Dear student
Oil spill is the release of the petroleum(hydrocarbons) in the water bodies. Yes, oil spills effect the aquatic animals .When oil releases into water, a layer of oil gets deposited and This layer does not allow air to pass through, due to which the aquatic animals do not receive the oxygen intake , resulting in death of the aquatic animals.
This contamination can be reduced by bioremediation (treatment with microorganisms) or by burning the oil.
Regards