On average, there are 450 million people living in the Mediterranean, and it is estimated that by 2025 this number will have risen to 520 million, of which 150 million will be concentrated along or close to the coastline. Moreover, the Mediterranean is a popular tourist destination attracting approximately one million visitors annually. In addition to this vast influx of visitors however, the Mediterranean and its coasts are hosts to unique ecosystems, plants and animals, and pollution is one of the major threats they face today.
While the environmental problems facing the Mediterranean Sea and its coasts have been apparent for many decades, it was only recently that the chronic reticence of governments and industrialists to admit to the problems and indicate their causes (dictated by their fear of slowing economic growth and social development) gradually vanished. The growing number of NGOs, the increasingly powerful media and finally the diffusion of the internet have made it practically impossible to continue to hide the reality of the Mediterranean being sacrificed for competitive development. With 150 million people concentrated in only 46,000 km of coastline, 110 million of them living in urban centres, roughly 200 million tourists per year, more than 200 petrochemical and energy installations, chemical industries and chlorine plants and more than 80 major rivers carrying heavy loads of pollutants from inland, the Mediterranean basin is now in an advanced state of deterioration.
Perhaps first among the environmental problems of the region is the inadequate treatment of municipal wastewaters. Today, a mere 60 per cent of the coastal cities are served by treatment plants which means that a load of about 3 billion m3 of untreated water enters the sea every year. Industrial pollutants impact the Mediterranean basin through air emissions, solid wastes and wastewater. Concerning industrial wastewater, it was calculated that 66 million m3 of untreated waters enter directly into the sea every year containing nutrients, phenols, mercury, lead, chromium, zinc and mineral oils. Rivers are also very important conveyors of wastewater with about 13 per cent of the total load of industrial wastewater being discharged into them.
Furthermore, the Mediterranean has the largest traffic density of tankers on the globe and therefore accidental spills of petroleum hydrocarbons are a constant danger. Aside from this threat however, routine discharges can account for large amounts of petroleum being regularly released into the sea. Although partially connected to the problems described above, agriculture merits separate consideration as it is believed to be the largest nonpoint source contributor of pollutants to the Mediterranean.
This presents the global picture, which makes it clear that urgent and focussed interventions are needed.
Marine litter presents a serious threat to the area’s ecosystems, especially if we consider that the waters of this beautiful enclosed sea are renewed only every about 100 years!
According to the United Nations Environment Programme (UNEP), “marine litter is defined as any persistent, manufactured or processed solid material discarded, disposed of or abandoned in the marine and coastal environment. Marine litter consists of items that have been made or used by people and deliberately discarded into the sea or rivers or on beaches; brought indirectly to the sea with rivers, sewage, storm water or winds; accidentally lost, including material lost at sea in bad weather (fishing gear, cargo); or deliberately left by people on beaches and shores.” (UNEP, 2009. Marine Litter: A Global Challenge. Nairobi: UNEP. 232 pp)
The European Commission expanded the above definition by including in the category of marine litter “semi-solid remains of for example mineral and vegetable oils, paraffin and chemicals that sometime litter sea and shores.” (MSFD Task Group 10 report, European Commission/JRC/Ifremer/ICES 2010).
Marine litter is a global issue that has an enormous environmental and economic impact, while also presenting a significant threat to human health and aesthetics. Litter and all sorts of rubbish are being dumped into the seas and oceans as an inexpensive method of disposal, even today. We come across cigarette butts, plastic and other kinds of litter even in the most remote corners of the earth, thousands of miles away from areas of human habitation. It is estimated that 80% of all marine litter originates from land-based sources while 20% of it is the result of human activities at sea.
The complex issue of marine litter has its roots in the inefficient management of solid waste, the lack of suitable infrastructure, the failure to adopt effective legislation, and the lack of control mechanisms and financial resources. Going hand in hand with this there is a significant lack of understanding when it comes to the consequences of our actions and attitudes.
Each year turtles, birds and other marine animals die unnecessarily after swallowing marine litter, especially plastic due to their shape and size. Specifically, sea turtles mistake the plastic bags that end up in the sea for their favorite delicacy, the jelly-fish. Plastics ingestion by sea turtles may cause them to suffocate, block their digestive tract, and make them feel full, though in reality they may be starving to death! Furthermore, air bubbles in plastics consumed can prevent turtles from diving for food.
Marine litter, including abandoned and derelict fishing gear, may either cause injuries to marine organisms or lead to their entanglement. This either prevents them from swimming or makes them more vulnerable to their predators. Litter on nesting beaches becomes a deadly trap to hatchlings. The tiny baby turtles are prevented from reaching the sea quickly, making them easy prey to their natural predators such as seabirds and crabs that lurk on the beach waiting for a tasty morsel. Moreover, if hatchlings are trapped on the beach until sunrise instead of making it straight to the sea, may become dehydrated in the heat and perish.
Over time, plastic breaks down into smaller particles also known as microplastics. All plastics contain several toxic substances acquired either during their production or during their time at sea. The microfibers released during the washing of synthetic clothes and the microplastics (aka microbeads) contained in personal care and cosmetics products (PCCPs), like scrubs and peeling creams, shower gels, toothpastes etc., pass through washing machine and sewage treatment plant filters, and end up in the marine environment. In many habitats throughout the world microplastics are more abundant than any other man-made material and can pollute not only water but also food and the air.
Microplastics are building up in the marine environment in significant quantities, and we still have only a limited understanding of the effect of this. Because of their small size, their ingestion by fish and other animals near the top of the food chain is highly probable. We can speculate as to the consequences for the health of the marine creatures that end up on our plates!