The Ragfish, Icosteus aenigmaticus Lockington, 1880: A Synthesis of Historical and Recent Records From the North Pacific Ocean and the Bering Sea

Knowledge of the distribution and biology of the ragfish, Icosteus aenigmaticus, an aberrant deepwater perciform of the North Pacific Ocean, has increased slowly since the first description of the species in the 1880’s which was based on specimens retrieved from a fish monger’s table in San Francisco, Calif. As a historically rare, and subjectively unattractive appearing noncommercial species, ichthyologists have only studied ragfish from specimens caught and donated by fishermen or by the general public. Since 1958, I have accumulated catch records of >825 ragfish. Specimens were primarily from commercial fishermen and research personnel trawling for bottom and demersal species on the continental shelves of the eastern North Pacific Ocean, Gulf of Alaska, Bering Sea, and the western Pacific Ocean, as well as from gillnet fisheries for Pacific salmon, Oncorhynchus spp., in the north central Pacific Ocean. Available records came from four separate sources: 1) historical data based primarily on published and unpublished literature (1876–1990), 2) ragfish delivered fresh to Humboldt State University or records available from the California Department of Fish and Game of ragfish caught in northern California and southern Oregon bottom trawl fisheries (1950–99), 3) incidental catches of ragfish observed and recorded by scientific observers of the commercial fisheries of the eastern Pacific Ocean and catches in National Marine Fisheries Service trawl surveys studying these fisheries from 1976 to 1999, and 4) Japanese government research on nearshore fisheries of the northwestern Pacific Ocean (1950–99). Limited data on individual ragfish allowed mainly qualitative analysis, although some quantitative analysis could be made with ragfish data from northern California and southern Oregon. This paper includes a history of taxonomic and common names of the ragfish, types of fishing gear and other techniques recovering ragfish, a chronology of range extensions into the North Pacific and Bering Sea, reproductive biology of ragfish caught by trawl fisheries off northern California and southern Oregon, and topics dealing with early, juvenile, and adult life history, including age and growth, food habits, and ecology. Recommendations for future study are proposed, especially on the life history of juvenile ragfish (5–30 cm FL) which remains enigmatic.

Guide to the identification of larval and early juvenile pricklebacks (Perciformes: Zoarcoidei: Stichaeidae) in the northeastern Pacific Ocean and Bering Sea

Stichaeidae, commonly referred to as pricklebacks, are intertidal and subtidal fishes primarily of the North Pacific Ocean. Broad distribution in relatively inaccessible and undersampled habitats has contributed to a general lack of information about this family. In this study, descriptions of early life history stages are presented for 25 species representing 18 genera of stichaeid fishes from the northeastern Pacific Ocean, Bering Sea, and Arctic Ocean Basin. Six of these species also occur in the North Atlantic Ocean. Larval stages of 16 species are described for the first time. Additional information or illustrations intended to augment previous descriptions are provided for nine species. For most taxa, we present adult and larval distributions, descriptions of morphometric, meristic, and pigmentation characters, and species comparisons, and we provide illustrations for preflexion through postflexion or transformation stages. New counts of meristic features are reported for several species.

Strong, low frequency (decadal) environmental fluctuations during the 20th century in the North Pacific Ocean, on the Washington coast, and in Puget Sound

At decadal period (10-20 years), dynamic linkage was evident between atmospheric low pressure systems over the North Pacific Ocean and circulation in a Pacific Northwest fjord (Puget Sound). As the Aleutian low pressure center shifts, storms arriving from the North Pacific Ocean deposit varying amounts of precipitation in the mountains draining into the estuarine system; in turn, the fluctuating addition of fresh water changes the density distribution near the fjord basin entrance sill, thereby constraining the fjord's vertical velocity structure. This linkage was examined using time series of 21 environmental parameters from 1899 to 1987. Covariation in the time series was evident because of the strong decadal cycles compared with long-term averages, interannual variability, and seasonal cycles.

Decadal variability over the North Pacific Ocean [abstract]

EXTRACT (SEE PDF FOR FULL ABSTRACT): In this study we use ocean and atmosphere datasets from observations and from an ocean general circulation model integration to examine decadal time scale variability that is centered in the Pacific basin. We know that decadal variability is likely to have a strong expression in the Pacific basin; for example, a marked "shift" of cool season climate in the mid-1970s introduced major changes in Pacific SST and atmospheric circulation, along with many other physical and biological properties.

C02 in the North Pacific Ocean.

