55 resultados para Bopp, Raul, 1898-1984. Cobra Norato

em Aquatic Commons


Relevância:

100.00% 100.00%

Publicador:

Resumo:

The effect of organotin compounds and copper, commonly used as antifouling agent, were studied on Mercenaria mercernaria larvae. They were reared under usual hatchery conditions until they reached 190 um in diameter. The larvae were subjected to four compounds, tributylin chloride (TBT), monobutyltin chloride (MBT), trimethyltin chloride (TMT), cupric sulfate (CuSo4) plus control. Mortality was measured at 24, 48 h, and 96h. Behavioral and/or metamorphic changes were recorded in triplicate at 24-48 and 96 h. The appearance in swimming larvae of a functional foot was considered a sign of competence to set and was recorded as a "pediveliger". Swimming larvae were considered as larvae that have not yet reached their total development and they were recorded as "swimming". Larvae that did not show foot or swimming activity and were static but alive on the bottom were recorded as "bottom". TBT was found to completely inhibit swimming activity at sublethal concentrations throughout the period of observation. Copper and MBT inhibited swimming from 48 h, TMT did not inhibit swimming activity at any of the times recorded. The four compounds ranked in order of decreasing toxicity were TBT>TMT>CU>MBT.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

(PDF contains 96 pages.)

Relevância:

20.00% 20.00%

Publicador:

Resumo:

Document contains 82 pages.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

This document is in Spanish. Catch statistics for Mexican waters 1983. (PDF has 293 pages.)

Relevância:

20.00% 20.00%

Publicador:

Resumo:

The United States and Japanese counterpart panels on aquaculture were formed in 1969 under the United States-Japan Cooperative Program in Natural Resources (UJNR). The panels currently include specialists drawn from the federal departments most concerned with aquaculture. Charged with exploring and developing bilateral cooperation, the panels have focused their efforts on exchanging information related to aquaculture which could be of benefit to both countries. The UJNR was begun during the Third Cabinet-Level Meeting of the Joint United States-Japan Committee on Trade and Economic Affairs in January 1964. In addition to aquaculture, current subjects in the program include desalination of seawater, toxic microorganisms, air population, energy, forage crops, national park management, mycoplasmosis, wind and seismic effects, protein resources, forestry, and several joint panels and committees in marine resources research, development, and utilization. Accomplishments include: Increased communication and cooperation among tecbnical specialists; exchanges of information, data, and research findings; annual meetings of the panels, a· policy-coordinative body; administrative staff meetings; exchanges of equipment, materials, and samples; several major technical conferences; and beneficial effects on international relations. (PDF file contains 56 pages.)

Relevância:

20.00% 20.00%

Publicador:

Resumo:

The food habits of 20 species of pelagic nekton were investigated from collections made with small-mesh purse seines from 1979-84 off Washington and Oregon. Four species (spiny dogfish, Squalus acanthias; soupfin shark, Galeorhinus zyopterus; blue shark, Prionace glauca; and cutthroat trout, Salmo clarki) were mainly piscivorous. Six species (coho salmon, Oncorhynchus kisutch; chinook salmon, O. tshawytscha; black rockfish, Sebastes melanops; yellowtail rockfish, S. f1avidus; sablefish, Anoplopoma fimbria; and jack mackerel, Trachurus symmetricus) consumed both nektonic and planktonic organisms. The remaining species (market squid, Loligo opalescens; American shad, Alosa sapidissima; Pacific herring, Clupea harengus pallasi; northern anchovy, Engraulis mordax; pink salmon, O. gorbuscha; surf smelt, Hypomesus pretiosus; Pacific hake, Merluccius productus; Pacific saury, Cololabis saira; Pacific mackerel, Scomber japonicus; and medusafish, Icichthys lockingtom) were primarily planktonic feeders. There were substantial interannual, seasonal, and geographic variations in the diets of several species due primarily to changes in prey availability. Juvenile salmonids were not commonly consumed by this assemblage of fishes (PDF file contains 36 pages.)

