British Sign Language Glossaries of Curriculum Terms

BSL Marine Glossary - Loggerhead Turtle - definition

Translation:

The Loggerhead Turtle is one of seven species of sea turtles and is the second largest in the world. It gets its name from its large head and powerful jaw. The shell on its back, called a ‘carapace’, is made of strong, hard plates that are reddish-brown in colour. Loggerhead Turtles typically grow to 120cm in length. The front flippers provide swimming power, while their rear flippers give direction and stability. They typically weigh between 135 - 140kg, though some exceptional specimens have reached an astonishing 450kg. Loggerhead Turtles are a ‘Keystone Species’, meaning other creatures depend on them - for example, some animals consume their faeces as a source of calcium. Loggerheads are also migratory, travelling vast distances across the oceans by following the circular currents of the North Atlantic and North Pacific Gyres. When ready to reproduce, they return to the exact beach when they themselves were born, navigating by sensing the Earth’s magnetic field. Once the eggs have been fertilised, the females come ashore and use their powerful front flippers to dig something in the sand called a ‘Body Pit’. Their back flippers then dig a deeper hole where between 100 - 120 eggs are deposited, usually over the course of two to three sessions. After incubating in the warm sand, the eggs hatch down and the young make their way to the surface. They instinctively look for the light on the horizon and head towards the sea, carried off by the tide. The tiny loggerheads are completely on their own and vulnerable - many fall victim to predators such as crabs, seabirds and foxes as they emerge. Unfortunately, human activity is having a serious impact on the Loggerhead population. They are sometimes caught up in fishing nets, and commercial developments along the nesting beaches can confuse hatchlings, leading them to head inland towards artificial lighting instead of out to sea. Climate Change is affecting the sand temperatures - warmer sands means more females are born whereas cooler temperatures result in more males. Rising sea levels are another concern, with higher tides increasingly covering nest sites and drowning hatchlings as they dig their way to the surface.