External Effects of Oil Spills on Marine Organisms

Once oil has been exposed to marine environments, the oil spreads rapidly, coating the surface waters with the aid of wind and currents: "A single gallon of oil can create an oil slick up to a couple of acres in size!" (Effects of oil spills). Over time, when the oil and the water begin to mix, the oil begins to weather, creating a "mousse", which is a sticky, oily substance that attaches to "whatever it comes in contact with" (Effects of oil spills). This "mousse" is extremely harmful to marine organisms, having both internal and external effects. Many marine organisms are incapable of escaping such oil slicks, not knowing how to avoid them, and many fish are, actually, attracted to them because they "can resemble food" (Effects of oil spills). (Effects of oil spills) 


Following a marine oil spill, the oil in the marine habitats coats the bodies of marine organisms with a thick layer of oil. This oil only becomes stickier over time. Because oil and water do not mix immediately once an oil spill occurs and coats the surface of the water, marine mammals and birds are targets of the harmful effects of oil spills. Seals, dolphins, and other marine mammals "have been seen swimming and feeding in or near an oil spill" (Effects of Oil on Wildlife). The fish that are attracted and lured to the oil spills that resemble food are prey to the sea birds who dive through the oil slicks in an attempt capture their prey. (Effects of Oil on Wildlife) 


Once the sticky, weathered oil, usually crude or bunker oil fuels, has attached itself to the fur and feathers of the marine organisms, many harmful effects to the marine organisms are the results. Many sea birds are susceptible to hypothermia because the oil can reduce or destroy "the insulation and waterproofing properties of their feathers" (Effects of Oil on Wildlife). Similarly, hypothermia is also a threat to fur seal pups because the oil can also reduce or destroy the insulation of their woolly fur. In addition, sea birds are prone to sinking and drowning when they come in contact with oil because "oiled feathers weigh more, and their sticky feathers cannot trap enough air between them to keep them buoyant" (Effects of Oil on Wildlife). Also, it is a possibility that seal pups will drown because the oil cam stick their flippers to their bodies. Many marine mammals lose much body weight because "they can not feed due to contamination of their environment by oil" (Effects of Oil on Wildlife). These are just some of the harmful, and, sometimes, fatal, effects of oil spills on marine organisms. (Effects of Oil on Wildlife) 




Sources: 
Effects of oil spills: <http://www.greenlivingtips.com/blogs/164/Effects-of-oil-spills.html> 
Effects of Oil on Wildlife: <http://www.amsa.gov.au/marine_environment_protection/educational_resources_and_information/teachers/the_effects_of_oil_on_wildlife.asp>