Thesis (M.M.A.)--University of Washington, 2009. / Title from Web page (viewed on Feb. 3, 2010). Includes bibliographical references (leaves 20-23).

Thesis (M.M.A.)--University of Washington, 2009. / Includes bibliographical references (leaves 20-23). Also available on the World Wide Web.

The objective of this study was to quantitatively document the culture performance and tissue quality of commercially important deepwater shellfish species (i. e., Pacific oyster, Crassostrea gigas; and Japanese scallop, Patinopecten yessoensis) cultured adjacent to marine finfish aquaculture operations, and to determine (from a production viability and seafood safety perspective) whether integrated finfish-shellfish Multi- Trophic Aquaculture (MTA), or polyculture, is a viable option for the aquaculture industry of temperate regions. Two study sites were employed for this research, one comprising an Atlantic salmon production facility and the other a Pacific salmonf arm. A 2-year assessment program for these sites detailed: (i) oceanographic and physiographicc haracteristics;( ii) organic waste flux, composition and dispersion; (iii) shellfish uptake and contaminant persistence; and (iv) shellfish culture performance. Organic waste flux ranged from 17.11 g/m2/day to 18.35 g/m2/day at the study sites. Phosphorus, calcium, carbon, zinc, cadmium, and strontium were waste constituents that were found at elevated levels at the farm sites with significant declines in concentrations with distance downstream (maximum effect to 100-115 meters). A mass balancee stimation suggested that 85.1% of the organic material (feed) entering the cage was used for fish growth/respiration, 6.8% was lost as settlable solids to the seafloor, and the remaining 8.1% was retained in the water column and a fraction that could affect non-target species (e. g., polyculture candidates) either directly or indirectly. A similar mass balance evaluation for trace metal and chernotherepeutic constituents indicated that 12.9% of the zinc, and an estimated 98.6% of the oxytetracycline contained in feed (during treatment), was released to the water column for potential uptake by co-cultured shellfish. The shellfish monitoring component of this study revealed that trace metal constituents of the feed did become available to the shellfish, although the quantifiable accumulation of trace metals in these non-target species occurred only in close proximity to the cage system and only for the tested scallops (Patinopectin yessoensis). Uptake rates of OTC by shellfish ranged from 0.056 - 0.100 ug/g/day with an associated clearance rate of 0.016 - 0.109 ug/g/day for the respective treatment periods. The comparison of uptake-clearance dynamics suggested asignificant seasonal component to these processes. The physical and biological processes affecting contaminant uptake and clearance rates were identified as important considerations in the management of a proposed integrated-MTA system. A simple Probable Effects Duration (PED) model was developed on the basis of Uptake-Clearance-Persistence plots, illustrating the basis upon which temporal effects of water quality deterioration could be managed in such a system. Shellfish growth was neither impeded nor enhanced as a result of being cultured directly within the influences of a salmon aquaculture facility. An organoleptic test demonstrated that shellfish palatability was not negatively impacted as a consequence of culture proximity to a finfish aquaculture facility. Results of this research suggested that two options are available for developing MTA in coastal temperate waters, i. e., an integrated MTA system and/or an adjacent MTA system. A wide range of MTA social, technical and economic benefits were identified and discussed as a result of this research. It was concluded that the development of a balanced MTA could add measurable environmental benefits to existing aquaculture systemss, setting the stage for future production efficiencies and growth. Given a proper regulatory framework, including seafood (MTA products) and environmental quality surveillanc, the potential water quality impacts on the shellfish component of a finfish-shellfish MTA (identified in this research initiative), and the associated risks over seafood safety, could be effectively managed to support this aquaculture evolution.

Thesis (Ph. D.)--University of Tasmania, 2004. / Title from PDF title page (viewed on June 11, 2005). Includes bibliographical references.

Thesis (Ph. D.)--Auburn University. / Abstract. Vita. Includes bibliographical references (p. 102-115).

