Environmental Biology of Fishes 48:319–334,1997.
© 1997 Kluwer Academic Publishers. Printed in the NetherlandsLife history, latitudinal patterns, and status of the shortnose sturgeon,
Acipenserbrevirostrum
Boyd Kynard
National Biological Service, Conte Anadromous Fish Research Center PO Box 796, Turners Falls MA 01376,
U.S.A. and Graduate Program in Organismic and Evolutionary Biology, University of Massachusetts,Am-
herst, MA 01003, U.S.A.Received 31.10.1994 Accepted 26.4.1996Key words: adaptation, spawning migration, dam impacts, behavior, anadromy, AcipenseridaeSynopsisHistorically, shortnose sturgeon inhabited most major rivers on the Atlantic coast of North America south of
the Saint John River, Canada. Today, only 16 populations may remain. Major anthropogenic impacts on short-
nose sturgeon are blockage of spawning runs by dams, harvest of adults (bycatch and poaching), dredging of
fresh/saltwater riverine reaches, regulation of river flows, and pollution. The pattern of anadromy (adult use
of salt water) varies with latitude. The pattern may reflect bioenergetic adaptations to latitudinal differences
between fresh and salt water habitats for thermal and foraging suitability. The greater adult abundance in
northern and north-central populations likely reflects a historical difference with southern populations that is
currently accentuated by increased anthropogenic impacts on southern populations. Adult abundance is less
than the minimum estimated viable population abundance of 1000 adults for 5 of 11 surveyed populations. and
all natural southern populations. Across the latitudinal range, spawning adults typically travel to about river
km 200 or farther upstream. Dams built downstream of spawning reaches block spawning runs, and can divide
amphidromous populations into up- and downstream segments. Conservation efforts should correct envi-
ronmental and harvest impacts. not stock cultured fish into wild populations.Introduction the Endangered Specics Act of 1973 indicated pop-
ulations are likely present in 16 rivers (Table 1). Ad-
Shortnose sturgeon, Acipenser brevirostrum,is a ditional surveys may yet find a few undiscovered
small sturgeon that attains a maximum length of populations.
about 120 cm weight of 24 kg, and lives a maximum Since Dadswell et al. (1984) compiled biological
of 50–60 years (Dadswell et al. 1984, Figure 1). information on shortnose sturgeon, additional
Adults resemble similar-sized juvenile Atlantic studies on location and characteristics of foraging
sturgeon, A. oxyrinchus oxrinchus that historically and spawning habitats, adult abundance, and mi-
co-occurred in the lower mainstenis of major Atlan- gration patterns have been conducted throughout
tic coast rivers from the Saint John River,New the species’ range. This is the best information on
Brunswick, Canada, to the St. Johns River, Florida, latitudinal variation of these life history traits for
United States. Fisheries data and surveys during the any sturgeon species. A comparison among intra-
22 years since listing of shortnose sturgeon under specific populations for life history characteristics