A Mechanistic Evaluation Of The Capacity Of Ohio Reservoirs To Support An Introduced Pelagic Piscivore

Download or read book A Mechanistic Evaluation of the Capacity of Ohio Reservoirs to Support an Introduced Pelagic Piscivore written by Emily A. Burbacher and published by . This book was released on 2011 with total page 62 pages. Available in PDF, EPUB and Kindle. Book excerpt: Abstract: Highly productive tributary reservoirs can become hostile environments for fish during summer, owing to high epilimnetic temperatures (> 30°C) and low hypolimnetic dissolved oxygen (DO) levels (3 mg · L-1), which can reduce access to quality habitat for growth and survival. As part of a research effort designed to explore the suitability of Ohio reservoirs for expansion of a hybrid striped bass (Morone saxatilis x M. chrysops) stocking program, I conducted laboratory experiments to quantify how temperature and DO influence hybrid striped bass consumption, growth, respiration, activity, and proximal body composition, and then combined these results with field data to assess habitat quality in a typical Ohio reservoir. Experiments were conducted in a 3x3x2 factorial design at three temperatures (20°, 22°, and 29°C) and three DO levels (3.0, 5.0, and 7.5 mg · L-1), using two sizes of age-0 hybrid striped bass (28 g and 62 g). My results show that, when DO was 5.0 mg · L-1, consumption increased with temperature, whereas growth increased up to 22°C but remained unchanged thereafter. Consumption and growth remained unchanged or declined for both size classes of fish at 3.0 mg · L-1 of DO regardless of temperature. Respiration and activity results were inconclusive, while proximal body composition (somatic energy density and percent water) showed a reduction of energy storage at 22° and 29°C, and possibly at low DO (3 mg · L-1). Incorporating my experimental consumption results with field observations of DO, temperature, and prey fish (e.g., Dorosoma cepedianum) biomass density in a spatially-explicit bioenergetics model, I show that habitat suitability (as measured by growth rate potential) for hybrid striped bass can vary substantially within a typical Ohio reservoir, providing moderate to completely unsuitable conditions. Additionally, modeling of striped bass habitat suitability under the same reservoir conditions suggest that hybrid striped bass are more tolerant of higher surface temperatures than striped bass, indicating that hybrid striped bass are better suited for stocking in Ohio reservoirs than striped bass.