THE PRODUCTIVITY OF HAWAIIAN FRINGING‐REEF CRUSTOSE CORALLINACEAE AND AN EXPERIMENTAL EVALUATION OF PRODUCTION METHODOLOGY 1

Estimates of the mean net total contribution to the Waikiki reef by Porolithon onkodes, P. gardineri, and Sporolithon erythraeum are quite close. Hydrolithon reinboldii and melobesioid “C” contribute 5 and 3 times more. The net contribution to the total reef system by fringing‐reef crustose Corallinaceae is 5.7 g C m −2 day −1 . Crustose coralline algae are comparable, as producers, to other photosynthetic reef organisms. Several measurements of productivity were used in replicate on the same thalli. The 14 C data, although somewhat higher, were not significantly different from the O 2 and pH electrode data; rates determined by all three techniques showed the same serial order, by species, from highest to lowest producer. The pH and O 2 electrode methods are more useful and reliable than the 14 C data where high sensitivity is not critical.