Executive Summary [pdf, 0.01 MB] Introduction [pdf, 0.01 MB] Synthesis of the WOCE/JGOFS global CO2 survey data in the North Pacific [pdf, 0.3 MB] Air-sea CO2 fluxes [pdf, 0.1 MB] DIC, TAlk and anthropogenic CO2 distributions in the North Pacific [pdf, 3 MB] Biogeochemical and global implications [pdf, 0.1 MB] Recommendations for the future of carbon studies within PICES [pdf, 0.1 MB] References [pdf, 0.1 MB] Appendix A. Summary of PICES Working Group 13 activities (1998-2001) [pdf, 0.1 MB] Appendix B. Results of Working Group 13 method inter-comparison studies [pdf, 0.6 MB] Appendix C. Results of Working Group 13 data integration workshops [pdf, 0.5 MB] (57 page document)

Charting multidisciplinary research and action priorities towards the conservation and sustainable management of sea turtles in the Pacific Ocean: a focus on Malaysia

The four sea turtle species found in Malaysia are the leatherback, olive ridley, green and hawksbill. The threats to these species are acute. Populations of leatherback, olive ridley and hawksbill turtles are on the brink of collapse – threatening a biodiversity crisis in Malaysia and the region. This proceedings contains 8 technical papers presented at a workshop convened in Kijal, Terengganu to chart new directions in the conservation of Malaysia's critically endangered sea turtles and to reverse population decline. They represent a wide range of issues from aspects of biology to a review of 40 years of sea turtle conservation. A paper on the socioeconomic linkages and impacts of fisheries was also included as the workshop adopted a multidisciplinary approach to address the issues. Two case studies, including successful restoration examples from international experiences and restoration efforts in Sabah, pave the way for enhancing turtle conservation in the country.

Commercially Important Crabs, Shrimps and Lobsters of the North Pacific Ocean

Table of Contents [pdf, 1 Kb] Summary [pdf, 85 Kb] Introduction [pdf, 0.8 Mb] Major Species and Stocks of Crabs in the PICES Region [pdf, 1.23 Mb] Major Species and Stocks of Shrimps in the PICES Region [pdf, 0.5 Mb] Oceanography [pdf, 0.4 Mb] Sampling and Data Analysis [pdf, 0.38 Mb] Acknowledgements [pdf, 0.27 Mb] References [pdf, 0.33 Mb] Appendices [pdf, 0.3 Mb] Plates 1-5 [pdf, 0.95 Mb] (Document contains 83 pages)

Predation by Marine Birds and Mammals in the Subarctic North Pacific Ocean

Study on the interactions between marine mammals or marine birds and fisheries in the PICES region of interest. (PDF contains 168 pages)

Marine life in the North Pacific Ocean: the known, unknown, and unknowable

Bacterioplankton [pdf] Phytoplankton [pdf] Zooplankton [pdf] Non-exploited fish and invertebrates [pdf] Commercially-important fish and invertebrates [pdf] Marine birds [pdf] Mammals [pdf] Supplemental table of Unknowns [html] (Document pdf contains 48 pages)

Additional information on the length-weight relationship of skipjack tuna from the Eastern Tropical Pacific Ocean

ENGLISH: Results of a study of the length-weight relationships of yellowfin (Neothunnus macropterus) and skipjack (Katsuwonus pelamis) tuna from several fishing areas of the Eastern Tropical Pacific Ocean have been published by Chatwin (1959). In that report, a very low exponential value of 2.6261 was obtained for skipjack from Area 14 (off northern Chile, see Chatwin, Figure 1). It was pointed out, however, that this estimate was based on two samples of fish with a very narrow range of total lengths, not representative of the range in the catch, and that it would be desirable to obtain a further estimate based on a larger range of total lengths. In addition, there proved to be significantly large differences among exponents for the areas sampled, precluding use of a single regression equation for all areas. Two important fishing areas remained unsampled (Areas 10 and 13, see Chatwin, Figure 1), and it appeared desirable to collect length-weight measurement data from them, so that estimating equations would be available for all areas. Subsequent to publication of Chatwin's study, samples of skipjack length-weight measurements were obtained from the desired areas. Estimates derived from these data, and their effects on the previous analysis are presented herein. SPANISH:Los resultados de un estudio sobre las relaciones entre la longitud y el peso del atún aleta amarilla (Neothunnus macropterus) y del barrilete (Katsuwonus pelamis) de las diferentes áreas de pesca en el Pacífico Oriental Tropical ya han sido publicados por Chatwin (1959). En ese informe se obtuvo un valor exponencial muy bajo de 2.626 para el barrilete del Area 14 (frente a la costa norte de Chile, ver Chatwin, Figura 1). Se hizo hincapié, sin embargo, en que esta estimación se basaba en dos muestras de peces con una amplitud muy estrecha de longitudes totales, no representativa de la amplitud en la pesca, y que sería deseable obtener una estimación adicional basada en una amplitud mayor de longitudes totales. Además, se comprobó que habian diferencias significativamente grandes entre los exponentes de las áreas muestreadas lo que impedía el usa de una sola ecuación de regresión para todas las áreas. Se quedaron sin muestrear dos importantes áreas de pesca (Areas 10 y 13, ver Chatwin, Figura 1) y pareció deseable recolectar datos de medidas de longitud y peso de estas áreas, de tal manera que hubiesen disponibles ecuaciones estimadoras para todas las áreas. Después de la publicación del estudio de Chatwin, so obtuvieron muestras de medidas de longitud y peso de barriletes de las áreas deseadas. Las estimaciones derivadas de estos datos y sus efectos sabre el análisis previo se dan en el presente informe.

