Marine Biodiversity and Climate Change: The Mediterranean Sea

You’ve probably heard the word “biodiversity” or the words “biological diversity” during a discussion about the environment or nature conservation. The simple definition of biodiversity is the variety of different forms of life in a specific ecosystem. Marine biodiversity, then, is the life present in the oceans and seas around the world. Because about 70 percent of Earth is covered with water, it’s not surprising that the well-being of this ecosystem is important for health of the entire planet. The Mediterranean Sea has been particularly hard-hit by environmental issues that threaten its biodiversity.

Climate Change

Not only have pollution and overfishing affected the overall well-being of fish and other aquatic animals, but climate change has emerged as a major threat to marine ecosystems. Marine animals and plants have experienced extensive changes in their distribution, abundance, and diversity. Some animals and plants have successfully adapted to temperature changes in the waters, but many have not; some animal populations have needed to migrate to survive, and in some cases, species have disappeared altogether. Atmospheric carbon dioxide has also led to ocean acidification, which affects the health of organisms living in the water. Climate change and the resulting decline in marine biodiversity has also had an impact on the supply of fish as a source of food for humans.

The Mediterranean Region and Sea

Climate change has had a particularly significant impact on the Mediterranean region. Temperatures in this area are increasing at a higher rate than the worldwide average, which is threatening both food and water supplies. Higher temperatures mean more extreme weather conditions, with some areas experiencing drought conditions while others flood due to torrential rainfall. The coastal areas around the Mediterranean Sea have experienced increased development, and this can also have an overall negative impact on marine life. Tourism is also popular around the Mediterranean Sea, including yacht and cruise ship traffic, which can sometimes be disruptive to marine life.

Scientists are tracking the rise in both the overall sea level and water temperature of the Mediterranean Sea. Another indication of negative environmental effects on the Mediterranean Sea is the acidification of the water, which has been detectable in the past few years. Overfishing and pollution in the Mediterranean Sea are also significant problems for both sea life and the humans who rely on fishing for food. Plans are underway to attempt to save the fish stocks in the Mediterranean.

Coral Reefs

Climate change is a huge threat to coral reefs as well as the plants and animals that depend on them. Higher water temperatures cause coral bleaching, which is when the coral expels the algae that live in their tissues; these algae provide the coral’s main food source. When this happens, the coral turns white. The coral isn’t dead, but it is severely stressed when bleaching happens. Carbon dioxide that is absorbed into the water from the atmosphere can also result in reduced calcification rates, slowing coral reef-building. Disrupted ocean circulation and storms are additional results of climate change that can negatively impact coral reefs. Millions of years ago, the Mediterranean Sea likely contained coral reefs, but it does not have any now, as far as we know. But it is the home of many different marine organisms that can be harmed by environmental problems.

Written by Katja Kukovic

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