Today during our adventure tagging sharks, we caught two female sandbar sharks. Sandbar Sharks go by the scientific name of Carcharhinus plumbeus. Some other common names that this species can be called is the thick skinned shark or the brown shark and it is one of the largest of all the coastal sharks. Their shape is heavier in the mid section with a rounded snout.
We learned today that there are over 500 different types of known species of sharks in the ocean and they are being exploited for commercial fishing, decoration and medicine at a rate of over one hundred million individuals per year. Sandbar sharks are just one of the species that are taking a drastic population decrease due to this horrific rate of removal from the ocean.
This is relevant to sandbar sharks because the rate they are being removed from the ocean doesn't match the rate at which they reproduce. Females don't reach sexual maturity until the age of thirteen and males around the age of twelve. Some are being harvested before that age and they are unable to contribute to the continuation of the population. They live about 35-40 years and they carry each litter of pups for one year before birth and they don't reproduce again until the following mating season.
Both of the female we tagged today had bite marks and scars on their skin. because males latch onto them by biting while mating. This is how females specifically developed even thicker more durable skin than their male counterparts. However, sometimes if they get injured enough while mating it could have an affect on their future survival. If they get into fights with other sharks, their injuries could be a big enough disadvantage for them to lose the fight.
We need to be more aware of preserving shark species and stop over exploiting them. Some efforts have been made, but if we keep going at this rate, then the sandbar sharks may not be around for much longer.
Going shark tagging was the activity that I was looking forward to the most on this trip and it definitely did not disappoint! It was one of the best experiences I have ever had.
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I wanted to add a little something to your blog! When I spoke with one of the girls on the boat about the sandbar sharks, she did say that they are the second most common shark in Florida waters (the most common being the nurse shark). Even though the worldwide populations are declining, it's a little comforting knowing that their populations here are still holding on!
ReplyDeleteI think that this post is great for people to read. Some people do not know how many sharks are killed a year. I did not know that sharks are being hunted for so many things! It never dawned on me until Derek said that the sharks are being used for medicine, decoration, and just for plain sport.
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