Halimeda composition and biomass along the Great Barrier Reef

Inter-reefal Halimeda communities from the far north to southern sections of the Great Barrier Reef were sampled: 1013 Van Veen grab samples from 281 stations, and 76 biomass samples collected by scuba divers from 12 stations. Halimeda, Udotea and Penicillus plants were air-dried, sorted into species, oven-dried and weighed. Organic content was calculated from weight loss after overnight combustion in a muffle furnace.Halimeda communities were differentiated as meadow, mound, and shoal. Species compostion variables were: location, % (of calcareous green algae); where found (within/outside meadows); other plant macrobiota was also recorded.Variables on biomass were: station location and number of samples; means of collection (grab, diver); area (m2); depth (shallow, Other algal species: Caulerpa brachypus, C. cupressoides, C. Mexicana, C. peltata, C. racemosa; Chaetomorpha spp.; Halophila decipiens, H. ovalis, H. spinulosa; Lobophora variegata; Monostroma spp.; Penicillus nodulosus; Struvea elegans; Tydemania expeditionis; Udotea flabellum, U. argentum; Vidalia spp.Locations: Far North section (Blackwood Channel, Creech Reef, Great Detached Reef, Hibernia Entrance, Pandora Reef, Quoin Island Entrance, Second 3-mile Opening, Waterwitch Entrance); Northern section (Lizard Island, Ribbon Reefs); Central section (Bowl Reef); Southern section (Swains reefs).Complements a study of Halimeda on reefs across the central Great Barrier Reef, see separate metadata record.