Tuesday, August 30, 2016

Death turns a near-blind eye to the Greenland shark:

According to marine biologists Peter Bushnell, the Greenland shark seems to be almost ageless.  Living in the deep Arctic ocean where they can thrive for decades, they mostly feed upon fish and the remains of other dead animals such as polar bears and even moose. The reason why scientists believe these sharks live for so long is the fact that they grow less than one centimeter a year. Based off of their growth rate, scientists were able to discover that female Greenland sharks do not reach sexual maturity until the old age of 152. Male sharks on the other hand can grow to be 6 meters long and live to the age of 500 according to some estimates.
Previously finding the age was more of a guessing game than anything else. The first method used in finding the age of these sharks was similar to finding the age of a tree. Scientists would count the calcified layers on the shark’s fins and scale to try and determine their age. This method didn’t work very well for the Greenland sharks due to the fact that they have spineless fins and too soft of vertebrae. The answer was in plain sight, for sharks of course. Scientist used radioactive carbon - 14 in the center of the shark’s eye lens in order to measure their ages.

I found this article to be very interesting because who would've thought that a shark of all creatures could live to be 500 years old or more. I want to know more about the ecosystem in which they live and how it may benefit them to live for so many years. Due to the fact that females don’t reach sexual maturity for many years, fishing and climate changes could have a massive impact on the number of Greenland sharks in the Arctic ocean.  Knowing that there is another animal out there that can out live the famous “long living turtle” is pretty good. ;) I would love to know more about these amazing creatures of the deep blue.

2 comments:

  1. I had heard about this type of shark before, but never knew that it was able to live for so long. I hope that scientists are able to capture safely a shark and very accurately determine its age. It would be amazing to see just how long a shark can live for in the cold water of the North Atlantic. Fishing in the area will be a large issue if the sexual maturity of the shark is so late in life, so we can only hope that the fisherman are kind enough to release these somewhat gentle giants.

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  2. It's incredibly interesting to hear how long these sharks can live, however, I am not all that surprised. We have no explored even close to how vast the ocean is and if we could I bet we would find all sorts of creatures that defy what we believe to be the norm. There may be animals down there that look nothing like anything we have ever seen before. Who knows, but I agree with you that this is very interesting, and I think we invest more time exploring the ocean.

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