Frank M. Parauka

Gulf Sturgeon Spawning Migration and Habitat in the Choctawhatchee River System, Alabama-Florida

Abstract Information about spawning migration and spawning habitat is essential to maintain and ultimately restore populations of endangered and threatened species of anadromous fish. We used ultrasonic and radiotelemetry to monitor the movements of 35 adult Gulf sturgeon Acipenser oxyrinchus desotoi (a subspecies of the Atlantic sturgeon A. oxyrinchus) as they moved between Choctawhatchee Bay and the Choctawhatchee River system during the spring of 1996 and 1997. Histological analysis of gonadal biopsies was used to determine the sex and reproductive status of individuals. Telemetry results and egg sampling were used to identify Gulf sturgeon spawning sites and to examine the roles that sex and reproductive status play in migratory behavior. Fertilized Gulf sturgeon eggs were collected in six locations in both the upper Choctawhatchee and Pea rivers. Hard bottom substrate, steep banks, and relatively high flows characterized collection sites. Ripe Gulf sturgeon occupied these spawning areas from late Mar...

Hormone-Induced Ovulation and Artificial Spawning of Gulf of Mexico Sturgeon (Acipenser oxyrhynchus desotoi)

Abstract Successful hormone-induced ovulation and artificial spawning of Gulf of Mexico sturgeon from the Suwannee River, Florida, with pituitary extract of common carp (Cyprinus carpio) was accomplished at two sites during spring 1989. Eggs were surgically removed from two fish weighing approximately 68 kg each. Two males, 18.3 and 19.3 kg, were used to fertilize the eggs of one female, and three males, 25.1, 25.9, and 26.2 kg, were used to fertilize the eggs of the second. Eggs were hatched on site in vertical tray incubators and McDonald hatching jars. Approximately 5,000 1 -d-old fry were produced from one female; however, the fry failed to accept an artificial diet, and all but two died within 3 weeks of hatching. Over 3,000 fry were produced from the second female, and 60 17-d-old fry were stocked in the Suwannee River, Florida. The remaining fry did not actively feed and died within 21 d of hatch.

Spawning Site Selection and Potential Implications of Modified Flow Regimes on Viability of Gulf Sturgeon Populations

Abstract Rapid human population growth and an associated increase in consumptive water demands within the ecologically diverse Apalachicola–Chattahoochee–Flint (ACF) River basin of the southeastern United States have led to a series of highly publicized water wars, exacerbated by recent drought conditions, between the states of Alabama, Georgia, and Florida. A key issue is how managing riverine flows to meet human water needs will affect the viability of species that are federally listed as threatened or endangered, including the Gulf of Mexico sturgeon Acipenser oxyrinchus desotoi. Our present understanding of Gulf sturgeon ecology within the Apalachicola River basin indicates that altered riverine flow regimes may affect spawning success and possibly the recruitment patterns of the population. Through intensive field work, we documented Gulf sturgeon spawning site selection in the Apalachicola River and then evaluated the relationship between river stage and the available spawning habitat at these sites...