22 resultados para 249
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Rice cultivation at any level in the Sacramento–San Joaquin Delta (existing or expanded) compels the need to quantify surface and subsurface loads of dissolved organic carbon (DOC), disinfection byproduct precursors (DBPPs) and nitrogen. This information can be used to develop Best Management Practices (BMPs) to reduce export of these constituents in order to improve drinking water quality. Although rice cultivation in the Delta is relatively limited, several factors outside of this research could contribute to increased rice acreage in the Delta: • Recently developed rice varieties seem more suitable for the Delta climate than earlier varieties which required warmer conditions; • Previous economic analyses (Appendix A.10) suggest rice is more profitable than corn, a dominant land use in the Delta; • Recent studies on wetlands at Twitchell Island suggest rice production can help mitigate oxidative subsidence (Miller et al. 2000); • The different oxidative states that result from flooding in rice as compared to those found in crops that require drained soils may help control crop specific weeds and nematodes when rice is incorporated into a crop rotation; and • Providing flooded conditions during a greater part of the year than other crops may benefit water birds. ... (PDF contains 249 pages)
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This bibliography attempts to list, with descriptive annotations and a subject index, important literature published between 1930 and 1953 dealing with the tunas and their fisheries in all parts of the world. It is thus a continuation of Corwin's (1930) work, which extended with similar scope through 1929, and an extension of Shimada's (1951), which was limited to the biology of Pacific tunas. The tunas with which it deals are those fishes customarily so-called in commercial parlance and usually classified in the genera Thunnus, Neothunnus, Parathunnus, Germo, Katsuwonus, Euthynnus and Auxis and their various synonyms. All aspects of the biology of the tunas are dealt with, as are descriptions and histories of all types of tuna fisheries, commercial and exploratory tuna fishing methods and results, fishing gear, catch statistics, and fishery management, but processing technology, economics and marketing, folklore, and purely literary references have been excluded.
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This document is in Spanish. El capítulo 1 concentra información sobre los volúmenes de producción obtenidos en la fase primaria de la actividad (captura y acuacultura). Las variables manejadas son: producción por principales especies, destino de consumo, litoral y entidad federativa, acuacultura, así como el valor de lo explotado o cultivado a precios de productor (precio en playa); al final se incorpora un conjunto de cuadros con series históricas de producción, desglosadas por principales pesquerías, litorales y entidades. En el capítulo 2 se presentan estadísticas sobre la transformación o industrialización de productos pesqueros. Sus indicadores más representativos se refieren a materia prima procesada y producción obtenida. desagregándola por entidad federativa y principales líneas de producción, es decir, congelado, enlatado, reducción (elaboración de harina de pescado y aceites) y otros procesos. El capítulo 3 contiene las estadísticas sobre la fase de la comercialización y consumo de los productos provenientes de la pesca: disponibilidad, consumo (aparente y per-cápita), precios y balanza comercial pesquera, incluyendo series históricas sobre estos mismos indicadores. Enseguida, en el capítulo 4, se· da a conocer información acerca de los principales activos disponibles en el sector, esto es, flota, planta industrial, instalaciones portuarias, granjas acuícolas comerciales y centros de acuacultura. De igual manera, aparecen las cifras de los empleos generados por la actividad, las organizaciones sociales pesqueras y su membresía, como también los créditos otorgados al sector por la banca de desarrollo. El capítulo 5 resume información sobre las Normas Oficiales Mexicanas (NOM) vigentes y proyectos de I'JOM que conciernen a la actividad pesquera, así como de las vedas que se aplican en las diferentes pesquerías. En el capítulo 6 se hace un compendio de las principales variables de la actividad pesquera mundial, en el que se puede apreciar la destacada participación de México. La estructura del Anuario concluye con la presentación del anexo, que- comprende el glosario de términos, la lista de las especies que integran cada una de las pesquerías para las cuales se presenta información desagregada y, por primera vez, se presentan cuadros sinópticos a manera de indicadores, sobre las principales variables de la pesca mexicana, de las pesquerías más importantes, al igual que las fases y especies con mayor participación relativa en la pesca mundial. (Catch statistics for Mexican waters 1999. (PDF has 249 pages.)
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ENGLISH: The rate at which increments are deposited on the sagittal otoliths of yellowfin (Thunnus albacares) and skipjack (Katsuwonus p elamis) tunas is determined by a markrecapture experiment using tetracycline. During growth in fork length from 40 to 110 em, and for a period of up to 389 days, yellowfin of the Revillagigedo Islands- Baja California region deposit one increment per day in either the postrostrum or rostrum position of the otolith. For skipjack of the same region, rostrum increments underestimate time by approximately 24 percent during growth from 42 to 64 cm and over the maximum interval of 249 days. The growth rate of each species is estimated from the recapture fork length and the linear change in an otolith dimension following tetracycline injection. Over specific ranges in fork length the rates are 3.06 and 1.15 em per month for yellowfin and skipjack, respectively. SPANISH: La rapidez (tasa) en la que se depositan los incrementos en los otolitos sagitales del aleta amarilla (Thunnus albacares) y el barrilete (Katsuwonus pelamis) se determina mediante un experimento al recapturar los peces que han sido marcados con tetraciclina. Durante el crecimiento de la longitud de horquilla de 40 a 110 cm y por un período hasta de 389 días, se forma en el aleta amarilla de la región de las Islas Revillagigedo-Baja California, un incremento diario ya sea en el parte del postrostrum o rostrum de los otolitos. Con respecto al barrilete de la misma region los incrementos en el rostrum subestiman aproximadamente el tiempo en un 24 por ciento durante el crecimiento de 42 a 64 cm y sobre un intervalo máximo de 249 días. El índice de crecimiento de cada especie se estima en la recaptura según la longitud de horquilla y el cambio lineal en la dimensión de un otolito después de la inyección de tetraciclina. La variación específica sobre la longitud de horquilla de los índices son 3.06 y 1.15 cm por mes para el aleta amarilla y el barrilete, respectivamente. (PDF contains 54 pages.)
