NURP and CRCP Collaboration Supports Research of HI's Deepwater Macroalgae
This story entered on 2nd Feb, 2005 09:15:52 AM PST

Green macroalgae consist of various species of rootless marine plants, many of which provide valuable services such as warning of the presence of high nutrient levels in the water column or serving as the dominant energy source in shallow water reef ecosystems. Though both shallow and deep water species occur in Hawaii, relatively few in situ studies exist of deepwater macroalgae which occur at depths up to 200 m, beyond the limits of standard SCUBA.

Recent research, funded collaboratively by NURP and the NOAA Coral Reef Conservation Program (CRCP) has shed light on many aspects of deepwater algal assemblages. For example, it had been unclear whether Hawaii's deep-and shallow- water algal communities are different taxonomically. Study results suggest Hawaii's deep- and shallow- water algal assemblages are taxonomically distinct, with many species exhibiting a high standing biomass and complex distributional patterns. About 30% of the species surveyed were observed for the first time in the Hawaiian Islands. The research findings, by providing a greater understanding of species make-up and distribution, may be applied toward deep water ecosystem management in marine environments.

The research was conducted at locations throughout Hawaii with the Pisces V submersible and RCV-150 ROV owned and operated by NURP's Center for Hawaii and the Western Pacific, the Hawaii Undersea Research Laboratory. Abundant algal meadows were found in various locations at depths from 30 to 100 meters. The calcified green alga Udotea sp., never before reported for the Main Hawaiian Islands, occurred between 29 to 90 m near the island of Oahu, and covered up to 100% of the substrate forming the most distinct, extensive deep water meadows surveyed. Meadows of Halimeda sp. occurring at 50 to 100m were also observed at most locations; while Cladophora sp. was found to be abundant at 212 m, yet absent at shallower depths.

Contact information
Name: John Smith
Tel: (808) 956-9669
jrsmith@soest.hawaii.edu