Holocene Sea-Level Rise and the Fate of Mangrove Forests Within the Wider Caribbean Region

Abstract

This paper (1) reviews mangrove forest peat accretion data obtained from carbonate settings of the Wider Caribbean Region and (2) evaluates the fate of these forests based upon current global eustatic sea-level rise projections. Historical peat accretion rates calculated using ¹³⁷Cs or ²¹⁰Pb average 3.7 mm yr^-1. Peat accretion rates calculated using ¹⁴C average 1.0 mm yr^-1. The discrepancy between historical and geological accretion rates, also recognized in salt marsh settings, is attributed to organic decomposition and sediment compaction. Our conceptual model, which is based upon comparisons between projected rates of global eustatic sea level rise and peat accretion, predicts stable forest conditions only if historical accretion rates persist during a conservative (low) sea-level rise of ~1.3 mm yr ¹. Best guess (middle) and high estimates of a sea-level rise of as much as 8 mm yr ¹ will likely submerge mangrove forests located within carbonate settings of the Wider Caribbean Region.