77 resultados para Special purpose operations


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There is increasing interest in the potential impacts that fishing activities have on megafaunal benthic invertebrates occurring in continental shelf and slope ecosystems. We examined how the structure, size, and high-density aggregations of invertebrates provided structural relief for fishes in continental shelf and slope ecosystems off southern California. We made 112 dives in a submersible at 32−320 m water depth, surveying a variety of habitats from high-relief rock to flat sand and mud. Using quantitative video transect methods, we made 12,360 observations of 15 structure-form-ing invertebrate taxa and 521,898 individuals. We estimated size and incidence of epizoic animals on 9105 sponges, black corals, and gorgonians. Size variation among structure-form-ing invertebrates was significant and 90% of the individuals were <0.5 m high. Less than 1% of the observations of organisms actually sheltering in or located on invertebrates involved fishes. From the analysis of spatial associations between fishes and large invertebrates, six of 108 fish species were found more often adjacent to invertebrate colonies than the number of fish predicted by the fish-density data from transects. This finding indicates that there may be spatial associations that do not necessarily include physical contact with the sponges and corals. However, the median distances between these six fish species and the invertebrates were not particularly small (1.0−5.5 m). Thus, it is likely that these fishes and invertebrates are present together in the same habitats but that there is not necessarily a functional relationship between these groups of organisms. Regardless of their associations with fishes, these invertebrates provide structure and diversity for continental shelf ecosystems off southern California and certainly deserve the attention of scientists undertaking future conservation efforts.

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Introductions of exotic finfish between 1948 and 1953 are reported in this paper, with a brief reference to earlier and later introductions. Exotic fish were introduced principally to develop the potential for aquaculture in fresh and brackish waters in order to increase the availability of fish for rural communities through the biological control of aquatic vegetation. The algal feeding tilapia (Sarotherodon mossambicus) has created a new food industry in inland and brackishwaters. It has supplemented marine fishery production in a community where animal protein intake consists mainly of fish. It is also being cultured in flooded rice fields and used in the control of malaria. This excellent table fish has not had any adverse environmental impact.

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Sources of wastes in fishing operations mainly include bycatch discards; processing wastes where catch is processed onboard; plastic wastes due to abandoned, lost and discarded fishing gear; bilges and other wastes from the vessel operations. Fishing systems in general have an associated catch of nontargeted organisms known as bycatch. Non-selective fishing gear that is not modified or equipped to exclude non-targeted organisms, may take a significant quantity of bycatch of non-targeted finfish, juvenile fish, benthic animals, marine mammals, marine birds and vulnerable or endangered species that are often discarded. Average annual global discards, has been estimated to be 7.3 million t, based on a weighted discard rate of 8%, during 1992-2001 period. Trawl fisheries for shrimp and demersal finfish account for over 50% of the total estimated global discards. Plastic materials are extensively used in fisheries, owing to their durability and other desirable properties, contributing to the efficiency and catchability of the fishing gear. However, plastics biodegrade at an extremely slow rate compared to other organic materials. Abandoned, lost or otherwise discarded fishing gear (ALDFG) and related marine debris have been recognized as a critical problem in the marine environment and for living marine resources. Prevention of excess fishing capacity by appropriate management measures could lead to enormous savings in terms of fuel consumption, emissions and bycatch discards from the excess fishing fleet, capital and operational investments and labour deployment in capture fisheries, with significant economic gains. In this paper, wastes originating from fishing operations are reviewed, along with their environmental impacts and possible mitigation measures

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Ring seines are lightly constructed purse seines adapted for operation in the traditional sector. Fish production and energy requirement in the ring seine operations, off Cochin, Kerala, India are discussed in this paper, based on data collected during 1997- 1998. The results reflect the Gross Energy Requirement (GER) situation that existed during 1997-1998. Mean catch per ring seiner per year worked out to be 211.9 t of which sardines (Sardinella spp.) constituted 44.3%, followed by Indian mackerel (Rastrelliger kanagurta) 29.7%, carangids 11.4%, penaeid prawns 2.2%, pomfrets 1.1% and miscellaneous fish 11.3%. Total energy inputs into the ring seine operations were estimated to be 1300.8 GJ. Output by way of fish production was determined to be 931.85 GJ. GER is the sum of all non-renewable energy resources consumed in making available a product or service and is a measure of intensity of non-renewable resource use. GER per tonne of fish landed by ring seiners was estimated to be 6.14. Among the operational inputs, kerosene constituted 73.4% of the GER, followed by petrol (12.7%), diesel (6.7%) and lubricating oil (2.4%). Fishing gear contributed 3.8%, engine 0.8% and fishing craft 0.3% of the GER. Energy ratio for ring seining was 0.72 and energy intensity 1.40.

