Recommendation domains for pond aquaculture: country case study: development and status of freshwater aquaculture in Malawi

This monograph is a result of a 3-year project to produce a decision-support toolkit with supporting databases and case studies to help researchers, planners and extension agents working on freshwater pond aquaculture. The purpose of the work was to provide tools and information to help practitioners identify places and conditions where pond aquaculture can benefit the poor, both as producers and as consumers of fish. This monograph is the case study for Malawi. Written in three parts, it describes the historical background, practices, stakeholder profiles, production levels, economic and institutional environment, policy issues, and prospects for aquaculture in the country. First, it documents the history and current status of the aquaculture in the country. Second, it assesses the technologies and approaches that either succeeded or failed to foster aquaculture development and discusses why. Third, it identifies the key reasons for aquaculture adoption.

Recommendation domains for pond aquaculture: country case study: development and status of freshwater aquaculture in Cameroon

This report is an output of the project “Determination of high-potential aquaculture development areas and impact in Africa and Asia”. This monograph is the case study for Cameroon. Written in three parts, it describes the historical background, practices, stakeholder profiles, production levels, economic and institutional environment, policy issues, and prospects for aquaculture in the country. First, it documents the history and current status of the aquaculture in the country. Second, it assesses the technologies and approaches that either succeeded or failed to foster aquaculture development and discusses why. Third, it identifies the key reasons for aquaculture adoption.

Recommendation domains for pond aquaculture: country case study: development and status of freshwater aquaculture in Bangladesh

This report is an output of the project “Determination of high-potential aquaculture development areas and impact in Africa and Asia”. This monograph is the case study for Cameroon. Written in three parts, it describes the historical background, practices, stakeholder profiles, production levels, economic and institutional environment, policy issues, and prospects for aquaculture in the country. First, it documents the history and current status of the aquaculture in the country. Second, it assesses the technologies and approaches that either succeeded or failed to foster aquaculture development and discusses why. Third, it identifies the key reasons for aquaculture adoption.

Recommendation domains for pond aquaculture: country case study: development and status of freshwater aquaculture in Henan Province, China

This monograph is the case study for China, with a particular focus on Henan Province, the project location. Written in three parts, it first describes the historical background, production levels and trends, economic and institutional environment, policy issues, and market situation in China in general. The main part of the study presents findings from two different surveys conducted in Henan Province. County-level information is used to analyze the current situation of aquaculture, providing a more disaggregated picture than what is generally available from national statistics. Data collected in a survey of fish farmers in two locations in Henan are then analyzed with regard to the prevailing aquaculture technology and production practices, economic performance of pond fish farming, and the key reasons for aquaculture adoption. In the final chapter, constraints and opportunities for the aquaculture sector in China in general are discussed. (pdf contains 68 pages.)

A study of changes in fishing effort, abundance, and yield for yellowfin and skipjack tuna in the Eastern Tropical Pacific Ocean

ENGLISH: The rapid growth of the Eastern Pacific fishery for yellowfin and skipjack tuna since the end of World War II has given rise to questions concerning the rational utilization of these resources. As part of the Inter-American Tropical Tuna Commission's program of research designed to investigate these problems, a study was undertaken to determine from the historical records of the fishery the effects of fishing upon the stocks of yellowfin and skipjack tuna of the Eastern Pacific region and to evaluate the present condition of these stocks with respect to the maximum equilibrium yield. SPANISH: EI rápido crecimiento, desde la terminación de la Segunda Guerra Mundial, de la pesquería de atún aleta amarilla y barrilete en el Pacifico Oriental, ha dado lugar a que se hagan algunos comentarios sabre la racional utilización de estos recursos. Como parte del programa de la Comisión Interamericana del Atún Tropical designado para la investigación de estos problemas, un estudio fué llevado a cabo para determinar, de los informes historicós de la pesquería, los efectos de la pesca sobre los stocks de atún aleta amarilla y barrilete de la región del Pacifico Oriental y para evaluar la presente condición de estos stocks con respecto al máximo rendimiento de equilibria. (PDF contains 123 pages.)

The Windermere perch and pike project: an historical review

This paper is an attempt to set the background, provide a brief history, review some of the Windermere perch and pike project's scientific achievements, note current developments and hopes for the future, and comment on some aspects of such long-term projects. The project was originally started in 1939 in order to provide fish in freshwater lakes which might be harvested to enhance the supplies of food in a country subject to blockade. Pike traps and gill-netting were trialed as fishing methods. Catch statistics are available from 1939 which can be used to study population dynamics or for modelling purposes. The author provides an overview of changes in the population dynamics of perch and pike but covers briefly other species like arctic charr and brown trout. Also covered are several aspects of the basic biology and ecology of the principal species involved.

