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| | Human homes, and particularly those in urban areas, produce a broad range of materials that impact on the marine environment, including sewage, solid waste, toxic pollutants and greenhouse gases. | | | | Pollution from domestic sewage is one of the most serious forms of ocean contamination. It affects every region of the world. In Chile for example, it is estimated 82 percent of all domestic sewage finishes up in the sea, transported there by 27 river basins. In the Mediterranean over 50% of wastewater, or over 3.2 billion cubic metres per year, are discharged untreated. Untreated sewage contains very high levels of nutrients which can lead to eutrophication. It is also responsible for introducing suspended solids, biological contaminants, and chemical waste, including persistent pollutants and toxins. In its raw form sewage can also contain significant amounts of solid waste and litter. |  | | | | The complex nature of sewage requires a range of treatments to neutralise all of the damaging compounds. Preliminary treatment such as filtration removes some of the solid waste, primary treatment can remove some of the suspended sediments. Secondary treatment, typically involves bacterial introduction to remove the soluble components, while tertiary treatment attempts to disinfect the remaining liquids. Significant levels of nutrients may remain, even in well treated sewage. Pathogenic micro- organisms are only thoroughly scoured in tertiary treatments and many persistant toxins may remain even in such highly treated sewage. In some cases disinfection methods, such as chlorination, can further add to pollution. Domestic homes are major source of solid waste, including plastics, which escape into the oceans. A number of countries deliberately dump their solid waste at sea, and others incinerate their waste at sea, but with considerable losses of solid waste during this process. Homes are also major energy consumers, fuelling the greenhouse effect with CO2 emissions, particularly associated with temperature regulation through heating or air conditioning. | | | | |
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| | | Title | Shark Depredation and Unwanted Bycatch in Pelagic Longline Fisheries
( DOCUMENT )
| | Author(s) / Editor(s) |  Western Pacific Regional Fishery Management Council | | Description | Substantial ecological, economic and social problems result from shark interactions in pelagic longline fisheries. Improved understanding of industry attitudes and practices towards shark interactions assists with managing these problems. Information on fisher knowledge and new strategies for shark avoidance may benefit sharks and fishers. A study of 12 pelagic longline fisheries from eight countries shows that incentives to avoid sharks vary along a continuum, based on whether sharks represent an economic disadvantage or advantage. Shark avoidance practices are limited, including avoiding certain areas, moving when shark interaction rates are high, using fish instead of squid for bait and deeper setting. Some conventionally employed fishing gear and methods used to target non-shark species contribute to shark avoidance. Shark repellents hold promise; more research and development is needed. Development of specifically designed equipment to discard sharks could improve shark post release survival prospects, reduce gear loss and improve crew safety. With expanding exploitation of sharks for fins and meat, improved data collection, monitoring and precautionary shark management measures are needed to ensure shark fishing mortality levels are sustainable. | | Keywords | SHARKS; PELAGIC LONGLINE FISHERIES; WESTERN PACIFIC | | Geography Keywords | WESTERN PACIFIC | | Content Language(s) | English | | File Location | 1189782027324_Shark_Depredation.pdf | | Web Address | http://www.unep.org/regi ... ation.pdf | |
| Type of Document | Bibliography (unpublished) | | Document Status | Finished | | Publisher | Western Pacific Regional Fishery Management Council | |
| Publication Date | 2007 | |
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| Related to Topics | Governance of high seas fisheries
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979 Topics - 5275 Related Knowledge - 11277 Members - 48 Editors |
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