Title: CHARACTERIZATION OF MESOPHOTIC BENTHIC COMMUNITIES IN THE NORTHWESTERN HAWAIIAN ISLANDS

Abstract: Historical surveys to characterize the marine biodiversity of the Northwestern Hawaiian Islands (NWHI) have largely focused on shallow (<30 m) or deep (>300 m) waters, with intermediate depths being largely ignored. This intermediate zone hosts mesophotic coral ecosystems (MCEs), which are notoriously undersurveyed worldwide and particularly in remote locations like the NWHI. Since 2012, annual expeditions have focused on systematically characterizing the mesophotic (50-90 m) biodiversity in the NWHI using mixed-gas technical diving. As part of these efforts, the bethic flora and fauna was surveyed using photoquadrat images taken along belt-transects, in combination with specimen collections that were identified by taxonomic experts. Benthic communities were largely dominated by macroalgae and crustose coralline algae, with hermatypic corals and other invertebrates generally covering less than 2% of substrates. Additionally, benthic communities in the NWHI exhibited latitudinal patterns, with linear decreases in coral cover and linear increases in macroalgal cover along a latitudinal gradient (23-28⁰ N). Finally, benthic communities were almost exclusively composed of species that are native to the Hawaiian Archipelago, with the featherduster worm (Sabellastarte spactabilis) being the only non-indigenous species recorded among the over 200 benthic species documented during our surveys. These results underscore the importance of protecting the unique biodiversity of this region using the highest conservation measures available.

Authors: Wagner D, Chang C, Barkman A, Tepper JR, Kosaki RK

Presentation: Poster (#328)

Session: 29

Date: 06/21/16

Time: 18:15 - 19:45

Location: Poster/Exhibit Hall

Back