4,218 research outputs found
The politics of Bluefin tuna in Malta
No full textThis paper analyzes the politics of bluefin tuna in Malta within the first years of EU accession (2004-9). The paper concludes that despite making certain impacts, ENGOs were unsuccessful in creating a hegemonic formation to stop the fishing of bluefin tuna until stocks recover.peer-reviewe
MAXIMIZING RESOURCE RENT FROM THE WESTERN AND CENTRAL PACIFIC TUNA FISHERIES
No full textRent generated by the tuna fisheries occurring in the waters of Pacific Islands Nations is estimated for various levels and combinations of purse-seine, pole-and-line, frozen tuna longline, and fresh tuna longline fishing effort, using a multi-species, multi-fleet bioeconomic model. The underlying population model integrates available information on the population dynamics of skipjack, yellowfin, bigeye, and Southern albacore tunas in the Pacific Ocean. The economic model utilizes the most recent data on fishing effort costs for the purse seine, pole-and-line, and longline fleets operating in the western and central Pacific Ocean, along with recent estimates of prices by species, method of capture and market, and estimates of demand elasticities. The results of the model indicate that fishery rent could be increased substantially above the current level by decreasing the size of all fleets, with the possible exception of the tuna longline fleet. The results also suggest that the countries of the region could benefit significantly by changing the level and structure of access fees levied as a percentage of total catch revenue.Resource /Energy Economics and Policy,
A Demand Analysis of the UK Canned Tuna Market
No full textThis study provides an analysis of the retail level demand for canned tuna in the UK using four-weekly scanned data for the period 1995–99. The role of product medium is analysed, looking at the interactions between the traditional tuna in brine and oil and the more recent value added tuna in sauces. A system of demand equations is estimated using the dynamic almost ideal demand system (AIDS) model. All products are demonstrated to have negative and inelastic own price elasticities. Tuna in brine and sauce is shown to be a normal good, while tuna in oil was demonstrated to be a luxury good. Tuna in oil was indicated as being a substitute for tuna in sauce., Consumer/Household Economics, Demand and Price Analysis, Food Consumption/Nutrition/Food Safety, Marketing, Q21.,
Allocating Yellowfin Tuna Between the Multispecies Purse Seine and Longline Fleets
No full textYellowfin tuna in the western Pacific are harvested as juveniles by purse seiners and as adults by longliners. The study presents estimates of the multi-species harvest technology of these two types of vessel operating in Papua New Guinea's Exclusive Economic Zone. The results, together with price and cost information and estimates of the impact of the purse seine catch on the catch rates of longline vessels are used to perform a benefit/cost analysis of a reallocation of juvenile yellowfin through a one percent decline in purse seine harvest in PNG's EEZ. The marginal benefit of investment in the yellowfin stock is found to exceed that of marginal cost, suggesting that there may be an economic case for a reallocation.resource sharing, multispecies fisheries, yellowfin tuna, Environmental Economics and Policy, International Development, International Relations/Trade, Resource /Energy Economics and Policy,
Time-Dependent Quotas for the Southern Bluefin Tuna Fishery
No full textIt is now officially recognized by the governments of Australia and Japan that the southern bluefin tuna fishery has been overexploited and that harvests must be controlled. A dynamic programming model applicable to multicohort fisheries is developed for finding approximately optimal time-dependent quotas. Results from applying the model to the southern bluefin tuna fishery indicate that restricting or eliminating the Australian catch of under 4-year-olds would benefit both countries.Environmental Economics and Policy, International Relations/Trade, Resource /Energy Economics and Policy,
Biology of Albacore tuna (Thunnus alalunga, Bonnaterre 1788) off the South West Coast of South Africa
No full textAlbacore tuna (Thunnus alalunga) is a highly migratory species found in all of the worlds oceans. The origin of albacore south of Africa is in question. This species constituted 85% of catches of the South African commercial tuna fishing fleet from 2000-2009 and is an important species in supporting a large boat-based recreational fishery. Albacore were sampled at angling competitions, which offer a repeatable and cheap source of tuna, in the Western Cape of South Africa during 2012 and 2013. 119 Samples were used to determine a length-weight relationship and to provide conversion ratios of various body measurements to fork length when total length was not available. Visual examination of testes and ovaries indicated that albacore are not spawning off the coast of South Africa.A comparison between the ease of using sectioned sagittal otoliths and first dorsal spines indicated that otoliths were more precise for estimating the age of albacore. Von Bertalanffy growth parameters were estimated from 51 fish, ranging from 2-9 years old (L∞=1100.07 mm; K=0.238 y-1; t₀=-2.14). Stomach content analysis indicated that the mesopelagic squid Lycoteuthis lorigera is the most important prey item for South African albacore. δ13C and δ15N stable isotope analysis of albacore and yellowfin tuna (T. albacares) muscle tissue showed that they feed on prey that may depend on different primary producers but that the two species of tuna share the same niche in the southern Benguela food web. Trophic levels of 3.8 and 3.76 were assigned to albacore and yellowfin tuna respectively