Relevância:

20.00% 20.00%

Publicador:

Resumo:

The 1984 International Symposium and Workshop on the Biology of Fur Seals originated in informal talks in 1981. However, the scope and focus of the symposium remained unclear until an informal workshop was held in San Diego in June 1983. This meeting synthesised data on the foraging and pup attendance activities of six species of fur seals, and attempted to formulate a coherent framework for the adaptations associated with their maternal strategies (Gentry et al. 1986). During the workshop it was clear that comparative data on many key aspects of fur seal biology and ecology were missing. This absence of data applied not only to less well known species, for some of which considerable unpublished data existed, but also to better known species for which research in some areas had either been neglected or unreported. The value of applying the comparative method to seals, especially comparisons integrating physiology, ecology, and reproductive biology, was amply demonstrated by the results of the 1983 workshop (Gentry and Kooyman 1986). However, we were also aware that many other problems outside the area of maternal strategies could benefit from comparative data, such as recovery of populations from the effects of harvesting. Therefore, to accommodate the range of potential research, we organized this symposium to produce an up-to-date synthesis of relevant information for all species of fur seals. It was also clear that fur seal research could benefit from increased communication and collaboration among its practitioners. To foster the spread of ideas, we held oral presentations on some topics of current research and techniques and organized workshops on specific topics, in addition to providing opportunities for informal talks among participants. Thanks to generous support from the British Antarctic Survey, the National Marine Fisheries Service of the United States, and the Scientific Committee on Antarctic Research, the International Fur Seal Symposium was held at the British Antarctic Survey, Cambridge, England, 23-27 April 1984. The 36 participants are shown in Figure 1. A list of Symposium participants and authors is presented in Appendix 1 of the Proceedings. (PDF file contains 220 pages.)

Relevância:

20.00% 20.00%

Publicador:

Resumo:

The trawl fishery for pelagic annorhead, Pseuaopentaceros wheeleri(fonnerly referred to as Pentaceros richardsoni), and alfonsin, Beryx splendens, over the central North Pacific seamounts has a relatively short history. Before 1967, fishery scientists were generally unaware of the resources on seamounts; however, the discovery of commercial concentrations of pelagic armorhead on seamounts in the southern Emperor Seamounts by a Russian commercial trawler in November 1967 led to almost immediate exploitation of the species by the Soviets. Unconfinned reports indicated that the schools of pelagic annorhead on the seamounts averaged 30 m thick and catches averaged from 3 to 50 metric tons on 10-20 min hauls (Sakiura 1972). Japanese trawlers entered the fishery in 1969. To assist in the development of this tishery, Japanese research vessels conducted extensive surveys in 1972 on the distribution and potential for development ofthe pelagic armorhead and alfonsin resources. The results of their surveys to the central North Pacific and mid-Pacific seamounts showed that many had summits that were too deep for trawling. Those found suitable were concentrated in the southern Emperor-northern Hawaiian Ridge. (PDF file contains 113 pages.)

Relevância:

20.00% 20.00%

Publicador:

Resumo:

This series will include all those people who, by means of their contributions, great and small, played a part in the consolidation of ichthyology in Argentina. The general plan of this work consists of individual factsheets containing a list of works by each author, along with reference bibliography and, whenever possible, personal pictures and additional material. The datasheets will be published primarily in chronological order, although this is subject to change by the availability of materials for successive editions. This work represents another approach for the recovery and revalorization of those who set the foundations of Argentine ichthyology while in diverse historical circumstances. I expect this to be the beginning of a major work that achieves the description of such a significant part of the history of natural sciences in Argentina.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

ENGLISH: One phase of the duties of the Inter-American Tropical Tuna Commission is the gathering and interpretation of data concerning the life history of the commercially important bait species throughout the Eastern Pacific Ocean. During 1958 the Commission established a laboratory in Manta, Ecuador to study tuna. It was subsequently found that this fishery was dependent upon one species of anchovy, Anchoa naso, which was locally referred to as "colorado." During the calendar year 1959 approximately 380,000 scoops of bait were taken by the Manta tuna fleet (Schaefer, 1960), which at that time numbered about 23 vessels. Since then the fleet has increased by about 25 per cent and it is probable that the bait catch has increased also. Virtually nothing has been reported concerning the life history of this species. Hildebrand (1943) reviewed its taxonomy and reported standard lengths ranging from 32 to 135 mm. Peterson (1956) examined specimens from Central America and found them to range from 27 to 66 mm. He also indicated that the species spawned over a long period of time. The present report describes some aspects of the life history of Anchoa naso in Ecuadorian waters. The findings are based on 121 collections taken during the period March 1959 through June 1961. SPANISH: Una fase de las obligaciones de La Comisión Interamericana del Atún Tropical es la obtensión e interpretación de los datos concernientes a la historia natural de las especies de carnada comercialmente importantes en todo el Océano Pacifico Oriental. En el año de 1958 la Comisión estableció un laboratorio en Manta, Ecuador, para estudiar el atún. Se encontró subsecuentemente que esta pesquería dependía de una especie de anchoa, Anchoa naso, conocida localmente con el nombre de colorado. Durante el año calendario de 1959, la flota atunera de Manta, que en ese tiempo alcanzaba a unos 23 barcos, obtuvo aproximadamente 380,000 copas (scoops) de carnada (Schaefer, 1960). Desde entonces la flota ha aumentado en un 25 por ciento, y es probable que la captura de peces-cebo haya aumentado también. Nada se ha informado virtualmente sobre la historia natural de esta especie. Hildebrand (1943) revisó su taxonomia e informó sobre su longitud estándar, que varia entre los 32 y 135 mm. Peterson (1956) examinó especímenes de la América Central, y encontró que variaban entre los 27 y 66 mm. También indicó que la especie desova durante un largo periodo de tiempo. El presente informe describe algunos aspectos de la historia natural de la Anchoa naso en aguas ecuatorianas. Los hallazgos están basados en 121 recolecciones hechas durante el periodo de marzo de 1959 a junio de 1961. (PDF contains 30 pages.)

