Environmental Science & Technology
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Item Advancing Ecosystem Based Fisheries Management: Biological Reference Points for Nutritional Status of Striped Bass (Morone saxatilis)(2014) Haus, William; Harrell, Reginal M; Environmental Science and Technology; Digital Repository at the University of Maryland; University of Maryland (College Park, Md.)Nutritional condition is a valuable metric in ecosystem-based fisheries management. However, the need for lethal sampling for the most accurate indicators ethically and logistically limits sample sizes. Percent moisture has been recommended for management of striped bass Morone saxatilis and a management threshold has been suggested. Past researchers have used bioelectrical impedance analysis (BIA) to non-lethally estimate percent dry weight, the inverse of percent moisture. We sought to develop species-specific BIA models for striped bass in a controlled, laboratory setting and later validate those models with independent, field-collected data. BIA models were developed for five size classes and sampled across three temperatures. Results in the lab suggest BIA is an accurate and robust method for estimating percent dry weight in striped bass. However, when implemented in field surveys results are less conclusive. Possible differences between wild and hatchery-reared striped bass that effect BIA need further exploration. Additionally, the effects of salinity and stress response on BIA warrant further work.Item Toward the Development of Integrated Oyster-Algae Aquaculture in the Chesapeake Bay(2014) Ray, Nicholas; Kangas, Patrick C; Environmental Science and Technology; Digital Repository at the University of Maryland; University of Maryland (College Park, Md.)Oyster aquaculture is a rapidly expanding industry in the Chesapeake Bay. Experiments were conducted to investigate the biogeochemical impact of a commercial oyster aquaculture facility on downstream waters at a facility on Maryland's Eastern Shore. An algal production system (ATS) was installed at the facility to assess the potential for bioremediation and algal production in an integrated multi-trophic aquaculture system (IMTA). Results of the experiments showed an increase in available ammonia downstream of the aquaculture facility, coupled with decreases in dissolved oxygen and total phytoplankton. The algal production system demonstrated an average productivity rate of 82.8 g/m2*day-1, a nitrogen (N) removal rate of 9.6 gN/m2*day-1, a phosphorus (P) removal rate of 0.20 gP/m2*day-1, and harvests consisted of an average of 7.8% organic content. Productivity and N and P removal rates from this study are higher than other systems tested in the Chesapeake Bay region at sites without an aquaculture facility.