Sharks smash the depths of scuba diving

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Sharks can dive to depths of almost 2km, about six times shallower than the deepest scuba diver, a global study reveals.

Led by the Zoological* Society of London and Stanford University’s Hopkins Marine Station, a global team of 171 researchers at 135 institutions around the world have installed hundreds of tracking tags on 38 species of sharks and rays .

Bringing together a wealth of knowledge about the diversity* of Australian marine life, Flinders University professor and co-author Charlie Huveneers said the immense scale of the study has enabled a breakthrough* in understanding the animals.

“This is the first time that such a large amount of data on the vertical movements* of sharks and rays has been collected,” said Professor Huveneers.

“Our collaborative team* gathered 96,169 days of data from 989 sharks and rays (to) tell us how they use the ocean.”

The study reflects a breakthrough in methodology*, mapping the movement of animals along a different axis* to focus on movement vertically across the depth of the ocean as well as horizontally* across it.

It revealed that while 26 of the 38 species studied spent 95% of their time within 250 m of the water surface, 13 species dipped more than 1 km below the surface.

Whale sharks have been seen diving to depths of 1896m, while the deepest recorded ray was the sickle devil ray, which reached a depth of 1637m.

Prof Huveneers said the aim of the study was to understand the depths at which the animals travel, in order to prevent sharks and rays from being accidentally caught by commercial fishing operations.

“We are fortunate in Australia that most of our commercial fisheries are relatively well managed and that many endangered species of sharks and rays* in other parts of the world are safe here, but some populations of sharks and rays are at risk of extinction in Australia,” he said.

“Our increased knowledge of their in-depth use will help managers better understand and mitigate* threats.”

The study’s co-lead author from the ZSL Institute of Zoology, Dr. David Curnick, said he hoped the wealth of knowledge provided by the findings would serve as a breakthrough for animal care.

“Knowing how deep certain species dive – or don’t dive – will help us inform much-needed conservation plans* for those species and their relatives,” Dr Curnick said.

“It will also help us understand how these animals are likely to respond to predicted climate-induced* changes in our oceans.”

GLOSSARY

  • zoological: scientific study of animals
  • various: have a lot of variety and difference
  • breakthrough: important discovery or event that improves something or solves a problem
  • vertical: perpendicular to the horizon, a rising or falling line or direction
  • collaborative: two or more people or organizations working together for a common purpose
  • methodology: system of ways of doing, teaching or studying something
  • axis: real or imaginary line dividing a symmetrical object in two
  • horizontal: flat or level, parallel to the ground or the horizon line
  • extinction: when a species goes extinct and ceases to exist
  • mitigate: reduce the impact, make something less serious or less serious
  • conservation: careful preservation and protection of animals and natural resources
  • induced: persuade someone to do something or cause something

FURTHER READING

Growing great white sharks

Shark cam captures the struggles of life and death

The relief of the Great Barrier Reef with the return of coral

QUICK QUIZ

  1. How many days of data did the researchers collect?
  2. How many sharks and rays have been tagged and studied?
  3. How many species dipped 1 km or more below the surface?
  4. How deep have whale sharks dived?
  5. What is the unusual name of the deepest-diving stingray?

LISTEN TO THIS STORY

CLASS ACTIVITIES
1. Marine animals and where they live
How amazing that sharks can dive up to 2000m (2km) below the surface of the ocean. Many other marine species are found at different depths. Using the information below, create a colorful and informative diagram showing the different sea animals, the different dangers, and the different ocean depths at which they live.

Autonomous diver – 20-40m

Orca – 60m

Whale shark – 70m

Professional diver – 100m

Giant octopus – 100-200m

Giant rower – 200m

Blue whale – 500m

Giant squid – 946m

White shark – 1280m

Trawl nets – 1500m

Whale sharks – 1896m

Sperm whale – 2250m

Deep sea coral reefs – 3000m

Sunken ship Titanic – 3800m

Monkfish – 4500m

Shrimps, invertebrates, microbes – 7600m

Time: allow 30 minutes for this activity
Curriculum links: English; Science; Critical and creative thinking

2. Extension
What other threats may exist to marine life at all depths of the ocean?

How could you use the study information reported in the Kids News article to help protect endangered marine species?

Time: allow 15 minutes for this activity
Curriculum links: English; Science; Critical and creative thinking

VCOP ACTIVITY
I spy names
Nouns are places, names (of people and objects) and times (months or days of the week).

How many names can you find in the article?

Can you sort them by places, names and times?

Choose three nouns and add an adjective (describing word) to the nouns.

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