Part 4: Leatherback Turtles
Part 4
Questions 31-40
Complete the notes below.
Write ONE WORD ONLY for each answer.
Leatherback Turtles
background:
31. The advantageous ………………………………… of leatherback turtles makes them swim efficiently than others.
32. it is one of the deepest …………………………. reptile.
33. Shell is …………………………. not bony to avoid from high pressure.
34. Leatherbacks can ……………………………. in the water for several hours due to their size of lungs.
35. Main food is jellyfish contains high proportion in …………………… and mineral.
Research methods:
36. Scientists can learn their ……………………….. pattern in Atlantic ocean.
37. Scientists can start tracking when the turtle reaches ……………………………
38. Huge front flipper can produce ……………………………… from strong muscles
39. A new recorder can monitor not only their location but also the ………………………. in the sea.
40. Leatherback turtles are found using more …………………………. to search food.
Key
- shape
- dives
- soft
- sleep
- protein
- migration
- surface
- power
- depth
- energy
Transcript
Speaker: Part 4: Secret creature called Leatherback Turtle.
Speaker: Janet Vanneken, of Florida Atlantic University, has shown that there are the advantages of the Leatherback’s streamlined shape. Swimming leatherback turtles have a lower drag, more efficient than other species, indicating more efficient force. To swim at the same distance to other sea turtles of the comparable size and weight, leatherback turtles spend on average 20% less energy.
Speaker: Among all the deep-diving animals, the champions have always been assumed to be the marine mammals,
the great whales and the earless seals. Our recent investigations, however, suggest that leatherback turtles may also be ranked among the ocean’s greatest air-breathing dive reptiles, while marrying the dives of the leatherback sea turtles. Turtles near St Crocs, in the U.S. Virgin Islands, scientists recorded a 650-pound female that sank to more than 3,330 feet and remained there for 37 minutes.
Speaker: High pressure also poses a challenge to the deep diver in terms of strong forces that could compress the chest, causing broken bones or tissue damage. Unlike its hard-shelled relatives, leatherbacks has a softer shell made up from widely separated bones, ribs and that it is in thick tissue, and whole structure is overlaid with leathery skin.
Speaker: How do the deep-diving animals, whales, seals, penguins and leatherback turtles avoid deep compression sickness and other hazards while they dive to the great depths for a long period of time. Many of the deepest diving marine mammals have small lungs and forcibly exhale before diving, in addition to reducing the buoyancy so that they can dive more easily. This severely limits the amount of nitrogen in their bloodstream.
Speaker: One reason the leatherback ranges so far may be to specialise the diet. This giant of the sea feeds mainly on jellyfish full of high protein and other useful minerals that require during the day. Although the variety of jellyfish and related prey are abundant, they are eaten by few other animals. As one might suspect, a life spent eating mostly jellyfish requires some special adaptions to make the job easier.
Speaker: During the 1984 and 1985 nesting seasons, with the assistance of scientists attached the recorders to 10 female leatherbacks that just laid eggs. As a result, we are able to monitor the pattern of migration in the Atlantic ocean when they return to the sea. Some of the longest travel recorded for many animals have been made by this marine turtle. In 1970 a female leatherback was tagged when she nested in Surami on the north-eastern coast of South America. Less than one year later she was captured off the coast of Ghana, West Africa, more than 3,700 miles across the Atlantic Ocean.
Speaker: Upon returning to the surface, the turtles changed a quick breath and immediately hanged straight down again. Little or no time was given to sleep on rest. We then begin the track and take the turtles when they swim back to the surface. On closer examination, we notice difference in dives depending on the time of the day. Night dives were shallower with less in-depth than day dives.
Speaker: Leatherbacks are such swimmers, and they rarely stop moving. A behaviour that has made it impossible to keep them in captivity. The front flippers are more than half the length of the dead of the body and they generate the power from huge muscles, which can accounted for 30% of the animal’s total body weight.
Speaker: Leatherbacks cannot easily be studied in captivity. Researchers have been developing methods of studying them at sea. They used a recorder instrument capable of recording location and depths in sea. Developed by Jero de Cumin, a psychological research laboratory, the device has been used to study diving marine animals.
Speaker: Why did they keep diving? Scientists have soon realised turtles were probably costing much of the energy to follow their food source. In tropical waters, jellyfish are most common at great depths. In a biological zone called the deep scattering layer, discovered shortly after the development of the sonar, this zone consists of a layer of zooplankton that hooves below 1,800 feet during the day and migrates to the surface at night.
