Marine pollution

Introduction of man, directly or indirectly, of substances or energy into the marine environment (including estuaries) resulting in such deleterious effects as harm to living resources, hazard to human health, hindrance to marine activities including fishing, impairment of quality for use of sea-water, and reduction of amenities. Marine pollution occurs when harmful, or potentially harmful, effects result from the entry into the ocean of chemicals, particles, industrial, agricultural and residential waste, noise, or the spread of invasive organisms. Most sources of marine ollution are land based. In the past many substances were recklessly dumped in the ocean and it was assumed that they could be easily absorbed without any damage to the marine environment. Ocean dumping includes such materials as sewage sludge, industrial waste, explosives, and particularly huge quantities of dredge spoils.Marine pollution includes a range of threats including from land-based sources, oil spills, un treated sewage, heavy siltation, eutrophication (nutrient enrichment), Invasive species, persistent organic pollutants (POPS), heavy metals from mine tailings and other sources, cidification, radioactive substances, marine litter, overfishing and destruction of coastal and marine habitats There are three main types of inputs of pollution into the ocean: Direct discharge of waste into the oceans, =>Pollutants enter rivers and the sea directly from urban sewerage and industrial waste discharges, sometimes in the form of hazardous and toxic wastes. ining for copper, gold. etc. , is another source of marine pollution. Most of the pollution is simply soil, which ends up in rivers flowing to the sea. Runoff into the waters due to rain, Surface runoff from farming, as well as urban runoff and runoff from the construction of roads, buildings, ports, channels, and harbours, can carry soil and particles laden with carbon, nitrogen, phosphorus, and minerals.This nutrient-rich water can cause f leshy algae and phytoplankton to thrive in coastal areas, known as algal blooms, which nave the potential to create hypoxic conditions by using all available oxygen Pollutants that are released from the atmosphere =>Wind blown dust and debris, including plastic bags, are blown seaward from landfills and other areas. >Climate change is raising ocean temperatures and raising levels of carbon dioxide in the atmosphere. These rising levels of carbon dioxide are acidifying the oceans.This, in turn, is altering aquatic ecosystems and modifying fish distributions, with impacts on the sustainability of fisheries and the livelihoods of the communities that depend on them Ship's pollution Ships can pollute waterways and oceans in many ways. Oil spills can have devastating effects. While being toxic to marine life, polycyclic aromatic hydrocarbons (PAHs), the components in crude oil, are very difficult to clean p, and last for years in the sediment and marine environment. Major effect- Impairm ent of marine life.Plankton, esp. neuston at highest risk – exposed to water soluble components leaching from oil. In Mangroves – lenticels clogged with oil oxygen level in sediments drops – death. Discharge of cargo residues from bulk carriers can pollute ports, waterways and oceans. In many instances vessels intentionally discharge illegal wastes despite foreign and domestic regulation prohibiting such actions. It has been estimated that container ships lose over 10,000 containers at sea each year (usually during storms).Ships also create noise pollution that disturbs natural wildlife Ballast water taken up at sea and released in port is a major source of unwanted exotic marine life. The invasive freshwater zebra mussels, native to the Black, Caspian and Azov seas, were probably transported to the Great Lakes via ballast water from a transoceanic vessel Invasive species can take over once occupied areas, facilitate the spread of new diseases, introduce new gen etic material, alter underwater seascapes and Jeopardize the ability of native species to obtain food.