Internal Effects of Oil Spills on Marine Organisms

The impact that exposed oil has on a marine environment is tremendous due to the external and internal damage that both directly and indirectly affects the marine organisms that inhabit these afflicted aquatic ecosystems when contact is made between the oil and the marine organisms. Because oil slicks coat the surface of the waters, marine organisms that remain close to the surface waters, whether for feeding or breathing (mammals), have the greatest potential of coming in contact with the toxic oil, and thus the greatest potential of coming to harm. Thus, the marine organisms that are at greatest risk include sea birds, marine mammals, cetaceans, sirenians, pinnipeds, sea turtles, and fish. Unfortunately, all these organisms are at risk to suffer from "poisoning" due to the consumption of the crude oil. (Effects of Maritime Oil Spills on Wildlife) Other direct internal effects on the wildlife include "the destruction of red blood cells" which damages the immune response, "pneumonia", "intestinal damage", "reduced reproduction ability", "hypothermia", "congested lungs" and "damaged airways", "inflammation and infection" caused by irritation of mucous membranes due to oil exposure, and "secondary organ dysfunction" caused by accidental consumption of oil. (Effects of Maritime Oil Spills on Wildlife) The indirect effects that oil exposure may have on these organisms can be just as harmful: "decreased body mass" caused by the disruption of their diet, making the animals a greater risk of being prey and unhealthy, "behavioral changes" due to the exposure of oil to an organism's habitat can cause great stress, "food searching instincts such as diving and swimming are inhibited", leading to to malnutrition due to the incapability of finding food, and indirect poisoning by consuming contaminated prey. (Effects of Maritime Oil Spills on Wildlife) Many oil-contaminated organisms die, and much less survive, due to these extremely hazardous oil spills.

Source:
http://www.amsa.gov.au/marine_environment_protection/national_plan/general_information/oiled_wildlife/Oil_Spill_Effects_on_Wildlife_and_Non-Avian_Marine_Life.asp