What factors contribute to the pollution in the Mediterranean?

"Tourists, dumping of sewage, garbage, and industrial waste. Also, the narrow Straight of Gibraltar does not allow for adequate ocean currents."

The United Nations Environment Program has estimated that 650 million tons of sewage, 129,000 tons of mineral oil, 60,000 tons of mercury, 3,800 tons of lead and 36,000 tons of phosphates are dumped into the Mediterranean each year.

Meanwhile, 70% of the waste water dumped into the Mediterranean is untreated.

The sea is also a major oil transportation route and up to one million tons of crude oil are discharged annually from accidental spills, illegal bunkering, and tank cleaning practices, as well as inadequate harbor facilities.