According to the data compiled by the National Oceanic and Atmospheric Administration (NOAA), approximately 1.4 billion lbs of trash is dumped in the oceans every year. On an average, 8 million items of marine litter are disposed in oceans every single year; approximately 5 million of which are either thrown off board or lost during a storm. It is estimated that 70 percent of the total marine litter is deposited at the seabed; the remaining 30 percent either keeps floating in the ocean or is washed ashore (beach trash). Interestingly, pollution caused by marine transportation only accounts for 10 percent of the total ocean pollution -- and even that is down from 12 percent in 1990. As a part of the annual International Coastal Cleanup campaign, 598,000 volunteers collected over 9 million lbs of trash from various sites across the world in 2011. Marine debris include a wide range of items -- right from cigarette butts and plastic bottles to abandoned fishing nets and oil spilled by vessels plying in these oceans. Marine animals either ingest these debris by mistake or get entangled in them, and end up dying in most of the cases. Even shorebirds and other terrestrial species are directly or indirectly dependent on the marine biome, and therefore vulnerable to ocean pollution. Approximately 80 percent of the total ocean pollution is attributed to land-based activities, i.e., non-point sources, like untreated sewage, industrial waste, agricultural runoff, surface runoff, etc. Actual ocean-based activities, on the other hand, only account for about 20 percent of the same. We have literally reduced our oceans to dumping grounds, in which we dump everything that we don't need -- either intentionally, or unknowingly. The list of marine pollutants is quite lengthy, and includes sewage, debris, oil (liquid petroleum hydrocarbon, to be precise), toxic chemicals, and so on. Developing nations, in particular, are notorious for dumping sewage and industrial waste directly into the sea. Urban sewerage and industrial waste discharging pipelines add volumes of toxic chemicals to the water. Other than household and agricultural waste, even the oil used in vehicles makes it to the oceans either as a result of surface runoff or through other sources of water. There is no denying the fact that large vessels carrying crude oil are also responsible for marine pollution. Incidents of oil spill triggered by accidents often make it to the headlines, but processes, like loading/unloading, discharging, ballasting, tank cleaning, etc., which are also known to contribute to this "cause", usually go unnoticed. Other than ships and oil tankers, oil slicks also occur at offshore platforms, drilling rigs, etc. Oil spills are categorized into major spills (over 700 tons), medium-sized spills (7-700 tons), and small spills (less than 7 tons). In 2011, 1 major and 4 medium-sized oils spills were recorded from different parts of the world. The Deepwater Horizon oil spill of 2010 -- also called BP oil disaster -- was the largest offshore oil spill in the history. It lasted for nearly 3 months and spilled 4.9 million barrels of oil into the Gulf of Mexico. Ocean-based activities account for 20 percent of the overall pollution, and cruise ships have a major contribution in this 20 percent share. The waste generated on cruise ships is categorized into greywater (i.e., the wastewater from sinks, showers, laundry, etc.) and blackwater (i.e., the wastewater from medical facilities aboard, toilets, etc.) According to the Cruise Report Card prepared for the Friends of the Earth in 2009, Ross A. Klein estimates that a moderate-sized cruise ship on a week-long voyage with 2,200 passengers and 800 crew members aboard generates 210,000 gallons of human sewage. In the United States, the Act to Prevent Pollution from Ships prohibits the ships from dumping any kind of waste within a distance of 3 nautical miles from the coast. For certain types of waste, the distance is 12 nautical miles from the coast. Note: The instances of oil spills are less compared to that of garbage dumping by cruise liners, and hence these cruise liners are considered the most polluting of the lot. However, one needs to understand that a single major oil spill can lead to tons of oil being dumped in the water causing a lot more pollution than what a single cruise ship does. Widely known as garbage patches, these are the areas with unusually high concentration of marine debris -- microplastics in particular -- which form a thin layer over the surface of the ocean. The use of the term 'garbage patch' can be misleading, as it makes one picture a huge island of garbage (made of plastic trash, floating wreckages, and other marine debris) floating in the middle of the ocean. In contrast, these formations are made up of debris, which are too small to be seen by the naked eye. Such formations are found in various parts of the world; the Great Pacific Garbage Patch is one of the most prominent examples of the same. Marine species, i.e., the plants, coral reefs, fish, sea turtles, etc., are the ones, who are directly affected by ocean pollution. Seabirds, marine mammals and other terrestrial animals (like the polar bears), which depend on oceans for food, are the ones, who are indirectly affected by it. Introducing toxic chemicals in the ocean is as good as introducing them in the food chain; once introduced, these chemicals will eventually make their way to the top of the food chain, and even the apex predators won't be spared. Although it's difficult to study the population of fish, the study of global trends of seabirds and animals depending on fish for food shows that there is a drastic decline in their numbers. While overfishing is no doubt a major culprit, ocean water pollution and resultant problems -- like habitat loss -- also have a crucial role to play in the same. If the fish are affected, subsequently all the other members of the food chain will also be affected. Chemicals dumped in oceans in the tropics are transported to the polar areas by ocean currents, and invariably the polar species also become vulnerable to these chemicals. Not just these toxic chemicals, but a range of other ocean pollutants also threaten marine animals. Leatherback sea turtles, for instance, end up ingesting plastic bags mistaking them for jellyfish and eventually die due to intestinal blockage. Similarly, excess nutrients (nitrogen and phosphorus) in ocean water results in Harmful Algal Blooms (HABs,) which lead to the formation of dead zones in the ocean and affect the marine organisms. Depletion of marine resources is bound to result in shortage of food for humans, but the effects of ocean pollution are not restricted to food shortage alone. Incidentally, we also happen to be a part of the food chain, which we have been talking about here, and it won't be long before the chemicals introduced in this food chain make it to our dining table. The adverse effects of eating "toxic seafood" may range from food poisoning to something as serious as birth defects. Seafood is an important constituent of diet for people in coastal areas, and that invariably means almost half of the world's population will be vulnerable to ocean pollution indirectly. The effects of ocean pollution that we get to see today are just the tip of the iceberg, and many more ill effects of the same are bound to surface with time. To satiate our craving of development, we have failed to take a note of all the damage that we have been causing to the nature. That isn't quite surprising, as it's basic human nature - we don't realize the seriousness of the issue until and unless it knocks down our own door. It's high time we "dump" the traditional approach of dumping waste in the oceans. Let's accept the fact that this approach is based on the principle, 'solution to pollution is dilution', which in itself is faulty, and come up with some stringent measures to tackle this environmental issue.