The Mediterranean covers an area of 2.5 million square kilometers and is surrounded by 22 countries, which together share a 46,000 kilometer coastline and are home to some 480 million inhabitants on three continents - Africa, Asia and Europe.
But it is also a kind of large salt lake as it is a semi-closed sea, since it only has two small points of contact with the open ocean, the Suez Canal to the east and the Strait of Gibraltar to the west.
This implies that its waters need to be renewed between 80 and 150 years, according to the Mediterranean Action Plan (PMA), the Athens-based project of the United Nations Environment Program (UNEP).
In other words, a drop of polluted water remains circulating in the Mediterranean for a century, on average.
Add to this that one in three of its inhabitants, or more than 160 million people, are permanent residents in the urban centers along its coast. In addition, 180 million tourists visit its beaches every year, bringing the number of human beings concentrated there during the peak season to 340 million.
The consequence is that millions of people dump their solid and liquid, domestic and urban waste into the Mediterranean. The problem is all the more evident if one takes into account that until a few years ago, more than 40 percent of coastal urban centers lacked wastewater treatment facilities, and that 80 percent of these were dumped into the sea untreated , according to UNEP / PAM.
More than 20,000 tons of gasoline per year
Industrial activities are also a key source of pollution, mainly from the chemical, petrochemical and metallurgical sectors, as confirmed by the following examples:
- Some 60 refineries pour about 20,000 tons of oil into the sea per year.
- Chemicals used in agriculture generate runoff containing pesticides, nitrates and phosphates.
- Other sources of pollution are the industries of waste treatment and solvent generation, metal treatment, paper production, paints and plastics, dyeing, printing and tanneries.
But the Mediterranean Sea is also under pressure from its intense maritime activities. Almost 30 percent of all international maritime trade passes through its ports or its waters, as well as approximately 25 percent of the oil that the planet transports by sea.
Bear in mind that approximately 2,000 merchant ships of more than 100 tons are at sea at any given time, and that 200,000 cross the Mediterranean each year.
But this maritime traffic not only causes pollution, it is estimated that 50 percent of the goods transported by sea have some degree of danger.
Some chemicals are more dangerous than oil, although the quantities of these products transported by sea in the Mediterranean are equivalent to a fraction of the volume of crude oil loaded by tankers.
On the other hand, oil pollution from ship operations includes a variety of oil spills and oily mixtures that are generated on board.
PAM / UNEP has just launched its Assessment of Marine Debris in the Mediterranean, within the framework of the United Nations Environmental Assembly, held in May in Nairobi.
Marine litter has been confirmed as a critical problem in the Mediterranean, exacerbated by the limited hydrological exchanges of the basin with the oceans, as well as the pressure of its densely populated coasts, highly developed tourism, and the impacts of the 30-minute pass. percent of the world's maritime traffic, in addition to the additional input from rivers and densely urbanized areas.
Compared to the previous assessment, from 2008, this updated report provides data on plastic waste and waste that each country dumps into the Mediterranean and specifies the most important sources of garbage, changes in its composition and transport patterns, as well as a review comprehensive data on the four compartments of the marine environment - beaches, surface, seabed and ingested debris.
World Oceans Day
All of the above could be lost in the tide of information related to World Oceans Day, which was celebrated yesterday on Wednesday.
A UN report notes that the world's oceans - their temperature, chemistry, currents and biodiversity - drive the global systems that make the Earth habitable for humanity.
“Our rainwater, drinking water, weather, climate, coasts, much of our food, and even the oxygen in the air we breathe, all are ultimately provided and regulated by the sea. Throughout history, the oceans and seas have been vital conduits for trade and transportation, ”the report highlights.
On the occasion of World Oceans Day, the UN highlighted facts and figures:
- The oceans cover 75 percent of the earth's surface and contain 97 percent of the planet's water.
- More than 3 billion people depend on marine and coastal biodiversity for their livelihoods.
- The oceans contain about 200,000 identified species, but the actual number could be in the millions.
- The oceans absorb approximately 30 percent of the carbon dioxide produced by mankind, cushioning the impact of global warming.
- The oceans are the main source of protein for more than 2.6 billion people.
- Sea fishing directly or indirectly employs more than 200 million people.
Translated by Álvaro Queiruga