Marine Pollution
Marine pollution is a global concern. Marine pollution happens when chemicals, particles, industrial, agricultural and residential waste, noise, or the spread of invasive organisms filter into the oceans and other bodies of water. Most sources of marine pollution are land based and often come from agricultural runoff and windblown debris.
There are many different methods to categorize the entry of pollution into marine ecosystems. Direct discharge is when pollutants enter rivers and the sea directly from urban sewerage and industrial waste discharges, sometimes in the form of hazardous and toxic wastes. (Wikipedia) Mining pollutants end up in rivers flowing to the sea via the soil. according to the United States Environmental Protection Agency” style=”color: blue; text-decoration: underline; text-underline: single” href=”http://en.wikipedia.org/wiki/United_States_Environmental_Protection_Agency”>United States Environmental Protection Agency, mining has contaminated portions of the headwaters of over 40% of watersheds in the western continental US.[3] Much of this pollution finishes up in the sea. (Wikipedia)
Land runoffs from farms as well as construction sites of roads, buildings, ports, channels and harbors can carry soil and particles containing carbon, nitrogen, phosphorous and various minerals. These nutrient-rich water causes algae and phytoplankton to grow. The negative effect is that they cause hypoxic conditions.
Ship pollution contributes to marine pollution in a multitude of ways. Oil spills kills off marine life and are very difficult and expensive to clean up. Discharge of cargo residues from bulk carriers pollutes the marine environment. It has been estimated that Container ship” style=”color: blue; text-decoration: underline; text-underline: single” href=”http://en.wikipedia.org/wiki/Container_ship”>container ships lose over 10,000 containers at sea each year (usually during storms).[6] Ships also create noise pollution that disturbs natural wildlife, and water from ballast tanks can spread harmful algae and other invasive species. (Wikipedia)
Atmospheric pollution occurs when windblown dust and debris (i.e. plastic bags) are blown to the water from landfills and other areas. The USGS links dust events to a decline in the health of coral reefs across the Caribbean and Florida, primarily since the 1970s. (Wikipedia) Dust is a component of atmospheric pollution.
Deep Sea Mining raises many questions about environmental damages to the surrounding areas. It is a moderately new mineral retrieval process which takes place on the ocean floor. Removing parts of the sea floor disturbs the habitats of organisms which inhabit the area and may cause permanent disturbances. Other concerns of deep sea mining include leakage, spills and corrosion would change the chemical area of the mining area. Sediment plumes are another major concern as the plumes could spread over large areas of the oceans and would contribute to light penetration and zooplankton which would affect the food chain of the region.
Acidification is turning our oceans more acidic. Normally oceans absorb carbon dioxide from the atmosphere. But due to the increasing levels of carbon dioxide our oceans are turning more acidic. Structures made up of calcium carbonate such as corals and shellfish will be affected. Collection of methane clathrate under the sediments of the ocean floors increases the ocean temperatures.
Eutrophication is an increase in chemical nutrients in an ecosystem. This can result in an increase in the ecosystems primary productivity and further effects including lack of oxygen and severe reductions in water quality, fish and other animal populations. (Wikipedia) River runoffs containing waste products are the biggest culprits.
Plastic and Marine Debris are found floating on our oceans. The majority of the debris is mainly discarded human rubbish. Plastic bags, six pack rings and other plastic wastes are dangerous to aquatic life. Fishing nets that have been left or lost at the ocean can entangle fish, dolphins, sea turtles, and other ocean creatures causing suffocation and ingestion of plastic products.
Toxins are another marine pollutant which is extremely harmful as they do not disintegrate rapidly. Examples of persistent toxins are PCBs, DDT, pesticides, furans, dioxins,phenols and radioactive waste. Heavy metals are metallic chemical elements that have a relatively high density and are toxic or poisonous at low concentrations. Examples are mercury, lead, nickel,arsenic, and cadmium. Such toxins can accumulate in the tissues of many species of aquatic life in a process called bioaccumulation. They are also known to accumulate in benthic environments, such as estuaries and bay muds: a geological record of human activities of the last century. (Wikipedia)
Noise pollution is usually from passing ships, oil exploration seismic surveys, and naval active sonar. Marine animals usually move around by acoustic information. According to the oceanographer Sylvia Earle, “Undersea noise pollution is like the death of a thousand cuts. Each sound in itself may not be a matter of critical concern, but taken all together, the noise from shipping, seismic surveys, and military activity is creating a totally different environment than existed even 50 years ago. That high level of noise is bound to have a hard, sweeping impact on life in the sea.” (Wikipedia)
control of marine pollution and integrated management of coastal development will play an essential role in building resilience and enhancing the ability and capacity of coral reefs to recover from severe events (Bellwood et al. 2004). While reducing pollution may not prevent corals from bleaching, it will help to ensure that the environment remains suitable for recolonization and rebuilding of reefs that have suffered mortality. Furthermore, it may enable reefs to become rapidly recolonized by soft and leather corals, thus reducing their likelihood of destruction by waves and storms. Such sites may become highly valuable for supplying new coral larvae recruitment to sites destroyed by bleaching. Nearly 80% of the marine pollution comes from coastal land based sources (UNEP, 2006). Hence, it is critical that (a) an ecologically representative system of effectively managed MPAs is implemented, and (b) that marine protected areas incorporate the coastal zone; and (c) that development and management of activities in the coastal zone elsewhere are undertaken in a responsible manner and in accordance with the principles of integrated coastal zone management. (UNEP)
References:
Marine Pollution. Wikipedia. Retrieved 10 May, 2011 from http://en.wikipedia.org/wiki/Marine_pollution
UNEP Rapid Response Assessments. Resilience and recovery of Coral Reefs and Coastal Habitats. Retrieved 10 May, 2011 from http://www.grida.no/publications/rr/our-precious-coasts/page/1293.aspx
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