11 resultados para impoverishment of children and the youth

em Aquatic Commons


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Fish collections under varying ecological conditions were made by trawling and seining, monthly and quarterly in depths of <1 m to depths of 3 m of the Florida Bay portion of Everglades National Park, Florida. From May 1973 through September 1976, a total of 182,530 fishes representing 128 species and 50 families were taken at 27 stations. An additional 21 species were identified from sportfish-creel surveys and supplemental observations. Most of the species collected were juveniles of species that occur as adults in the Florida Bay creel census survey, or were small species that were seasonal residents. Marked temporal and spatial abundance of the catches was observed. The greatest numbers and biomass of the fishes occurred in the wet season (summer/fall), whereas lowest numbers and biomass appeared during the dry season (winter/spring) The greatest abundance and diversity of fishes was found in western Florida Bay followed by eastern and central Bay regions respectively. Overall, five species comprised 75% of the numerical total while eleven species made up 75% of the total biomass. Collections were dominated numerically by anchovies (Engraulidae), especially Anchoa mitchilli, in western Florida Bay. Mojarras (Gerridae), mostly silver jenny Eucinostomus gula, and porgies (Sparidae), especially pinfish Lagodon rhomboides, dominated numerically in central and eastern portions of the Bay, respectively. Except for salinity, other measured physico-chemical parameters (water temperature, pH, dissolved oxygen, and turbidity) showed no variation beyond ranges considered normal for shallow, tropical marine environments. Salinity varied from 0 to 66 ppt near the mainland. Nearshore hypersaline conditions (>45 ppt) persisted for nearly 2 years during the 1974 - 1975 severe drought period. Significant reductions in fish abundance/diversity were observed in relation to hypersaline conditions. Bay-wide macrobenthic communities were mapped (presence/absence) and were primarily comprised of turtle grass (Thalassia), shoalgrass [(Diplanthera = (Halodule)], and/or green algae Penicillus. Seasonal dieoff of seagrasses was observed in north-central Florida Bay. (PDF contains 107 pages)

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Sampling was concentrated on the North Moor region and the series of ditches which drained this area to the Bristol Channel. Although most ditches were not deep the mud substratum precluded sampling from within the habitat. All samples were taken with a pond net from the banks. Efforts were made to sample each part of the habitat although in some ditches the macrophyte growth was so intense as to make sampling difficult particularly of the sediments. Organisms were identified on the 10 sampling sites.

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The fisheries of Hawaii and other U.S.-associated islands in the Pacific Ocean are characterized by high diversity, both in the species exploited and the human cultures that exploit them. The commercial sector has undergone rapid growth in recent years, but recreational and subsistence sectors remain important. Information on these fisheries is generally not available in published form. This paper presents an overview and introduction to a volume of papers describing fisheries in the region, with the goal of making the information available to scientists and the general public. A great deal remains to be learned about the dynamics of these fisheries as well as the associated issues in biological research, fisheries management, and environmental protection.

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The precious coral fishery in Hawaii and the Western Pacific consists of one industry but two distinct and separate fisheries. The first is the harvest of black coral by scuba divers from depths of 30-100 m. The second is a fishery for pink and gold coral at depths between 400 and 1500 m and employs either a human-operated submersible that permits selective harvest or tangle net dredges which are nonselective. The modern history of these fisheries date from 1958 until the present. In this paper the ecology, life history. and management of the dominant species that make up these fisheries are reviewed. Research needs of the fisheries and the economic and future prospects of the precious coral industry are also described. At the present, the precious coral jewelry industry in Hawaii (all species) is valued at about $25 million at the retail level.

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EXTRACT (SEE PDF FOR FULL ABSTRACT): Coral-based reconstruction of past variability of sea surface conditions is improving our understanding of the tropical ocean-atmosphere system. We present oxygen isotope records from corals collected near the tip of Baja California (Baja) and the Gulf of Panama (Saboga).

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There is growing recognition that the performance of the fisheries sector depends on the communities responsible for activities within it. These communities include fishers, processors, fish mongers, traders, local leaders, fishery administrators etc. On the basis of this, characterisation and diagnostic studies were conducted in 1995 focussing on mainly the fishers and opinion leaders on the major and some minor water bodies in Uganda. The study revealed that the desire to earn income is the driving force behind the malfishing practices experienced on Uganda fisheries. The destructive fishing gears and fishing methods as responses advanced by the fishers and opinion leaders were seines and cast nets on lakes Victoria, Kyoga and Albert and to a less extent traps