Oil spills cause large scale damage, destruction and death to marine environments. The type of oil determines the type of damage. Crude oil is suffocating and toxic effect because it is like a heavy tar. Refined petroleum precuts such as gasoline are generally more toxic but evaporate quickly. Crude oil causes much damage to birds and mammals; it sticks to animalsâ€™ fur or feathers, causing hypothermia in birds and seal pups by reducing insulation and making them easy prey. Oil also causes birds and seal pups to lose weight due to lack of ability to feed, to lose ties with family groups due to lack of scent, and/or to drown altogether. Crude oil also causes damage to the digestive systems of wildlife when the oil is ingested. Refined petroleum causes damage not due to stickiness but due to toxicity. Animals become poisoned when they ingest refined petroleum products, and the poisoning travels up the food chain. Respiratory, immune and adrenal systems are also damaged. Blood and organs are damaged. Breeding is interrupted or halted, or offspring become poisoned and die.