Hatcheries whose purpose is to provide for a recreational fishery must minimize impacts on wild fishes. Management to reduce hatchery and wild interactions is especially important on river systems that contain Endangered Species Act (ESA) listed species. I examined adult hatchery summer steelhead, Oncorhynchus mykiss, behavior, current management and a...
Cyanobacteria are photosynthetic bacteria capable of producing toxins, including complex cyclic peptides called microcystins. Hazardous cyanobacterial blooms are an emerging public health concern and are monitored throughout Oregon in various recreational and drinking water bodies. Oregon has been proactive and responsive to the problems associated with toxic cyanobacterial blooms, but...
A number of steelhead (Oncorhynchus mykiss) populations are at risk throughout Oregon, including five populations that are federally listed as threatened or endangered. However, little is known about behavior and survival of these fish as they transition from freshwater to seawater. We investigated whether estuarine survival varies on a temporal...
Understanding the origin and nature of intra specific biodiversity enables us to better conserve and manage animal populations. Biological diversity is seen at different scales and for different traits such as behavior, morphology, physiology, and life history. Behavior is especially important since behavioral changes are believed to precede changes in...
The collagen content and composition of collagens in
different age classes of shrimp were determined. Their
physical and chemical characteristics were investigated.
The interrelationship of shrimp size and muscle collagen
content to raw and cooked meat yield was established.
Total collagen content for three lots of round shrimp
with weights...
Proteases present in shrimp processing waste are factors in the
technology of shrimp. The distribution of proteolytic activity in
shrimp parts was determined using hemoglobin and casein as substrates. The effects of various parameters upon activity of proteases
in the inedible portion were determined using muscle protein as a
substrate....
The effects of ambient temperature storage on the chemical
and nutritional characteristics of phosphoric and sorbic acid-stabilized
fish autolysates were determined. Variations in sample
composition due to autolysis, deboning, and acidification were also
evaluated.
Autolysates of English sole (Parophrys vetulus), true cod
(Gadus macrocephalus), Dover sole (Microstomus pacificus), and
orange...
Chilling (2-4°C) (10 min) in a solution containing 10% condensed
phosphate, 5% potassium sorbate, and 0.9% citric acid (pH 6.7)
stabilized round shrimp to microbial spoilage. This treatment procedure
allowed refrigerated storage of round shrimp eliminating the
need for ice and the accompanying deteriorative effects of water
absorption and protein...
The abundance and low fat content of Pacific whiting
support Its use for the production of surimi. The
degradation of muscle proteins by myxosporidian secreted
proteinase(s) has been associated with its soft texture.
High residual activity is retained through the washing
process used in the production of surimi and precludes...