SHARK LAB: An Update from the Bahamas
Jillian Morris, our SHARK correspondent in the Bahamas has just filed this report:
Duncan Brake and I recently spent 2 weeks at the Bimini Biological Field Station, filling in as assistant managers. The BBFS ( Sharklab) was started in 1990 by Dr. Samuel Gruber and has been pioneering shark research since its inception.
World renowned for its influential work, the Sharklab draws scientists, researchers, volunteers, conservation groups and production companies from across the globe.
We spend most of our time these days filming and photographing sharks for various conservation projects, but we both got our start as research assistants on various shark projects. It is always tremendously rewarding to return to that world because science is the core of conservation.
The work at the lab varies depending on PhD projects, production company requests, college courses or the work of visiting scientists. This creates a very diverse and exciting work schedule. Study sites range from shallow mangrove forests and sea grass beds to the deep waters of the Gulf Stream. Most days are consumed with catching, tagging, tracking or observing sharks. Methods of capture include fishing with rod and reel, gillnetting and longlining. Rod and reel fishing is reserved for adult lemon sharks most of the time while gillnetting is most commonly used for juvenile lemons. Longlining is used to catch a variety of sub-adult to adult species from tiger sharks to blacktips and bull sharks.
Catching the sharks is not only crucial for the research, but one of the most exciting forms of field work at the lab. Duncan and I lucked out with the monthly 24 hour longline falling during our visit. 5 lines, each with 15 hooks, are set in specific locations and checked regularly. Our team had the 9:30 pm and 6:30 am checks. Under a starry sky, mirrored by a glassy phosphorescent sea, we raced towards the first line. Checking the lines is like Christmas morning for us shark geeks, anxiously wondering what awaits us. The check was pretty eventful with 3 sharks on 3 different lines. Our first being a 110cm recap lemon shark from June of this year. Recaps provide insight to the behavior, growth and movement of the sharks, so finding one on the line is pretty exciting. This little guy covered a minimum of 5 miles across open water since his last capture and considering his size, this is a pretty impressive feat. A 140cm recap nurse shark was our second shark followed by a 195cm nurse. Even though it was late, or early in the morning, everyone was really energized and psyched to be out on the water. Bugs, rain or exhaustion disappear when there are sharks to be tagged.
While at the lab we were also able to be part of a 24 hour track on a juvenile lemon shark. A transmitter tag was surgically implanted in the shark allowing it to be tracked actively with a hydrophone. The tag gives off a specific frequency of beeps that is the shark’s identity. Volunteers and staff were divided into teams of 3, each on a different 8 hour shift. Duncan and I had the 3 am to 11 am shift, not the easiest to be awake for, but made possible with massive caffeine injection. A constant track is challenging especially in the dark when you cannot see the shark or the bottom. One person drives or pulls the boat, following the commands of the tracker. The tracker has the hydrophone in the water off the bow of the boat, listening to the beeps with headphones. Directions are given to keep within range of the signal, but not to influence the movement of the shark.
As daylight breaks the tracking becomes a lot easier; at least you can see what you are wading through as you pull the boat. Our shark covered some serious ground, spending most of its time in the mangroves along the edge of the sound. This area is being impacted by a massive holiday resort that is seeking expansion by filling in large portions of the mangrove forest. Tracking the sharks and quantifying how much time they spend in this region is crucial for the fight against its destruction.
Taking a break from our cameras has allowed us to get a different glimpse into the world of sharks. Although we still took some photos and did a bit of video work, our focus was on being in the field and helping with the current projects. Both of us were first exposed to sharks as research interns and that is what catalyzed our continuous work with and for these incredible creatures. The Sharklab is a crazy and incredible place, like no where else I have ever been. The work being done is contributing to the fight for the survival of these animals and it is amazing to be a part of it!
For more information about the lab or to get involved check out