Browsing by Author "Nance, James M."
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Item Definition of Overfishing and Trend Analysis for Brown, White, and Pink Shrimp(U.S. Department of Commerce, National Oceanic and Atmospheric Administration, National Marine Fisheries Service, Southeast Fisheries Science Center, Galveston Laboratory, 1992) Nance, James M.; Proceedings of the Southeast Fisheries Science Center Shrimp Resource ReviewNine shrimp species contribute to the Gulf of Mexico fishery. However, brown, white and pink shrimp of of the genus Penaeus comprise over 95% of the commercial harvest. These three shrimp species are found in all continental shelf waters in the U.S. Gulf of Mexico inside 60 fathoms (fm). Gulf of Mexico shrimp fishery trends for the past 30 years indicate that both bbrown and white shrimp catch levels have significantly increased, while pink shrimp catch, which was very stable until about 1985, has declined the past few seasons.Item Estimating Shrimp Fishing Effort(U.S. Department of Commerce, National Oceanic and Atmospheric Administration, National Marine Fisheries Service, Southeast Fisheries Science Center, Galveston Laboratory, 1992) Nance, James M.; Proceedings of the Southeast Fisheries Science Center Shrimp Resource ReviewTo estimate shrimp fishing effort for each location cell (statistical subarea/depth zone) on a monthly basis, there must be two elements of data for each cell: 1)total pounds of shrimp caught by species and, 2)the average catch per unit of effort (CPUE; pounds per twenty-four hours fished). Total pounds caught by species are acquired from commercial seafood dealers located along the Gulf coast, while CPUE is obtained from interviews with captains from shrimp vessels at the termination of their trips.Item Gulf of Mexico Pink Shrimp Assessment Modeling Update From a Static VPA to an Integrated Assessment Model Stock Synthesis(National Oceanic and Atmospheric Administration National Marine Fisheries Service, 2010-06) Hart, Rick A.; Nance, James M.This report is intended as a template to document and outline the steps taken to update the SEFSC shrimp stock assessment models.Item Incidental Capture of Sea Turtles in Shrimp Trawls With and Without TEDs in U.S. Atlantic and Gulf Waters(Chelonian Conservation and Biology, International Journal of Turtle and Tortoise Research, 1997-04) Renaud, Maurice L.; Nance, James M.; Scott-Denton, Elizabeth; Gitschlag, Gregg R.The intent of this note is to estimate catch rates of turtles in shrimp trawls, excluding try nets, with and without TEDs in U.S. waters.Item Offshore Oceanographic and Environmental Monitoring Services for the Strategic Petroleum Reserve - Response to Decision Maker's Questions: Benthos - FINAL(1985) Nance, James M.; Harper, Donald E., Jr.; ;The seemingly infinite capacity of the oceans to absorb and hide refuse has been used by man to dispose of all manner of material for thousands of years. Most of this material was relatively innocuous and there was not resulting "back-lash". However, with the advent of the industrial revolution, more and more of the substances produced by man, particularly by the chemical industry, were toxic to some degree. It is no longer feasible to simply "dump" byproducts, wastes, and other cast-off material into the ocean and pretend they no longer exist. This is proved by the mercury poisoning incident in Minimiata, Japan, the uproar over incineration of chemicals at sea, disposal of petrochemical products into shallow waters and the furor that was generated when the Strategic Petroleum Reserve brine disposal array was first proposed, to name a few examples. Brine is probably among the least toxic substances being disposed in the oceans. In narrow bayous and streams, brine can form a dense bottom layer whose salinity exceeds the tolerance ability of many benthic invertebrates and nektonic organisms (Harper, in prep.). In the oceanic environment, brine is not restricted and can speard and flow with the prevailing currents. Potential problems associated with brine are: 1) increased salinity from incomplete mixing which not only covers the bottom, but percolates into the sediments; and 2) an ionic ratio that is different from sea water and may cause ionic imbalance in soft bodied organisms that do not have the ability to regulate their internal osmotic concentration. Any given benthic assemblage is not a static entity. The components of the assemblage are constantly shifting as new members are recruited and existing members are removed by death or in some cases migration. Death can be caused by a number of agents, i.e. predation, old age, abiotic stress (high or low temperature, anoxia, salinity changes) and introduction of toxic substances. To be capable of making decisions concerning disposal of substances in the ocean, one must be capable of distinguishing between natural death and toxic-induced death. And to obtain this capability, one must know how much variability exists in the natural community.Item Texas Closure/Tortugas Closure(U.S. Department of Commerce, National Oceanic and Atmospheric Administration, National Marine Fisheries Service, Southeast Fisheries Science Center, Galveston Laboratory, 1992) Nance, James M.; Proceedings of the Southeast Fisheries Science Center Shrimp Resource ReviewIn 1976 the United States extended its jurisdiction over fisheries, exclusive of tuna, to 200 nautical miles and provided a program of management. Before that time fisheries in the territorial sea were managed by the states. In the U.S. Gulf of Mexico there are five state jurisdictions which were not changed by the extended federal jurisdiction. Louisiana, Mississippi, and Alabama each have three nautical miles of sea and Texas and Florida's west coast have nine nautical miles. The goal of the shrimp fishery management plan, developed by the Gulf of Mexico Fishery Management Council, is to manage the shrimp fishery of the United States waters of the Gulf of Mexico in order to attain the greates overall benefit to the nationt with particular reference to food production and recreational opportunities on the basis of the maximum sustainable yield as modified by relevant economic, social or ecological factors.Item Virtual Population Analysis(U.S. Department of Commerce, National Oceanic and Atmospheric Administration, National Marine Fisheries Service, Southeast Fisheries Science Center, Galveston Laboratory, 1992) Nance, James M.; Proceedings of the Southeast Fisheries Science Center Shrimp Resource ReviewVirtual population analysis is used to make age specific estimates of the instantaneous rates of fishing mortality (f) and stock sizes for each shrimp species. The analysis: 1) a complete and accurate catch by age table, 2) a known instantaneous rate of natural mortality (M), 3) a known instantaneous rate of fishing mortality (F) for at least one age in each cohort.