Overview
The Mediterranean Sea is the world’s largest inland sea. It is located between Europe and Africa and is bordered by the Ionian, Aegean and Adriatic Seas. It covers an area of approximately 2.5 million square kilometers and has a depth of an average 4-5,000 meters. The sea’s topography is dominated by mosaic of platform and coastal ridges, continental islands and mountain islands. The prevailing currents and winds in the Mediterranean Sea are generally seasonally variable, characterized by an eastward flow of warm surface water. As a result, the Mediterranean Sea is quite salty and has some of the highest concentrations of dissolved salts at depths of up to 3,000 meters.
Temperature
The Mediterranean Sea has a complex climate and its temperature is highly variable. The highest temperature is usually observed in summer, where temperatures can reach 33-35 degrees centigrade near the coasts and up to 20 degrees in the Mediterranean. During winter, the Mediterranean displays quite a more moderate climate with temperatures ranging from low to 12-13 degrees Centigrade, while the northern and eastern parts are often colder. Of course, temperature also depends on the sea depth, as the deep waters of the Mediterranean remain at around 4 degrees Celsius all year round.
Salinity
The Mediterranean Sea is characterized by a very high salinity level, usually ranging from 38-40 parts per thousand (ppt). This is due to the relative constant inflow of salt from the Atlantic Ocean, combined with the fact that the Mediterranean Sea is an almost-closed body of water. Additionally, the presence of evaporation processes, river and stream inflow, and groundwater discharge contribute to the high saline levels in the Mediterranean Sea. Furthermore, the topography of the sea contributes to the salinity as well, since most of the Mediterranean is an enclosed basin with submerged ridges and lower shorelines that impede the circulation of the waters.
Marine Ecosystem
The Mediterranean is rich in biodiversity and boasts many unique marine species. The high salinity levels contribute to the biodiversity of the Mediterranean sea by creating a varied landscape of coastal and offshore ecosystems, including deep sea deposits, high salinity and low salinity areas, coastal lagoons, mudflats and seagrass beds. These ecosystems are home to a variety of microbial life, as well as plant and animal species, including the world’s largest living organism living in the waters of the Mediterranean sea—the giant manta ray.
Water Quality
The Mediterranean Sea is characterized by a low phosphate and nitrate level, which is an indication of the high water quality. In addition to its high salinity, the Mediterranean is also known for its very low nutrient load, due to its almost closed nature. This low nutrient load acts to maintain the balance of the natural ecosystem, by preventing the overgrowth of certain species of marine organisms. In addition, the Mediterranean is quite clear due to its relatively low nutrient concentrations.
Impact of Human Activity
Human activities have caused a significant decline in the quality of the Mediterranean Sea, by introducing contaminants and pollutants to the water. These contaminants include heavy metals, persistent organic pollutants, and algae-treatment products, as well as wastewater that is discharged into the sea. These pollutants threaten the health of the marine ecosystem and the biodiversity of the Mediterranean sea.
Conservation Policy
In recent years, European Union (EU) member countries have developed policies and laws to protect and conserve the Mediterranean Sea. This includes the establishment of the Mediterranean Marine Protected Areas Network (MEDPA), which was adopted in 1992 with the objective of maintaining the marine habitat and biodiversity of the Mediterranean. This network consists of Natura 2000 sites, which are designated as important marine habitat areas. In addition, the EU is encouraging countries to adopt more sustainable fishing practices and has implemented regional limits on the catch and sale of certain species in the Mediterranean, to protect them from overfishing.
Tourism
The Mediterranean offers a variety of tourism opportunities, including beach resorts and cruises. The Mediterranean Sea is an attractive destination for tourists, due to its warmth, clear waters, and abundance of marine species. It is also known for its historic sites and ancient ruins. The tourism sector has made an impact on certain areas of the Mediterranean, but it has also provided economic and social benefits to the coastal communities.
Noise Pollution
The Mediterranean Sea is subject to noise pollution from commercial vessels and naval ships, as well as from recreational activities such as fishing boats and pleasure craft. In certain areas, the noise levels can reach levels that are highly disruptive to the marine ecosystem. Responsible boating practices and noise reduction strategies are important measures to ensure that the Mediterranean remains a tranquil oasis for its many species.
Aquaculture
Aquaculture is an increasingly important industry in the Mediterranean Sea. It involves the farming of aquatic species, and as of 2011, aquaculture in the Mediterranean was estimated to provide over 500,000 tonnes of fish and shellfish each year. Aquaculture can provide local communities with sources of employment and revenue, but unsustainable and intensive farming practices can have damaging impacts on the marine ecosystem.
Industrial Fishing
Industrial fishing is another major activity taking place in the Mediterranean Sea, which has caused a decline in the abundance of certain fish species. This has led to overfishing, as a result of the use of unsustainable fishing practices, as well as illegal fishing activities. As a result, the EU has taken action to encourage countries to implement sustainable fishing practices. In some cases, this has included the creation of protected areas and restrictions on permitted fishing activities.
