In marine environments, the open system (OS) theory, whereby populations are assumed to be well connected through large-scale dispersal, is currently being challenged by studies demonstrating limited dispersal. Using a novel metapopulation framework featuring nonequilibrium within-site disturbance cycles and limited dispersal, I investigate the large-scale response of marine mussel populations to changes in oceanographic productivity. By altering the fecundity parameter, I am able to shift from open to dynamically-coupled systems (DCS), thereby generating predictions that can be used to test the connectivity of marine populations. Within-site disturbance cycles scale-up and drive regional dynamics in both OS and DCS. Fast disturbance cycles induce synchronized oscillations that promote regional extinction risk in response to changes in oceanographic productivity for DCS but not OS. Slow disturbance cycles maintain spatial variability and temporal stability in both OS and DCS. These predictions can be used to test the applicability of OS theories to natural coastal ecosystems.

Mussel colonization is assumed to result from factors affecting recruitment and post-recruitment survival. Despite evidence of passive migration and habitat engineering by adult mussels, the contribution to population dynamics of these processes remains unknown. This research attempts to elucidate the relative importance and scale of (1) adult movement vs. recruitment and (2) of local habitat engineering vs. habitat heterogeneity, for colonization by the blue mussel, Mytilus spp., in the St. Lawrence Estuary, Quebec. Transplants of marked mussels were used to test these ideas. Our results support the hypothesis that colonization mostly occurs through disturbance-mediated adult movement. The scale of this displacement was quantified. Colonization was accelerated by topographic heterogeneity and engineered habitat propagation. These results counter the notion that mussel population dynamics are solely regulated by recruitment and growth, and suggest that distribution patterns are also upheld by adult aggregation and movement from the local scale to landscape level.

Recently, the assumption that marine populations are demographically open due to long-distance larval dispersal has increasingly been challenged. Here we present a large-scale, multi-year survey of blue mussel ( Mytilus spp.) abundance and recruitment along the Southern shore of the St. Lawrence Estuary, Quebec. Using spatial statistical tools we detected significant positive cross-covariance between upstream adults and downstream recruitment at a 14-35 km scale. Adult abundances in subsequent surveys proved to be best explained by past patterns of recruitment, rather than growth indices, or the local supply of recruits. Fucus spp., large macroalgae with much shorter planktonic periods, displayed no evidence of dynamic coupling. Recruitment was instead correlated with growth rate, indicating that local conditions may drive rates of reproduction by Fucus spp. plants. These results provide the first direct quantification of spatio-temporal demographic coupling between adult production and recruitment using survey data, with consequences for metapopulation and marine reserve design.

Assessing the timing of seasonal movements by the prehistoric peoples of Otago has long been a problem in the archaeology of this region. The oxygen isotope ratio (18 o/16o) of mollusc shell carbonate is temperature dependent. By sampling successive increments of shell growth, palaeotemperature curves can be constructed to provide �season of death� estimates for individual shells. In this work carbonate samples from the blue mussel (Mytilus edulis) were used to estimate the seasonality of four prehistoric fishing sites. A total of 275 samples of shell material were analysed for carbon and oxygen isotope ratios at the Institute of Nuclear Sciences, Lower Hutt. Where fishing and shellfishing were important activities they were consistently associated with the winter season. A model of seasonal activity is presented for the Early part of the prehistoric period.

Thesis (Ph. D.)--Florida State University, 2004. / Advisor: Dr. Robert H. Reeves, Florida State University, College of Arts and Sciences, Dept. of Biological Science. Title and description from dissertation home page (viewed Sept. 23, 2004). Includes bibliographical references.

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

Thesis (Ph. D.)--University of Florida, 1981. / Description based on print version record. Typescript. Vita. Includes bibliographical references (leaves 173-175).

Ocean acidification and warming have been shown to affect a wide range of marine organisms and impact assemblages and ecosystems. Many of the species experiencing negative biological effects provide valuable ecosystem services, yet it is unclear how these biological effects will affect ecosystem services provision. This thesis aimed to appraise the consequences of ocean acidification and warming on important shellfish species, from physiology to provision of ecosystem services, using a multidisciplinary approach. The responses to ocean acidification and warming of two ecologically and commercially important species of oysters – the native European Flat oyster Ostrea edulis, and the non-native Pacific oyster Magallana gigas – were assessed in laboratory mesocosms following long-term exposures to a range of scenarios predicted for 2050 and 2100. Oysters provide numerous ecosystem services, including improvement of water quality, reef formation, and food provision, but are at risks from ocean acidification and other stressors due to negative impacts occurring at multiple life-stages and threatening reef maintenance and functioning (Chapter 1). The physiology of adult oysters appeared susceptible to ocean acidification and warming, with evident sub-lethal effects (Chapter 2). Magallana gigas experienced a greater degree of stress than O. edulis, displaying increased Standard Metabolic Rate, reduced Clearance Rate, and poorer Condition Indices. Reductions in Clearance Rates of M. gigas are especially concerning and may have important ecological impacts by limiting their ability to improve water quality in the future. The physiological changes experienced by individual oysters held important implications for the functioning of the reefs through changes in predation resistance. Again, M. gigas appeared to undergo more pronounced changes than O. edulis, displaying increased muscle strength but weakened shell strength. These changes are expected to alter its susceptibility to predators and influence community level interactions. Both O. edulis and M. gigas also underwent important changes to their biochemical composition with trends for impoverished nutritional quality, which holds direct implications on the provision of sea food. In particular, M. gigas contained lower lipid, carbohydrate, and protein levels, but higher contaminant concentration (copper); this change holds concerns for both future food security and future food safety. It was apparent that the physiological stress experienced (Chapter 2), led to significant energy reallocation from somatic growth to metabolism by depleting energetic reserves (Chapter 4), at the detriment of its nutritional quality. No negative effects on the eating quality of M. gigas (appearance, aroma, texture, taste, and overall acceptability) were recorded following a short-term exposure to ocean acidification and warming (Chapter 5), which was considered positive for the aquaculture sector. In order to secure future food provision and economic revenue, the UK aquaculture industry might need to reconsider its management strategy in the future, and encourage the production and consumption of O. edulis, in addition to the already popular M. gigas. It is clear that the impacts of ocean acidification and warming on oysters are multifaceted and occurring at multiple scales and levels of organisation. The risks to oysters and oyster reefs appear species-specific; in the UK, introduced M. gigas may be more vulnerable than native O. edulis. To secure benefits and minimise costs related to the management of introduced species, these findings could be integrated into the current management and conservation measures in place for these species and the reefs they can form.

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