Ecological surveys were conducted at seven stations across the reef flat and two stations on the fore reef following a protocol similar to previously established methods for characterizing benthic cover on coral reefs. Pre-bleaching surveys were conducted between 29 May and 7 June, and post-bleaching surveys were conducted between 27 July and 2 August. At each station, 5 \u00d7 50 m transects were laid out and photographed every meter (0.5 m by 0.5 m image area), giving a total of 250 photographs per station. Transects were oriented N-S (along-shore) and spaced 5 m apart (cross-shore).\u2028
Benthic photo-quadrat\u00a0surveys on Dongsha Atoll.
\nRelated publications:
\nDeCarlo T.M., Cohen A.L., Wong G.T.F., Davis K.A., Lohmann P., & K. Soong (2017). Mass coral mortality under local amplification of 2 \u00b0C ocean warming. Scientific Reports 7, 44586. doi:10.1038/srep44586
Images were analyzed using the program Coral Point Count with 5 randomly placed points per image identified to coral genera or benthic substrate type. The same survey methodology was repeated at the same locations pre- and post-bleaching for reef flat stations (E2-E5), while fore reef station E1 was surveyed only post-bleaching. The channel north of Dongsha Island was inspected visually for bleaching on 24 June and 29 July, but no photo surveys were conducted. In total, we made 22,500 point identifications in our study. All corals, whether alive and pigmented, bleached, or recently dead were identified to genera level. Bleached corals were identified based on lack of pigment and the presence of live polyps, whereas recently dead corals were distinguished based on structurally intact corallites without any live polyps present.
\nBCO-DMO Processing:
\n- transposed data so sample data are in columns;
\n- replaced spaces with underscores and removed parentheses from site identifiers.