Mesophotic coral reefs generally occur from depths of 50-150 m. We used a combination of telemetry, stable isotopes and technical diving to understand how and why predators (Galapagos sharks and giant trevally) uses these deeper reefs. Our results were just published in Marine Ecology Progress Series
We have published a new review on the migration patterns of sharks and how these relate to conservation management. We also try to clear up some of the movement terminology used in the shark research literature.
We have been working at Palmyra atoll since 2003 and frequently see sharks; primarily blacktip, grey and whitetip reef sharks. We sometimes see other species such as Galapagos sharks and scalloped hammerhead sharks. However, we only started seeing sicklefin lemon sharks from 2010 onwards. Since that time the number of lemon shark sightings has really started to increase. We likely witnessed a recent colonization event as previously lemons were only recorded as far north as Fanning Atoll. We document the presence of lemon sharks at Palmyra in a new paper in Marine Biodiversity Records.
A juvenile sicklefin lemon shark at Palmyra Atoll (photo Y. Papastamatiou)
Manta ray in the Palmyra lagoons. Photo: Y.Papastamatiou
We have a new paper in Marine Biology (McCauley et al. In Press) where we use a variety of tools to find out how filter feeding manta rays use lagoon habitats at Palmyra atoll. We show that manta rays spend a lot of their time in lagoons, and are getting most of their energy from plankton in these areas. These lagoons may also be nursery habitat for juvenile mantas, as there are fewer large sharks which might make these habitats safer. These results show how important lagoons may be to manta rays, which could have consequences for manta rays in other locations. Lagoons are often heavily used by human populations and suffer from pollution or habitat modification.
We are interested in the processes that structure vertical communities on the wall of Grand Cayman. I just returned from a preliminary scouting trip where we used mixed gases to survey the wall down to depths of 98 m. Below is a clip of one of our dives: