Leatherback Turtles

Reading Passage 3

In 1988, the world’s largest known leatherback turtle, measuring over three metres across and weighing an incredible 916 kilogrammes, was found washed up on a beach in Harlech, Wales, UK. The giant specimen is currently a prime attraction at the National Museum of Wales. Until now, experts have failed to explain how this massive reptile came to end its days in cool northern waters, thousands of kilometres from the tropical Caribbean nesting sites where hatchling leatherback turtles first enter the sea.

But Jonathan Houghton of the Irish Sea Leatherback Turtle Project, working with marine ecologists from universities in Wales and Ireland, thinks that the mystery may have been solved. The team’s research findings suggest that, contrary to previous assumptions, these giants of the sea habitually frequent northerly latitudes for extended periods, lured by the opportunity to feast on the plentiful jellyfish found in certain bays around the Welsh and Irish coasts from April to November. According to Houghton, the exact cause of the jellyfish proliferation is as yet uncertain, though further studies by the project hope to provide an explanation for this seasonal abundance.

If the results from the team’s ongoing surveys in the Irish Sea corroborate these early findings, conservationists will have to turn their strategy for saving this critically endangered species on its head. Studies of Atlantic leatherback turtles have hitherto centred on their breeding sites, principally the Caribbean Basin, but also Suriname, French Guiana and Gabon. Unusually low numbers of nesting females returning to these locations over the last two decades have prompted conservationists to worry that pollution, fishing, egg-snatching and coastal development were taking their toll on leatherback populations. Experts are still in no doubt that the species is under severe threat, but the focus will need to shift, as Houghton explains: “The general perception is that leatherback turtles spend most of their time in warm waters.

However, our studies suggest that many migrate north from the tropics after breeding,

and frequently enter the waters around the British Isles.”

Leatherback turtles have patrolled the oceans since dinosaurs roamed the earth, but

we know less about their behaviour than that of almost any other marine creature.

Because they spend most of their time away from accessible coastal areas and often

dive below the surface, scientists have had little chance to study their behaviour or

map their distribution. Any close encounters invariably take place in summer when

females come ashore every three years or so to lay their eggs. Until the mid-1980s,

up to 115,000 adult females regularly appeared on beaches around the Atlantic,

Pacific, and Indian Oceans, population has dwindled to between 26,000 and 43,000.

In the Pacific, as few as 2,300 adult females remain. In 2003, no females turned up

at the nesting colony at Terenggu, Malaysia, where 3,000 turtles regularly

congregated in the 1960s.

Houghton and the team are working to fill the gaping holes in our understanding of

Atlantic turtles before these reptiles meet the same fate as their Pacific cousins.

Working in collaboration with the Caribbean environmental organisation Ocean

Spirits Inc, the team attached satellite transmitters to ten females nesting in Grenada

in the Caribbean. The devices recorded the animal’s location, depth and swim speed,

plus the water temperature, and sent the information via satellite-receiving stations

back to Swansea University in Wales each time the creature surfaced over a

two-year period. The data from Irish Sea, are revealing the most extensive picture of

turtle migration ever seen.

Though the team needs to shadow the turtles for longer to understand their three-year journey from and back to their breeding sites, the tracking carried out so far shows turtles spend considerable periods of time in the deep, open waters of the North Atlantic. This has implications for conservation because of the threat facing turtles from longline fishing fleets, who daily set over three million hooks across the world’s oceans. After integrating figures from international observer programmes, scientists at Duke University Marine Laboratory in the USA estimate that many tens of thousands of leatherbacks are lost every year in accidental catches (known as ‘bycatch’) by longline fishing fleets, and that numbers of casualties may be rising.

There is some positive news, however. Research into the types of hooks and bait placed on long lines suggests that a ‘circular’ type hook, soon to be tested in Ecuador, could reduce snagging of leatherback turtles by as much as 66 percent. Currently, many fisheries use ‘J’-shaped hooks, which can cause internal bleeding or suffocation to turtles if swallowed or snagged on flippers. Other devices, such as placing sharks made of fibreglass near lines or sending acoustic signals to scare turtles away, using blue dye to make bait less appealing, and laying hooks below the level of the migratory paths along which most leatherbacks travel, are also being trialled.

‘The declines are caused by humans, but the solutions are within our grasp,’ says Houghton. ‘We just have to find the political will.’ If governments can work with fisheries to prevent deaths, there is a chance the Atlantic will endure as the world’s last leatherback stronghold. If not, these reptiles may go the same way as their dinosaur contemporaries, and our experience of them will be reduced to dusty exhibits in museums.

Questions 27-30

Complete each sentence with the correct ending, A-F, below. Write the correct letter, A-F, in boxes 27-30 on your answer sheet.

27 Until recently, it has been thought that

28 Houghton’s team’s research reveals that

29 Houghton admits that he is unsure why

30 Conservationists have had several theories as to why

A the giant leatherback turtle appeared on a beach in Wales.

B numbers of Atlantic leatherback turtles are declining.

C leatherback turtles are mainly resident in warm waters.

D a leatherback turtle will return to the same breeding site year after year.

E jellyfish occur in large numbers around the British Isles during certain months.

F Atlantic leatherback turtles spend a large part of their time in cool northern waters.

Questions 31-34

Do the following statements agree with the information given in Reading Passage 3? In boxes 31-34 on your answer sheet, write:

TRUE if the statement agrees with the information
FALSE if the statement contradicts the information
NOT GIVEN if there is no information on this

31 The leatherback turtle is thought to be more difficult to study than almost any other marine creature.

32 Scientists are only able to observe leatherback turtles at close range during certain times of the year.

33 The decline in the population of Atlantic leatherback turtles is more advanced than that of their Pacific relatives.

34 Data from satellite transmitters suggests that annual variations in water temperature influence the migratory patterns of leatherback turtles.

Questions 35-39

Complete the notes below. Choose NO MORE THAN TWO WORDS from the passage for each answer. Write your answers in boxes 35-39 on your answer sheet.

Efforts to Reduce the Impact of Longline Fishing

Current measures aim to minimize the bycatch caused by commercial fishing fleets.
One strategy involves the use of hooks that are 35 ______ in shape.
Artificial 36 ______ made of fibreglass or the emission of 37 ______ may be used to deter turtles from the area.
Bait can be made less attractive by using 38 ______.
Hooks are positioned at depths below the turtles’ 39 ______.