Every year, gallons of oil enters the ocean from sources such as large spills, routine maintenance, surface run-off and offshore drilling[1]. The largest amount to enter the ocean is caused by surface run-off; around 363 million gallons of oil every year enters the sea through run-off from land, industrial drainage and waste disposal – mostly from the improper disposal of motor oil.
Offshore drilling and tanker spills contribute to less than 8% of oil pollution in the ocean, it is the routine maintenance of ships that plays a large part in effecting the ocean of up to 20%. The rest of the pollution comes from processes such as natural seeps from the seafloor.
Figure 1 Tanker ship releasing oil into the ocean[2].
As oil enters the ocean, it floats on the surface and often heads towards land where it affects sea and shore life such as sea birds and seals[3]. Oil slicks spread further in warmer temperatures, and wave action can cause the oil to form into droplets which sink and form a secondary slick. Through the smothering of the sea bed and shore, hypoxia and anoxia take place which poison and kill sea life.
Figure 2 Sea bird covered in oil from the sea[4].
Animals affected by the oil suffer from deterioration of their reproductive organs, hormones and thermal insulation which can lead to hypothermia, also having an effect on heart and respiration rates[5]. They ingest the oil during the cleaning of their fur or feathers and poison themselves in the process.
Coral reefs are extremely sensitive to oil exposure; it damages the habitat of thousands of species and they take a long period of time to regenerate[3]. The oil slick interferes with the photosynthesis of algae that live within the tissues of the corals, as it stops the sunlight from reaching the reef and cannot feed. Depending on the habitat, it can take from a few months to up to 20 years for a habitat to be restored to its natural state, affecting the homes of many species.
By Kerri Jackson
[1]Water Encyclopedia (2016) Oil spills: impact on the ocean. Available at: http://www.waterencyclopedia.com/Oc-Po/Oil-Spills-Impact-on-the-Ocean.html (Accessed: 9 March 2016).
[2] World Maritime News (2016) Tanker spills diesel fuel off Quebec. Available at: http://worldmaritimenews.com/archives/173646/tanker-spills-diesel-fuel-off-quebec/ (Accessed: 9 March 2016).
[3]World Ocean Review (2016) Pollution. Available at: http://worldoceanreview.com/en/wor-1/pollution/oil/2/ (Accessed: 9 March 2016).
[4]Vickers, T. (2015) When self-help is no help. Available at: http://bibleandculture.org/blog-1/2015/7/16/no-simple-fix-for-sin (Accessed: 9 March 2016).
[5]NOAA (2014) How does oil impact marine life? Available at: http://oceanservice.noaa.gov/facts/oilimpacts.html (Accessed: 9 March 2016).
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