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.

Submitted by (edna.saturno@ufrpe.br) on 2017-02-22T16:09:14Z No. of bitstreams: 1 Vanessa Baptista Pedrosa.pdf: 733342 bytes, checksum: 553e5fd04a4d2eccb1338f8210bc81ba (MD5) / Made available in DSpace on 2017-02-22T16:09:14Z (GMT). No. of bitstreams: 1 Vanessa Baptista Pedrosa.pdf: 733342 bytes, checksum: 553e5fd04a4d2eccb1338f8210bc81ba (MD5) Previous issue date: 2011-06-28 / Albacore is one of the main species of tuna caught in the South Atlantic for tuna Brazilian fishing vessel. Moreover, it has a little knownledge available about albacore biology in this portion of Atlantic Ocean, mainly regard to reproduction, aim of this study. Histological analysis of 735 gonads (370 males and 365 females)captured in the southwest atlantic were conducted during 2005 to 2010. Fork length of specimens ranged from 89 cm to 138 cm. Gonad index was determined monthly and observed the spawning activity from September to March. also, females exhibiting hydrated oocytes and post ovulatory follicles indicating an imminent spawning stage and post spawning, respectively.The sex ratio prior the reproductive period was 1:1 (males:females) with males mainly in the larger length classes (> 114 cm FL). At the first sexual maturity the length was 92 cm for females and 100 cm for males. The batch fecundity ranged from 0.5 to 1.2 million oocytes with approximately 3.700 oocytes/g. The oocyte diameter frequency showed a parceled spawning due to the occurrence of successives modes of unyolked oocytes, yolked and hydrated. These results contribute with information about the reproduction of the species in the South Atlantic both these life history parameters will allow to assess the albacore stock from this region. / A albacora branca é uma das principais espécies de atuns capturadas no Atlântico sul pela frota atuneira brasileira. Entretanto, pouco é conhecido sobre a biologia da espécie nesta parte do Atlântico, principalmente no que se refere à reprodução, objetivo do presente estudo. Análises histológicas das gônadas de 735 indivíduos de Thunnus alalunga (370 machos e 365 fêmeas) capturados no Atlântico Sudoeste foram realizadas no período de 2005 a 2010. O comprimento dos espécimes variou de 89 cm a 138 cm. Através do acompanhamento mensal do índice gonadal foi observada atividade de desova entre os meses de outubro a março, com fêmeas apresentando ovócitos hidratados e folículos pós-ovulatórios, indicando iminente estado de desova e pós-desova, respectivamente. A proporção sexual anterior ao período reprodutivo entre machos e fêmeas foi de 1:1, com os machos predominando nas maiores classes de comprimento (> 114 cm CF). O tamanho de primeira maturidade sexual determinado para as fêmeas foi de 92 cm e para os machos de 100 cm. A fecundidade variou de 0,5 a 1,2 milhões de ovócitos com cerca de 3.700 ovócitos/g. Pela freqüência do diâmetro dos ovócitos de fêmeas (37 - 1200 μm) foi verificada a desova do tipo parcelada devido a ocorrência de modas sucessivas de ovócitos avitelogênicos, vitelogênicos e hidratados. Esses resultados contribuem com informações sobre a reprodução da espécie no Atlântico Sul que junto com outros parâmetros do seu clico de vida permitirá avaliar o estoque dessa região.

Aquest treball es centra en el coneixement de l'estructura poblacional de tres espècies piscícoles de la família Scombridae, el bonítol (Sarda sarda), la bacora (Thunnus alalunga) i la tonyina (Thunnus thynnus) en la seva distribució de l'atlàntic i el mediterrani. / This work focuses on understanding the population structure of three fish species of the family Scombridae, bonito (Sarda sarda), the figs (Thunnus alalunga) and bluefin tuna (Thunnus thynnus) distribution in the Atlantic and the Mediterranean.

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