Relevância:

20.00% 20.00%

Publicador:

Resumo:

Some aspects of the reproduction of Nematopalaemon hastatus in the artisanal shrimp fishery in the outer Cross River estuary (Nigeria) was investigated. 2 kg samples were taken from the daily catch of the N. hastatus fishery on a twice-weekly basis. The N. hastatus in the sample were then observed for gravidity, using a hand lens, and their post-orbital carapace length (POCL) taken. This was done over a 12-month period. The eggs in formalin-fixed samples showed colour changes from light orange to dark brown with maturation. Gravid females with eggs in different stages of maturation, from light orange to dark brown were observed in the samples. The reproduction occurs all year-round. The proportion of gravid females observed in samples had two distinct peaks in June and November, and two distinct troughs in May and October. The lowest length at which gravidity was observed was 6.0 mm POCL. There were no Penaeus notialis in the samples

Relevância:

20.00% 20.00%

Publicador:

Resumo:

Examination of 40 time series of multidisciplinary environmental variables from the Pacific Ocean and the Americas, collected in 1968 to 1984, demonstrated the remarkable consistency of a major climate-related, step-like change in 1976. To combine the 40 variables (e.g., air and water temperatures, Southern Oscillation, chlorophyll, geese, salmon, crabs, glaciers, atmospheric dust, coral, carbon dioxide, winds, ice cover, Bering Strait transport) into a single time series, standard variants of individual annual values (subtracting the mean and dividing by a standard deviation) were averaged. Analysis of the resulting time series showed that the single step in 1976, separating the 1968-1975 period from the 1977-1984 period, accounted for 89% of variance within the composite time series. Apparently, one of the Earth's large ecosystems occasionally undergoes large abrupt shifts.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

ENGLISH: The Inter-American Tropical Tuna Commission operates under the authority and direction of a convention originally entered into by the Republic of Costa Rica and the United States of America. The convention, which came into force in 1950, is open to adherence by other governments whose nationals fish for tropical tunas in the eastern Pacific Ocean. Under this provision Panama adhered in 1953, Ecuador in 1961, the United Mexican States in 1964, Canada in 1968, Japan in 1970, and France and Nicaragua in 1973. Ecuador withdrew from the Commission in 1968, Mexico in 1978, Costa Rica in 1979, and Canada in 1984. On October 16,17, and 18, the Commission held its 42nd meeting in La Jolla, California. SPANISH: La Comisión Interamericana del Atún Tropical funciona bajo la autoridad y dirección de un convenio establecido originalmente por la República de Costa Rica y los Estados Unidos de América. El convenio, vigente desde 1950, está abierto a la afiliación de otros gobiernos cuyos ciudadanos pescan atún en el Pacífico oriental tropical. Bajo esta estipulación, Panamá se afilió en 1953, Ecuador en 1961, los Estados Unidos Mexicanos en 1964, Canadá en 1968, Japón en 1970, Francia y Nicaragua en 1973. Ecuador se retiró de la Comisión en 1968, México en 1978, Costa Rica en 1979 y Canadá en 1984. La XLII reunión de la Comisión fue convocada en La JoBa (California) el 16, 17 Y18 de octubre de 1984. (PDF contains 270 pages.)