Sediment-associated gross primary production, oxygen uptake, microalgal biomass expressed as chlorophyll a concentration, macroalgal biomass and total organic matter concentration expressed as ash-free dry weight were measured monthly at medium sand, fine sand and coarse silt sites between 0.5 m and 2.0 m above MLLW during an entire year at...
While growth and survival of marine fish larvae in the sea may be dependent on prey type, size and concentration, nutritional quality of prey may also play an important role. This study investigates the relationships of lipid content of prey with growth, gas bladder size, sinking rate, behavior and survival...
This study examined, under controlled laboratory conditions, behavioral responses of larval walleye pollock (4 to 8 mm) to various physical factors that may potentially play a role in vertical movements and distribution. Diel periodicity in vertical distribution was evident and appeared to be under exogenous control. During the day, with...
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...
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...
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...
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...
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...
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...
This is a student report which studies the effects of wave action on intertidal zonation at Yaquina Head. It includes hand-drawn diagrams of quadrants sampled at the location.
