Thesis (M.S.)--Virginia Polytechnic Institute and State University, 1993. / Vita. Abstract. Includes bibliographical references (leaves 89-92). Also available via the Internet.

Thesis (M.S.)--Virginia Polytechnic Institute and State University, 1992. / Vita. Abstract. Includes bibliographical references (leaves 134-143). Also available via the Internet.

Thesis (Ph.D.)--University of Washington, 1994. / Vita. Includes bibliographical references (leaves [62]-65).

Mémoire (M. Sc.)-- Université du Québec à Chicoutimi, 1985. / Bibliogr.: f. 99-102. Document électronique également accessible en format PDF. CaQCU

Mémoire (M.P.aquat.)-- Université du Québec à Chicoutimi, 1992. / Bibliogr.: f. 97-101. Document électronique également accessible en format PDF. CaQCU

Eight identical and independent pilot scale recirculating aquaculture production systems were populated with fingerling hybrid striped bass <i>(Morone chrysops</i> female x <i>Morone saxatilis male</i>). Three population densities were established with two replicates at 132 fishlm3 and three replicates each at 66 and 33 fishlm3. Water chemistry and water quality characteristics were monitored throughout the 228 day growth trial for all eight systems. A system component performance analysis was done for both the multi-tube solids clarifier and rotating biological contactor (RBC). Water chemistry and water quality analysis included dissolved oxygen (DO), alkalinity, ions, carbonaceous biochemical oxygen demand (CBODS), chemical oxygen demand (COD), dissolved organic carbon (DOC), total suspended solids (TSS), volatile suspended solids (VSS), total ammonia nitrogen (TAN) , nitrite and nitrate. The major ions present were chloride, nitrate, sulfate, phosphate, sodium, calcium, magnesium and potassium. Trace levels of TAN, nitrite, iron and copper were also observed. Sodium, calcium and chloride levels were controlled based on a preplaned water exchange and chemical management method. TAN, nitrite and nitrate levels increased over time with increasing feed rates but never reached levels toxic to the fish population. CBODS,COD, DOC, TSS and VSS increased over time increasing as a function of increasing feed rates. No correlation was observed between fish mortality or fish growth rates for the range of organic and solids parameters observed during this study. On average 67% of the TSS present was between 1.5 and 30 microns in size. Diurnal cycles were observed for DO, TAN and alkalinity. The magnitude of these cycles were population dependent. Multi-tube clarifiers removed an average 56% of all suspended solids in a single pass with 81 % removal efficiency for particles above 70 microns in size. Analysis of the system effluent generated by the clarifier indicates a high degree of similarity between the aquaculture effluent and standard municipal waste on a nutrient basis but with much higher levels of nitrogen and phosphate species. RBC nitrification performance was fitted to an empirical equation. A nearly constant TAN removal rate was observed over the range of mass loading experienced in this growth trial. This implies that within a reasonable range higher flow rates resulting in higher mass loading will yield higher TAN removal rates for a given RBC. / Master of Science

Mémoire (M.Sc. pures) --Université du Québec à Chicoutimi, 1986. / Document électronique également accessible en format PDF. CaQCU

Economic viability of fish production in recirculating aquaculture system (RAS) facility depends on minimizing the energy requirements of operating such facilities. The fish growth and water quality aspects of RAS have been studied in considerable details. However, the understanding of the thermal environment of RAS lags behind. A step-wise steady-state thermal model was developed to simulate the daily heating, ventilation, water pumping, biofilter operation, and lighting energy requirements over a production cycle. The model was validated using temperature and energy data collected from RAS facility of Virginia Tech during 1992. Model simulations were performed with various production scenarios. The energy cost of fish production ($/kg) was used to evaluate different scenarios with and without heat recovery from discharged system water. Building heating required the most (40 % - 70 % of total) energy followed by water pumping, biofilter operation, lighting, and ventilation. Water replacement was the most dominant factor in determining the facility’s heating energy requirement. Heat recovery from discharged system water indicated significant drop (up to 40 %) in energy cost of fish production. / Master of Science