Protective capacity of mangroves during tropical storms: a case study from ‘Wilma’ and ‘Gamma’ in Belize

Abstract

Globally threatened mangrove forest habitat is often considered an important buffer protecting coastlines from wave and storm impacts and coastal erosion. However, there is little empirical data quantifying the protective effects of mangroves during storms, primarily because of the difficulty of predicting where and when a storm will intersect the shoreline, to facilitate data collection before and after storm events. In 2005, opportunistic results from an ongoing study quanti- fying differences between intact and cleared mangrove areas on Turneffe Atoll, Belize, provided such pre- and post-storm data from tropical storms 'Wilma' (later a Category 5 Hurricane) and 'Gamma'. We compared differences in equipment retention rates of 3 types of experimental devices previously installed in adjacent intact and cleared mangrove areas. Retention rates were greater in intact mangrove areas, empirically demonstrating the protective capacity of mangroves during moderate magnitude storm events. The results support the assumption that removal of mangroves diminishes coastal protection not only during catastrophic storm events such as hurricanes or tsunamis, but also during less energetic but more frequent events, such as tropical storms. This high- lights the importance of improved coastal zone management, as storm events may increase in frequency and intensity with changing climate, and coastal mangrove forest habitats continue to decline in size and number.