Recent concerns about the health of marine environments have led to the worldwide creation of new marine conservation initiatives. Multiple-use marine protected areas (MPAs) are one potential solution; however, they may be perceived by some as 'economic sterilizers' and threats to certain livelihoods, such as marine tourism or aquaculture. For instance, shellfish growers may perceive MPAs as favouring tourism as an economic activity, attracting recreational boaters who may inflict a negative impact on shellfish health through sewage or chemical discharge. Conversely, recreational boaters may perceive shellfish aquaculture as a threat to safe navigation and desirable anchorages. One significant challenge for resource managers then, is to design MPAs in ways that are acceptable to different stakeholder groups. This research, a partial application of the "Limits of Acceptable Change" (LAC) visitor management framework, examines acceptability of recreational boating and shellfish aquaculture within a proposed MPA from a community stakeholder perspective. This study examined Gulf Islands residents’ attitudes, perceptions and values towards the Gulf Islands marine environment. Gaining a clear understanding of the views of stakeholders is key in allowing coastal planners and marine resource managers to proceed effectively towards achieving their mandates. Specifically, this knowledge allows them to (1) identify what is important to different users; (2) determine public relations needs; (3) justify management decisions; (4) promote resource protection; (5) identify potential conflict areas; and (6) address negative concerns and build on positive perceptions. This project samples the views of a random selection of residents (n = 302) from Thetis. Salt Spring and Saturna Islands during the summer of 2004. This research applies respondents' values towards the marine environment as an independent variable in the analysis of (1) perceptions of threats towards the marine environment; (2) attitudes towards recreational boating and sewage from boating; (3) attitudes towards shellfish aquaculture: and (4) attitudes towards different strategies for zoning the marine environment.

Mussels are important ecological engineers on intertidal rocks where they create habitat that contributes substantially to overall biodiversity. They provide secondary substratum for other free-living, infaunal or epifaunal organisms, and increase the surface area for settlement by densely packing together into complex multilayered beds. The introduction of the alien invasive mussel Mytilus galloprovincialis has extended the upper limit of mussels on the south coast of South Africa, potentially increasing habitat for associated fauna. The aim of this study was to describe the structure of mussel beds, the general biodiversity associated with multi- and monolayered mussel beds of indigenous Perna perna and alien M. galloprovincialis, and to determine the relationship between mussels and epibiotic barnacles. This was done to determine the community structure of associated macrofauna and the role of mussels as biological facilitators. Samples were collected in Plettenberg Bay, South Africa, where M. galloprovincialis dominates the high mussel zone and P. perna the low zone. Three 15 X 15 cm quadrats were scraped off the rock in the high and low zones, and in the mid zone where the two mussel species co-exist. The samples were collected on 3 occasions. In the laboratory mussel-size was measured and sediment trapped within the samples was separated through 75 μm, 1 mm and 5 mm mesh. The macrofauna was sorted from the 1 mm and 5 mm sieves and identified to species level where possible. The epibiotic relationship between mussels and barnacles was assessed by measuring the prevalence and intensity of barnacle infestation and the condition index of infested mussels. Multivariate analysis was used on the mean abundance data of the species for each treatment (Hierarchical clustering, multidimensional scaling, analysis of similarity and similarity of percentages) and ANOVA was used for most of the statistical analyses. Overall, the results showed that tidal height influences the species composition and abundance of associated fauna. While mussel bed layering influenced the accumulation of sediments; it had no significant effect on the associated fauna. Time of collection also had a strong effect. While there was an overlap of species among samples from January, May and March, the principal species contributing to similarity among the March samples were not found in the other two months. The outcomes of this study showed that low shore mussel beds not only supported a higher abundance and diversity of species, but were also the most structurally complex. Although the condition index of mussels did not correlate to the percentage cover of barnacle epibionts, it was also evident that low shore mussels had the highest prevalence. The levels of barnacle infestation (intensity) for each mussel species were highest where it was common and lowest where it was least abundant. This is viewed as a natural artefact of the distribution patterns of P. perna and M. galloprovincialis across the shore. Mussels are more efficient as facilitators on the low mussel zone than the high mussel zone possibly because they provide habitats that are more effective in protecting the associated macrofauna from the effects of competition and predation, than they are at eliminating the effects of physical stress on the high shore. Although mussels create less stressful habitats and protect organisms from the physical stress of the high shore, there are clear limitations in their ability to provide ideal habitats. The biological associations in an ecosystem can be made weak or strong depending on the external abiotic factors and the adaptability of the affected organisms.