Ngư nghiệp - Ship - Source marine pollution

Lecture 5SHIP-SOURCE MARINE POLLUTIONShip-source Sewage Sewage includes drainage from urinals and toilets, medical premises and spaces containing live animals. It varies depending on the type of ship but the general sources include galleys, baths, scuppers and bilges.SewageThe discharge of raw sewage into the sea can create health hazards. When sewage is discharged in coastal areas, it can lead to oxygen depletion and obvious visual pollution which is a major problem for countries with large tourist industries.MARPOL - annex IV Sewage can be dumped when a ship:has in operation an approved sewage treatment plant and is discharging comminuted and disinfected sewage using an approved system at a distance of not less than 4 nautical miles from the nearest land; oris discharging sewage which is not comminuted or disinfected at a distance of not less than 12 nautical miles from the nearest land.Ship-source GarbageGarbage from ships can be just as deadly to marine life as oil and chemicals. The greatest danger comes from plastics which can float around for years. Fish and marine life can, in some cases, mistake plastics for food and can also become trapped in plastic ropes, bags and nets.Time taken for objects to dissolve at seaGarbage typeTimePlastic bottle450 yearsTin can100 yearsAluminum can200-500 yearsWoolen cloth1 yearCotton cloth 1-5 monthsRope3-14 monthsPainted wood13 yearsAir pollution from shipsThe main exhaust emission pollutants are nitrogen oxides, sulphur oxides, carbon oxides and un-burnt hydrocarbon particulates. These pollutants are potentially damaging to the environment as contributors to smog and acid rain, and in the case of carbon oxides, to Greenhouse effect.Air pollutionEmissions from ocean-going ships are responsible for about 60,000 deaths a year from heart and lung related cancers. But sulphur emissions from international shipping represent about 8% of sulphur emissions from all fossil fuels. Practical prevention of air pollution from ships:Switching to distillates – cleaner fuel for ships??Alternative fuel for ships? Wind, fuel cell, etcFitting vessels with exhaust cleaning systems Reducing engine usage when approaching shore and stopping engines altogether in ports, etcWind-powered container vesselSolar-powered vesselWorld’s first Cruise Vessel partly solar-poweredWind-powered VesselShip-Source Chemical PollutionCarriage of chemicals in bulk is covered by regulations in SOLAS chapter VII – CARRIAGE OF DANGEROUS GOODS and MARPOL Annex II – REGULATIONS FOR THE CONTROL OF POLLUTION BY NOXIOUS LIQUID SUBSTANCES IN BULK.Chemical PollutionBoth conventions require chemical tankers built after 1 July 1986 to comply with the International Bulk Chemical Code (IBC Code)Chemical Pollution The IBC Code lists chemicals and their hazards and gives both the ship type required to carry that product as well as the environmental hazard rating. Product hazard properties include:FlammabilityToxicityCorrosivityReactivityPOLLUTION PREVENTION MEASURES FOR OILLoad-on-top (LOT)Segregated Ballast tanks (SBT) Crude oil washing (COW)Oil discharge monitoring and control system (ODMC)Reception facilitiesShipboard Marine Pollution Emergency PlansDouble hullLocation of slop tank31-Mar-20Ports and Shipping Department 16Slop tank18Akpe na mi!