- Pets and Animals
The Great White Sharks of the Mediterranean Sea.
A Hidden Population of Great White Sharks?
The Great White Shark is an endangered, majestic and fearsome predatory fish which has managed to scar its form into the minds of many of us. It is not the monster of the deep, as previous generations had once believed. The Great White Shark is an apex predator, whose continued survival is vital to the well-being of a marine ecosystem.
A handful of fatal Shark attacks are recorded each year around the globe, yet their numbers are slender when compared to the number of deaths attributed to those who are killed by domestic pets. The mosquito is responsible for millions of human deaths each year, yet is nowhere near as feared as the dark eyed predator of the salty oceans.
North America and Australia see the bulk of Shark attacks or unexpected encounters. But the Mediterranean Sea also experiences a few encounters with these fearsome predators. In times long past, it was usually the Tuna fisherman who encountered the local Shark populations as they brought in their catch. But with the increased use of camera, mobile phones and social media. A greater level of evidence is continually recorded despite the dwindling numbers of these often misunderstood marine creatures.
An Apex Predator in Action.
Sharing the Environment with Sharks
It would surprise many a tourist, if they were to be told that the blue waters of the Mediterranean Sea actually hold close to fifty species belonging to the Shark family. Although the majority of these fish are relatively small and confine themselves to the deeper channels of the sea. It would surely shock and concern many who visit the sunny coastal hot spots, if they were to learn that the Mediterranean is also home to ocean going predatory fish such as the Tiger Shark and the "infamous" Great White Shark.
Their numbers are not as large as say Australia or South Africa, but despite official records chronicling aggressive interactions over the last century. Many tourists are unaware of the majestic creatures that share the warm water with swimmers and divers.
Many suspected encounters with Great White Sharks in the Mediterranean can often be attributed to mistaken identification. There are video's posted on You Tube that clearly mistake a Thresher Shark with a Great White. There are also Porbeagle Sharks which are a distant cousin to Great White Sharks, these sharks are well represented across the northern hemisphere, they are very similar but behave very differently. There are also Short and Long-fin Mako Sharks in the Mediterranean Sea, these fish which share many of the Great White Sharks distinctive characteristics but tend to keep themselves in deep and open water.
The Mediterranean Sea
The Mediterranean Sea is connected to the vast Atlantic Ocean and serves as a barrier between Africa, Europe and Asia. The Mediterranean Sea was once completely isolated from the Atlantic Ocean but nearly 6,000,000 years ago, the water levels flooded into the Mediterranean Basin and allowed the two bodies of salt water to become linked. It is believed that Great White Sharks first settled in the Mediterranean Sea around 450,000 years ago.
It is hypothesized that larger shark species swam into the Mediterranean and became stuck in the new sea due to firm water currents. Scientists have discovered that the Great White Sharks of the Mediterranean share a genetic ancestry with those that can be found around the coast of Australia. It would have been very easy for a group of pregnant females to follow the North African coast and become confused by strong magnetic fields. Once they entered the Mediterranean and birthed their pups, a new colony of Great White Sharks would have been established.
Great White Sharks share a trait with Salmon. All members of the Salmon family return to the waters that they were born in and Great White Sharks appear to follow exactly the same type of behaviour. This has allowed a population of visiting Great White Sharks to become resident in these waters.
The Mediterranean Sea Basin.
Recorded and Verified Locations of Great Whites in the Mediterranean Sea
- France. Saint-Tropez. (2012).
- Spain. Tosser de Mar (1992).
- Balearic Islands. Mallorca (1969).
- Italy. Along the Coast of Sardinia. (1972).
- Tunisia. Sousse. (2015).
- Greece. Samos. (2014).
- Cyprus. Famagusta. (2016).
There are also reports of Great White Sharks in Croatia, Montenegro, Israel, Egypt, Malta, Corsica and many other coastlines around the region.
The Habitat of the Great White Shark
The warm waters of the Mediterranean Sea offers a rich marine environment which offers a wide variety of prey fish. Sardines are abundant along much of the western coast of the Mediterranean. This fish is a staple foodstuff for juvenile Great White Sharks, the majority of reported sightings seem to congregate around Greece, Italy, Turkey and Croatia.
In the last hundred or so years, Croatia tops the list of areas where a shark attack is most likely to occur. The UK comes second on the list, but most of these instances are attributed to small bites from by-catches when unloading trawlers of their haul.
Great White Sharks also patrol the southern shores of the Mediterranean. Tunisia, which is a popular tourist destination, has many reports of large sharks in its waters. There are many fisherman who have encountered large sharks through their profession and a Great White weighing in excess of 1900 kg was caught there in recent years.
It is believed that the main birthing grounds for Great White Sharks are around the Ionian and Adriatic coast lines. The last two fatal Shark attacks in the Mediterranean Sea were in the 1970's and they were also in those two alleged nursery areas. There has been no confirmed reports of Great White Sharks in the Black Sea, this area may have a salinity that Great White Sharks are unable to tolerate.
Great White Shark at Rimini-Italy.
What do the Great White Sharks Feed Upon?
As there is not a large population of Great White Sharks in the Mediterranean Sea, there is not the usual need for marine mammals such as Whales and Seals to sustain the needs of fully mature adults. It is likely that adult Great Whites are able to leave the Mediterranean Sea and feed in the Atlantic Ocean where there is an abundance of their usual prey.
It is entirely likely that the Mediterranean Sea is used as a nursery and when female Great White Sharks give birth, their appetite is naturally suppressed to avoid eating either their own offspring or other juveniles. The suppression of appetite only extends to birthing females and there is evidence of cannibalistic behaviour by other Great White Sharks from across the globe.
The Mediterranean Sea has a wide variety of fish that would satisfy juvenile Great Whites. There are also many big game fish such as Swordfish and Tuna, which provide a good meal for any resident Shark population. There are also Seal colonies spread across the Mediterranean Sea, especially around the Greek Islands. The Seal is a favoured prey of the Great White Shark, especially as they are full of blubber and have enough calorific content to allow the fish to not worry about hunting its next meal for a few days.
What do you think?
Should you be scared swimming in the Mediterranean Sea?
Long Term Survival for These Great White Sharks
The population of Great Whites in the Mediterranean is small and like all sharks, the Great White faces very real dangers to its long term existence. Illegal hunting, fishing nets, pollution and a dwindling supply of its prey are severe threats to their future survival. It is believed that their may only be a few hundred Great White Sharks in the Mediterranean Sea and the more mature adults may not be resident for most of the year. Juvenile Great Whites are at risk from other predators and they exist upon a fish based diet.
Over fishing in the Mediterranean Sea has had a drastic impact on the younger generation of these apex predators. Experienced fisherman have noticed a decline in the numbers of fish caught over the years and many of the fish that the juvenile Great Whites feed upon are as critically endangered as the Sharks themselves.
The Great White Shark is offered protection by law by a number of countries that border the Mediterranean Sea. Israel, Egypt and European Union member states in the region ban the hunting of Great White Sharks in their territorial waters. International agreed treaties on the preservation of the Great White Sharks is implemented in the region yet enforcement over such a wide area is very difficult to police. Many countries have or are attempting to limit interference in areas know to be Shark birthing grounds. Yet tourism and divers, will continue to encroach upon these sensitive areas.
© 2018 Andrew Stewart