Since the 1950s, more than 6 million dolphins have died as by-catch in the American yellowfin tuna fishery. These deaths were not caused by accidental incidents between fishermen and dolphins but resulted from a method of fishing that purposefully targeted these animals in order to catch yellowfin tuna. Referred to as “fishing on porpoise,” this technique remained an industry secret for decades. By the early 1970s, however, dolphin by-catch had become a major environmental issue in the United States, thanks to the work of William F. Perrin. In the following years, politicians, scientists, environmentalists, and members of the tuna industry struggled with how best to resolve the problem. While the debates that arose from the “tuna-porpoise controversy” helped to dramatically reduce dolphin by-catch, these solutions did not come easily. This thesis looks to bring this forgotten moment in American environmental history to the historical forefront by exploring the origins and early years of the tuna-porpoise controversy. By examining this period, this thesis will show why fishermen first used dolphins to catch tuna in the 1950s, how and why dolphin by-catch became such a major environmental issue in the 1970s, and what various groups and individuals did to ameliorate the problem during the period. / Graduate

Made available in DSpace on 2014-12-17T14:02:00Z (GMT). No. of bitstreams: 1 EudrianoFSC_DISSERT.pdf: 4107766 bytes, checksum: 4869c74d441a0dacea2217f661f2635e (MD5) Previous issue date: 2010-04-29 / Knowledge of the environmental factors influence on the spatial-temporal variation of fishes is important to fisheries management and conservation. Thus, the aim of this work was to analyze the influence of the abiotical factors on the spatial-temporal distribution of Paralonchurus brasiliensis (Pisces, Sciaenidae) caught by-catch with the shrimp fishing of Ubatuba and Caraguatatuba regions, north coast of S?o Paulo State. The fishes were captured every month from January to December 2002. Samples were collected by otter trawl at 5, 10, 15, 20, 25, 30 and 35m depths. The temperatures (surface and bottom), salinities (surface and bottom), sediment features and organic matters were verified for each depth. During all period of the study 12.642 specimens of P. brasiliensis were captured at Ubatuba and 17.166 at Caraguatatuba, which totalized the biomass of 267 for the first and 339kg for the other region. The females outnumbered males in fish population. The greatest values of biomass and number of individuals were registered at the summer and autumn seasons, while the lowest values were observed at the winter and spring seasons. The greatest abundances were found from 15 to 25m depth. In this study, it was verified that P. brasiliensis is a coastal waters associate species. The spatialtemporal distribution of P. brasiliensis is affected by intrusion of SACW and depth for the coastal region and by depth and sediment in sheltered areas such as Caraguatatuba / A compreens?o dos processos ambientais que controlam a distribui??o espa?o-temporal dos peixes ? de fundamental import?ncia para o manejo e conserva??o dos estoques pesqueiros. Desse modo, o presente trabalho analisou a influ?ncia dos fatores ambientais sobre a varia??o espa?o-temporal de Paralonchurus brasiliensis (Pisces, Sciaenidae) componente da fauna acompanhante da pesca de camar?es nas regi?es de Ubatuba e Caraguatatuba, litoral norte do estado de S?o Paulo. As capturas foram realizadas mensalmente, durante o per?odo de janeiro a dezembro de 2002, nas is?batas de 5, 10, 15, 20, 25, 30 e 35m com o aux?lio de um barco de pesca camaroneiro equipado com redes do tipo mexicanas. A temperatura (superf?cie e fundo), salinidade (superf?cie e fundo), granulometria e a quantidade de mat?ria org?nica do sedimento foram determinados em cada transecto. Foram capturados 12.642 esp?cimes de P. brasiliensis na regi?o de Ubatuba e 17.166 em Caraguatatuba, correspondendo a uma biomassa total de 267 e 339kg, respectivamente. As f?meas predominaram na popula??o. Os maiores valores de biomassa e n?mero total de indiv?duos capturados ocorreram durante o ver?o e outono, e os menores no inverno e primavera. As maiores abund?ncias ocorreram em profundidades entre 15 e 25m. Constatouse que P. brasiliensis ? uma esp?cie associada a ?guas costeiras. A intrus?o da ACAS e a profundidade s?o fatores ambientais preponderantes que influenciam na distribui??o espa?o-temporal de P. brasiliensis na regi?o de Ubatuba, enquanto a profundidade e o tipo de sedimento exercem maior influ?ncia em ?reas abrigadas como Caraguatatuba