Population structure of Pacific yellowfin tuna

ENGLISH: The population structure and production of Pacific yellowfin tuna, Thunnus albacares, were examined by studying most of the basic data available on stock assessment, as well as other data, for the period 1965 to 1972. The data were obtained mainly from the Japanese longline fishery in the Pacific Ocean east of about 1200E and from the purse-seine fishery in the eastern Pacific east of about 140oW. Data from genetic studies of subpopulations were not used due to their preliminary nature. It was concluded that the concept of "semi-independent" subpopulations proposed by Kamimura and Honma (1963) and Royce (1964) defines the population structure of Pacific yellowfin. At least three stocks (i.e. western, central and eastern), relatively independent of each other, are thought to exist, but the actual number and location of subpopulations is still unclear. Possible north-south separations, indicated to some extent by genetic studies and tagging, could be neither substantiated nor rejected on the basis of this study. Finally, unless some major change in the fishing technology occurs, it is doubtful if any significant sustainable increase in yellowfin production from the Pacific is possible. The greatest potential for increase, if any, appears to be based on changing the size structure of yellowfin in the catch from the central Pacific. SPANISH: Se examino la estructura de la población y la producción del atún aleta amarilla del Pacifico Thunnus albacares para estudiar la mayoría de los datos básicos que se tenían sobre el avalúo de la población, como también otra información correspondiente al periodo de 1965·1972. Los datos fueron obtenidos principalmente de las pescas palangreros japonesas del Océano Pacifico al este de los 1200 E y de las pescas con redes de cerco del Pacifico oriental, al este de los 140oW. No se emplearon los datos de estudios genéticos de las subpoblaciones porque eran mas bien preliminares. Se concluyo que el concepto propuesto por Kamimura y Honma (1963) y Royce (1964) de subpoblaciones "semiindependientes" define la estructura de la población del aleta amarilla en el Pacifico. Se cree que existen por 10 menos tres existencias (e.d. la occidental, central y oriental), relativamente independientes la una de la otra, pero no se conoce con certeza cuantas subpoblaciones hay y donde se encuentran. La posible separación norte-sur, indicada, hasta cierto punto, por los análisis genéticos y del marcado, no puede ni confirmarse ni rechazarse basados en este estudio. Finalmente, a no ser que ocurra algún gran cambio en la tecnología pesquera es dudoso que sea posible obtener un aumento constante e importante en la producción del aleta amarilla del Pacifico. El potencial mayor de aumento, si es que existe alguno, parece que se basa en el cambio de la estructura de talla en la captura del aleta amarilla del Pacifico central. (PDF contains 169 pages.

Octahedral ruthenium(II) complexes for C-H bond activation and olefin hydroarylation

The study of inert C-H bond activation of hydrocarbons has been gaining interest. As these hydrocarbons are used in the production of many consumables such as fuel, plastics, and detergents, it is necessary to efficiently utilize the finite quantity of petroleum feedstocks. Transition metal complexes are incorporated as catalysts into synthetic routes to create new C-X (X = C, N, O) bonds in order to increase the chemical value of organic molecules. The complex [Ru(η6-p-cymene){P(OCH2CF3)3}(Ph)(OTf)] (1) (P{OCH2CF3}3 = tris(2,2,2-trifluoroethyl) phosphite, Ph = phenyl, OTf = trifluoromethanesulfonate) was prepared and tested for functionality as a catalyst in olefin hydroarylation. Catalytic reactions were attempted with 5 mol % of 1 in ethylene (15 psi) and benzene-d6 at a varying temperatures, which resulted in the decomposition of 1 and no formation of an organic product. With the observed decomposition of the complex in catalytic attempts, three different directions were pursued: the coordination of ligands 1,4,7-trimethyl-1,4,7-triazacyclononane (9N3Me) and 1,4,7-trithiacyclononane (9S3) to complex 1 to replace η6-p-cymene as the ancillary ligand, the synthesis of a Ru(η6-p-cymene) complex that had the caged phosphite ligand trimethylolpropane phosphite {P(OCH2)3CEt} coordinated, and the synthesis of Ru complexes containing the anionic ancillary ligand pentamethylcyclopentadiene (Cp*). The ligands 9S3 and 9N3Me did not coordinate to complex 1. The new complex [Ru(η6-p-cymene){P(OCH2)3CEt}{Ph)(Cl)] (2) was synthesized. The new complex [Ru(Cp*){P(OCH2CF3)3}2(Cl) 3 was synthesized, characterized, and reactivity with AgOTf, AgOAc, PhMgBr, PhLi, and MeLi have been tested (AgOAc = silver acetate)