LEMON TREE

April 20, 2020

Scientists Estimate Age of World’s Largest Fish

Exercise 1- Vocabulary

1. vertebrae – n. one of thesmall bones that are linked together to form the backbone

Ex. The needle is inserted betweentwo of the vertebrae.

2. data -- n. facts orinformation used usually to calculate, analyze, or plan something

You have some accessto data bases that could be helpful.

3. atmospheric -- adj. of orrelating to the atmosphere of the Earth or another planet

Ex. The largest pond is as sensitiveto atmospheric changes as the globule of mercury in its tube.

4. elevated -- adj. higherthan normal

Holding herhead elevated, as Mums had instructed, he offered the bottle.

5. saturate – v. to fill(something) completely with something

Ex. She ran her hand down his armand side, unable to shake the desire to saturate hersenses with every part of him.

6. species -- n. a group ofanimals or plants that are similar and can produce young animals or plants : agroup of related animals or plants that is smaller than a genus

Buffalo are adifferent species – like the water buffalo.

7. resilience – n. the abilityto become strong, healthy, or successful again after something bad happens

Ex. A diamond is the hardest,most resilient, most beautiful gem of all.

Excercise2 - Article

Scientists Estimate Age of World’s Largest Fish

Scientistshave recently discovered how to compute the age of whale sharks, Earth’slargest fish.

Researchers used information aboutradioactivity levels from Cold War-era atomic bomb testing. They determinedthat bands form in the shark vertebrae every year, like a tree’sgrowth rings.

Theyreached their conclusion by measuring levels of carbon-14. The naturallyoccurring radioactive element is also a product of nuclear explosions.

It wasalready known that these bands existed and increased in number as sharks aged.But it was unclear whether new rings appeared yearly or every six months.

Theresearchers compared carbon-14 levels in the rings to data on changesin carbon-14 levels over time. They compared them, especially, to the yearsof atmospheric nuclear tests in the 1950s and 1960s.

Joyce Ongis a marine scientist at Rutgers University in New Jersey. She was the leadauthor of the study that was published recently in the journal Frontiers inMarine Science.

“These elevated levelsof carbon-14 first saturated the atmosphere, then oceans and movedthrough food webs into animals, producing elevated levels in structures such asthe vertebrae of whale sharks,” Ong said.

Whale sharkshave a brownish-grayish color on the back and sides with white spots. Thelargest ones measure some 18 meters in length. They swim great distancesthrough the world’s tropical oceans to find food and feed on small organismstaken out of the water.

Thediscovery enables scientists to measure a whale shark’s age after its death.But just as importantly, it shows that these endangered marine giants growslowly.

MarkMeekan, a co-author, is with the Australian Institute of Marine Science inPerth. He said, “For the management of any marine species, knowledge ofgrowth rate is critical as it determines the resilience ofpopulations to threats such as fishing.”

Meekansaid, “We thought that it was possible that they could reach ages of as much as100 years, but we weren’t really sure...”

Theresearchers tested carbon-14 levels in long-dead whale sharks whose remainswere stored in laboratories. The oldest one tested, stored in Pakistan, hadlived 50 years.

Questions:

1. How do scientist compute the age ofwhale sharks?

2. Who was the marie scientist and alead author of a book published in the journal frontiers in Marine Sciene?

3. HOw long is the largest whale shark?

4. Why is their study about the lifespan of whale shark important?