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...
Prior studies have demonstrated that juvenile walleye pollock Theragra chalcogramma forage socially in schools for spatially and temporally clumped food, but forage more independently for spatially and temporally dispersed food. One advantage of social foraging is that fish in schools may be able to locate more food clumps than fish...
Walleye pollock and sablefish, as 0+ yr juveniles, are pelagic particulate feeding planktivores. We conducted a series of laboratory experiments to determine how illumination influences prey consumption in these species, utilizing live Artemia sp. as prey. Both juvenile walleye pollock and sablefish were characterized by a sigmoidal relationship between the...
Research was undertaken to examine the influence of light intensity on the shoaling behavior, activity and anti-predator behavior of juvenile walleye pollock Theragra chalcogramma. Under a 12 h light/12 h dark photoperiod, juveniles displayed a diurnal shoaling and activity pattern, characterized by fish swimming in cohesive groups during the day,...
Larval and age-0 sablefish Anoplopoma fimbria reside in neustonic waters of the North Pacific during spring and summer. We estimated the potential impacts of elevated surface temperatures on ecological processes of growth, conversion efficiency, and behavior in early juvenile sablefish. Growth experiments tested a wide range of temperatures from 6...
The effects of reduced food availability on the behavior of juvenile walleye pollock Theragra chalcogramma were examined in laboratory experiments designed to test for potential energy-conserving responses. Groups of juvenile fish were held on 1 of 6 ration treatments ranging from ad libitum to near starvation, and then vertical distribution...
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...
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...