Many shark species are in decline due to overfishing . Conservation can be difficult because shark do not grow or mature very quickly so rebuild population numbers ask decades . New research has show that shark grow even slower and can subsist significantly longer than what was previously believed - making rebuilding declining populations all the hard . This research was led by Li Ling Hamady from the Woods Hole Oceanographic Institution ( WHOI ) and was published inPLOS ONE .
Typically , it has been believed that great white sharks can live about twenty years in the wilderness . This was found off banding of alternate light and sinister tissue paper that roll up on the shark ’s vertebra over the course of their lifetime , not completely unlike counting doughnut to date a tree . This method was based on the assumption that the bands signify one yr of growth . unluckily , it appear that that while yearly growth can be take note in other Pisces , the proficiency does not really solve for sharks .
The WHOI team was able to execute thefirst successful carbon 14 go out on shark , made possible due to the thermonuclear examination that consider place 60 years ago . radiocarbon permeated the marine life and became bushel in their tissue paper . This capitulum of ∆14C in the vertebral layers was something the squad could use as a fixed time reference and analyze the isotope through mass spectrometry to estimate old age with much greater accuracy than ever before .
sample of vertebrae that were collected from eight white shark between 1967 and 2010 by theNOAA ’s Northeast Fisheries Science Centerwere all test using this technique . Before doing the radiocarbon dating , the tissue bands were analyzed in the traditional manner to set a point of comparison . By using carbon 14 dating , the largest shark was estimated to have lived 73 year . The longest - lived female person was 40 . These results dramatically vary the await life of great white sharks . The squad concluded that there might be sexual dimorphism involve with maturation rates and the age process .
It is critically important to understand the life of sharks in society to comfortably alleviate their preservation . If females are living twice as long as we thought they did , it means that it takes even longer for them to mature and start to reproduce than we thought . This needs to be accounted for as preservation functionary develop plans to recover the species . Great clean sharks arelisted as vulnerableby the IUCN ’s Red List , yet are still targeted by poacher for their teeth , jaw , and fins . Some incorrectly trust shark fins have special healing properties , while others merely angle the sharks for sport .
