How oil spills affect the environment | Earth.Org – Past | Gift
Oil is an essential part of our lives; beyond the oil used for cooking, but black crude oil deep in the ground. Fuels and plastics are made from this oil, which is transported and exported around the world. However, poor management and maintenance often lead to oil spills. But how do oil spills affect the environment, marine life and ecosystems, and to what extent?
Crude oil, the liquid remains of ancient plants and animals, is a fossil fuel that is used to make a wide range of fuels and products. Oil resides underground or under the ocean floor in reservoirs, where oil droplets reside in “pores” or holes in the rock. After drilling and pumping crude oil, oil companies transport it by pipe, ship, truck or train to processing plants called refineries. There, the oil is refined so that it can be made into different petroleum products, including gasoline and other fuels, as well as products used in our daily lives such as plastics, soaps and paints. However, when oil is released into the ocean, accidentally or not, it creates monumental environmental damage. Every year, 706 million gallons of waste oil enter the ocean with devastating consequences.
Causes of Oil Spills
Oil spills in the oceans can occur naturally, which can have huge impacts on nature itself. In fact, up to half of the oil that enters the coastal environment comes from natural seeps of oil and natural gas. This oil regularly seeps from the bottom of the oceans due to the erosion of sedimentary rocks and enters the marine environment. There are also other natural factors such as climatic conditions and disturbances at play, where oil seepage is often found in places where oil and gas extraction activities also occur – although studies do not be unable to determine whether human activities have exacerbated natural factors. Fortunately, despite large spills, the soil infiltrates at a very low rate and is more natural and less toxic than processed refined oil, allowing marine life to adapt to it.
But the most damaging oil spills that occur come from anthropogenic causes, which are leaks and spills from petroleum refining, handling and transportation, storage and use of crude oil and one of its distilled products. Among them, most are mainly accidental spills, which can occur under various circumstances. For example, when stored improperly without proper maintenance, oil can leak from the containers. But for large and sudden spills, they usually come from accidents in offshore boreholes and ruptures from large transport vessels such as tankers.
There are also intentional discharges of oil such as tanker captains cleaning their tankers and leaching oily residues directly into the ocean. This may seem insignificant; however, due to the large number of ships and the large size of tankers, the amount of oil discharged could accumulate to a substantial number.
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Major oil spills in the ocean
Oil spills occurred frequently in the past, with an average of 78.8 spills per year in the 1970s. One of the most disastrous spills at the time was the Amoco Cadiz oil spill, when a very large crude carrier stored with nearly 69 million gallons of light crude oil, ran aground on shallow rocks off the coast of Brittany, France, in 1978. The impact dug holes in the hulls and tanks of the containers, subsequently releasing oil from the ship. About 321 km of the French coast was polluted by the oil slick, which killed millions of invertebrates, such as molluscs and crustaceans, and around 20,000 birds, as well as contaminated oyster beds in the region.
With better control and management, the number of oil spills has dropped significantly, from an average of 78.8 starting in the 1970s to 6.2 spills per year in the 2010s. However, the few spills that have occurred in recent years still have major environmental consequences. The largest accidental oil spill in history occurred in the Gulf of Mexico on April 20, 2010, after natural gas surged through a cement well plug that had recently been installed to seal off a drilled well by the Deepwater Horizon oil rig. The accident killed 11 workers and injured 17 others. 206 million gallons of oil were spilled and approximately 2,100 km of the US Gulf Coast from Texas to Florida were covered in oil.
Effects of Oil Spills on Marine Life
So how do oil spills affect the environment? Depending on where and when a spill occurs, a few thousand animals and plants can be killed or injured. These oil spills are not only harmful to marine animals such as fish and shellfish, but also to other species such as seabirds, sea turtles and other mammals. Oil destroys the insulating ability of furry mammals like sea otters and the water-repellent abilities of a bird’s feathers, exposing them to harsh elements. Many birds and animals also swallow oil and are poisoned when they attempt to clean themselves or eat oiled prey.
Fish and shellfish can also digest the oil, which could lead to changes in reproduction, growth rates, or even death. Important species such as oysters, shrimp, mahi-mahi, grouper, swordfish and tuna could also suffer population declines or become too contaminated to be safely caught and eaten by their predators, including humans.
Fortunately, oil spills do not stay in the affected area indefinitely. Nature itself can help solve the problem; wind and waves will naturally disperse the oil over time, and parts of the oil reservoir will eventually evaporate. The natural microbes will also do their job to start breaking down the oil. But this is a slow and unreliable process that needs to be closely monitored.
There is not much we can do in the event of an oil spill, especially in the beginning. Experts and professionals do their best to pick up and absorb, as well as burn off the oils on the ocean surface. Others can volunteer to help clean up the beaches. However, these are just damage checks.
There have been a total of six major oil spills in 2021, and 2022 has already seen thousands of barrels of crude oil spill from a refinery off the Peruvian coast about 30km north of Lima – following the violent eruption of a volcano near Tonga. Although accidents, man-made or natural, can occur, oil transportation will always involve risk. The devastating effects of the environment and marine life therefore further strengthen the case against our dependence on oil.
Learn more about how oil spills affect the environment: Oil spill affecting dolphins 10 years later
Image courtesy of: Wikimedia Commons