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The biography of Charles Bradford Hudson that follows this preface had its seeds about 1965 when I (VGS) was casually examining the extensive files of original illustrations of fishes stored in the Division of Fishes, National Museum of Natural History, Smithsonian Institution. I happened upon the unpublished illustration of a rainbow trout by Hudson and was greatly impressed with its quality. The thought occurred to me then that the artist must have gone on to do more than just illustrate fishes. During the next 20 years I occasionally pawed through those files, which contained the work of numerous artists, who had worked from 1838 to the present. In 1985, I happened to discuss the files with my supervisor, who urged me to produce a museum exhibit of original fish illustrations. This I did, selecting 200 of the illustrations representing 21 artists, including, of course, Hudson. As part of the text for the exhibit, Drawn from the Sea, Art in the Service of Ichthyology, I prepared short biographies of each of the artists. The exhibit, with an available poster, was shown in the Museum for six months, and a reduced version was exhibited in U.S. and Canadian museums during the next 3 years.

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South African (Cape) fur seals, Arctocephalus pusillus pusillus, interact with the South African trawl fisheries-offshore demersal, inshore demersal, and midwater fisheries. These interactions take thef ollowing forms: Seals take or damage netted fish, on particular vessels they become caught in the propeller, seals drown in the nets, live seals come aboard and may be killed. Except in specific cases of seals damaging particular trawler propellers, interactions result in little cost to the offshore and midwater trawl fisheries. For the inshore fishery, seals damage fish in the net at an estimated cost in excess of R69, 728 (US$18,827) per year, but this is negligible (0.3%) in terms ofthe value of the fishery. Seal mortality is mainly caused by drowning in trawl nets and ranges from 2,524 to 3,636 seals of both sexes per year. Between 312 and 567 seals are deliberately killed annually, but this most likely takes place only when caught and they enter the area below deck, where they are difficult to remove, and pose a potential threat to crew safety. Overall, seal mortality during trawling operations is negligible (0.4-0.6%) in terms of the feeding population of seals in South Africa.

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Energy is a key input into the fish harvesting process. Efficient use of energy helps in reducing operational costs and environmental impact, while increasing profits. Energy optimisation is an important aspect of responsible fishing as enunciated in the Code of Conduct for Responsible Fisheries. Gross Energy Requirement (GER) is the sum of all non-renewable energy resources consumed in making available a product or service and is expressed in energy units per physical unit of product or service delivered. GER is a measure of intensity of non-renewable resource use and it reflects the amount of depletion of earth’s inherited store of non-renewable energy in order to create and make available a product or service. In this study, GER in fish harvesting up to the point of landing is estimated in selected fish harvesting systems in the small-mechanised sectors of Indian fisheries and compared with reported results from selected non mechanised and motorised fishing systems to reflect the situation during 1997-1998. Among the fish harvesting systems studied, GER t fish-1 ranged from 5.54 and 5.91 GJ, respectively, for wooden and steel purse seiners powered by 156 hp engines; 6.40 GJ for wooden purse seiner with 235 hp engine; 25.18 GJ for mechanised gillnet/line fishing vessel with 89 hp engines; to 31.40 and 36.97 GJ, respectively, for wooden and steel trawlers powered by 99-106 hp engines.

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This is the report from the West Cumbria Special Fisheries Advisory Group meeting, which was held on the 25th June, 1982. The report contains sections on the Application by British Nuclear Fuels Limited (BNFL) for a temporary licence to abstract additional quantities from Wastwater, and River Derwent Abstraction (Prescribed Flows). The Fisheries Advisory Committee was part of the Regional Water Authorities, in this case the North West Water Authority. This preceded the Environment Agency which came into existence in 1996.

