Oil spills have severe impacts on wildlife and the environment depending on :
(1) the type of oil spilled,
(2) the location of the spill,
(3) the species of wildlife in the area,
(4) timing of breeding cycles and seasonal migrations,
(5) as well the weather during the oil spill
Lake Edward, at the center of Virunga National Park, is a semi-closed water system. It contains of many species of fish. “Fishing is an important activity among local residents. Fauna living on the banks of the lake – including chimpanzees, elephants, crocodiles, and lions – are protected by the park. The area is also home to many perennial and migratory bird species.”
“Lake Edward used to be the most important hippo population in the world. In 1959 there were over 27,000 hippos. When Congo Rangers completed an aerial survey of the hippos last December, there found only 315. This is a catastrophic decline that led to hippos being listed on the IUCN Red list as an endangered species.”
How will oil spills affect Virunga wildlife and Lake Edward’s ecosystem?
Oil and water quality 
- Declining or low water quality impacts the ecological, economical and social value of the lake
- Toxins in oil and other chemical compounds have direct and long-term negative impacts on water quality
- Productive capacity of the lake system reduced or destroyed, limiting the biological resources of the lake.
- Pollution of drink water sources
- Reduce recreational activity and nearby land values
Oil and fish
- Oil is toxic to animals including fish.
- Fish are particularly susceptible to absorbing these compounds because they naturally have a high oil or fat content, and the compounds dissolve easily into their tissues through contact with the skin and gills.
- Oil effects on fish larvae range from mortality to abnormal development and deformities. Since the effects of oil spills last for years, they have a devastating effect on local fish populations.
- Damage to coastal habitats affects the breeding areas of many fish, interfering with their reproduction cycles.
Oil and terrestrial wildlife 
- Poisoning of wildlife higher up the food chain occurs when they eat other organisms that have taken oil into their tissues.
- Poisoning of wildlife also occurs when drinking contaminated water (eg. lions, water buffalo’s…).
- Inflammation or infection and difficulty eating due to oil sticking to the sensory hairs around their mouths.
- Damage to the insides of animals and birds bodies, for example by causing ulcers or bleeding in their stomachs if they ingest the oil by accident.
- Damage to the airways and lungs of mammals, congestion, pneumonia, emphysema and even death by breathing in droplets of oil, or oil fumes or gas.
Oil and Hippos 
- Oil damages the hippos’ eyes, which can cause ulcers, conjunctivitis and blindness, making it difficult for them to find food, and sometimes causing starvation.
- Oil induces irritation or ulceration of skin, mouth or nasal cavities.
- Oil results in damage to and suppression of a mammal’s immune system, sometimes causing secondary bacterial or fungal infections.
- Young hippos are poisoned through the mother, the young can absorb toxic substances through its mothers milk.
Oil and birds 
- Oil interferes with breeding, making the animal too ill to breed, as well as with breeding behavior such as time spent on a nest, or by reducing the number of eggs laid.
- Oil damages red blood cells; causes organ damage and failure such as a bird liver.
- Damage to a bird’s adrenal tissue which interferes with a bird’s ability to maintain blood pressure, and concentration of fluid in its body.
- Oil leads to decreased thickness of egg shells.
- Behavioral stress.
Oil, environment and habitat 
- Oil causes loss of habitat and food sources as it washes into the lake shores and coastal wetlands.
- Hippopotamus and other wildlife could lose grazing habitat and oil pollution in the habitat where they reside will be a serious threat to their survival.
- Contamination of interconnected flood plains and streams.
Even a minor oil spill will have devastating consequences on the entire Lake Edward ecosystem, part of Virunga National Park. Livelihoods of the communities depending on the lake’s ecosystem resources and services will be irreversibly destroyed. Habitat will be lost leaving no chance for the survival of the last remaining hippos in Lake Edward.
 Source AMSA
 Source Wikipedia
 Source Wildlife Extra
 Source Lake Scientist
 Source: Read more: How Do Oil Spills Affect Fish? | eHow.com
 Based on the problems and effects of oil spill on wildlife presented in the article of the Australian Maritime Safety Authority