The Mediterranean Sea is surrounded by 20 nations with more than 400 million people living in the surrounding regions. However, all the Mediterranean Sea animals are subjected to serious threats for several reasons. This includes overfishing, and a number of fish being killed as unintended bycatch, which also includes whales and dolphins. Additionally, human activity in the area is responsible for subjecting animals to collisions with vessels, habitat destruction, noise pollution, and pollution caused by plastics and chemicals.

The carnivorous loggerhead turtle is the Mediterranean's most common turtle. One of the largest of the Chelonia sea turtles, the reddish brown loggerhead carries more of the encrusting organisms, like barnacles, on its shell than other marine turtle. Highly migratory, the loggerhead turtles are known to have made some of the longest journeys of all the marine turtle species. Being migratory has made the turtles subject to accidental capture in the nets of the world's fisheries.

Several types of sharks and rays are found in the Mediterranean. This includes the shortfin mako shark (Isurus oxyrinchus), the probeagle shark (Lamna nasus), the giant devil ray (Mobula mobular) and the seabed-hugging Maltese ray, also known as the Maltese skate (Leucoraja melitensis). However, the great white shark (Carcharodon carcharias) is among the 30 species of sharks and rays at risk for extinction, according to the National Geographic website.

The Mediterranean monk seal (Monachus monachus) is one of the rarest animals on earth. The seal has a uniform brown body with a lower underside that is a yellowish-white. The name of the seal comes from the fact that its coloration resembles that of a monk's habit. Monk seals weigh up to 400 pounds and live between 20 to 30 years. Its diet consists of octopus, mollusks and fish. The monk seal is the most endangered of the fin foot species with probably fewer than 400 remaining on earth, according to the World Wildlife Federation.

About 20 different species of whales and dolphins are found in the Mediterranean with eight species being residents. This includes the sperm whale, orca, bottlenose dolphin and the common dolphin. The common dolphin, once the most abundant species of dolphin in the Mediterranean, is now classified as endangered, according to the Whales and Dolphins Conservation Society.

Marine fish found in the Mediterranean include commercial species like sea bass, (Dicentrarchus labrax), hake ((Merluccius merluccius), blue fin tuna (Thunnus thynnus) and dusky grouper (Epinephelus marginatus). However, the fish are all threatened with extinction, according to the International Union for Conservation of Nature website. There are more than 40 species of marine fish in the Mediterranean that can disappear in the next few years with 12 species of bony fish also threatened with extinction.

The poisonous pufferfish (Lagocephalus sceleratus) is one of more than 900 species of alien fish that in the last few decades have been found in the coastal regions of the eastern Mediterranean Sea. The invasion is changing the whole food chain, according to the Physorg website. The completion of the Suez Canal in 1869 created a corridor that allowed the spread of alien species into the Mediterranean. The impact of alien species is known as biological contamination.