Phytophthora borealis and Phytophthora riparia, identified in recent Phytophthora surveys of forest streams in Oregon, California and Alaska, are described as new species in Phytophthora ITS Glade 6. They are similar in growth form and morphology to P. gonapodyides and are predominately sterile. They present unique DNA sequences, however, and...
Phytophthora species were systematically sampled, isolated, identified and compared for presence in streams, soil and roots of alder (Alnus species) dominated riparian ecosystems in western Oregon. We describe the species assemblage and evaluate Phytophthora diversity associated with alder. We recovered 1250 isolates of 20 Phytophthora species. Only three species were...
We gathered baseline data to assess alder tree damage in western Oregon riparian ecosystems. We sought to determine if Phytophthora-type cankers found in Europe or the pathogen Phytophthora alni subsp. alni, which represent a major threat to alder forests in the Pacific Northwest, were present in the study area. Damage...
Fisheries models often assume that discarded undersized fish and target species will survive and contribute to future recruitment and yield. If smaller fish are more susceptible to capture stressors than larger fish, then the assumption that smaller discards would contribute to recruitment may not be true. We tested the hypothesis...
Wildlife habitat mapping has evolved at a rapid pace over the last few decades. Beginning with simple, often subjective,
hand-drawn maps, habitat mapping now involves complex species distribution models (SDMs) using
mapped predictor variables derived from remotely sensed data. For species that inhabit large geographic areas,
remote sensing technology is...
The mortality of discarded bycatch is a critical problem in the management of fisheries worldwide. Little is known about the key principles involved in the mortality of discarded bycatch. These principles are best elaborated under controlled conditions in the laboratory where the actions and interactions of stressors found in fishing...
Experiments were performed to determine the rate of recolonization of sediment-associated microalga and effects of infauna on microalgal biomass and production. Estuarine sediment was defaunated and transplanted to the field and the laboratory. Recolonization of sediment by flora and fauna, relative to control sediment, was measured by chlorophyll a, gross...
Sediment-associated microalgal biomass expressed as chlorophyll a concentration, total organic matter concentration expressed as ash-free dry weight, and hourly rates of net community primary production and community oxygen consumption were measured at monthly intervales at medium sand, fine sand, and silt sites between 0.5 and 2.0 m above MLLW during...
The extent of stress and eventual mortality in Pacific halibut Hippoglossus stenolepis that resulted from simulated capture by hooking or towing in a net, followed by abrupt exposure to warmer seawater temperature and air, were determined under laboratory conditions. Abrupt exposure to 16degreesC seawater and air after either method of...
Age-1 and age-2 Pacific halibut Hippoglossus stenolepis were exposed to a range of times in air (0-60 min) and air temperatures (10 degrees C or 16 degrees C) that simulated conditions on deck after capture to test for correspondence among responses in plasma constituents and mortality. Pacific halibut mortality generally...