The spatial distribution of shallow-water (<150 m) black corals (Cnidaria: Antipatharia) in the Hawaiian Archipelago

Abstract

The Hawaiian Archipelago contains some of the best surveyed black coral populations on the globe; however, most previous surveys have grouped all black coral species into a single category. As a result, the unique ecological features of individual species have not been identified. This study mapped the spatial distribution of eight antipatharian species (Antipathes griggi, Antipathes grandis, Cirrhipathes cf. anguina, Stichopathes echinulata, Stichopathes? sp., Aphanipathes verticillata, Acanthopathes undulata and Myriopathes cf. ulex) found in shallow-waters (,150 m) along the Hawaiian Archipelago, and compared data on substrate type, depth and temperature among species. All black coral species were exclusively recorded on hard substrates and were generally widely distributed along the Hawaiian Islands. Additionally, antipatharian species were found at overlapping depths and temperatures, although there were significant differences in the mean depths and temperatures between most species. In cases where species did not have significant differences in mean depths, the overlapping species had different colony and polyp morphologies, which may serve to minimize competition by allowing species to grow most efficiently under particular current regimes. This study represents one of the first to map the spatial distribution of sympatric antipatharian species, and indicates that individual species exploit unique environments in terms of depth and temperature or have unique morphologies to avoid overlap.

A comprehensive investigation of mesophotic coral ecosystems in the Hawaiian Archipelago

“…However, the reliability of coral phylogenies has been challenged due to limited genetic variation ( Sinniger, Reimer & Pawlowski, 2010 ). In addition to scleractinian corals, eight antipatharian coral species were documented from MCE depths through work associated with this study and published previously ( Wagner et al, 2010 ; Wagner et al, 2011 ; Wagner, 2015a ; Wagner, 2015b ).…”

Structure of Mesophotic Reef Fish Assemblages in the Northwestern Hawaiian Islands

“…They are part of the Papahānaumokuākea Marine National Monument and UNESCO World Heritage Site, a marine protected area encompassing over 362,000 km 2 that is one of the largest in the world. Previous mesophotic studies in the NWHI focused on the taxonomy, geographic ranges and sexual reproduction of black corals [ 18 , 33 – 36 ], on the distribution of benthic communities [ 17 ], and on endemism among mesophotic reef fish assemblages [ 37 , 38 ]. Here, we investigated changes in the composition and trophic structure of reef fish assemblages with depth in the NWHI.…”

Low vulnerability of the Mediterranean antipatharian Antipathella subpinnata (Ellis & Solander, 1786) to ocean warming

“…This mesophotic tropical species was experimentally exposed to medium-term (16 days) heat stress (up to 4.5°C), and results highlighted metabolic depression, impairment of healing capacities and activation of stress response mechanisms (i.e., tissue necrosis, mucus production and antioxidant responses). In the Mediterranean Sea, the effects of increasing temperature on antipatharian species have never been investigated, despite the fact that temperature has been shown to significantly influence their distribution (Etnoyer et al, 2018;Wagner, 2015;Yesson et al, 2017). Investigating the effects of ocean warming is particularly relevant for A. subpinnata forests, whose vulnerability is increased by the low genetic connectivity between offshore and coastal populations (Terzin et al, 2021).…”