Establishing a weight-length baseline for evaluating changes in yellowfin tuna (Thunnus albacores) body condition in the Western Indian Ocean
No full textStandard weight (Ws) equations were established for yellowfin tuna (Thunnus albacares) in the Western Indian Ocean and used as a baseline for calculating relative weight (Wr) indices. Length-weight data for yellowfin tuna were obtained from the Indian Ocean Tuna Commission (IOTC) for 1984 to 1991 and 2003 to 2013. Four quadratic standard weight equations were established (based on mean, median, first and third quartile statistics for each length class) using log10-transformed weight (W, in grams) and fork length (FL, in mm) data. The median Ws equation (log10(W) = -3.903 + 2.425(FL) + 0.103(FL)2) was the preferred baseline for the Wr analysis. Relative weight estimates for individual fish ranged from 92 to 110. Annual and monthly Wr estimates ranged from 99 to 101 and 99.9 to 100.5 respectively. A GLM was fitted to separate the effects of year, month and sex on the response variable Wr. Year, month, sex and the interaction terms Year:Sex and Month:Sex all contributed significantly to the variability in Wr explained. Correlations between environmental variability and yellowfin tuna condition were observed. Concentrations of suitable prey in 2003 and 2004 correlated to above average condition, although 2005 and 2006 were below average condition during similar prey availability and environmental conditions. Relative weight followed an increasing trend from 2008 to 2013 despite lower biological enrichment. Mechanisms such as a shallower thermocline and reduced fishing pressure are proposed explanations. This study provided a reference study for body condition studies of yellowfin tuna in the Indian Ocean. It also provided support for the application of the Wr index to other tuna species in the Indian Ocean managed by the IOTC
A Note on Optimal Effort in the Maldivian Tuna Fishery
No full textThis note argues that spatial considerations and travel costs should be taken into account in devising tax/subsidy regulations for island-based tuna fisheries. In particular, the effect of a landings tax on distant fishing grounds should be considered when setting the level of the tax. A fuel subsidy is suggested as a means of offsetting the impact of the landings tax on marginal grounds.Environmental Economics and Policy, Research Methods/ Statistical Methods, Resource /Energy Economics and Policy,
Cross-Platform Analysis with Binarized Gene Expression Data
No full textWith widespread use of microarray technology as a potential diagnostics tool, the comparison of results obtained from the use of different platforms is of interest. When inference methods are designed using data collected using a particular platform, they are unlikely to work directly on measurements taken from a different type of array. We report on this cross-platform transfer problem, and show that working with transcriptome representations at binary numerical precision, similar to the gene expression bar code method, helps circumvent the variability across platforms in several cancer classification tasks. We compare our approach with a recent machine learning method specifically designed for shifting distributions, i.e., problems in which the training and testing data are not drawn from identical probability distributions, and show superior performance in three of the four problems in which we could directly compare
Import regulations in the United States : a focus on tuna commodities from the Pacific Islands region
No full textFor more about the East-West Center, see http://www.eastwestcenter.org/The United States of America has a free trade policy on all categories of fish and fishery products except canned tuna. Import deposits and licenses are not required by U.S. fish importers, and foreign exchange is freely obtainable to finance fish imports. Exporters of fish and fishery products to the United States, however, must pay close attention to several regulations governing imports to the United States. The opening section of this paper describes U.S. import regulations for fish and fishery products in general. The remaining sections focus attention on tuna commodity imports from the Pacific islands region in particular.U.S. Import Regulations -- U.S. Import Regulations on Tuna Commodities. Frozen tuna - Canned tuna -- Changes in the U.S. Tuna Canning Industry -- Court Actions -- Conclusion -- Appendixes. A. United States government trade agencies - B. Sample canned tuna labels - C. Action levels for pesticides or contaminants for fish and fishery products - D. Glossary of trade terms - E. Frozen tuna quality standards - F. Quota and imports of canned tuna not in oil to the United States, 1979-84 - G. Imports of canned tuna not in oil to the United States, 198
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