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The Lagunas Encadenadas form a large endorheic wetland. The system comprises a chain of five main lagoons (Alsina, Chochico, Del Monte, Del Venado, and Epecuen). During two recent collection trips, 13 species of fish were caught. From the collected material and available data in the literature the following points can be made: The fish fauna of this wetland comprises 18 species from 11 families and six orders. Four species (Cyprinus carpio, Hoplias malabaricus, Loricariichthys anus and Parapimelodus valenciennis) are new records for these water bodies. Fish species diversity decreases from east to west, ie from the most freshwater lagoon (Alsina, with 15 species) to the most saline (Epecuen, 1 species). A similar diversity pattern has been found in zooplankton species.
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In this study we describe the courtship and spawning behaviors of captive yellowfin tuna (Thunnus albacares), their spawning periodicity, the influence of physical and biological factors on spawning and hatching, and egg and early-larval development of this species at the Achotines Laboratory, Republic of Panama, during October 1996 through March 2000. Spawning occurred almost daily over extended periods and at water temperatures from 23.3° to 29.7°C. Water temperature appeared to be the main exogenous factor controlling the occurrence and timing of spawning. Courtship and spawning behaviors were ritualized and consistent among three groups of broodstock over 3.5 years. For any date, the time of day of spawning (range: 1330 to 2130 h) was predictable from mean daily water temperature, and 95% of hatching occurred the next day between 1500 and 1900 h. We estimated that females at first spawning averaged 1.6−2.0 years of age. Over short time periods (<1 month), spawning females increased their egg production from 30% to 234% in response to shortterm increases in daily food ration of 9% to 33%. Egg diameter, notochord length (NL) at hatching, NL at first feeding, and dry weights of these stages were estimated. Water temperature was significantly, inversely related to egg size, egg-stage duration, larval size at hatching, and yolksac larval duration.
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Fecundity was estimated for shortspine thornyhead (Sebastolobus alascanus) and longspine thornyhead (S. altivelis) from the northeastern Pacific Ocean. Fecundity was not significantly different between shortspine thornyhead off Alaska and the West Coast of the United States and is described by 0.0544 × FL3.978, where FL =fish fork leng th (cm). Fecundity was estimated for longspine thornyhead off the West Coast of the United States and is described by 0.8890 × FL3.249. Contrary to expectations for batch spawners, fecundity estimates for each species were not lower for fish collected during the spawning season compared to those collected prior to the spawning season. Stereological and gravimetric fecundity estimation techniques for shortspine thornyhead provided similar results. The stereological method enabled the estimation of fecundity for samples collected earlier in ovarian development; however it could not be used for fecundity estimation in larger fish.
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Dedicated at-sea surveys for marine birds and mammals conducted in lower Cook Inlet in late July and early August from 1995–99 failed to locate any belugas, Delphinapterus leucas. Surveys covered a total of 6,249 linear km and were conducted in both nearshore and offshore habitats. Sightings included 791 individual marine mammals of 10 species. Both historical data and local knowledge indicate that belugas were regularly seen in summer in nearshore and offshore areas of lower Cook Inlet up until the early 1990’s. Diminished presence of belugas in lower Cook Inlet may be a direct function of reduced numbers but may also indicate changes in habitat quality that may inhibit recovery.
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Report of Opening Session (p. 1). Report of Governing Council (p. 15). Report of the Finance and Administration Committee (p. 65). Reports of Science Board and Committees: Science Board Inter-Sessional Meeting (p. 83); Science Board (p. 93); Biological Oceanography Committee (p. 105); Fishery Science Committee (p. 117); Marine Environmental Quality Committee (p. 129); Physical Oceanography and Climate Committee (p. 139); Technical Committee on Data Exchange (p. 145); Technical Committee on Monitoring (p. 153). Reports of Sections, Working and Study Groups: Section on Carbon and Climate (p. 161); Section on Ecology of Harmful Algal Blooms in the North Pacific (p. 167); Working Group 19 on Ecosystem-based Management Science and its Application to the North Pacific (p. 173); Working Group 20 on Evaluations of Climate Change Projections (p. 179); Working Group 21 on Non-indigenous Aquatic Species (p. 183); Study Group to Develop a Strategy for GOOS (p. 193); Study Group on Ecosystem Status Reporting (p. 203); Study Group on Marine Aquaculture and Ranching in the PICES Region (p. 213); Study Group on Scientific Cooperation between PICES and Non-member Countries (p. 225). Reports of the Climate Change and Carrying Capacity Program: Implementation Panel on the CCCC Program (p. 229); CFAME Task Team (p. 235); MODEL Task Team (p. 241). Reports of Advisory Panels: Advisory Panel for a CREAMS/PICES Program in East Asian Marginal Seas (p. 249); Advisory Panel on Continuous Plankton Recorder Survey in the North Pacific (p. 253); Advisory Panel on Iron Fertilization Experiment in the Subarctic Pacific Ocean (p. 255); Advisory Panel on Marine Birds and Mammals (p. 261); Advisory Panel on Micronekton Sampling Inter-calibration Experiment (p. 265). 2007 Review of PICES Publication Program (p. 269). Guidelines for PICES Temporary Expert Groups (p. 297). Summary of Scientific Sessions and Workshops (p. 313). Report of the ICES/PICES Conference for Early Career Scientists (p. 355). Membership (p. 367). Participants (p. 387). PICES Acronyms (p. 413). Acronyms (p. 415).