,200 juveniles in the Nanticoke River in 1996; however, the capture of wild fish in the
Maryland Reward Tagging program conducted from 1996 to present shows identical rates of
capture for wild fish (see additional information below and Figure 9).
The Maryland reward tagging has resulted in the capture of 1,700 Atlantic sturgeon. Five
hundred and sixty seven of these fish were hatchery fish, of which 462 were first time captures
(14% recapture rate), the remaining captures (1,133) were wild (Figure 9). However, none of
these 1,700 Atlantic sturgeon were considered YOY based on length data (S. Minkkinen,
USFWS, Pers. Comm. 2006). Similarly, Virginia initiated a reward tagging program in 1996
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