This research was designed to broaden the understanding of how timber-harvest affects aquatic macroinvertebrates in perennial and intermittent headwater streams. This study compared emergent and benthic macroinvertebrate assemblages from 20 headwater streams in the central Oregon Coast Range that varied by harvest condition and flow duration. Through comparison of the...
Recent studies of headwater streams have demonstrated their importance to overall watershed biodiversity, nutrient cycling, and energy flux. However, little attention has been paid to long-term effects of forest harvest on macroinvertebrate communities in headwater streams. This study investigated headwater stream macroinvertebrate communities in the H.J. Andrews Experimental Forest, Oregon,...
Structure-forming invertebrates belong to a polyphyletic group of primarily sessile and sedentary megafauna that can significantly enhance the complexity of physical habitats. A number of these organisms, including cold-water corals and sponges, are known to be slow growing and vulnerable to physical disturbance. In addition, as filter feeders, these invertebrates...
This report is concerned with environmental and animal internal temperatures in the intertidal zone at low tide. Daily sea surface temperatures at Agate Beach, Ore., are compared to weekly measurements made near-by. Greater range and fluctuations are revealed by daily measurements. Data are provided on animal internal temperatures at low...
This study describes streams in the Blue Mountains and Wallowa Mountains of Northeastern Oregon in order to characterize the interactions between the terrestrial and aquatic ecosystems and to determine how logging affects those relationships. Five stream reach pairs, each consisting of an undisturbed reach and a similar reach flowing through...
Forest floor vertebrate species presence and abundance may be influenced by the volume and cover of coarse woody debris (CWD) in managed forests. I studied macro- and microhabitat associations of vertebrate species in 18 closed-canopy stands ranging in CWD volume from 14 to 859 m3/ha. Pitfall traps were used to...
Foundation species are important components of ecosystems because they provide habitat and ameliorate stressful conditions for residents. This thesis considers the role of surfgrasses (Phyllospadix spp.) as dynamic foundation species on the coast of Oregon in two studies. Chapter 2, which presents an observational survey of two Phyllospadix congeners, investigates...
Establishment of marine protected areas (MPAs) has been documented to effectively manage marine resource's diversity and enhance fisheries productivity. However, there must be a critical consideration of how these sites are selected and the actual description of the site itself. Its effectiveness is greatly dependent on understanding these habitats and...
The high productivity of Eastern Boundary Upwelling Ecosystems (EBUE), some of the most productive ecosystems in the globe, is attributed to the nutrient rich waters brought up through upwelling. Climate change scenarios for coastal upwelling systems, predict an intensification of coastal upwelling winds. Associated with intensification in upwelling are biogeochemical...
Macroinvertebrates constitute the backbone of megafaunal communities in benthic ecosystems around the globe. Many macroinvertebrates have vital roles in benthic ecosystems, ranging from enhancing habitat complexity to providing staple food sources for other organisms. Regardless of how familiar macroinvertebrates are to the general public, very few studies have attempted to...
This study was an investigation of lotic macroinvertebrate distribution in northeastern Oregon at two different spatial and biological scales. Examination of assemblages at a limited spatial scale revealed relationships with natural and disturbance gradients and led to questions about distribution of a population at broader spatial scales. In a 16...
Heceta Bank is a large reef on the edge of the central Oregon continental shelf that supports a wide variety of commercial fisheries. Using the research submersible Delta, we studied fish abundances on Heceta Bank and the relationship between species composition of fish assemblages and bottom types. Cluster analysis indicated...
Mitigating for increased human impact to the seafloor associated with resource extraction activities and renewable energy development can benefit from an understanding of the distribution of sensitive marine benthic species. Habitat suitability predictive modeling is a cost effective statistical tool to infer species distribution patterns from constrained sampling locations. However,...
Most benthic marine organisms have a bipartite life with an early pelagic stage that enables dispersal of offspring, connecting spatially separated populations, and a late stage where individuals reside in a benthic habitat. Settlement of pelagic offspring to bottom associated substrates is the process that connects the two life history...
Artificial radionuclides, induced in water used as a coolant in the Hanford reactors, are discharged into the Pacific Ocean by the Columbia River. Gamma-ray spectrometric measurements show that levels of 65Zn decrease in both sediments and benthic animals with distance from the mouth of the river and with depth of...