International Great White Shark Research Team Work With Dyer Island Conservation Trust
June 15, 2017 Brenda du Toit
The Dyer Island Conservation Trust and Marine Dynamics team were recently joined by past Master’s students, Oliver and Michelle Jewell, to continue Oliver’s studies on great white sharks.
Oliver is a PhD candidate affiliated with Murdoch University. Oliver is looking at the foraging and swimming patterns of great white sharks by observing body movements and tail beats using camera loggers attached with a special clamping system. The team included Oliver’s supervisors Dr Adrian Gleiss (Murdoch University) and Dr Taylor Chappell (UC Davis); and a research and film crew from Monterey Bay Aquarium – Dr Salvador Jorgenson, Presley Adamson and Paul Kanive. Further support was given by past employee of the Trust, David ‘Ed’ Edwards and his partner Anna Phillips. Ed assisted with the white shark population study the Trust released in 2013.
Michelle gave us a summary of their experience:
“Chum & Hope”
Written by Michelle Jewell
Anyone who works in nature knows the golden rule – patience. You can make the best plans, have the best equipment, and an extremely qualified team, but your ability to be patient will be tried again and again. This was the theme for our third CATS-Cam Tagging Expedition with the Dyer Island Conservation Trust.
CATS-Cams are composite camera/accelerometer/daily diary tags that attach temporarily to sharks using a clamping system that partially dissolves in salt water. The tags float and have two tracking systems attached to them in order to recover and download the data from the tags. You can read the methodology here.
This is the third campaign with the Dyer Island Conservation Trust. We were able to get an average of ~20 deployments on the previous two trips, so we were looking forward to another successful expedition. However, we arrived in Gansbaai on 1 May – one day after the orcas. Infamously, three dead white sharks were recovered within a week displaying clear orca predation injuries. You can read the full timeline of events here. No sharks were seen in the bay for the next two weeks and our research was abruptly abated. Patience took over and our program shifted from Tag & Retrieve to Chum & Hope!
Then, finally, a shark was spotted in Joubertsdam. Then another one. And another! New sharks were in the bay and we were able to get five deployments to add to our three-year dataset. This information will be used for DICT alumnus, Oliver Jewell’s PhD at Murdoch University (you can follow Oli on twitter to get updates on his various travels and tagging expeditions).
Thank you very much to the Dyer Island Conservation Trust, Monterey Bay Aquarium, and all of the team at Marine Dynamics shark tours for their incredible assistance in the many interesting situations we found ourselves in!
Team picture from L-R: Oliver Jewell, Presley Adamson, Dr Adrian Gleiss, Dr Taylor Chappell, Paul Kanive, Dr Salvador Jorgenson, Michelle Jewell, Ed Edwards.
Oliver placing the CATS-cam.
Photo credits: Anna Phillips-Dyer Island Conservation Trust