Diet composition of fish species from the southern continental shelf of Colombia

The diet composition of 30 fish species belonging to 16 families from the Pacific Coast of Colombia is described. Benthic crustaceans (37.5%) and bony fishes (23.7%, chiefly demersal) were the most important food items for the fish species analyzed. Data on diet composition of the fish species are presented for the first time which can be a source of information for trophic modeling.

Reports of the ICSF seminar / workshop on the conditions of fishworkers on distant water vessels, Manila, Philippines, 1-3 February 1991

This ICSF Exchange Programme held in Manila is an offshoot of the Bangkok Conference on “Global Fisheries Trends and Future of Fishworkers” held on January 22–27, 1990. One of the issues raised in that conference was about the operation of Taiwanese fishing vessels outside its territorial waters and the impact of such operations on small fishermen from the countries concerned. The presence of a Taiwanese fishworker as well as an NGO supporter contributed to an enlightening discussion as the former shed light on the sad plight of Taiwanese fishworkers who are the victims of such structural problems. This meaningful exchange between groups of fishermen, particularly Taiwanese and Filipinos, resulted in the plan of the Taiwanese delegation to have some Taiwanese fishermen visit the Philippines and immerse in fishing communities.

Studies of the age, growth, sexual maturity and spawning of populations of anchoveta (Cetengraulis mysticetus) of the coast of the Eastern Tropical Pacific Ocean

ENGLISH: Three hundred and twenty-six collections of anchoveta (Cetengraulis mysticetus), an important tuna bait species, taken between April 1951 and April 1960 from seven major baiting areas in the Eastern Tropical Pacific Ocean (Almejas Bay, Guaymas, Ahome Point, Banderas Bay, Gulf of Fonseca, coast of Colombia and Ecuador-Peru) are the basis of this study of age, growth, sexual maturity and spawning. The study of the temporal progression of modal size groups from plots of monthly length-frequency distributions provided estimates of age and rate of growth. The study of sexual maturity and time of spawning was based on gross examination of ovaries, and application of the gonad index. SPANISH: Trescientas veintiseis recolecciones de anchovetas (Cetengraulis mysticetus), una importante especie de carnada para la pesca del atún, cogidas entre abril de 1951 y abril de 1960 en siete de las mayores áreas de pesca de peces de carnada en el Océano Pacífico Oriental Tropical (Bahía de Almejas, Guaymas, Punta Ahome, Bahía Banderas, Golfo de Fonseca, y las costas de Colombia y de Ecuador- Perú), sirven de base a este estudio de la edad, crecimiento, madurez sexual y desove de dicha especie. El estudio de la progresión temporal de los grupos de tamaños modales según los gráficos de las distribuciones de la frecuencia de las longitudes proporcionó estimaciones de la edad y de la tasa de crecimiento. La investigación de la madurez sexual y la época de desove se basó en el examen macroscópico de los ovarios y en la aplicación del índice de gónadas.

Larvae of Nearshore Fishes in Oceanic Waters near Oahu, Hawaii

Larvae of over 50 families of nearshore fishes were taken in oceanic waters about 13 km offshore of the leeward (southwest) coast of Oahu, Hawaii during 1977-78, The five most frequently taken families (Labridae, Parapercidae, Serranidae, Gobiidae, and Carangidae) made up over 50% of the total nearshore larvae. Most other families were taken very infrequently. Comparison of catch data from three types of nets indicated that 1.25-m diameter bongo nets often sampled larvae as well or better than a 3-m Isaacs-Kidd trawl and that smaller, 70-cm diameter bongo nets were often as effective as the larger nets for certain abundant taxa. Only a few taxa showed evidence of seasonal patterns in abundance. Irregular temporal variability in abundance of some taxa may have been related to occasional recent influxes of surface water from closer to shore. Most larvae taken were late preflexion stage or older. Densities of even the most abundant taxa were rarely greater than 0.001 m-3. The nearshore fish larvae were not dominated by taxa with large larvae or with larvae possessing apparent specializations to pelagic existence, Most taxa taken were pelagic spawners as adults, but larvae of demersal spawners were roughly as well represented as demersal spawners are among the nearshore fish fauna. Previous studies of waters closer to shore probably sampled insufficient volumes for any but a few exceptionally abundant taxa. Sampling with volumes filtered of the order of 104-105 m3 will be necessary to determine if the dominant taxa taken by the present study are ever more abundant closer to shore, (PDF file contains 23 pages.)

