Thesis (Ph. D.)--University of Washington, 2001. / Vita. Includes bibliographical references (p. 158-169).

Thesis (Ph. D.)--University of Washington, 2001. / Vita. Includes bibliographical references (leaves 74-85).

Thesis (Ph. D.)--Oregon State University, 2002. / Typescript (photocopy). Includes bibliographical references. Also available on the World Wide Web.

Thesis (M.S.) in Zoology--University of Maine, 2009. / Includes vita. Includes bibliographical references (leaves 60-73).

Diss. (sammanfattning) Göteborg : Göteborgs universitet, 2009. / Härtill 4 uppsatser.

Thesis (M. Sc.)--York University, 2000. Graduate Programme in Biology. / Typescript. Includes bibliographical references (leaves 233-246). Also available on the Internet. MODE OF ACCESS via web browser by entering the following URL: http://wwwlib.umi.com/cr/yorku/fullcit?pMQ59547.

The Atlantic salmon (Salmo salar) has two developmental processes which are clearly seasonal; smoltification is restricted to the spring and maturation to late autumn. In the farming industry the seasonality of juvenile production is primarily responsible for the seasonal production in market-sized fish. Both smoltification and maturation appear to be controlled by mechanisms timed by photoperiod. This thesis investigates the effects of photoperiod on smoltification and maturation. The performance of both out-of-season eggs and particularly smolts are closely examined and the possible application of photoperiod techniques in the industry discussed. Both potential SI and S2 parr were subjected to natural photoperiods or a range of artificial photoperiods under constant and ambient temperature conditions. S I and S2 smolts reared under natural photoperiods were transferred to sea water during April and May. A 2-3 month period of short days followed by a period of long days was observed to advance smoltification; 0+ and 1+ smolts were transferred to sea during December (4 month advance) and October (6 month advance), respectively. A 12 month seasonal photocycle delayed by 3 months delayed smoltification by 2 months. Out-of-season smolts were produced in January, March, April, May, June, July, October, November and December. All groups of out-of-season smolts exhibited the same growth potential as natural smolts. The different transfer date of out-of-season smolts therefore resulted in different harvest periods compared to natural smolts. The age at maturity of out-of-season smolts was positively related to the length of the seawater growing period prior to the completion of maturation. Out-of-season smolts exhibited increased maturation in association with an increased size (compared to natural smolts) for a particular time of year. These large maturing fish were generally harvested as superior salmon prior to flesh deterioration. Mortality during the first month in sea water was significantly higher in a number of out-of-season smolt groups compared to natural smolts. This was considered to be related to site-specfic environmental conditions rather than the smoltification process. Smoltification was also examined under constant photoperiods and a 4 week period of short daylengths. Dissociation and suppression of certain aspects of smoltification were observed. The different aspects of smoltification: the development of bimodality, hypoosmoregulatory ability, decrease in condition and smolt coloration appeared to be controlled by different independent mechanisms. The development of bimodality, hypoosmoregulatory ability and possibly coloration appeared to be controlled by independent endogenous rhythms. The decrease in condition factor, associated with the parr-smolt transformation required a period of short day length greater than 2 months followed by a period of long daylength. Smoltification and maturation were examined in salmon retained in constant 1DOC borehole water. Smolts held in fresh water grew steadily and matured producing eggs and sperm both in- and out-of-season. There was, however, a period of increased mortality after smoltification and egg quality was reduced especially in fish subjected to photoperiod manipulation. The salmon responded to photoperiodic manipulation. Abrupt changes in photoperiod advanced spawning by 12 weeks and a reciprocal seasonal photoperiod (6 month out of phase with a natural photoperiod) advanced spawning by 22 weeks. The maturation process in the Atlantic salmon would appear to be controlled by similar mechanisms to those described for the rainbow trout. Freshwater holding conditions appeared to decrease the age at maturity and reduce egg quality. The progeny of freshwater broodstock (FI generation) successfully completed smoltification and seawater transfer. Photoperiodic manipulation can be used to produce out-of-season smolts and eggs. Through the use of photoperiod, farms could increase and target production. This could remove the seasonality from the production cycle and help stabilise the pricing structure for market salmon.