Species and size relationships within schools of yellowfin and skipjack tuna as indicated by catches in the Eastern Tropical Pacific Ocean

ENGLISH: Yellowfin tuna, Neothunnus macropterus, and skipjack tuna, Katsuwonus pelamis, are fished intensively off the west coast of the Americas in an area from about the California-Mexico border in the north to the Peru-Chile border in the south. The historical development of this fishery, and its expansion by the long-range California fleets of bait and purse-seine vessels, are well documented by Godsil (1938), Scofield (1951) and Shimada and Sehaefer (1956). The quarterly distribution of the tuna catches within this area has been reported for some recent years by Alverson (1959). SPANISH: Los atunes aleta amarilla, Neothunnus macropterus, y barrilete, Katsuwonus pelamis, son pescados con intensidad frente a la costa occidental del continente americano, en un área comprendida más o menos entre la frontera California-México en el norte y el límite Perú-Chile en el sur. El desarrollo histórico de esta pesquería y la expansión que le han dado las flotas californianas de largo radio de acción, formadas por los barcos de carnada y rederos, están bien documentados por Godsil (1938), Scofield (1951) y Shimada y Schaefer (1956). La distribución trimestral de las pescas de atún dentro de esta área ha sido tratada por Alverson (1959) con referencia a años recientes.

Size and year class composition of catch, age and growth of yellowfin tuna in the Eastern Tropical Pacific Ocean for the years 1954-1958

ENGLISH: Data on the size composition of catch for the years 1954-1958 have been studied to determine year class composition, age and growth of yellowfin tuna in the Eastern Tropical Pacific Ocean. Direct age determination of tropical tunas has not yet proven reliable; however, this analysis has shown that the length-frequency distributions themselves are adequate to determine year class structure and growth rates. Absolute age has been estimated by comparing the average time of spawning with the time at which age groups initially appear in the catch. SPANISH: Los datos sobre la composición del tamaño de la pesca durante los años 1954-1958 han sido estudiados con el objeto de determinar la composición de las clases anuales, la edad y el crecimiento del atún aleta amarilla en el Océano Pacífico Oriental Tropical. Las determinaciones directas de la edad de los atunes tropicales no han probado todavía ser de confianza; sin embargo, este análisis ha demostrado que las distribuciones de la frecuencia de las longitudes son adecuadas para determinar la estructura de las clases anuales y de las tasas de crecimiento. La edad absoluta ha sido estimada mediante la comparación de la época promedio de desove con la epoca en que los grupos de edades comienzan a aparecer en la pesca.

The relationships between length and weight of yellowfin tuna (Neothunnus macropterus) and skipjack tuna (Katsuwonus pelamis) from the Eastern Tropical Pacific Ocean

ENGLISH: The purposes of the Convention which established the Inter-American Tropical Tuna Commission have been discussed in the Commission's Annual Report for 1950-51 (Schaefer, 1952) and in subsequent Annual Reports. One of its functions is to gather and report on biological information for the tunas of the Eastern Tropical Pacific, the yellowfin tuna (Neothunnus macropterus) and skipjack tuna (Katsuwonus pelamis). This report gives the results of a study of the relationships between the length and the weight of individuals of each of these species, derived from samples of fish of commercial sizes captured during the course of regular fishing operations in several areas of the Eastern Tropical Pacific Ocean SPANISH: Los propósitos de la Convención que estableció la Comisión Interamericana del Atún Tropical han sido expuestos en el Informe Anual de dicho organismo correspondiente a 1950-51 (Schaefer, 1952), y en los siguientes informes anuales. Una de sus funciones es la de recoger información biológica sobre los atunes del Pacífico Oriental Tropical, es decir, el aleta amarilla (Neothunnus macropterus) y el barrilete (Katsuwonus pelamis) y darla a conocer a las partes interesadas. El presente trabajo informativo proporciona los resultados de un estudio de las relaciones entre la longitud y el peso tomados en individuos de cada una de estas especies, mediante muestreo en pescados de tamaños comerciales capturados en el curso de operaciones regulares de pesca, en diversas área del Océano Pacífico Oriental Tropical.