Catalog of Osteological Collections of Aquatic Mammals from Mexico

This paper compiles available information on osteological and other anatomical specimens of at least 51 species of aquatic mammals (34 extant, one recently extinct and 16 fossil) collected in Mexico between 1868 and 1990 and housed in 29 scientific institutions (18 in the USA, nine in Mexico, one in the Netherlands, and one in England). These collections contain a total of 1427 specimens representing 10 families of odontocetes (Squalodontidaet , Rhabdosteidaet , Pontoporiidae, Albireonidaet , Monodontidae, Phocoenidae, Delphinidae, Ziphiidae, Kogiidae, and Physeteridae), three of mysticetes (Cetotheridaet , Eschrichtiidae, and Balaenopteridae), three of carnivores (Otariidae, Phocidae, and Mustelidae) and one of sirenians (Trichechidae). Of the aquatic mammals recorded from Mexico, seven species are not represented by specimens (Stenella frontalis, Lagenodelphis hosei, Feresa attenuata, Hyperoodon sp., Eubalaena glacialis, Balaenoptera borealis, and Enhydra lutris). (PDF file contains 40 pages.)

Aquatic insects as target organisms for the study of effects of projected climate change in the British Isles

One of the objectives of the Terrestrial Initiative in Global Environmental Research is to assess the sensitivity of British plant and animal species to climate change. The first phase of the program involved the identification of criteria for selecting species suitable for the study of effects of projected climate change in the British Isles. Apart from shallow ponds, annual temperature ranges of 0 to 25 C in temperate freshwater habitats are narrower than those in most temperate terrestrial habitats. Although freshwater organisms have to exist within a narrower range than their terrestrial equivalents, few species can survive throughout their life cycle over the whole temperature range. Field studies on the effects of natural and artificial thermal discharges into streams and rivers have shown that increases in water temperature affect aquatic insects at both the species and community level. Although field data provide valuable information, a more productive approach is to determine experimentally the requirements of different species. Although there are just over 1850 species of aquatic insects in the British Isles, detailed quantitative information on the relationship between temperature and development of eggs, larvae and pupa is available for relatively few species. One exception is the egg stage of stoneflies (Plecoptera). The range for egg hatching in stoneflies clearly show that some species could be threatened while others could benefit from a defined increase in water temperature as a result of climate change. A critical review of the available data on this group would produce a set of equations that could be used to predict the ecological effects of climate change on this group of indicator species.

Estimation of the abundance of yellowfin tuna, Thunnus albacares, by age groups and regions within the Eastern Pacific Ocean

