Eakin,-C.M. The 1982-1983 El Nino: Impact of eastern Pacific reef carbonate budgets and implications for severe bleaching disturbances. PAC.-SCI. 1992. vol. 46, no. 3, p. 377. Sea surface warming during the severe and prolonged 1982-1983 El Nino-southern oscillation (ENSO) event resulted in bleaching and mortality of over 50% of reef coral cover at Uva Island, Panama. Subsequently, densities of the eroding echinoid Diadema mexicanum increased from pre-ENSO values of 3 individuals/m super(2) to at least 50 individuals/m super(2) in the seaward reef base zone, where erosion of the reef framework currently exceeds 13 kg CaCO sub(3)/m super(2)/yr, producing a vertical loss of 22 mm of framework per year. A preliminary CaCO sub(3) budget of Uva Island reef has been calculated from estimates of production by corals and coralline algae, framework destruction by D. mexicanum), infaunal eroders, fishes and other motile eroders, and sediment retention within the framework. Damselfish and their algal lawns protect portions of the reef from erosion, contributing significantly to the budget. The combination of coral mortality and increased densities of eroding echinoids resulted in a 60% decline in net CaCO sub(3) deposition.