Benthic Composition of a Healthy Subtropical Reef: Baseline Species-Level Cover, with an Emphasis on Algae, in the North
The Northwestern Hawaiian Islands (NWHI) are considered to be among the most pristine coral reef ecosystems remaining on the planet. These reefs naturally contain a high percent cover of algal functional groups with relatively low coral abundance and exhibit thriving fish communities dominated by top predators. Despite their highly protected status, these reefs are at risk from both direct and indirect anthropogenic sources.
This study provides the first comprehensive data on percent coverage of algae, coral, and non-coral invertebrates at the species level, and investigates spatial diversity patterns across the archipelago to document benthic communities before further environmental changes occur in response to global warming and ocean acidification. Monitoring studies show that non-calcified macroalgae cover a greater percentage of substrate than corals on many high latitude reef sites. Forereef habitats in atoll systems often contain high abundances of the green macroalga Microdictyon setchellianum and the brown macroalga Lobophora variegata, yet these organisms were uncommon in forereefs of non-atoll systems.
Species of the brown macroalgal genera Padina, Sargassum, and Stypopodium and the red macroalgal genus Laurencia became increasingly common in the two northernmost atolls of the island chain but were uncommon components of more southerly islands. Conversely, the scleractinian coral Porites lobata was common on forereefs at southern islands but less common at northern islands. Currently accepted paradigms of what constitutes a ''healthy'' reef may not apply to the subtropical NWHI, and metrics used to gauge reef health (e.g., high coral cover) need to be reevaluated.
Competing Interests: The authors have declared that no competing interests exist.
Funding: Funding to the National Oceanic and Atmospheric Administration (NOAA) Pacific Island Fisheries Science Center (PIFSC) Coral Reef Ecosystem Division (CRED) for scientific expeditions to the Northwestern Hawai'ian Islands was provided through NOAA's Coral Reef Conservation Program. The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.
Contacts:
Peter Vroom
National Oceanic and Atmospheric Administration
Coral Reef Ecosystem Division, Joint Institute for Marine and Atmospheric Research
Peter.Vroom@noaa.gov
Jen Laloup
Public Library of Science
jlaloup@plos.org
415-624-1220
Citation: Vroom PS, Braun CL (2010) Benthic Composition of a Healthy Subtropical Reef: Baseline Species-Level Cover, with an Emphasis on Algae, in the Northwestern Hawaiian Islands. PLoS ONE 5(3): e9733. doi:10.1371/journal.pone.0009733
Provided by Public Library of Science
