Thesis (M.S.)--Oregon State University, 2007. / Printout. Includes bibliographical references. Also available on the World Wide Web.

Thesis (M.S.)--Oregon State University, 2010. / Printout. Includes bibliographical references (leaves 64-69). Also available on the World Wide Web.

Thesis (M.S.)--Oregon State University, 2009. / Printout. Includes bibliographical references (leaves 87-94). Also available on the World Wide Web.

The purpose of this study is to identify the intrinsic and extrinsic quality characteristics of West Coast albacore tuna (Thunnus alalunga). Albacore tuna were troll caught off the Oregon coast and transferred to the Oregon State University Seafood laboratory in Astoria, Oregon. Core samples were extracted from six designated body zones of 16 fish and analyzed for lipid, moisture, protein, ash, and fatty acid distribution. Proximate distribution was constant throughout the body zones. Protein and ash made up 25% of the composition, lipid and moisture made up the remaining 75%. The lipid content ranged from 3.9 ± 0.2 to 36.3 ± 1.1%, with a distribution of higher lipid towards the head and lower lipid towards the tail. Total omega-3 content averaged 40% of the identified fatty acids for each body zone, with omega-3 (g/100g tissue) ranging from 2.1 ± 0.5 to 3.5 ± 0.4. Furthermore, an inverse correlation (R²= -0.95) was found for lipid and moisture content, enabling a faster estimate of lipid content derived from moisture content. Onboard handling techniques for West Coast albacore tuna were evaluated using sensory and analytical methods. Chilling (immediately and after 3 h), spiking, and bleeding at the throat and gills were evaluated by a sensory panel for overall quality, color, smell, texture and flavor. 2-Thiobarbituric acid-reactive substances (TEARS) and pH were also compared. Rapid chilling significantly and positively influenced overall quality, color, texture, and flavor; and significantly reduced oxidative rancidity. Bleeding at the throat significantly and positively influenced all sensory attributes tested, but did not significantly influence TEARS or pH. Neither spiking nor bleeding at the gills significantly affected sensory attributes. / Graduation date: 2003

Thesis (M.S.)--Oregon State University, 2001. / Typescript (photocopy). Includes bibliographical references. Also available online.

The main purpose of this research is to provide the commercial seafood industry of the Pacific Northwest information on preferences of restaurateurs, retailers, and wholesalers for whole albacore, low-value added albacore products (chunks, medallions, and steaks), albacore loins, and high-value added albacore products (hot smoked and lox). All of these products were categorized as non-traditional market forms of albacore products, except whole albacore. The empirical analysis was based on self explicated and conjoint analysis. The demand models for albacore products were estimated using weighted least squares. Profitability equations for albacore products were estimated using a two-limit Tobit model. From the self explicated section, it was found that the attributes of price, flavor, blood spots/bruising, and bleeding of whole albacore were considered highly important by respondents. From the conjoint analysis section, it was found that, as expected a priori, price had a statistical significant effect on the demand and profitability models for all albacore products. Other variables, such as location of the firm, type of firm, experience with tuna species, and ranking of albacore had statistical significant effects on the demand and profitability equations. Wholesalers, restaurateurs, and retailers agreed that quality is a major concern and will influence their preferences when purchasing albacore can products. Overall, the findings from this research provide guidance to the commercial seafood industry of the Pacific Northwest to enhance the markets for albacore products. / Graduation date: 1997

