Preliminary observations of some smaller fish of the freshwaters of the Calabar area

About 43 species of fish from sites within approximately 50 km north and 100 km northeast of Calabar are listed. Brief ecological and taxonomic data for some of the species are given

Observations on the purse-seine fishery for Northern bluefin tuna (Thunnus thynnus) in the Eastern Pacific Ocean

ENGLISH: This report presents information on the fishery for bluefin in the northeastern Pacific Ocean derived from purse seiner logbook records and landing statistics. Information on the size composition of the fish in the catch is also presented. The logbook records cover the period 19611980; however, catch statistics and length-frequency data from previous years are also presented. SPANISH: Este informe presenta los datos sobre la pesca del T. thynnus en el Océano Pacífico nordeste, obtenidos de los cuadernos de bitácora de los barcos cerqueros y de las estadísticas de desembarque. Se presenta además la información sobre la composición de talla de los peces en la captura. Los registros de bitácora abarcan el período de 1961 a 1980; no obstante, se presentan además las estadísticas de captura y los datos de la frecuencia de talla de años anteriores. (PDF contains 105 pages.)

Preliminary observations on the feeding, habits and reproduction biology of Gymnarchus niloticus from Lake Chad

The preliminary results obtained from the study of stomach contents of specimens of Gymnarchus niloticus of a size ranging from 56 cm (66 grams) to 152 cm (12.0 kg.) from August to December, 1982 indicate for these sizes an exclusively piscivorous diet. The predominant prey species in Lake Chad are Tilapia/Sarotherodon , and Clarias . The prey is often cut in two parts before it is swallowed. Small prey may be swallowed whole. The implication of this prey capture method on prey-predator relationship and therefore the impact of the predator is discussed. The breeding season of Gymnarchus niloticus in Lake Chad has been deduced from observation of changes in gonad maturity stages and the results indicate that breeding takes place between August and November. Data are also presented on the fecundity, size of ripe eggs and probable size at maturity

Some observations on bigeye tuna (Thunnus obesus) caught by the surface and longline fisheries for tunas in the Eastern Pacific Ocean

(PDF contains 58 pages.)

Oceanographic observations in the Gulf of Guayaquil, 1962-1964. Part I. Physical and Chemical

ENGLISH: During 1961 the government of Ecuador, with the financial assistance of the Special Fund of the United Nations and the technical assistance of FAO experts, initiated an extensive program of fisheries research centered in a fisheries institute established in Guayaquil. In cooperation with this program, and in connection with Ecuador's adherence in 196l to the Convention for the Establishment of an Inter-American Tropical Tuna Commission, a two-and-a-half year investigation of the ecology of the Gulf of Guayaquil and adjacent waters was started by the Inter-American Tropical Tuna Commission. SPANISH: En 1961 el gobierno del Ecuador con el apoyo financiro del Fondo Especial de las Naciones Unidas y la asistencia tenica de los expertos de la FAO, inicio un programa extensivo de investigacion pesquera centralizado en el instituto de pesquerias establecido en Guayaquil. En cooperacion con este programa y en conexion con la adhesion del Ecuador en 1961 a la Convencion para el establecimiento de una Comision Interamericana del Atun Tropical, se comenzo por esta misma Comision una investigacion de dos anos y medio sobre la ecologia del Golfo de Guayaquil y las aguas adyacentes. (PDF contains 1532 pages.)

