Marine Pollution

I am writing to convince the UK Government that it is time to take action to protect the seas around us. The harm being done to our oceans is damaging in many ways – not least because with increasing speed, we are severely depleting the world’s stock of fish.

For four centuries the seas have been considered on inexhaustible resource from which people could take as much as they wanted. Now we have to face up to the fact that our oceans are not limitless – more and more people competing for less and less fish are which is making the existing crisis worse. Many marine ecosystems are at the point of collapse and will be destroyed unless we act quickly to protect them from the most serious threats.

Pollution from ships

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 up, and last for years in the sediment and marine environment.

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. Ships create noise pollution that disturbs natural wildlife, and water from ballast tanks can spread harmful algae and other invasive species.

Eutrophication

Eutrophication is an increase in chemical nutrients, typically compounds containing nitrogen or phosphorus, in an ecosystem. It can result in an increase in the ecosystem's primary productivity (excessive plant growth and decay), and further effects including lack of oxygen and severe reductions in water quality, fish, and other animal populations.

The biggest culprit are rivers that empty into the ocean, and with it the many chemicals used as fertilizers in agriculture as well as waste from livestock and humans. An excess of oxygen depleting chemicals in the water can lead to hypoxia and the creation of ...

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Eutrophication

Acidification

The oceans are normally a natural carbon sink, absorbing carbon dioxide from the atmosphere. Because the levels of atmospheric carbon dioxide are increasing, the oceans are becoming more acidic. The potential consequences of ocean acidification are not fully understood, but there are concerns that structures made of calcium carbonate may become vulnerable to dissolution, affecting corals and the ability of shellfish to form shells.

A report from NOAA scientists published in the journal Science in May 2008 found that large amounts of relatively acidified water are upwelling to within four miles of the Pacific continental shelf area of North America. This area is a critical zone where most local marine life lives or is born. While the paper dealt only with areas from Vancouver to northern California, other continental shelf areas may be experiencing similar effects.

‘By catching’

Bycatch are species caught in a fishery while it is intended to catch another species or reproductively immature juveniles of the target species.

Example

Cetaceans, such as dolphins, porpoises, and whales, can be seriously affected by entanglement in fishing nets and lines, or direct capture by hooks or in trawl nets. Cetacean bycatch is increasing in intensity and frequency. In some fisheries, cetaceans are captured as bycatch but then retained because of their value as food or bait. In this fashion, cetaceans can become a target of fisheries.

One example of bycatch is dolphins caught in tuna nets. As dolphins are mammals and do not have gills they may drown while stuck in nets underwater. This bycatch issue has been one of the reasons of the growing ecolabelling industry, where fish producers mark their packagings with something like "Dolphin Friendly" to reassure buyers. However, "dolphin friendly" does not mean that dolphins were not killed in the production of a particular tin of tuna, but that the fleet which caught the tuna did not specifically target a feeding pod of dolphins, but relied on other methods to spot tuna schools.

Who’s under more threat?

The species of fish which are under most threat are the Atlantic Sharks. More than 25 per cent of sharks in the North-East Atlantic are at risk of extinction, a new study warns. Because sharks are long-lived and slow to mature they are prolific breeders which makes them even more vulnerable to over-exploitation. Because of their position at the top of the food chain they have a critical role in maintaining the balance of ocean ecosystem.

What is over fishing?

Overfishing can be defined in a number of ways. However, everything comes down to one simple point: Catching too much fish for the system to support leads to an overall degradation to the system. Overfishing is a non-sustainable use of the oceans.

What is causing overfishing?

Worldwide, fishing fleets are two to three times as large as needed to take present day catches of fish and other marine species and as what our oceans can sustainably support. On a global scale we have enough fishing capacity 4 to cover at least four Earth like planets.

On top of the overcapacity many fishing methods are unsustainable in their own way. These methods have a large impact on the basic functioning of our marine ecosystems. These unselective fishing practices and gear cause tremendous destruction on non target species. Bycatch / discards and bottom trawling destruction are two examples of this.

Solutions

Marine pollution is part of the problem of too much pollution by humans in general. There are only two ways to remedy this: either the human population is reduced, or the ecological footprint left behind by the average human is reduced. If we do not follow the second way, then the first way may be imposed upon us, as world ecosystems falter and cease to support us.

The second way is for us, individually, to consume and pollute less than we do currently. For this there must be social and political will, together with a shift in awareness, so more people respect their environment and are less disposed to abuse it.

Peer Reviews

Here's what a star student thought of this essay

skatealexia

16th of Aug 2012

Quality of writing

The tone is that of a letter and the way the candidate writes fits this well although they do not follow this up right until the end. Punctuation, grammar and spelling all done to a very high level with excellent formatting.

Level of analysis

The candidate includes a picture at the start which should be explained with a short notation or referred to at least once so we understand the purpose of it fully, although it does fit the topic well. The introduction is done well, and leads into the variety of ways in which we are polluting the ocean. The essay considers both environmental impacts on the wildlife, and economical impacts which is done to a very high level of detail. They consider a number of reasons for the damage to the sea, and also point out good viable solutions in a conclusion.

Response to question

A very well done essay which concentrates all available reasons for the polluting of the ocean and expands on them in good detail for this level. To improve the candidate could suggest other improvements, relate to each problem, such as with overfishing the creation of replenishable stocks of fish that can be grown in large tanks on land known as aquaculture.

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