Underwater canyons have long been considered important habitats for marine life, but until recently, only canyons on continental margins had been intensively studied. Researchers from Hawaii Pacific University (HPU) and the Universtiy of Hawaii at Manoa (UHM) have now conducted the first extensive study of canyons in the oceanic Hawaiian Archipelago and found that these submarine canyons support especially abundant and unique communities of megafauna (large animals such as fish, shrimp, crabs, sea cucumbers, and sea urchins) including 41 species not observed in other habitats in the Hawaiian Islands The research is published in the the March issue of the journal Marine Ecology.
The researchers used both visual and video surveys from 36 submersible dives (using UHM's Hawaii Undersea Research Laboratory submersibles Pisces IV and Pisces V) to characterize slope and canyon communities of animals at depths of 350-1500 meters along the margins of four islands of the Hawaiian Archipelago. The coastlines of Oahu and Molokai were selected as examples of high, mountainous islands with large supplies of terrestrial and marine organic matter which can be exported down slopes and canyons to provide food to deep-sea communities. Nihoa Island and Maro Reef were chosen to represent low islands and atolls that are likely to export less organic matter to feed the deep-sea fauna.
Eric Vetter, the lead author of this paper and a Professor of Marine Biology from HPU, had previously studied four canyon systems off the coast of California and found that the productive waters along southern California had resulted in the delivery and accumulation of substantial amounts of organic material. "Craig Smith (Professor of Oceanography at UHM and co-author of this study) and I wondered if the same dramatic contrast in benthic food resources between canyon and non-canyon settings seen in continental margins would also occur on tropical oceanic islands," says Vette
|Contact: Tara Hicks Johnson|
University of Hawaii at Manoa