Zugl.: Hamburg, Universiẗat, Diss., 2008.

Thesis (M.S.)--University of Delaware, 2007. / Principal faculty advisor: Haiqiang Chen, Animal & Food Sciences. Includes bibliographical references.

Thesis (M.S.)--Washington State University, December 2007. / Includes bibliographical references.

Thesis (Ph. D.)--University of Rhode Island, 2006. / Includes bibliographical references (leaves 138-154).

No description available.

Thesis (Ph. D.)--University of Texas at Austin, 1999. / Vita. Includes bibliographical references (leaves 338-352). Available also in a digital version from Dissertation Abstracts.

Oregon’s fish hatchery system developed in the late 1800’s in response to salmon fishery losses. Salmon hatcheries consist of a number of built components. ‘Growing fish’ requires a variety of building types which support the hatchery process as well as constant input of resources. In addition to surveying and inventorying fish hatchery resources, this study will analyze the social, economic, cultural, and environmental conditions under which these fish hatcheries were organized and commissioned. Ultimately, this survey will not only serve as a baseline for future, more intensive-level surveys, but will also provide a foundation for a National Register Multiple Property Submission. The use of hatcheries to sustain native Oregon fish species constitutes a major aspect of Oregon’s fishing and environmental conservation efforts. Oregon’s heritage hatcheries stand as physical reminders of early conservation activity and while their preservation provides a more complete picture of Oregon’s relationship with natural resources

A well-accepted idea in geomorphology is that landforms control the type and distribution of biological habitat. However, the linkages between geomorphology and ecology remain poorly understood. In rivers, the geomorphic template controls the hydraulic environment, partly shaping the river ecosystem. But what processes shape the geomorphic template? Here, I examine how two hillslope processes dominant in the Oregon Coast Range, debris flows and deep-seated landslides, affect valley floor width and channel slope, key components of the geomorphic template in riverine ecosystems. I then investigate how patterns in potential salmon habitat differ between streams dominated by deep-seated landslides and streams dominated by debris flows. I show that terrain influenced by deep-seated landslides exhibits (1) valley widths that are more variable throughout the network but less locally variable, (2) more variable channel slopes, and (3) more potential salmon habitat as well as significantly more connectivity between habitat types.

The farming of Atlantic salmon (Salmo salar) is challenged by parasitic infestations caused by Lepeophthreirus salmonis and Caligus elongatus. A convenient and effective way to control sea lice and treat farmed salmon is by in-feed treatments such as Slice®. A reliable, accurate and reproducible method for the determination of emamectin benzoate (EB), the active ingredient of Slice®, and its desmethylamino metabolite (DES) in sediment was developed and validated. It involved methanolic extraction, clean-up using solid-phase extraction with a strong cation exchanger, and derivatisation with trifluoroacetic acid anhydride and N-methylimidazole. Analytes were quantified following HPLC separation with fluorescence detection. The method was successfully applied to determine EB and DES in salmon flesh and skin, seawater, mussels (Mytilus edulis) and seaweed (Palmaria palmata). A laboratory study showed that EB was persistent under anaerobic conditions in two different sediments at 4 and 14 ºC. A further study also demonstrated that the growth of seaweed (P. palmata) was not affected by the presence of EB and that EB did not accumulate significantly in the seaweed. This result is encouraging in view of proposed polyculture systems involving seaweeds. Studies conducted on a working Scottish salmon farm investigated the fate of EB and DES in target and non-target matrices. For three months post-treatment, EB was detected, by mass in descending order, in the salmon flesh, skin, faeces, then mucus and sea lice with concentrations in each matrix declining steadily over the period. As EB had never been quantified in sea lice before, it was unclear whether they were a significant sink for EB in the environment, following their exposure to the medicine and dislodging from salmon after feeding. However, due to the low concentrations of EB detected in the sea lice, faeces are most probably the main route for emamectin entering the environment. Sediment collected directly below and around two active walkways, over five or six months following treatment, showed that the spatial dispersion of EB and DES was mainly limited to the area within 25 m of the cage edge, although concentrations depended on sampling location in relation to water currents. Maximum EB concentrations were recorded three months after treatment. Seven days after treatment, 6 % of the total EB input was present in the sediments within 25 m of the cage edge. Neither EB nor DES were detected in seawater, mussels, periwinkles, dogwhelks and seaweed samples collected from the walkway and the surrounding environment. This work, one of the few studies of the uptake of EB by indigenous fauna and flora of an active salmon farm, suggests that it is not significantly accumulated in matrices outwith the target organism and the sediment.

Growth hormone-releasing hormone (GHRH) is a neuropeptide which stimulates the synthesis and release of growth hormone (GH) from the pituitary gland. The primary structure of this peptide has been identified in 7 mammalian species while the gene has been isolated from only rat and human. GHRH is a member of the glucagon superfamily which includes vasoactive intestinal peptide (VIP), glucagon, secretin, peptide histidine methionine (PHM), gastric inhibitory peptide (GIP) and a recently identified peptide, pituitary adenylate cyclase activating polypeptide (PACAP). The evolutionary relationships of this superfamily are not well understood because the gene structure of these molecules has only been identified in mammals. This thesis presents immunological evidence of a GHRH-like molecule, and identifies a GHRH/PACAP precursor and gene that encode two peptides, a GHRH-like molecule structurally related to PACAP-related peptide (PRP) and PACAP, from sockeye salmon brain. An antiserum directed against a topologically assembled epitope of human GHRH 1-44 (NH2) was produced and used to develop a radioimmunoassay for detection of immunoreactive GHRH in brain extracts of salmon, guinea pig, mouse and alligator. An immunoreactive GHRH from salmon brain extracts with a retention time on reverse phase high-performance liquid chromatography (HPLC) distinct from human GHRH was present. In alligator, the same antiserum also detected a GHRH-like molecule. During attempts to purify alligator GHRH, alligator brain neuropeptide Y (NPY) was identified. Alligator NPY is the first non-mammalian vertebrate to have 100% sequence identity to human NPY. The sequence identity between alligator and human NPY suggests that this sequence is the same as the ancestral amniote NPY. Molecular biological techniques were used for the structural identification of the salmon GHRH-like molecule and another peptide. The salmon GHRH/PACAP precursor contains 173 amino acids and has dibasic and monobasic processing sites for cleavage of a 45 amino acid GHRH-like peptide with a free acid C-terminus and a 38 amino acid PACAP with an amidated C-terminus. The salmon GHRH-like peptide has 40% amino acid sequence identity with the human GHRH and 56% identity with human PACAP-related peptide (PRP). Salmon PACAP-38 is highly conserved (89%) with only 4 amino acid substitutions compared with the human, ovine and rat PACAP-38 peptides. Nucleotide sequencing and use of the polymerase chain reaction show the exon/intron organization of the salmon GHRH/PACAP gene to be similar to the human PACAP gene. Unlike the mammalian PACAP genes, the salmon gene produces two precursor forms by post-transcriptional processing. One form is similar to the mammalian PACAP precursors, while the second form is shorter due to the excision of exon 4. This deletion results in the loss of the first 32 amino acids of the GHRH-like peptide from the precursor. The high sequence identity and structural organization between the GHRH(PRP)/PACAP and PHM(PHI)/VIP genes suggest a duplication event occurred in an ancestral gene after the divergence from the other glucagon superfamily members. GHRH in mammals may have arisen by gene duplication after the divergence of the tetrapods from the other vertebrate lines. Thus, GH in fish may be controlled by the two molecules, GHRH-like peptide and PACAP, located on a single GHRH/PACAP gene. / Graduate