Two of the most powerful ways in which humans have altered ecosystems are by increasing productivity and changing the densities of important consumers. The bottom-up effects of productivity and the top-down effects of consumers have been identified as primary determinants of biological diversity, though the links between them remain unclear....
Releasing hatchery reared salmon and steelhead to supplement threatened and endangered populations is a widely used conservation tool. One issue with this strategy is hatchery fish have lower reproductive fitness than wild fish when spawning in the wild. One of the drivers of fitness loss in steelhead is adaptation to...
My thesis explored the effects of and potential mediating mechanisms for an important environmental stressor, ultraviolet-B (UVB) radiation. UVB radiation has negative effects on organisms in both terrestrial and aquatic systems. I used meta-analysis to quantify the effects of UVB radiation on a diversity of aquatic organisms (Chapter 2). UVB...
Understanding the dynamics of open marine populations is difficult. Ecological processes may vary with the spatial structure of the habitat, and this variation may subsequently affect demographic rates. In a series of observational and experimental studies in the Bahamas, I examined the roles of emigration, mortality, and predation in the...
While community ecologists have traditionally focused on local-scale processes, it has become apparent that a broader perspective, which explores the community-level ramifications of material fluxes within and between ecosystems, is necessary to effectively evaluate bottom-up influences on community structure and dynamics. In this dissertation, I employed ecosystem principles to understand...
Interface habitats are considered valuable natural systems, tightly linked to adjacent habitats through the flow of matter and energy. However, there is limited research on mechanisms of connectivity such as movement of organisms and particulate matter and ways in which anthropogenic disturbance to interface habitats may affect immediate and adjacent...
This dissertation focuses on science relevant to the design and implementation of marine reserves. The chapters explore a range of topics related to among-site variation in population, community, and ecosystem dynamics. My results demonstrate the value and feasibility of integrating this knowledge into more comprehensive conservation and management approaches. While...
Biological invasions and climate change represent two preeminent threats to ecological communities and biodiversity, altering the distribution and abundance of species, disrupting existing species interactions and forming unprecedented ones, and creating novel ecological communities. Many of the most successful invasive species are also ecosystem engineers, species that physically modify the...