ENGLISH: Monthly estimates of the abundance of yellowfin tuna by age groups and regions within the eastern Pacific Ocean during 1970-1988 are made, using purse-seine catch rates, length-frequency samples, and results from cohort analysis. The numbers of individuals caught of each age group in each logged purse-seine set are estimated, using the tonnage from that set and length-frequency distribution from the "nearest" length-frequency sample(s). Nearest refers to the closest length frequency sample(s) to the purse-seine set in time, distance, and set type (dolphin associated, floating object associated, skipjack associated, none of these, and some combinations). Catch rates are initially calculated as the estimated number of individuals of the age group caught per hour of searching. Then, to remove the effects of set type and vessel speed, they are standardized, using separate weiznted generalized linear models for each age group. The standardized catch rates at the center of each 2.5 0 quadrangle-month are estimated, using locally-weighted least-squares regressions on latitude, longitude and date, and then combined into larger regions. Catch rates within these regions are converted to numbers of yellowfin, using the mean age composition from cohort analysis. The variances of the abundance estimates within regions are large for 0-, 1-, and 5-year-olds, but small for 1.5- to 4-year-olds, except during periods of low fishing activity. Mean annual catch rate estimates for the entire eastern Pacific Ocean are significantly positively correlated with mean abundance estimates from cohort analysis for age groups ranging from 1.5 to 4 years old. Catch-rate indices of abundance by age are expected to be useful in conjunction with data on reproductive biology to estimate total egg production within regions. The estimates may also be useful in understanding geographic and temporal variations in age-specific availability to purse seiners, as well as age-specific movements. SPANISH: Se calculan estimaciones mensuales de la abundancia del atún aleta amarilla por grupos de edad y regiones en el Océano Pacífico oriental durante 1970-1988, usando tasas de captura cerquera, muestras de frecuencia de talla, y los resultados del análisis de cohortes. Se estima el número de individuos capturados de cada grupo de edad en cada lance cerquero registrado, usando el tonelaje del lance en cuestión y la distribución de frecuencia de talla de la(s) muestra(s) de frecuencia de talla "más cercana/s)," "Más cercana" significa la(s) muestra(s) de frecuencia de talla más parecida(s) al lance cerquero en cuanto a fecha, distancia, y tipo de lance (asociado con delfines, con objeto flotante, con barrilete, con ninguno de éstos, y algunas combinaciones). Se calculan inicialmente las tasas de captura como el número estimado de individuos del grupo de edad capturado por hora de búsqueda. A continuación, para eliminar los efectos del tipo de lance y la velocidad del barco, se estandardizan dichas tasas, usando un modelo lineal generalizado ponderado, para cada grupo por separado. Se estima la tasa de captura estandardizada al centro de cada cuadrángulo de 2.5°-mes, usando regresiones de mínimos cuadrados ponderados localmente por latitud, longitud, y fecha, y entonces combinándolas en regiones mayores. Se convierten las tasas de captura dentro de estas regiones en números de aletas amarillas individuales, usando el número promedio por edad proveniente del análisis de cohortes. Las varianzas de las estimaciones de la abundancia dentro de las regiones son grandes para los peces de O, 1, Y5 años de edad, pero pequeñas para aquellos de entre 1.5 Y4 años de edad, excepto durante períodos de poca actividad pesquera. Las estimaciones de la tasa de captura media anual para todo el Océano Pacífico oriental están correlacionadas positivamente de forma significativa con las estimaciones de la abundancia media del análisis de las cohortes para los grupos de edad de entre 1.5 y 4 años. Se espera que los índices de abundancia por edad basados en las tasas de captura sean útiles, en conjunto con datos de la biología reproductiva, para estimar la producción total de huevos por regiones. Las estimaciones podrían asimismo ser útiles para la comprensión de las variaciones geográficas y temporales de la disponibilidad específica por edad a los barcos cerqueros, y también las migraciones específicas por edad. (PDF contains 35 pages.)

Fishery management plans and the development of artisanal fisheries in Nigeria: a review

Management of natural resources all over the world is of paramount importance to their sustainability in developing countries like Nigeria, there is less emphasis on proper management especially of fishery and other aquatic resources due to lack of sensitization and enlightenment of the rural dwellers who are closer to such natural resources. The main thrust of this review is to examine the management plans for Nigerian freshwater bodies (rivers and lakes) and the impact of such plans on the artisanal fisheries development in Nigeria. From the on-shelf information gathered there is scarcity of information on the management of Nigerian freshwater body's information available indicates that there is the traditional fisheries management and the government legal approach in form of fisheries Laws and Regulations. However, these management techniques are poorly carried out since there is a poor follow-up. Appreciable impact of fisheries management introduced on Kanji Lake by the Nigerian-German Kanji Lake Fisheries Promotion Project (NGKLFPP) between 1993 and 2001 proves worthwhile as this introduced some management measures such as implementation of fisheries Laws and Regulations, the ban of obnoxious fishing methods, introduction of fishing license, constitution of a management unit and appointment of liaison fishermen. Within the operative years of the project a lot of success was achieved and it is recommended that the approach in Kainji should be replicated in other freshwater bodies in Nigeria to alleviate poverty in the rural poor fishing communities

Report of the Inter-American Tropical Tuna Commission for the year 1963

ENGLISH: The Inter-American Tropical Tuna Commission was created by a Convention between the Republic of Costa Rica and the United States of America. The Convention came into force in 1950. One of the provisions of the Convention was that other governments whose nationals participate in the fisheries covered by the Convention could adhere if they so desired and if the existing members agreed. Under this arrangement, the Republic of Panama adhered to the COl1vention in 1953. The Republic of Ecuador adhered in 1961. The Senate of the Republic of Mexico approved adherence in 1963; and the Republic of Colombia has indicated her desire to adhere. Full members during 1963 were Costa Rica, Ecuador, Panama, and the United States. SPANISH: La Comisión Interamericana del Atún Tropical fue creada en virtud de una Convención entre la República de Costa Rica y los Estados Unidos de América. La Convención entró en vigencia en 1950. Una de las estipulaciones de la Convención, permite a los gobiernos de otros países cuyos habitantes participen en las pesquerías a que dicha Convención se refiere, adherirse a ella si así lo desean y si los Gobiernos Miembros están de acuerdo. Acogiéndose a esa estipulación, la República de Panamá se adhirió a la Convención en 1953. La República del Ecuador se adhirió en 1961. El Senado de la República de México aprobó la adhesión en 1963; y la República de Colombia ha manifestado su deseo de adherirse. Durante el año de 1963 han sido miembros Costa Rica, Ecuador, Panamá y los Estados Unidos. (PDF contains 89 pages.)