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This is the report from the West Cumbria Special Fisheries Advisory Group meeting, which was held on the 28th July, 1982. The report contains sections on minutes of the meeting held on the 25th June, 1982, Application by British Nuclear Fuels Limited (BNFL) for a temporary licence to abstract additional quantities from Wastwater, and River Derwent Abstraction (Prescribed Flows) and fisheries implications. The Fisheries Advisory Committee was part of the Regional Water Authorities, in this case the North West Water Authority. This preceded the Environment Agency which came into existence in 1996.

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This is the report from the West Cumbria Special Fisheries Advisory Group meeting, which was held on the 9th March, 1983. The report contains sections on Fish Passes at Yearl Weir River Derwent, Ennerdale, and Ehen; River Calder abstraction and augmentation from boreholes; and the augmentation of River Ehen by minewater to support increased abstraction by BNFL. The Fisheries Advisory Committee was part of the Regional Water Authorities, in this case the North West Water Authority. This preceded the Environment Agency which came into existence in 1996.

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This is the report from the West Cumbria Special Fisheries Advisory Group meeting, which was held on the 16th May, 1986. The report contains sections on a Fish Pass at Ennerdale, Authority proposals for discharge of compensation water from Ennerdale and a diagram of fish pass at Ennerdale. The Fisheries Advisory Committee was part of the Regional Water Authorities, in this case the North West Water Authority. This preceded the Environment Agency which came into existence in 1996.

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This is the River Ehen and Tributaries SSSI consultation Protocol for the Environment Agency with English Nature, produced in 1998. The Protocol is intended to provide for consistency of approach, to clarify responsibilities and help to streamline the statutory consultation and consenting procedures in which both organisations are involved. It provides guiding principles on the approach to management issues. Based on the operations likely to damage the special interest (OLDSI) which forms part of the SSSI notification, the protocol identified acceptable management activities which contribute to the special interest of the site and those which may adversely affect that interest. OLDSI includes activities such: land drainage consents, discharge consents, herbicides approvals, fish-stocking consents, fishing licences, abstraction and impoundment licences, consents to construct/test pump boreholes, integrated pollution Control Licences and Waste Management Licences, capital projects, flood defence maintenance works, water resources, fisheries, pollution control, ecology surveys and Recreation works.

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This is a report on the Conservation Plan for Rostherne Mere. The project primarly involved collating existing information from a variety of sources, supplemented by a limited amount of survey work commissioned for the project, including identification of the surface water catchment, water flows, and land use within the catchment. The section 1 outlines the physical situation of the Site of Special Scientific Interest (SSSI), its geological setting and hydrological regime. A summary of the ecological characteristics, conservation interest and objectives is provided in Section 2, and the issues affecting the site are identified in Section 3. . Operations and mechanisms for addressing the issues are suggested in Section 4, compiled from field visits, information held on file by English Nature and the Environment Agency, and English Nature. The last Section 5 provides a brief summary of the site’s condition and a discussion of the issues and operations suggested. A summary table is provided of the recommended actions for each site. Supporting information on the hydrology and aquatic ecology (where relevant) is provided in appendices.

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This is the River Eden RHS and geomorphology evaluation: Final report October 2001 produced by the Environment Agency North West in 2001. This report analysed the River Habitat Survey (RHS) and geomorphology data to evaluate the level of habitat quality and the geomorphological characteristics of the River Eden and sub-catchments. RHS data and geomorphological assessment data was collected within the study areas by CEH and Fluvial Environmental Services Ltd. The River Eden and its sub-catchments are being considered as a Special Area for Conservation (SAC) due to the presence of habitat types and species, which are rare or threatened within Europe. The purpose of the project is to provide an overview of the state of the catchment in terms of river habitats and geomorphological processes in order to aid the derivation of sound management for this proposed SAC.The aim of this report was to determine the state of the environment within the Eden and sub-catchments and identify the main pressures on the system in order to derive sound management options.