Types of Ocean Pollution
From what has gone before, it will come as no surprise that the ocean plays unwilling host to a vast array of types of ocean pollution. The most obvious types of pollution are the ones that make the news such as the recent oil spill disaster in the Gulf of Mexico which caused loss of life and widespread damage to the environment involving hefty clean-up bills. Rig accidents and tanker sinkings may make the news, but rare, minor spillages such as oil tankers purging their tanks, may also harm the local environment. Following the Gulf War, the UNEP set up a program to monitor the marine environment in the region (ROPME) for petroleum hydrocarbon and heavy metal pollution. It involved an active ocean pollution monitoring campaign. This was necessary because of the deliberate pollution of the environment by burning oil fields carried out by Iraq.
Maritime wrecks can pose an ocean pollution hazard because of harmful products used in the vessel (fuel, for instance), but also because of the cargoes that they may be carrying. As the hulks decay, they can also cause severe (local) heavy metal pollution.
Deliberate, illegal dumping in the sea probably represents the most significant pollution hazard since it is unregulated and often times believed that the most dangerous waste pays the best premium. Certain types of dumping do remain legal (for instance, of dredged material) and these are regulated under the London Dumping Convention.
Until 1982, the dumping of certain radioactive waste at specific sites by civilian nuclear authorities was permitted. The world’s military powers have also dumped reactor cores in certain seas and of course, some nuclear powered vessels have been lost in accidents. This practice made sense since dump sites were well away from civilization and fishing activities, sources were supposedly sealed and seawater makes a good shield for any radioactivity that may have seeped out.
Much concern has been expressed about the fate of polythene bags that escape into the marine environment. Apart from the physical hazard that the plastics may cause, the breakdown products of the hydrocarbons that produce them may also be harmful.
This article just scratches the surface of this topic, but for the sake of future generations and the marine ecosystem, the solution to pollution better not be dilution!