There are many threats to Loggerhead sea turtles, from both natural and man made. The Loggerhead sea turtle is classified as endangered by the IUCN (International Union for the Conservation of Nature and Natural Resources).
The sea turtles in Laganas Bay are severely threatened by development (both legal and illegal) of nesting beaches. The pressures of the tourist industry lead to considerable amounts of litter, noise, light pollution, traffic, coastal degradation and over development. Each year, sea turtle spotting boats and illegal fishing kill several sea turtles in the Bay.
In the evening noise from bars, low flying aircraft and the lights, frighten and disorientate nesting sea turtles and hatchlings. Failure by the state to somehow compensate local landowners affected by conservation legislation has resulted in strong opposition to the conservationists and sea turtle conservation in general.
Loggerheads face a large number of predators, especially early in their life. The eggs and hatchlings are small and have very little protection, and therefore often fall prey to crabs, birds, foxes, ants, rats, fish and humans. The few turtles that do make it to adulthood are less susceptible to predator attacks due to their large size, but they have been known to be injured by bigger marine animals like killer whales and sharks.
Loggerhead sea turtles are also susceptible to a variety of diseases and infections including pseudomonas, salmonella, fibropapillmatosis, a herpes that causes tumors and blindness, as well as trematode which destroys organ tissues.
As well as being a sea turtle nursery, Zakynthos is, of course, also a popular holiday destination. In the summer months, at the same time that the turtles return to nest, the island becomes a holiday location for thousands of tourists from all over the world. With unchecked tourist development of the land, nesting areas are under immense pressure from illegal buildings & beach furniture, pollution and traffic. Obstacles such as boats, fishermen, and beach furniture prevent the turtles from nesting. From 11.5km of nesting beach in Laganas Bay, only 5.5km remain in a good state to host nesting turtles.
Tourism is a critical and worsening situation in Zakynthos in terms of nesting beach destruction, this coupled with the fact that only 1 or 2 out of every 1000 hatchlings naturally survive to reach adulthood and reproduce, means that the species is teetering precariously on the edge. Yannis Vardakastanis, ESS’ founder, says that when he was a child growing up at Gerakas, he remembers the beaches black with hatchlings and females nesting during the daytime. 30 years on this is no longer seen, due to the degradation of nesting beaches, tourists on the beaches day and night, falling nest numbers and many hatchlings not even making it to the sea. Moreover each summer many adults are seriously injured or die as a direct result of tourism.
Although water sports have been banned in Laganas Bay, boating activity is unchecked. Private yachts come and go as they please with little regard for speed limits and buoys indicating the restricted Marine Park maritime zones. Turtle spotting boats are rife; many chase the turtles, some pull them out of the water to show tourists, and cause immense distress to these animals which are only trying to rest after their exhausting nesting process. Then there are the glass bottom boats which operate in such a way as to force the turtles to dive underneath in order for paying customers to see them.
Although fishing is banned in Laganas Bay over the summer months, laws are not enforced and as a result turtles are still being caught in nets, ingesting hooks and fishing lines and becoming ill and dying. They also swallow plastic bags which float in the water like jellyfish. These become twisted in the gut, the turtles are unable to eat, grow weak and starve to death.
However, the most horrific injuries occur when speed boats collide with turtles. Injures consist of deep cuts to the carapace (shell) and internal organs, from which turtles can die a slow and agonizing death. We have not included such graphic images to avoid any distress – however, unfortunately such injuries and deaths are becoming more and more frequent.
Fishing and trawling also kills many sea turtles that get entangled in nets and drown.
The increase in tourism since the 1970s has increased all kinds of pollution, from noise and light to greenhouse gas emission. Light pollution, caused by establishments staying open after dark and planes flying at night, is a big problem for sea turtle hatchlings. When they hatch, sea turtles are programmed to swim towards the brightest source of light, which is usually the reflection of the moon and stars in the water; this insures that they crawl out of their nest directly into the sea. However, nowadays the light coming from clubs and bars on the seafront can be brighter than the natural light of the moon, causing hatchlings to become confused and make their way inland. This can be fatal.
Each year 24,000 metric tons of plastic is dumped into the sea. Jellyfish are a big component of a sea turtles’ diet, and because they often mistake plastic bags for them, they can end up eating them. When ingested, plastic bags can choke or starve the sea turtle, and toxic compounds can accumulate in internal tissues causing thin egg shells, tissue damage or deviation from natural behaviour.
Due to the importance of Zakynthos as a reproduction area for the Loggerhead sea turtle, with around 80% of the Mediterranean population nesting here, the state has introduced protective measures since 1984. The purpose of the legislation is to control and regulate development as well as maintaining the quality of the nesting beaches. Tourism development is not prohibited behind nesting beaches, artificial light isn’t prohibited to affect nesting beaches, vehicle use is not allowed on the beaches and the number of visitors and sunbeds is to be limited in nesting season with strict curfews in place between 7pm-7am (19.00-7.00) to allow the sea turtles to nest.
In 1988, marine zones were established in Laganas bay. Speed limits are enforced, fishing is banned and speed boats are prohibited. In 1994 night flights were prohibited as the take off and landing of aircraft disturb nesting sea turtles.
In 2006 we successfully lobbied the Government and the National Marine Park of Zakynthos to ban tourists hacking away at the unique, mineral-rich clay cliffs found at Gerakas. It had become popular for visitors to carve out huge amounts of these natural deposits using them in self-administered ‘spa’ treatments. This practice was causing irreparable damage, speeding up decades of natural erosion and degradation to the cliffs, with huge rock falls that posed a serious risk of injury or death to tourists as well as damaging the sea turtle nesting beaches.
Sea turtle spotting boats are popular on the island and are required to remain 15 meters away from the animal, are only allowed to stay for 15 minutes, over crowding the animal is to be avoided, speed limit of 2 knots is enforced and no physical contact with the animal is allowed.
Unfortunately, all this legislation is poorly enforced. Illegal umbrellas, sunbeds and buildings continue to occupy nesting beaches. Sea turtle spotting boats don’t always follow the rules leaving sea turtles stressed, exhausted and often causing serious injuries that can result in the death of the animal. Several flights are arriving during the evening when it is dark. However large hotel development has been prevented on nesting beaches and Marathonissi islet and Gerakas Beach remains completely undeveloped.