Description of fish assemblages in the black coral beds off Lahaina, Maui, Hawai'i, A

Abstract

A series of scuba dives surveyed patches of black corals and their associated deep-reef fish community in the channel waters (50-73 m depth) of Maui, Hawaii. Most of the corals were identified as Antipathes dichotoma and averaged 76 cm (±.37) in height. Forty fish taxa were surveyed in the patches. Only Oxycirrhites typus was found exclusively within these coral trees. Sixty percent of the fish taxa surveyed were observed to frequent and pass through the coral branches. However, only four fish species were documented to reliably take shelter in the coral branches when evading an approaching diver. An archival video monitored movement patterns of fishes around a cluster of black coral trees for a 60-hr period. During daylight hours Dascyllus albisella, Centropyge potteri, Forcipiger flavissimus, Aulostomus chinensis, and Canthigaster jactator were observed to be the routine users of the coral patch, but only Dascyllus albisella and Centropyge potteri appeared to be resident to specific trees. At night Sargocentron sp. were observed feeding around the base of the coral trees, and Heniochus diphreutes dropped from their daytime position high in the water column to hide in the tree branches throughout the night. These observations indicate that black coral trees are used by many fishes as a general form of habitat, and if the coral trees are the largest relief feature at a site, their removal will likely impact the fish assemblage.