The relationship between nutrients and community structure is poorly understood in open-coast habitats. I created a system of artificial tidepools, of identical age and physical dimensions, at two sites that differed in wave exposure, and manipulated nutrient levels and the abundance of herbivores. Using these unique field mesocosms, I explored...
Oceanic uptake of rising anthropogenic CO₂ emissions has caused the emergence of ocean acidification as a major threat to marine ecosystems worldwide. Along eastern boundary current systems, seawater is naturally acidified due to coastal upwelling of low pH seawater from depth. Compounded by ocean acidification, upwelling regions are expected to...
Collective robotic systems are biologically-inspired and exhibit behaviors found in spatial swarms (e.g., fish), colonies (e.g., ants), or a combination of both (e.g., bees). Collective robotic system popularity continues to increase due to their apparent global intelligence and emergent behaviors. Many applications can benefit from the incorporation of collectives, including...
Previous observations of light levels and phytoplankton abundances along the Oregon coast demonstrated that phytoplankton attenuated light sufficiently to potentially limit the growth of intertidal macrophytes and therefore structure local intertidal communities. Inspired by this observation, in spring 2004, I initiated a study to quantify the direct and indirect benthic...
1. Theoretical and empirical ecology has transitioned from a focus on the role of negative interactions in species coexistence to a more pluralistic view that acknowledges that coexistence in natural communities is more complex, and depends on species interactions that vary in strength, sign, and reciprocity, and such contexts as...
Ecosystems are shaped by processes occurring and interacting over multiple temporal and spatial scales. Theory suggests such complexity can be simplified by focusing on processes sharing the same scale as the pattern of interest. This scale-dependent approach to studying communities has been challenged by multiscale meta-ecosystem theory, which recognizes that...
Ocean acidification (OA) has emerged as an important focus of research and policy in this decade. Ocean acidification specifically refers to changes in the inorganic carbon system in the ocean resulting from its absorption of human-released CO₂ from the atmosphere. Anthropogenic atmospheric CO₂ levels are rapidly increasing; much of this...
Decades of experimental work has illustrated the high degree to which the partitioning of most elements is dependent on phase composition, temperature and pressure. In order to quantitatively describe clinopyroxene partitioning it is required to derive expressions using theoretical constraints calibrated with experimental data.
The experimental database available for such...
Stocks of salmon are declining in the Pacific Northwest. Based on region-wide studies that list and categorize the status of salmon stocks (Nehlsen et al., 1991; Huntington et al., 1994; and Nawa, 1995), I analyze the watersheds where stocks of salmon spawn for several anthropogenic variables, most of which are...