No description available.

Recognition and use of indigenous knowledge in resource management can increase the information available about the resource and facilitate establishment of a larger management role for local resource users. This paper examines the use of indigenous knowledge in resource management using the case of knowledge of Pacific salmon {Oncorhynchus spp.) among the Upper St'at'imc, near Lillooet, British Columbia (B.C.). Salmon in the study area are currently managed by the federal Department of Fisheries and Oceans (DFO). This system was established in the 1940s and overlays a traditional management system consisting of fishing site ownership, a well-defined system of access to sites, rules of conduct at fishing sites for the catching and processing of fish, and harvest restrictions. Recent DFO policy changes, signified by the Aboriginal Fisheries Strategy, indicate a movement toward a larger management role for First Nations. This study addresses what indigenous knowledge is available, how it compares to knowledge used by the Department of Fisheries and Oceans, and how indigenous knowledge can be used in modern salmon stock management. A literature review was supplemented by interviews with elders, young Upper St'at'imc leaders, and both DFO and non-DFO biologists. Current indigenous knowledge pertains to salmon stocks, habitat, and practices and philosophy. Indigenous knowledge can be primarily distinguished from western scientific knowledge on the basis of the following properties of the indigenous system: a greater amount of qualitative vs. quantitative information; an obvious recognition and discussion of anomalies; the perception of a wide range of variables in a region; the use of specific local technology; the development of analysis based on both observations over a medium-sized area and traditional ideologies; and differences in institutional arrangements for gathering knowledge. Differences between indigenous and western scientific knowledge are related to the requirement that DFO accumulate and process a large amount of information over a very large geographical area. Several barriers exist to using indigenous knowledge in modern resource management, including the fact that indigenous knowledge does not fit readily into established methods for gathering and analyzing data. Using indigenous knowledge may be facilitated by innovations at both the local and state levels.

Climate is emerging as a primary determinant of marine survival and migratory behaviour for Pacific salmon. For example, a regime shift in the mid-1990s was correlated to a major change in the migratory behaviour of coho salmon (Oncorhynchus kisutch) in the Strait of Georgia, BC. The details of this new behaviour pattern remain relatively unknown. Furthermore, many coho stocks have been declining during the past three decades. Mitigative strategies –such as hatchery programs— have done little to reverse the trend, and little is known about how hatchery fish are affecting wild populations. The objective of this dissertation was to identify key mortality areas and provide the first look at the migratory behaviour of juvenile wild and hatchery coho in southwestern British Columbia using new telemetry technologies. As coho pre-smolts are relatively small compared with other salmonid species that are typically studied using acoustic telemetry, the identification of the appropriate sizes of fish and tags to use was critical. The first study tested the effects of surgically implanting the three smallest sizes of acoustic tags available on the growth, survival, performance and condition of coho pre-smolts. The first of three field studies to follow investigated the early migratory behaviour and survival of an endangered coho population. The second field study examined differences in physiology, survival and migratory behaviour between wild and hatchery-reared coho smolts. Finally, the third study analysed the altered marine migratory behaviour of juvenile coho in the Strait of Georgia. This dissertation provides the first evidence of high freshwater mortality rates in the endangered coho population, which has implications for the management and conservation of this and other at-risk stocks. I found differences in migratory behaviour and physiology between wild and hatchery-reared coho, suggesting that mitigative strategies need further evaluation. Finally, the timing of the anomalous coho migration out of the Strait of Georgia confirmed that population changes in the strait are a consequence of ecosystem-related impacts. These findings demonstrate how new technologies could be used to fill major information gaps and improve the management and conservation of Pacific salmon.