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Life History Analysis of James River Atlantic Sturgeon (Acipenser oxyrinchus oxyrinchus) with Implications for Management and Recovery of the SpeciesBalazik, Matthew 10 December 2012 (has links)
Sturgeon species (family Acipenseridae) are threatened globally due to habitat destruction, pollution, and overfishing. The Atlantic sturgeon Acipenser oxyrinchus oxyrinchus was listed as a federally endangered species in 2012. Atlantic sturgeon have a complex life history that utilizes a wide range of habitats. Timing of life history varies in different areas requiring each population to be studied. Very little work has been published on Atlantic sturgeon reproduction in the James River, Virginia. To aid the recovery of James River Atlantic sturgeon, aspects of life history need to be addressed. To increase understanding of Atlantic sturgeon life history a length at age model was created to show population structure and age of sexual maturity. Telemetry experiments were conducted to determine what types of boats are likely to cause boat strike mortalities of adult fish during a spawning season. Morphometrics, sperm characteristics, and telemetry data were used to determine if Atlantic sturgeon have a fall spawning season. Strontium/calcium ratio analysis was conducted on Atlantic sturgeon fin spines to better understand migration patterns. Cortisol levels were examined in Atlantic sturgeon exposed to MS222, electronarcosis or no anesthetic 1 and 24 hr after a small incision mimicking tag implantation. I also determined the feasibility of using electronarcosis in the field and the effect of salinity on electronarcosis. The length at age data show male Atlantic sturgeon beco,e sexually mature at age 10 y and females around age 15 y. Telemetry data showed that deep draft ocean-cargo ships are most likely responsible for boat strike mortalities and there is a greater chance of Atlantic sturgeon being hit in the narrow portion of the river. Electronarcosis is an effective anesthetic and has various attributes that make it better suited for field applications then frequently used chemical anesthetics. The data generated from this research will help management produce effective recovery plans and create a safer research environment for both the fish and researcher.
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