"June 1981" / Thesis (M.Sc.)--Macquarie University, School of Biological Sciences, 1982. / Bibliography: leaves 176-185. / This study was undertaken at the behest of the Papua New Guinea Government in 1973 and extended to 1978. It aimed at elucidating the various aspects of the life history of longtail tuna Thunnus tonggol with a consideration of the factors influencing distribution, relative abundance and exploitation. During this period, 414 tagged fish were released with an overall recapture rate of 8.6% being recorded. Age at first maturity was established at approximately 60 cm for both sexes with a spring-summer spawning being postulated on the basis of gonadal development as evidenced by increasing gonadal indices. No significant departure from the 1:1 sex ratio was observed. -- Von Bertalanffy growth eguations were derived from the reading of increments on sagittal otoliths and modal progression analysis, and yielded respectively:- Lt = 131.8 [1-e⁻·³⁹⁵ ⁽t⁻·⁰³⁵⁾] and Lt = 122.91 [1-e⁻·⁴¹ ⁽t⁻·⁰³²⁾] Both curves were consistent with growth indications from tag recoveries. The predictive length-weight relationship was determined to be ln(Wt) = -9.67+2.656 ln(L.C.F.) and no significant differences existed between the sexes. -- Longtail were shown to be opportunistic feeders: fish constituted the major portion of the diet and increased in accord with longtail size. It is postulated that longtail undergo longshore migrations due to thermal requirements and that these allowed for a hypothetical spawning site around the Aru Island region - an acknowledged nutrient rich area during spring. Both morphometric and biochemical analyses failed to establish the existence of an eastern and western Australian longtail tuna population although there is strong evidence to suggest that sub-specific differences occur between Malaysian and Australian-P.N.G. stocks. -- The exploitation of longtail at three levels; artisanal, amateur and commercial are reported. Concern is expressed as to the lack of data collection and collation of the Taiwanese gillnet fleet operating in the Australian Fishing Zone and about the exploitation of pre-adult longtail tuna. Accordingly, recommendations are made to alleviate the statistical problems and that consideration be given to a detailed study of the fishing parameters which affect the population dynamics of longtail tuna. The latter recommendation in particular should examine the impact that the foreign operated fishery has had on the stocks in Oceania. / Mode of access: World Wide Web. / ix, 195 leaves ill., maps

Regional organisations have often played a catalytical role in developing regional ocean regimes that directly pertain to the peculiar needs and circumstances of a given region. As a response to the challenges imposed by the United Nations Convention on the Law of the Sea, the island States of the South Pacific region established the South Pacific Forum Fisheries Agency, with the specific mandate to assist them manage the enormous tuna resource of the region. The thesis seeks to ascertain the extent to which those needs have been satisfied. The thesis begins with the hypothesis that the Forum Fisheries Agency has in fact fulfilled those needs. The analysis is based on inferences which are drawn from the functions and responsibilities of the Forum Fisheries Agency, and certain significant legal developments it has helped spawn. The thesis does not engage in a cost/benefit evaluation of the Forum Fisheries Agency because that is an issue best left to the purview of individual member States to determine. Two conclusions are drawn from the analysis. First, the Forum Fisheries Agency has met the needs of the island States. Secondly, through the Forum Fisheries Agency, the island States are implementing the United Nations Convention on the Law of the Sea. / Law, Peter A. Allard School of / Graduate