Wetlands’ Inventory, Mapping and Land Cover Index Assessment on Mauritius

Past studies conducted on wetlands of Mauritius lead to the conclusion that half of the wetlands have been backfilled for touristic and housing development and that the ecological condition of the remaining wetlands is being seriously challenged by numerous threats, natural and anthropogenic. This research aimed to fill the information gap concerning wetland type and distribution. For this, using published maps and satellite imagery, wetlands were digitised resulting in 144 wetlands and categorised into 8 ecological units. Afterwards, a number of wetlands were ranked according to their environmental condition based on a series of Land Cover Indices (LCIs). These indices were derived by analysis of land cover types and slope gradient within a 50 m and a 950 m watershed-bounded buffer zone. Wetlands in forested areas were the least disturbed, with LCI of typically 0.30, but potentially threatened by sediment accumulation due to a high slope gradient (>20 %). Three wetlands in Mauritius are classified as Ramsar wetland. One of them, the Blue Bay Marine Park (BBMP) has moderately good condition (LCI = 0.55). The other one, the Rivulet Terre Rouge Estuary Bird Sanctuary (RTREBS) was among the most heavily impacted (LCI = 0.87) due to intensive urbanization.