Marine pollution due to growing of coastal population – Must be checked:
The health of the world’s oceans and marine life is degrading rapidly as a result of excess human activities. Furthermore, as the human population continues to grow and extend the range of its activities, as well as increase its demands for marine goods and services, the world’s oceans and coasts will be increasingly stressed. In fact, growing coastal populations and overuse of marine resources are the main source of the problem. The pollution - linked with rising coastal populations, availability of inadequate treatment infrastructure of sewage and other waste handling facilities - is putting at risk human health and wildlife as well as livelihoods from fisheries to tourism.
A. Marine pollution can be classified in various ways. It can be categorized by its essential elements (what it is) or where it comes from (the source). A combination of these two is often most useful because it helps us determine the likely impacts and where to focus our efforts to stop the polluting activities. The most serious pollution impacts on the marine environment result from:
(a) Sewage — Untreated or poorly treated waste waters from human settlements. Sewage in the marine environment is linked to several problems including human diseases, excessive sediments and nutrients in the water, and sometimes, toxic chemicals and marine debris.
(b) Persistent Pollutants— Industries, factories, and mines generate toxic chemicals and heavy metals such as polychlorinated biphenyls or PCBs, some pesticides, and lead that do not break down over time in the environment or in the food chain.
(c) Nutrients— Fertilizers used in agriculture, the nitrogen and phosphorous found in sewage, power plant emissions, and common household products promote excessive algal growth in coastal waters, destroying the delicate balance that keeps reefs and other coastal ecosystems alive. At times, the algae rapidly consume all the oxygen in the water of a particular area, leading to fish kills.
(d) Sediments— Runoff from construction sites, agriculture, and deforestation often send excessive amounts of sediments to coastal areas, smothering corals and degrading other marine habitats.
(e) Solid waste— Litter, especially plastics, makes coastal areas unattractive and harms wildlife. Trash originates from a wide variety of human activities, including poor trash disposal practices on land as well as from all types of boats, especially cruise ships.
(f) Hydrocarbons— Oil, gasoline, and other petroleum products spilled or dumped from offshore drilling platforms and tankers as well as from many businesses, industries, and boats are not only unsightly, but also damage coastal habitats and are deadly to marine wildlife.
(g) Physical alteration and destruction of habitats— Marine, coastal, and inland construction often destroy important habitats such as wetlands. Wetlands not only act as pollution filters, keeping pollutants from reaching marine waters, they are also important spawning and nursery grounds for fish. Their destruction thus worsens the problem of declining fish populations caused by over-fishing.
(h) Heat— Power plants and other industries in coastal areas harm the marine environment by artificially elevating the water temperature which makes these areas inhospitable for the species that have evolved there.
(i) Activities on land pollute the ocean - Pollution generated on land can reach the ocean directly, through the pipes we use to dump our waste. It can also reach the ocean indirectly, through surface water (street runoff into rivers and streams), groundwater, or the air. When we emit chemicals such as persistent organic pollutants, heavy metals such as lead, and nutrients such as nitrogen into the air, much of that ends up in the ocean through rainfall.
B. The oceans are a vast resource whose usefulness to the global society is continuing to be realized. Thus, it is in the best interest of humanity that they are exploited in a manner that is protective and sustainable, in order to preserve their health and guarantee their continuing viability.