The effect of predation (current and historical) by humpback whales (Megaptera novaeangliae) on fish abundance near Kodiak Island, Alaska

Humpback whales (Megaptera novaeangliae) are significant marine consumers. To examine the potential effect of predation by humpback whales, consumption (kg of prey daily) and prey removal (kg of prey annually) were modeled for a current and historic feeding aggregation of humpback whales off northeastern Kodiak Island, Alaska. A current prey biomass removal rate was modeled by using an estimate of the 2002 humpback whale abundance. A historic rate of removal was modeled from a prewhaling abundance estimate (population size prior to 1926). Two provisional humpback whale diets were simulated in order to model consumption rate. One diet was based on the stomach contents of whales that were commercially harvested from Port Hobron whaling station in Kodiak, Alaska, between 1926 and 1937, and the second diet, based on local prey availability as determined by fish surveys conducted within the study area, was used to model consumption rate by the historic population. The latter diet was also used to model consumption by the current population and to project a consumption rate if the current population were to grow to reach the historic population size. Models of these simulated diets showed that the current population likely removes nearly 8.83

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.

The effect of water quality on coarse fish productivity and movement in the Lower River Irwell and Upper Manchester Ship Canal a watercourse recovering from historical pollution

This is the Effect of water quality on coarse fish productivity and movement in the Lower River Irwell and Upper Manchester Ship Canal: a watercourse recovering from historical pollution report produced by the Environment Agency in 2003. The aim of this study was to investigate the impact of water quality upon coarse fish population dynamics in a lowland, urban watercourse. All of the research carried was undertaken in the lower River Irwell and upper Manchester Ship Canal, between February 1998 and December 2001. Of particular interest was the natural sustainability of the urban fishery given recent concern raised in the angling community over an apparent decline in coarse fish populations in lowland rivers. The research described in this report has concentrated upon the role of water quality in determining coarse fish population dynamics, and in particular: The impact of water quality upon fish growth and productivity; The impact of poor water quality and low dissolved oxygen concentrations upon fish distribution and movement; The impact of water quality upon the sexual development of fish.

Historical knowledge of sharks: ancient science, earliest American encounters, and American science, fisheries, and utilization

In western civilization, the knowledge of the elasmobranch or selachian fishes (sharks and rays) begins with Aristotle (384–322 B.C.). Two of his extant works, the “Historia Animalium” and the “Generation of Animals,” both written about 330 B.C., demonstrate knowledge of elasmobranch fishes acquired by observation. Roman writers of works on natural history, such as Aelian and Pliny, who followed Aristotle, were compilers of available information. Their contribution was that they prevented the Greek knowledge from being lost, but they added few original observations. The fall of Rome, around 476 A.D., brought a period of economic regression and political chaos. These in turn brought intellectual thought to a standstill for nearly one thousand years, the period known as the Dark Ages. It would not be until the middle of the sixteenth century, well into the Renaissance, that knowledge of elasmobranchs would advance again. The works of Belon, Salviani, Rondelet, and Steno mark the beginnings of ichthyology, including the study of sharks and rays. The knowledge of sharks and rays increased slowly during and after the Renaissance, and the introduction of the Linnaean System of Nomenclature in 1735 marks the beginning of modern ichthyology. However, the first major work on sharks would not appear until the early nineteenth century. Knowledge acquired about sea animals usually follows their economic importance and exploitation, and this was also true with sharks. The first to learn about sharks in North America were the native fishermen who learned how, when, and where to catch them for food or for their oils. The early naturalists in America studied the land animals and plants; they had little interest in sharks. When faunistic works on fishes started to appear, naturalists just enumerated the species of sharks that they could discern. Throughout the U.S. colonial period, sharks were seldom utilized for food, although their liver oil or skins were often utilized. Throughout the nineteenth century, the Spiny Dogfish, Squalus acanthias, was the only shark species utilized in a large scale on both coasts. It was fished for its liver oil, which was used as a lubricant, and for lighting and tanning, and for its skin which was used as an abrasive. During the early part of the twentieth century, the Ocean Leather Company was started to process sea animals (primarily sharks) into leather, oil, fertilizer, fins, etc. The Ocean Leather Company enjoyed a monopoly on the shark leather industry for several decades. In 1937, the liver of the Soupfin Shark, Galeorhinus galeus, was found to be a rich source of vitamin A, and because the outbreak of World War II in 1938 interrupted the shipping of vitamin A from European sources, an intensive shark fishery soon developed along the U.S. West Coast. By 1939 the American shark leather fishery had transformed into the shark liver oil fishery of the early 1940’s, encompassing both coasts. By the late 1940’s, these fisheries were depleted because of overfishing and fishing in the nursery areas. Synthetic vitamin A appeared on the market in 1950, causing the fishery to be discontinued. During World War II, shark attacks on the survivors of sunken ships and downed aviators engendered the search for a shark repellent. This led to research aimed at understanding shark behavior and the sensory biology of sharks. From the late 1950’s to the 1980’s, funding from the Office of Naval Research was responsible for most of what was learned about the sensory biology of sharks.