3 resultados para abelianized obstruction

em Aquatic Commons


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A worker drilling in Colton Beck,, North West England, UK, trying to make it more accessible for fish passing in 1953. This photo is part of a Photo Album that includes pictures from 1935 to 1954.

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The Gulf of Mexico Fisheries Management Council tasked the National Marine Fisheries Service with determining the extent, if any, of loss oft rawlable bottom in the Gulf of Mexico based upon fishing industry concerns. There are approximately 31 million hectares in the 21 shrimp statistical zones in the Gulf, approximately 23 million hectares of waters that are <35 fathoms (where most shrimp trawling effort occurs), and approximately 11 million hectares in zones 10-21, <35f athoms, which were examined. There are 31,338 known hangs, snags, artificial reefs, hazards to navigation, oil rigs, and similar obstructions which cause trawling to be unfeasible in these zones. There are several refuge (i.e. untrawlable) areas associated with the Alabama Artificial Reefs. Conservatively assuming 1 hectare for each known obstruction, coupled with the known area of each refuge, the estimate of total untrawlable bottom in zones 10-21 less than 35 fathoms in the Gulf is 185,953 hectares, or roughly 1.7% of this total trawlable area. Sensitivity analysis demonstrated the robustness of this assumption, with a range of 0.3-4.3% possible. In specific shrimp zones, untrawlable area is much less than 1% except in zones 10 (26%) and 11(2.5%), both of which possess a refuge. Other than the implementation periods of these refugia, no temporal trends were detectable with respect to the amount of untrawlable bottom.

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A list is given of the provisions for aquaculture in the Philippine Fishery Code, passed by Congress on its third and final reading on 5 August 1997, under the following headings: 1) Code of practice for aquaculture; 2) Fishpond lease agreements; 3) Fish pens, fish cages, fish traps, etc.; 4) Non-obstruction to navigation and to defined migration paths of fish; 5) Insurance; and, 6) Registration.