Image of a person holding a sandshark in the water

Courtesy of David Doubilet & Jennifer Hayes

STANDARDS

CCSS:  6.EE.A.2, 7.EE.B.4, MP3, MP4

TEKS: 6.10A, 7.11A, 8.8C

Can We Save Sharks?

A bold plan. A 5,200-mile journey. Meet the zebra sharks sent from Australia to Indonesia, where scientists hope they will help increase wild shark populations.

Bubbling water echoes around a biologist at Sea Life Sydney Aquarium in Australia. She leans over a tank to pick up a zebra shark egg. The baby shark growing inside the brown leathery pouch is about to go on an incredible journey. It will travel more than 5,200 miles by car, airplane, and boat from Australia to a remote island in Indonesia (see Going the Distance, below).

Why go to such great lengths for zebra sharks? This endangered species needs all the help it can get. Unfortunately, it isn’t the only one. Of the 1,199 shark and ray species on the planet, more than one-third are threatened with extinction.

In 2019, biologists from around the world gathered to see what they could do to help. They discussed the idea of transporting sharks bred in zoos and aquariums to their native habitats, and the ReShark program was born. Today more than 90 aquariums, conservation groups, and government agencies are part of ReShark.

After years of planning, the first captive-bred sharks were released in January 2023. “It marked an incredible milestone for us,” says Erin Meyer, chief conservation officer at the Seattle Aquarium. “We’re now ready to scale up!”

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Watch this video about the Re-Shark program in Indonesia

Hatching a Plan

Why were zebra sharks chosen for the first project? This species lays eggs instead of having fully-developed young. This means aquariums could ship the eggs to their new home, which would be easier to do than sending live baby sharks. We also already know a lot about zebra sharks: what they eat, when they’re ready to mate, and how long they live. “We know a lot about their basic biology because they’ve been in human care for so long,” says Meyer.

ReShark partners designed and built two nurseries in Indonesia. Once the eggs hatch, local biologists monitor the baby sharks and then release them when they are big enough to live on their own.

The nurseries are located at the Raja Ampat Research and Conservation Centre on Kri Island and the Misool Foundation’s resort on Batbitim Island. Both are in a marine sanctuary created in 2012 that protect sharks and rays. Fishing is prohibited in this network of aquatic habitats that covers more than 7,700 square miles.

Today, there are more and more black-tipped reef sharks and mantas in this marine park. But zebra shark numbers have yet to bounce back. The baby sharks will eventually be released near the nurseries. Biologists hope that they will stay within the boundaries of the protected marine park where they can grow without the threat of human predators

Photo of people gathered on the beach taking photos of small sea creatures

Courtesy of Indo-Pacific Films

Erin Meyer from the Seattle Aquarium works with ReShark staff.

Releasing the Sharks

On January 13, 2023, two of the first four sharks were released. Scientists, government officials, and others gathered to watch. Each shark was outfitted with a monitor to help researchers see where it travels. So far, they have seen two of the four released pups in the wild.

Biologists hope to release up to 500 zebra sharks over the next decade. About 20 more shark pups are now growing in the Indonesian nurseries. Scuba divers and snorkelers can come see them.

ReShark’s partner aquariums plan to send more zebra shark eggs to Indonesia this year. Biologists are also getting more aquariums in Europe to join the effort to help diversify the shark gene pool.

If the zebra shark program is successful, it can be a model for other endangered shark and ray species too. “There are more critical species out there,” says Lisa Hoopes, the director of research and conservation at the Georgia Aquarium, another ReShark member. “We can take advantage of the knowledge of zoos and aquariums to help contribute to these efforts.”

Image of people taking the measurements of a sandshark

Courtesy of David Doubilet & Jennifer Hayes

The pups get regular checkups as they grow.

math-instructional-writingalgebraicexpressionsmp4
Watch an instructional video about writing algebraic expressions.
Expression Scramble
Play a cool math game about equations.

Write and evaluate expressions based on information about zebra sharks and the ReShark program. Record your work and answers on our answer sheet.

A. A zebra shark egg is sent to Indonesia 11 weeks after it’s laid. It was checked for a shark embryo w weeks earlier. Write an expression to find when biologists checked for an embryo.

B. Evaluate it! Biologists checked for an embryo 5 weeks earlier.

A. Zebra shark pups are about 6 inches long when they hatch. After two months, they are m inches longer. Write an expression to find how long the pups are after two months.

B. Evaluate it! Pups grow 24 inches in the first two months.

A. U.S. aquariums sent a total of 9 eggs to Indonesia last year. Each aquarium sent b eggs. Write an expression to find out how many U.S. aquariums sent eggs to Indonesia.

B. Evaluate it! Each aquarium sent 3 eggs.

A. ReShark plans to release a total of 500 sharks in Indonesia. Write an expression to find out how many sharks will be released per year over t years.

B. Evaluate it! Biologists plan to run the project for 10 years.

A. At one nursery, 4 zebra sharks each eat an average of c pounds of food in a day. Write an expression to find out how much food in total the zebra sharks consume in d days.

B. Evaluate it! The sharks each eat 4 pounds of food in 6 days.

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