Despite the regulations and efforts to limit overfishing, most fish populations aren’t rebounding enough, because pollution is an additional problem. Human waste, garbage, poisonous byproducts of industry, and agricultural chemicals continually end up in the sea, making the waters unlivable. Oil spills, though accidental, pose a considerable threat to marine life. When supertankers (such as the Torrey Canyon in 1967 or the Exxon Valdez in 1989) crash, they dump hundreds of thousands of tons of oil into the water, which destroys ecosystems and can cause fish to develop abnormalities. The impact of spills at this scale is hard to measure because even after they have been cleaned up, damaging effects linger. Compared to the tanker spills, leaks from underwater oil drilling are even worse. When an oil rig in the Gulf of Mexico exploded in 2010, the well leaked approximately two million gallons of oil a day for three months—equivalent to a major tanker disaster every day. The Gulf of Mexico is an important breeding ground for fish, birds, and marine mammals, so the long-term impact of this disaster on the natural order is almost impossible to measure. With the more easily accessible oil supplies running out, unless we curb our use of oil and look to renewable sources, oil companies will turn more and more to the risky endeavor of drilling underwater to meet demand.