Morphometric comparisons among yellowfin tuna, Neothunnus macropterus, from the Eastern Tropical Pacific Ocean

ENGLISH: The fishery for yellowfin tuna in the Eastern Tropical Pacific Ocean extends from Southern California to Northern Peru and offshore to a distance of several hundred miles. Sound management of this resource is dependent on knowledge of the relationships among stocks of the many fishing regions within this oceanic area of about one and one quarter million square miles. Godsil (1948), Godsil and Greenhood (1951), Schaefer (1952, ]955) and Royce (1953) have previously examined the morphometry of the yellowfin tuna of the Pacific Ocean and, although these studies were helpful in delineating the major yellowfin stocks of this region, they were of limited value in examining possible sub-divisions f the population fished off the West Coast of the Americas. The importance of this problem and the increase in fishing effort, in recent years, in the new areas off Peru, suggested a re-examination of selected body measurements from fish taken in the various areas of the Eastern Tropical Pacific Ocean, including the more recently exploited grounds off Peru. SPANISH: La pesquería de atún aleta amarilla en el Océano Pacífico Oriental Tropical se extiende desde la California del Sur hasta la región septentrional del Perú, y mar afuera en una extensión de varios cientos de millas. La acertada administración de este recurso depende del conocimiento de las relaciones entre los stocks de las muchas regiones de pesca que se encuentran dentro de esta área oceánica, cuya dimensión es de alrededor de un millón y cuarto de millas cuadradas. Godsil (1948), Godsil y Greenhood (1951), Schaefer (1952, 1955) y Royce (1953) han examinado la morfología del atún aleta amarilla del Océano Pacífico, y a pesar de que los estudios de estos científicos contribuyeron a delinear los más importantes stocks de dicha especie en esta región, han sido, sin embargo, de un valor limitado para el examen de posibles subdivisiones de la población explotada por la pesca frente a la costa occidental de las Américas. La importancia de este problema y el aumento en el esfuerzo de pesca, en años recientes, en las nuevas áreas frente al Perú, han hecho pensar en una revisión de las medidas anatómicas seleccionadas en pescados que se han obtenido en las diversas áreas del Océano Pacífico Oriental Tropical, incluyendo las localidades más recientemente explotadas a la altura de la tierra peruana.

A study of measures of population density and of concentration of fishing effort in the fishery for yellowfin tuna, Neothunnus macropterus, in the Eastern Tropical Pacific Ocean, from 1951 to 1956

ENGLISH: This study shows how the catch and effort statistics, from 1951 to 1956, of the fishery for yellowfin tuna, Neothunnus macropterus, in the Eastern Tropical Pacific Ocean, have been used to compute: (i) two indices of average population density; (ii) an index of concentration of effort on areas of greatest density of available yellowfin. These three indices were then used to determine: (i) quarterly and annual variation in each of them; (ii) the relationship between the two indices of density; (iii) the relationship of each of the indices to the number of exploited one-degree rectangles. To remove extreme sampling variation at low levels of effort, the data from all one-degree rectangles subjected to less than five logged days' fishing in a quarter were eliminated, and the computations were repeated for comparison with those of the original data. SPANISH: Este estudio da a conocer cómo las estadísticas sobre la pesca y el esfuerzo de pesca de la pesquería del atún aleta amarilla, Neothunnus macropterus, en el Océano Pacífico Oriental Tropical, durante 1951 a 1956, han servido para computar: (i) dos índices del promedio de la densidad de la población; (ií) un índice de la concentración del esfuerzo en las áreas de mayor densidad de atún aleta amarilla disponible. Estos tres índices han sido luego usados para determinar: (i) la variación trimestral y anual en cada uno de ellos; (ií) la relación entre los dos índices de densidad; (iii) la relación de cada uno de los índices con el número de rectángulos de un grado explotados. Para evitar la extrema variación del muestreo a bajos niveles de esfuerzo, se eliminaron los datos de todos los rectángulos de un grado sujetos a menos de cinco días de actividad pesquera durante un trimestre según los registros de los cuadernos de bitácora, y las computaciones se repitieron para compararlas con las de los datos originales.