Report of the Inter-American Tropical Tuna Commission for the year 1961

ENGLISH: The Inter-American Tropical Tuna Commission operates under the authority and direction of a Convention, originally negotiated between the Republic of Costa Rica and the United States of America, which entered into force in 1950. The Convention is open to adherence by other governments whose nationals participate in the fisheries covered by the Convention. The Republic of Panama adhered to the Convention in 1953. The Republic of Ecuador adhered during 1961. The Republic of Colombia has indicated her desire to adhere, and is expected to do so early in 1962. SPANISH: La Comisión Interamericana del Atún Tropical funciona bajo la autoridad y dirección de una Convención originalmente negociada entre la República de Costa Rica y los Estados Unidos de América, que entró en vigencia en 1950. A esta Convención pueden adherirse los gobiernos de otros países cuyos nacionales participen en las pesquerías cubiertas por la Convención. La República de Panamá se adhirió en 1953, y la República del Ecuador durante 1961. La República de Colombia ha indicado su deseo de adherirse también y se espera que lo haga a principios de 1962. (PDF contains 171 pages.)

The occurrence of two new plankton diatom populations in the English Lake District: Aulacoseira islandica

Samples of planktonic algae from major lakes in the English Lake District have been investigated over many years as part of a long-term monitoring programme set up by the Freshwater Biological Association and continued by the Institute For Ecology. Some lakes have been sampled regularly for long periods, others less frequently or only occasionally. Windermere north and south basins, and the neighbouring lakes Blelham Tarn and Esthwaite Water, have been under observation, mostly on a weekly basis, since the programme began in 1945. During this time diatoms have played a significant role in the population dynamics of these lakes.

Eggs of British Meniscus midges (diptera;dixidae) observed by scanning electron microscopy

The egg of Dixella martinii is described for the first time. The eggs of the Dixidae are placed in three morphological groups: bulbous and meshed; streamlined and smooth; streamlined and minutely spiculated. Ten of the fourteen species known from Britain are placed in these groups. After a detailed description of the egg of D. martinii, the three morphological groups are described and scanning electron micrographs are provided.

A new synoptic survey of Northern Ireland lakes: sampling from the air

Northern Ireland has approximately 1670 lakes, which cover 4.4% of the land surface. However, most of the water area is accounted for by the large lakes such as Lough Neagh (385 km2) and Lower Lough Erne (109.5 km ). The majority of lakes are less than 100 hectares in area. They tend to be distributed towards the south and west of the Province, where extensive drumlin swarms are rich in small waterbodies. In 1988-1991, 610 of the 708 lakes between one and 100 hectares were sampled by the Northern Ireland Lake Survey. The objective was to assess their conservation status based on their aquatic macrophyte flora, but in addition to extensive plant surveys, the water of each lake was analysed for a range of chemical variables. This article reports on a full-scale survey carried out in early March 2002. The survey was taken with help of two helicopters. The authorise summarise the results of the chemical analysis of the survey.

Report of the Inter-American Tropical Tuna Commission for the year 1989

ENGLISH: The Inter-American Tropical Tuna Commission operates under the authority and direction of a convention originally entered into by Costa Rica and the United States. 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, Mexico 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. Costa Rica re-adhered to the convention in 1989. The Commission held its 46th meeting in Paris, France, on May 10-12, 1989. SPANISH: La Comisión Interamericana del Atún Tropical funciona bajo la autoridad y dirección de un convenio suscrito originalmente por Costa Rica y los Estados Unidos de América. El convenio, vigente desde 1950, está abierto a la afiliación de cualquier pais cuyos ciudadanos pesquen atunes tropicales en el Oceano Pacífico oriental. Bajo esta estipulación, la República de Panamá se afilió en 1953, Ecuador en 1961, Mexico 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. Costa Rica se adhirió de nuevo al Convenio en 1989. La Comisión celebró su XLVI Reunión en Paris (Francia) del 10 al 12 de mayo de 1989. (PDF contains 270 pages.)