The Feasibility of Enhancing Red Sea Urchin, Strongylocentrotus iranciscanus, Stocks in California: An Analysis of the Options

The California fishery for red sea urchins, Strongylocentrotus franciscanus, has undergone explosive growth in recent years and is approaching full exploitation. Thus, there is considerable interest in enhancing stocks to maintain a high rate of landings. Fishable stocks of red sea urchins in different areas appear to be limited at three stages in their life history: By the availability of larvae, by the survival of newly settled to mid-sized animals, and by the food available to support growth and reproduction of larger animals. Here I review other efforts, notably the extensive Japanese work, to enhance fishable stocks of benthic marine invertebrates, and consider the potential options for red sea urchins at different points of limitation. These include collecting or culturing seed for outplanting, physical habitat improvement measures, improving the food supply, and conservation measures to protect existing stocks until alternate methods are proven and in place. The options are compared in terms of biological feasibility, capital and labor requirements, and potential implications for change in the structure of the fishing industry.

Effects of water quality in Bassenthwaite Lake on anglers' catches of salmon and sea-trout in the River Derwent

This is the report on the Effects of Water Quality in the Bassenthwaite Lake on Anglers Catches of Salmon and Sea-trout in the River Derwent April 1993 by the Institute of Freshwater Ecology. An analysis of the catch statistics for salmon and sea-trout in the Rivers Derwent and Cocker was undertaken in relation to available information on the algal water quality in Bassenthwaite Lake to test the hypothesis that poor catch returns were associated with a deterioration of water quality within the lake. Analysis of the catch statistics failed to reveal any correlation between water quality and catch returns for either species of fish and it is concluded that any water deterioration in Bassenthwaite Lake has not caused any major damage to the salmon and sea trout fisheries of the Derwent/Cocker system. This conclusion is supported by the analysis of the Windermere/Leven and Crake system, where no correlation could be found between lake water quality and downstream catches of migratory salmonid fish. However, the possibility still exists and such an effect might be detected by further field work on the macroinvertebrates and on the composition of potential salmonid spawning in the area.

Planting Sea Trout Ova 1952

Three men planting out Sea trout ova in a beck in North West England, UK, in 1952. This photo is part of a Photo Album that includes pictures from 1935 to 1954.

Harry Hess and sea-floor spreading

Harry Hess's hypothesis of sea-floor spreading brought together his long-standing interests in island arcs, oceanic topography, and the oceanic crust. The one unique feature of Hess's hypothesis was the origin of the oceanic crust as a hydration rind on the top of the mantle -- an idea that was not well received, even by the early converts to sea-floor spreading. Hess never changed his mind on this issue, and his stubbornness illuminates the logic of his discovery. Published and archival records show that 1) Hess became convinced the oceanic crust was a hydration rind as early as mid 1958, when he was still a fixist, 2) he devised sea-floor spreading in 1960 to reconcile the hydration-rind model with the newly discovered, high heat flow at oceanic ridge crests, and 3) Hess's new mobilist solution did the least amount of violence to his older fixist solution.

International legal instruments relevant to fisheries and fishing communities : a handbook. Theme V. Fishing vessels and safety at sea

This handbook provides detailed information for a wide range of legal instruments relevant to fisheries and fishworkers. It covers 114 legal instruments, categorized into the following seven themes: Theme I. Human Rights, Food Security, Women and Development. Theme II. Environment and Sustainable Development. Theme III. Oceans and Fisheries Management. Theme IV. Environmental Pollution Theme V. Fishing Vessels and Safety at Sea Theme VI. Labour Theme VII. Trade The handbook also includes the working of the instruments (decision-making bodies, monitoring and implementation agencies, periodicity of meetings, rules for participation in meetings of the decision-making bodies and implementation agencies for States and non-governmental organizations), regional instrument and agencies. Apart from being a ready reckoner to the instruments, it highlights the important sections of relevance to fisheries or small-scale fisheries and fishworkers. The companion CD-ROM provides the full texts of the instruments in a searchable database. The handbook will be useful for fishworker and non-governmental organizations, and also for researchers and others interested in fisheries issues.