Oceanic Turtles on Gozo
The loggerhead sea turtle (Caretta caretta) is spotted laying her eggs on the beach in Gozo. These magnificent reptiles are distributed throughout the world and are members of our planet for over 200 million years.
The loggerhead sea turtle is the world’s largest hard-shelled turtle. It is the second-largest extant turtle after the Leatherback sea turtle in the world. The head and carapace (upper shell) range from a yellow-orange to a reddish-brown colour. The underside of the turtle or ‘the plastrom’ is typically a pale yellow colour. If you look closely, the carapace is divided up into large plates or scutes. Normally a loggerhead turtle has 11 to 12 pairs of smaller scutes surrounding the carapace, these form the outer rim of the upper shell. Five vertebral scutes run down the midline of the carapace, while five pairs of coastal scutes border them. At the base of the head, we find the nuchal scute. The plastron joins the carapace by three pairs of inframarginal scutes forming the bridge of the shell. A loggerhead turtles shell serves as external amour against predators, however, it is not able to retract its head or flippers into the shell.
Loggerhead turtles Gender;
Determining the gender of a loggerhead turtle is possible only in adults. Males have longer tails and claws and their plastrom is shorter than that of the female. It is thought that the shorter plastrom of the male is due to having to accommodate a larger tail. A males carapace is less domed, but wider than the female, while males typically have larger heads than a female turtle. Juveniles and subadults do not show gender externally. A dissection of a juvenile or subadult reptile is the only way to determine gender in these age categories.
Keeping the balance on land and in water;
Behind each eye, the loggerhead turtle has a gland by the name of Lachrymal glands. These glands allow the reptile to eliminate excess salt in which they obtain from ingesting seawater. The Lachrymal glands help keep the turtle’s osmotic balance in water by maintaining fluid balance and electrolyte content. On land the loggerhead turtle excretes excess salt through the same glands, giving you the impression that the turtle is weeping.
Indeed, they have numerous predators, especially in the younger stages of their lives. Eggs laid in the sandy beach and fledgelings are food for ghost crabs, flesh flies, gulls, rats and many more.
Once they hatch, the baby turtle must dash from their nest to the ocean, a perilous journey for many. Their prey, standing and waiting as they scuttle towards the open sea are seabirds, snakes, lizards and frigate birds. Once in the sea, the loggerhead juveniles face parrotfish, moray eels, portunid crabs and many others who are out to take them as food. Adult turtles, due to their size are rarely attacked. Seals, orcas and large sharks may be the only ones who will attempt an attack. Nesting females must defend off feral dogs, flesh flies and most of all the human being.
Female loggerhead turtles reproduce first between the ages of 17 and 33 years of age. The mating period of the winning male may last up to six weeks. Whilst the male mounts the female in an attempt to breed, his rivals will bite his flippers and tail often causing damage through to the bone. Female turtles usually suffer damage to the shoulders of there shells due to the curved structure of the male’s claws.
A nesting female on average will produce 3.9 egg clutches, then she will not produce any more for two to three years. Turtle courtship does not take place at the nesting ground, it takes place along migration routes or between feeding grounds. In the Northern Hemisphere, loggerhead turtles mate from late March to early June. The nesting season is short, between May and August in the Northern Hemisphere and between October and March in the Southern Hemisphere.
Disease and parasites;
Bacteria such as Salmonella and Pseudomonas attach loggerhead hatchlings and even eggs. Fungus such as Penicillium infects loggerhead sea turtle nests and cloacae. A herpes-type virus threatens loggerheads with external and internal tumours. These tumours disrupt normal life and may even cause blindness. Vital organs, heart, brain and other tissue can fall to infection of the Trematodes, this disease is extremely debilitating and leads to very poor quality of life.
Sadly, due to pollution, climate change and loss of sandy beaches to development they are now an endangered species. Plastic pollution is an ever-increasing danger to marine creatures around the island of Gozo. In many places workers and volunteers search the coastlines around the world for nests, helping to protect eggs against human poachers and predators.
A message to all; PLEASE take your litter home. Do not use disposable plastic and do not discard YOUR WASTE into the ocean!
Stay safe all and let’s hope the turtles all hatch on Gozo!