Oceanographic observations for the Mazatlan Project: October 1966 - August 1967

ENGLISH: To learn more about the early life of yellowfin tuna in their immediate environment, the Inter-American Tropical Tuna Commission initiated a 2-year cooperative investigation with the Direccion General de Pesca e Industrias Conexas (DGP) of Mexico in August 1966. The project called for monthly cruises of about 5 days duration to be made in a triangular track between Mazatlan, Cape San Lucas and the Tres Marias Islands. Laboratory space for the field work was provided by the DGP in their biological station in Mazatlan and the research vessel Yolanda, property of the DGP, was made available for the monthly cruises. SPANISH: Con el fin de obtener un conocimiento mas avanzado sobre la vida temprana de estos atunes aleta amarilla, y del ambiente que los rodea, 1a Comision Interamericana del Atun Tropical inicio una investigacion colaborativa de 2 anos con la Direccion General de Pesca e Industrias Conexas (DGP) de Mexico, en agosto de 1966. El proyecto requirio cruceros mensuales de unos 5 dias de duracion para que fueran realizados en un rumbo triangular entre Mazatlan, Cabo San Lucas y las Islas Tres Marias. La Direccion General de Pesca ofrecio amab1emente las facilidades del laboratorio para el trabajo experimental en la estacion biologica de Mazatlan, y e1 barco de investigacion Yolanda para los cruceros mensuales. (PDF contains 256 pages.)

Observations on the ecology of Hepsetus odoe, Bloch, 1794 (Pisces: Hepsetidae) in Epie Creek floodplain, Niger Delta, Nigeria

The distribution, abundance, age and growth, the food and feeding habits, condition factor and reproduction of Hepsetus odoe in the Epie Creek Floodplain (Nigeria) was studied. H. odoe occur in the creek, swamp channel and lake. It is a very common, abundant and one of the major commercial species. A total of 457 specimens weighing 76.90 kg were caught during the period of investigation. The catches were more abundant in the dry season than in the wet season. The total length ranged from 10 cm to 46 cm while the weight varied between 50 g and 900 g. Six distinct components or year classes were observed using Bhattacharya's method. A growth exponential value 'b' was 3.35 with condition factor, 'k' values ranging from 0.69 to 0.83. The main diets of Hepsetus odoe were fish, including crustaceans (shrimps) and insects. The mean fecundity was 6060 plus or minus 358 eggs (range 2,769 to 6.667 eggs). The ova diameter of H. odoe was found to range from 2.2 mm to 2.6 mm with overall mean = 2.4 plus or minus 0.1)

Oceanographic observations in the Gulf of Guayaquil, 1962-1964. Part II. Biological, chemical and physical.

ENGLISH: During 1961 the government of Ecuador, with the financial assistance of the Special Fund of the United Nations and the technical assistance of FAO experts, initiated an extensive program of fisheries research centered in a fisheries institute established in Guayaquil. In cooperation with this program, and in connection with Ecuador's adherence in 1961 to the Convention for the Establishment of an Inter-American Tropical Tuna Commission, a two-and-a-half year investigation of the ecology of the Gulf of Guayaquil and adjacent waters was started by the Inter-American Tropical Tuna Commission. SPANISH: Durante 1961 el gobierno ecuatoriano con el apoyo financiero del Fondo Especial de las Naciones Unidas y la ayuda técnica de los expertos de la FAO, inició un programa extensivo de investigación pesquera, centralizado en el instituto pesquero establecido en Guayaquil. En cooperación con este programa y en conexión a la afiliaci6n del Ecuador a la Convención, en 1961, para el establecimiento de una Comisión Interamericana del Atún Tropical, Cue iniciada por la Comisión una investigación de dos aftos y medio sobre la ecología del Golfo de Guayaquil y de las aguas adyacentes. (PDF contains 501 pages.)

Oceanographic and meteorological observations for project Little Window: March 1970

