A yellow tag is placed at the base of the dorsal fin. This helps identify the shark in the event it is recaptured. They also do satellite tagging but that is often reserved for larger and more threatened sharks like the Great Hammerhead.
“Historically in order to see what sharks eat you cut them open and see what's in their stomach,” Dr. Hammerschlag told the group.
These days they can do that by taking a tiny clipping from the trailing edge of the shark’s dorsal fin, “there are no nerves in their fins so it doesn’t hurt” said Dr. Hammerschlag.
From the fin clipping they can run a chemical composition to see what the shark ate over a long period of time. They also take a blood sample from the shark which helps them identify what it ate over a short period and will let them know if the female Black Nose shark they captured is pregnant.
Finally the circle hook is removed and the shark is released back into the water.
On this shark tagging trip we would tag two black nose sharks and one feisty nurse shark. RJD averages about 300 sharks a year.
“We are collecting real data and this data is going to be published in scientific journals,” said Dr. Hammerschlag, “my hope is that wildlife managers will use the data to make informed policy decisions and effective conservation strategies.”
“Oceans are changing,” Gallagher explained, “everyday people look at the surface of the ocean and it looks the same but the honest truth is beneath the waves things are changing drastically, populations of sharks are declining rapidly, even in our waters here and so that's one of the questions we are trying to answer and one of the points we are trying to drive home. We need to be good stewards of the ocean and it starts now. This is their world, we're just visiting.”
RJD also runs an “adopt-a-shark” program. For $2,500 you buy a satellite tag and you can come on the research boat, tag and name the shark yourself and then follow him or her in real time on the internet.
To learn more about the researchers and how you can help, click here.