During my 14 years living on Johnston Atoll ( 800 miles SW of Honolulu ) in the South Pacific, my main job was managing the engineering and logistics support division for one of the organizations on the Atoll. Although not part of my job description, I also provided scuba and photography support for such organizations as Wood Hole Oceanographic Institute, the Boston University Marine Program and National Geographic. Woods Hole and later Boston University were providing environmental research to determine how years of military use of the islands that made up Johnston Atoll and the pollution it generated were affecting the reefs as well as the fish population. In addition, National Geographic came to the island to study the grey shark. Also Phil Lobel, Ichthyologist, PhD, the program director, brought a number of students mainly finishing their PhDs to assist in the research programs. Lisa Kerr Lobel, ecotoxicologist, PhD, Greg Skomal, Marine Sciences, PhD, are just a couple of the many students and researchers who participated in projects on the atoll. Additionally, Greg Marshall, National Geographic, and inventor of the Crittercam spent time on the atoll, using the Crittercam photo system to track and study shark movement in real time underwater. Phil had several different marine science research projects going on during his time on the atoll. I am only presenting a couple of the programs. The enclosed images show Grey Reef sharks being caught, a blood sample was taken and the shark was weighed. When the sharks were caught they were turned onto their back where they become docile and can be easily examined etc. An acoustic tag, about the size of a cigar was mounted near the tail. Prior to catching the sharks, Lobel and his researchers set several acoustic recorders in several underwater locations around the atoll. Once a tagged shark would swim in close proximity to the recorder, the shark ID and other information was recorded. The recorders could then be removed from the water, the information downloaded and the recorder could be placed back into the water. The acoustic tag wires would rust off after 6 or so months. At the same time Phil was attaching the acoustic tag to the shark, Greg Marshall and his team were attaching the Crittercam to the dorsal fin of the shark. The Cam would film for 1-2 hours, monitor depth and temperature and was set to release from the fin in around 3 hours. While the Cam was attached to the shark, the shark could be tracked by an underwater ultrasonic pinger that was emitted from the Cam. Once the Cam rose to the surface, the floating Cam could be tracked using VHF telemetry equipment and a directional antenna. Great care was taken to track and find the floating CAM since if the Cam did go over the reef, it was probably going to be lost. This actually happened to one Cam. I believe the approximate cost for that loss was around 10,000 dollars. The sharks were caught with barbless hooks that over time would rust away. One image shows part of the hook being cut away from the shark before release.
Category:Animals
Subcategory:Fish
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© David L. Shogren Photography
