There are many causes for oil in the ocean environment. Oil naturally seeps into the ocean but natural concentrations have been far exceeded. The transportation of oil from one place to another contributes the most to the production of oil in the oceans. Crude oil from transport b is released into the ocean during the cleaning of the holds, which constitute the lowest compartment of ships, and the transfer of oil from one tank to another at sea. "Disasters such as Shipwrecks, tanker accidents and offshore oil rig fires continue to exacerbate this problem, as do the disposal of urban waste into the oceans, the dumping of waste oil from passing ships, commercial entertainment coastal and offshore industrial activities and nuclear waste dumps” (“Marine Water Quality”). The oil industry is another major polluter. Oil ports and refineries are located along the coast for shipping purposes. Coastal areas suffer considerable damage from spills. “Large numbers of seabirds are killed each year, their oil-covered plumage making flight impossible and exposing them to hypothermia. The oil-soaked fur of marine mammals loses its water repellency, also leading to death from hypothermia. Ingestion of oil by fish, birds and mammals can also cause death” (“Marine Pollution”). Another source of oil pollution comes from city streets. Oil runoff from streets and city sewers enters waterways and the ocean. Oil has a very long-term ecological impact on the ocean and marine ecosystems. “The presence of oil in marine waters seriously degrades water quality by obstructing the feeding structure of animals, killing larvae, and blocking available sunlight for photosynthesis” (“Marine Water Quality "). Oil pollution has been a major problem for a very long time. "As early as 197p, oceanographic ecologists noted that they could rarely drag a net across the ocean surface without collecting some form of tar or tar.