Approximately 70% of our planet is covered by water, and less than 1% of more than 350 million square kilometres of ocean surface corresponds to the Mediterranean Sea. However, about 700 species of marine fishes, cetaceans, crabs, sea turtles, molluscs and plants are developing within its waters, and some groups, like the sharks and rays, are more highly diversified within this semi-enclosed sea than globally.
Strange undersea life
The under-surface landscape is not a uniform universe. An amazing variety of underwater worlds can be found, including sandy stretches, forests of giant kelp, hydrothermal springs, canyons, abysses, and open-sea. Within this context, the oceans host thousands of species, from the tiniest bacteria to the biggest whales.
About one third of the species were assessed as Data Deficient, meaning that there is insufficient information to determine at which level of threat they are.
Reaching the limits
Over the centuries, humans thought that oceans were an unlimited resource, providing food and absorbing waste. However, during the last 50 years, dramatic decreases in fisheries have shown that human activities are having a significant impact.