This study investigated long-term (1961-2008) changes in albacore (Thunnus alalunga) abundance and distribution in relation to local environmental and large-scale climate indices in the Northeastern Pacific using time series and spatial analyses. Prior to the time series analysis, a wavelet analysis was conducted to examine nonrandom patterns of cyclical variability which revealed that monthly and annual time scales had the highest non-random variability. Thus, the time series analysis was done at these two scales using non-linear generalized additive models (GAMs) and threshold GAMs. At the monthly scale, sea surface temperature (SST) was found to be the variable with the strongest (positive) association to albacore catch per unit effort (CPUE). This association was likely driven by the seasonal migrations of juvenile albacore into and out of the U.S. coastal waters. At the yearly time scale over large geographical areas, the SST association broke down, and the scalar wind speed cubed (an indicator of mixed layer depth) at a five year lag became the dominant variable. The scalar wind speed cubed index explained 65% of the variability and was highly significant, even after adjusting for multiple tests (Bonferroni corrected P-value<0.001). These results suggest that a deeper mixed layer in the Northeastern Pacific may provide favorable foraging habitat for juvenile (mostly age 3) albacore, resulting in successful growth, spawning, and recruitment into the fishery in later years. This mixed layer depth association could help managers and stock assessment groups in their efforts to integrate environmental factors into the estimate of albacore population size. The spatial/spatio-temporal analyses involved modeling the CPUE with four competing GAM formulations, each representative of a different hypotheses for albacore distribution: 1) spatial, 2) spatial and environmental (SST, PDO, and MEI), 3) spatially variant, and 4) nonstationary, as indicated by the North Pacific regime shift of 1977. Results indicate that SST had a predominantly positive but spatially-variable effect on albacore CPUE, while the PDO had a negative overall effect. Specifically, CPUE was found to increase with increased SST, particularly off of Oregon and Washington. These results imply that if ocean temperatures continue to increase, west coast communities reliant on commercial albacore fisheries are likely to be negatively impacted in the southern areas but positively benefited in the northern areas, where current albacore landings are highest. / Graduation date: 2012

Submitted by (edna.saturno@ufrpe.br) on 2017-02-08T16:07:31Z No. of bitstreams: 1 Bruno de Oliveira.pdf: 2373684 bytes, checksum: 5f89aaf529fed3c21f21b9c51546d9b8 (MD5) / Made available in DSpace on 2017-02-08T16:07:31Z (GMT). No. of bitstreams: 1 Bruno de Oliveira.pdf: 2373684 bytes, checksum: 5f89aaf529fed3c21f21b9c51546d9b8 (MD5) Previous issue date: 2010-08-31 / Conselho Nacional de Pesquisa e Desenvolvimento Científico e Tecnológico - CNPq / Analysis between the environmental variability in the pelagic ocean environment, distribution and abundance of the main oceanic fishing resources, have been evaluated in several studies, mainly with the intensification of global climate changes in the recent decades. The main objective of this study was to evaluate the relations between the catches (CPUE) of albacore(Thunnus alalunga) and some environmental parameters, together with spatio temporal data of fishing activities during the period between 1980 and 2007. The fishing data used, including the spatio temporal distribution of effort and catches are referred of long line fleet operations of Brazil (BNDA) and China Taipei (ICCAT). The environmental parameters (SST– Sea Surface Temperature and DML – Depth Mixed Layer) were obtained in international oceanographic data banks. Generalized Additive Models (GAM’s) were used for analyses between CPUE (dependent variable) and the environmental variability. Furthermore, spatio temporal aspect(latitude, longitude, month and year) of fish activity were included, in order to evidence the seasonality in catches. The results obtained show that the environmental variability on oceanographic conditions have a strong influence in the distribution and abundance of albacore, and, consequently, in its catch rate (CPUE). The SST (positive correlation with latitude, for the area of this study) was the most important environmental parameter in catch rates (CPUE). Besides that, we inferred that catches received a positive influence in areas where the thermocline is more superficial and there is a seasonal pattern in the distribution and abundance characteristic. These aspects seem to be in relation with the migratory movements of this specie in the South Atlantic Ocean, including the concentration along the Brazilian coast for spawn in austral summer. / Relações entre a variabilidade ambiental do ambiente pelágico oceânico e a distribuição e abundância relativa dos principais recursos pesqueiros oceânicos, vêm sendo avaliadas em diversos estudos, principalmente com a intensificação dos processos de mudanças climáticas, ocorridos em décadas recentes. O objetivo principal deste estudo foi avaliar a relação entre a captura (CPUE) da albacora branca (Thunnus alalunga) e algumas variáveis ambientais, juntamente com dados espaço-temporais da atividade pesqueira, referentes ao período compreendido entre 1980 e 2007. Os dados de pesca utilizados, incluindo a distribuição espaço-temporal do esforço de pesca e das capturas, são referentes à operação da frota espinheleira do Brasil (Banco Nacional da Pesca de Atuns e Afins) e de China Taipei (International Comission for Conservation of Atlantic Tunas, em inglês). Os dados ambientais (TSM – Temperatura da Superfície do Mar e PCM – Profundidade da Camada Mistura) foram obtidos de bancos internacionais de dados oceanográficos. Modelos Aditivos Generalizados (GAM’s) foram utilizados para averiguar as relações entre o rendimento pesqueiro, expresso através da CPUE (variável dependente), e à variabilidade ambiental. Além disto, aspectos espaço-temporais (latitude, longitude, mês e ano) foram incorporados, de modo a evidenciar a sazonalidade das capturas na área do estudo. Os resultados obtidos mostram que à variabilidade ambiental do ambiente oceanográfico influencia fortemente à distribuição e abundância da espécie e, consequentemente, das capturas. A TSM (correlação positiva com a latitude, para a área de estudo) foi o fator ambiental que mais influenciou a CPUE. Além disto, podemos inferir que as capturas sofrem influência positiva em áreas com a termoclina mais próxima da superfície aquática e que existe um padrão sazonal de distribuição e abundância bem marcado. Estes aspectos parecem estar relacionados com o padrão migratório da espécie no Atlântico sul, incluindo a concentração da mesma ao largo da costa brasileira para fins reprodutivos, durante o verão austral.

