Four successful deployments, each with 5 – 8 hours of footage and data, have been collected over the past two weeks. One of the main shortfalls of our 2004 and 2005 missions was that the clamps to which the cameras are attached would slip off the shark when it chased something. Thanks to some brilliant engineering by National Geographic’s Crittercam Teamthe clamp and cameras have been completely re-designed and are staying on for the full mission time – providing the first step to answering our burning questions on white shark prey choice and social nature. Photos courtesy Mike Meyer, Alison Kock and Morne’ Hardenberg.
Getting the cameras on
The first step to deploying Crittercam is to lure the sharks’ close to our research boat. A specially designed pole is used to position the clamp over the dorsal fin of the shark as it swims by. When in position, a button is pushed on the pole, which pulls a zip-tie closed at the back of the clamp, pulling both clamp arms together, cutting the zip-tie and releasing the camera. The clamps are non-invasive as they simply attach around the dorsal and do not pierce the skin. All the sharks we deployed the cameras on came straight back to the boat allowing us to observe their immediate behaviour after deployment.
Deployments
Shark activity is up-and-down at this time of year at Seal Island and the weather has been terrible – allowing us just a few days at sea in the last two weeks. However, we have managed to get four deployments and collect almost the same amount of video footage as we did in 2004 and 2005 with 23 deployments. The clamp has proved to work incredibly well and stayed on all four sharks until the end of mission. But, it’s also been a roller coaster of emotion as we have had incredible successes, but also some pretty hairy experiences. On Saturday we deployed both cameras and set them to release at 15h00 and 15h30 respectively. The day started off with perfect flat seas and little wind, but by 15h00 that quickly changed to gale force conditions, which made locating the camera extremely difficult as waves kept breaking over the boat. Added to this my one boat motor decided to cut out on us and so not only did we have to deal with two-meter wind swells, but we had to do it on one motor. It took us two hours to locate the one camera in these conditions, but unfortunately the other one we couldn’t locate.
Finding the Crittercams
Crittercams are truly ingenious. We can programme the cameras to release at any time of day or within a certain time period of being deployed. The cameras will also release when the battery voltage reaches a certain point, making sure that there is always enough power to cut the zip-tie. A VHF transmitter is attached to the system and is enabled as soon as the mission starts. Once the camera releases from the shark, it floats to the surface and the VHF signals can be used to locate the system. This worked well for three out of the four deployments. However, on the last deployment it required more than the VHF to locate the camera, it required luck and goodwill from a fellow sea user. After missing the camera for three days I got a call from Gary McFarland, a crayfish fisherman working in False Bay, telling me that one of his crew had just found our Crittercam bobbing on the water surface near Cape Hangklip, 35 km from Seal Island. Needless to say we were overjoyed at the return of the camera and extend our deepest thanks to Gary and his crew of Nommer Sewe.
Shark care and animal ethics
It’s vitally important to us that we make sure that we do not hurt any sharks. I have personally clamped by arm to make sure that there is no pain or severe discomfort to the shark. Further proof is that as soon as the camera goes on the sharks all come straight back to the boat behaving as they did before we put the cameras on. The cameras only stay attached temporarily for a few hours and once the mission ends they simply release from the shark and float to the surface. The process has been through a rigorous animal ethics process to get independent substantiation of the protocol so you can rest assured that the cameras are not harmful to the well being of any shark.
Why attach Crittercams?
White sharks are apex predators in our waters and understanding their ecological needs is important to their conservation. What are they eating besides seals? Which areas are they hunting in? Are they social? They are listed as protected, but what does this really mean when we don’t have the basic knowledge needed to make sure the measures in place are effective. Are we effectively protecting their prey populations or their habitats? Observing sharks around a boat or from the surface only provides us with a glimpse into their world.Crittercam will hopefully help us unlock many of the mysteries still surrounding the nature of these sharks and ultimately contribute to a better understanding of these incredible animals and how we can ensure their survival into the future.
I would like to say a special thank-you to Graham and Mark for their tireless efforts on my behalf – thanks guys, you rock! To read Mark’s account of the deployments click here. Thank-you also to my colleagues at MCM, namely, Mike, Deon, Darrel, Sarika and Steven for all the help on the boat! Lastly, Julie and Paul…I couldn’t have done it without you!
P.S. We have already recorded two unexpected feeding events. However, the details of these will have to be our secret for now…but stay tuned.