The islet of Marathonisi in Laganas Bay, known as “Turtle Island” for its characteristic shape and because it is a vital breeding ground for sea turtles, is one of the lesser-known of the many attractions of the Ionian Sea.
The islet, near the larger island of Zakynthos, is located just off Keri Beach, in Laganas Bay. Marathonisi also includes two, even tinier, islets, which are together called Pontikonisia.
There are two main beaches on the islet of Marathonisi, one with pebbles, while the other has fine white sand.
This latter beach is included in Zakynthos Marine Park because endangered sea turtles use just this stretch of sand every year to dig a total of 1,300 different nests in which to lay their eggs.
National Marine Park of Zakynthos
The National Marine Park of Zakynthos, established in 1999, was the first national park created for the protection of sea turtles in the Mediterranean. It is part of the Natura 2000 ecological network.
The loggerhead is a species of oceanic turtle which lives in various locales around the world. They can be found in the Atlantic, Indian, and Pacific Oceans, as well as in the Mediterranean sea.
Unfortunately, despite being prevalent in many of the world’s seas, the loggerhead has a low reproductive rate; females lay an average of four groups of eggs at one time and then produce no eggs at all for a span of two to three years.
The loggerhead is the world’s largest hard-shelled turtle, and has a lifespan of 47–67 years.
It is also the world’s second largest extant turtle after the leatherback. Adults can weigh from 80 to 200 kg (180 to 440 pounds), but usually have an average weight of about 135 kg (298 pounds). The largest loggerhead specimen ever caught weighed in at an astounding 545 kg (1,202 pounds).
The biggest threat these gentle giants face is loss of nesting habitat due to coastal development, predation of nests, and human disturbances, such as housing developments and coastal lighting.
Even the seemingly innocuous lights along beachfront homes and other buildings can wreak havoc with loggerhead survival, since they may cause disorientation during the emergence of hatchlings as they race toward the sea.
Female loggerheads swim through the pristine waters of Marathonisi each and every summer to lay their eggs on its sandy beaches.
For this reason, if anyone ever decides to visit this special, protected islet, they should take extra precaution to not disturb the environment in any way during their trip, especially the sandy beach which is critical to the survival of the loggerhead.
All marine parks have limited recreational use, and are often set aside to preserve a specific habitat, to ensure that their fragile ecosystem will be protected for the animals which live, breed, or lay eggs there. This is no different in Zakynthos Marine Park in the waters around Marathonisi — but there is yet another endangered species which is also protected there.
The second species is the “Monk seal,” or Monachus Monachus, which annually makes its way to the islet to reproduce and rest. Despite their large size, these seals are believed to be the most endangered carnivorous aquatic species in the entire world.
As of 2015, it is estimated that fewer than 700 Monachus Monachus seals survive in three or four isolated sub-populations in the Mediterranean. These include areas in the Aegean Sea, an archipelago off Madeira, Portugal, and Cabo Blanco Peninsula, on the Atlantic coast of Africa.
This species of seal grows from approximately 80 centimeters (2.6 feet) long at birth up to an average of 2.4 meters (7.9 feet) as adults.
Female monk seals weigh 300 kilograms (660 pounds), while the males weigh an average of 320 kilograms (710 pounds).
A white strip of fur is found on their bellies which differs in shape and color between the two sexes. Females have a more rectangular shape, while males have a butterfly shape.
The seals’ habitat has changed over the years due to human encroachment upon their territory. In ancient times, and even up until the twentieth century, Mediterranean monk seals had been known to gather, seek refuge, and even give birth right on beaches.
However, in more recent years, monk seals have been driven out of their their former habitat and currently are known to gather together only in caves along the seashore.
It has been confirmed by scientists that this is a recent adaptation, most likely due to increased human population, industry, and tourism activities, which have disturbed the seals’ habits and destroyed some of their natural habitat.
TIP: If you ever decide to visit Marathonisi, keep in mind that it is a completely natural, undeveloped island which does not have any tourist amenities whatsoever.
For this reason, it is advised that visitors take enough supplies with them for their trips and that they leave no trace of their visit, nor cause any distress to the endangered marine animals there.