The study is based on Gordon-Schaefer model, using statistic data from Western and Central Pacific Fishery Commission to estimate the resource stock of Albacore between 1960 and 2009. Compare the equilibrium levels of open access model and present value maximization model with the real data, and the result shows that the real stock is close to the equilibrium of present value maximization model. The thesis uses sensitivity analysis to understand the impact of the changed parameters on stock and effort, and by using real examples to understand the impact of the changed situation on stock and effort. Finally, by simulating the stock of open access fishery and present value maximization fishery and government management nowadays fishery. The result shows the stock of government management fishery is higher than the stock of the present value maximization fishery, and the stock both are closed. The management is conservative and effective, hence the management will make the profit maximize and the resource continue forever to develop.

The objects of this study were to investigate the differences of total mercury(THg), organic mercury(OHg) concentrations in the muscles of albacore and bigeye tuna from the Pacific Ocean, and the THg and OHg concentration in the livers , and the trace elements (Cu, Fe, Mn and Zn) in the muscles and livers of albacore, in order to evaluate the bioaccumulative status of the oceanic migratory fishes. Meanwhile, The relationships between mercury concentration and size (length and weight) and age were established, and the differences of mercury concentrations in the tuna between species and geography were examined. And that the safety consumption level was also discussed. One hundred eighty-five albacore and 134 bigeye tuna were sampled from the period October 2001 to April 2006 and from September 2005 to November 2006, respectively, in the Western and Central Pacific Ocean. The results showed that the average THg (mg/kg flesh wt.) and OHg (mg/kg flesh wt.) of muscles were 0.435¡Ó0.145 and 0.279¡Ó0.087, respectively, for albacore, and 0.935¡Ó0.655 and 0.544¡Ó0.396, respectively, for bigeye tuna. The THg and OHg of livers of albacore were 0.426¡Ó0.363 and 0.193¡Ó0.121, respectively. The average OHg percentages of the THg in albacore and bigeye tuna were 67¡Ó19 % and 62¡Ó20 %, respectively. Except there was no significant correlation between OHg and age in the liver of albacore, the THg and OHg in the muscles, and THg in the livers of albacore, and THg in the muscles of bigeye tuna showed a positive correlation with size and age. The THg and OHg levels in the muscles of albacore were lower than those of bigeye tuna, and the accumulative rates of THg and OHg in albacore were lower than those in bigeye tuna. No significant different of muscles-THg and -OHg concentrations of albacore from the four samplind areas. However, the THg and OHg levels in muscle of bigeye tuna showed that north group higher than those in equator. The concentrations of THg were similar in muscle and liver of albacore, but those OHg, Cu, Fe, Mn and Zn concentrations in liver were significantly higher than those in muscle. A detoxificated mechanism may be commenced when the concentration of THg in liver of albacore exceed 0.8 mg/kg, to maintain the muscle concentration of THg at a level about 0.7 mg/kg. The OHg concentrations of all albacore and 88% of bigeye tuna were below WHO food safety standard for migratory fishes(1.0 mg/kg). The consumption amount of albacore and bigeye tuna were no more than 300 and 150g, respectively, will not exceesed the PTWI(provisional tolerable weekly intake) set by WHO, that will not cause any health threat for consumer.