ENGLISH: Project Little Window was planned to provide some answers to the important scientific question of whether or not the HRIR (high resolution infrared radiometer) sensors aboard NASA and NOAA satellites can provide useful data for much of the oceanographic community. The sensors aboard these satellites were designed in response to the initial needs of meteorologists for temperature measurements integrated over a distance of 5-10 nautical miles and extending over a range from 30°C to about -75°C (i2-4°C). To this end the sensors have been a very powerful tool to the meteorologist in preparing daily weather advisories and in carrying out research. SPANISH: El proyecto Little Window fue planeado para suministrar algunas respuestas al importante tema científico sobre si los captadores (ltsensors") infrarrojos de alta resoluci6n (IRAR) a bordo de los satélites NASA y NOAA, pueden o no proveer datos útiles para la mayor1a de los oceanógrafos. Los captadores a bordo de estos satélites fueron concebidos en respuesta a las necesidades iniciales de los meteor6logos para obtener mediciones de temperatura integradas sobre una distancia de 5-10 millas náuticas, y entre 30°c y aproximadamente -75°C (~2-4°C). Con este fin los captadores han sido un instrumento poderoso para el meteor6logo en la preparaci6n de las informaciones diarias de tiempo y en la realizaci6n de las investigaciones. (PDF contains 171 pages.)

Oceanographic, meteorological, satellite and aircraft observations for project Little Window 2: May 1971

ENGLISH: In May 1971, a joint united states - Mexican experiment, Project Little Window 2, (LW-2) involving data collected by satellite, aircraft and ship sensors was made in the southern part of the Gulf of California. LW-2 was planned as an improved and enlarged version of LW-l (conducted the previous year; Stevenson and Miller, 1971) with field work scheduled to be made within a 200 by 200 km square region in the Gulf of California. The purposes of the new field study were to determine through coordinated measurements from ships, aircraft and satellites, the utility of weather satellites to measure surface temperature features of the ocean from space and specifically to evaluate the high resolution infrared sensors aboard N~ 1, ITOS 1 and NIMBUS 4 and to estimate the magnitude of the atmospheric correction factors needed to bring the data from the spacecraft sensors into agreement with surface measurements. Due to technical problems during LW-2, however, useful data could not be obtained from ITOS 1 and NIMBUS 4 so satellite information from only NOAA-1 was available for comparison. In addition, a new purpose was added, i.e., to determine the feasibility of using an Automatic picture Transmission (APT) receiver on shore and at sea to obtain good quality infrared data for the local region. SPANISH: En mayo 1971, los Estados Unidos y México realizaron un experimento en conjunto, Proyecto Little Window 2 (LW-2), en el que se incluyen datos obtenidos mediante captadores de satélites, aviones y barcos en la parte meridional del Golfo de California. Se planeó LW-2 para mejorar y ampliar el proyecto de LW-l (conducido el año anterior; Stevenson y Miller, 1971), realizándose el trabajo experimental en una región de 200 por 200 km cuadrados, en el Golfo de California. El objeto de este nuevo estudio experimental fue determinar mediante reconocimientos coordinados de barcos, aviones y satélites la conveniencia de los satélites meteorológicos para averiguar las características de la temperatura superficial del océano desde el espacio, y especialmente, evaluar los captadores infrarrojos de alta resolución a bordo de NOAA 1, ITOS 1 Y NIMBUS 4, y estimar la magnitud de los factores de corrección atmosféricos necesarios para corregir los datos de los captadores espaciales para que concuerden con los registros de la superficie. Sin embargo, debido a problemas técnicos durante LW-2, no fue posible obtener datos adecuados de ITOS 1 y NIMBUS 4, as1 que solo se pudo disponer de la información de NOAA 1 para hacer las comparaciones. Además se quiso determinar la posibilidad de usar un receptor de Trasmisión Automático de Fotografias (APT) en el mar para obtener datos infarojos de buena calidad en la región local. (PDF contains 525 pages.)

Preliminary observations on the use of a frame trawl in hydroacoustic surveys

Thirteen hauls were made during the hydroacoustic survey of the Ugandan waters of Lake Victoria from 7-19 February 1999. Ten of the hauls were made above the oxycline which was clearly visible as a strong echo on the echogram at between 25 and 35 m depth in most of the sampled areas. The remaining three hauls targeted the oxycline. Approximate equal weights of Rastrineobola argentia and Haplocromine cichlids were caught in total, but with marked differences between hauls. Near the surface R. argentia dominated the catches. In midwater Haplochromines were dominant. At the oxycline Caridina niloticus was abundant