Branch coral wall of
mini-atoll
| T. `Aulani Wilhelm Public Information Officer Hawai`i Department of Land and Natural Resources 1151 Punchbowl Street, Room 130 Honolulu, HI 96813 808/587-0330 (phone) 808/361-0650 (pager) dlnrpio@aloha.net News Release 18 |
DIVERS FIND UNUSUAL 'ATOLL WITHIN AN ATOLL' AT PEARL AND HERMES REEF, LARGE ULUA CONTINUE TO SWARM SCIENTISTS
While conducting their scientific assessments of coral reef habitat, scientists today dove at a site they described as an 'atoll within and atoll.'
Geologically speaking, the site wasn't an atoll at all. It was simply a place where the reticular (line) reefs within Pearl and Hermes lagoon networked together to form a nearly perfect circle of reef within its lagoon. According to Jim Maragos, principal investigator for the expedition, these reef holes, as they are technically called, occur at several places in the lagoon.
Regardless of its technical name, these reef structures are unusual, especially when compared to coral reef structures normally found in the main Hawaiian islands. The surrounding reef structures were comprised of gentle sloping walls of branch coral.
Branch coral wall of
mini-atoll
This particular area of interconnected reef was approximately 150 meters in diameter and only 15 feet in depth. Inside divers found hundreds of baby uhu, or parrotfish. The fish scientists believe that these reef holes serve as important nursery grounds for reef fish because they are so protected by the circular shaped reefs.
Diver exploring atoll
within an atoll
When divers first entered the site they were once again greeted by a swarm of over 100 giant trevally (ulua). They were also greeted by eight or nine galapagos sharks. These giant fish are found throughout the atoll and have been particularly curious about the divers.
The presence of these large predatory fish confirm for scientists the importance of limiting human presence at these islands and atolls. At places where human presence is limited, these large predators are found in abundance.
Due to weather, divers weren't able to access the outside of Pearl and Hermes atoll as they had hoped. The Rapture moved back to the southern end of the atoll this evening, to stay clear of the increasing north swells. As a result, divers will explore the south and eastern sides of the atoll tomorrow.