*Jaws theme plays in the distance*
In the #FloridaKeys, charter boats are frequently seen a couple miles off the shore up and down the coastline. On today's adventure, our group went out with the Guy Harvey Research Institute to do some shark tagging on one of these vessels off of the coast of Fort Lauderdale.
The gear we used for this sampling was called a "drumline". A fifty pound cement weight is attached to a buoy and deployed off of the back of the vessel with a line attached to it holding a hook and bait.
Ten lines were dropped three separate times - allowing about an hour in between sampling events for the line to soak and attract sharks. When the lines were retrieved, if a shark wasn't caught, the state of the bait was recorded. In all events today, there was no bait left on the line when a shark wasn't present.
The fish used for today's bait was fresh bonita, a member of the Scombridae family.
The hooks attached to the fishing line were called circle hooks. Traditionally for fishing, j-hooks are used. These are your typical hooks that come to a small point at the very tip. Circle hooks take this shape and bend at the bottom to make it safer for the fish consuming the bait. J-hooks are easily swallowed and can cause severe internal damage while the circle hook, when swallowed, usually moves its way back up to the lip - where it is meant to be.
Three sharks were caught today, two being nurse sharks and the other being a brown shark. The first two were caught off of lines nine and ten. The brown shark was caught on the 29th line.
For more information on the Guy Harvey Research Institute, check out this link: https://cnso.nova.edu/ghri/index.html.
For more information on shark conservation in Florida, check out this link: https://www.floridamuseum.ufl.edu/fish/discover/sharks/conservation-research/.
#savethesharkies #circlehookorDIE #muchjaw #verywow
I remember reading about Derek's technique in one of our papers but, seeing and doing it in person was a whole new experience. His methods are definitely well thought out and have the best interest of the animals in mind.
ReplyDeletei had such a fun time pulling up the drum line, and you never knew if there would be a shark on it or not. who needs to go to the gym or workout every morning when you're hauling up 100 foot lines, and a 50 pound weight.
ReplyDeleteI agree with Tehesia, after reading Derek's research article, it was definitely cool to see it in action and being able to put them together ourselves.
ReplyDeleteShark tagging was a day to remember for sure. I have already told all of my friends about me and Mark wrangling the brown shark. Cannot wait for pics! Circle hooks were definitely the move because I cannot tell you how many bass I have caught in my life where I had to dig down their throats to retrieve hooks that were in their gut. #savethesharks
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