Effects of seagrass bed removal for tourism purposes in a Mauritian bay

Stresses and shocks are increasing on the main natural assets in Mauritius (Western Indian Ocean) by tourism (marine-based) development activities. Seagrasses are removed by hotels in the belief that they are unsightly or harbour organisms causing injury to bathers. Environmental changes (e.g. sediment characteristics and infauna distribution, water quality, seagrass biomass) resulting from clearing of a seagrass bed to create an aesthetically pleasant swimming zone for clients of a hotel were monitored during June 2000–July 2001, and compared to conditions prevailing in an adjacent undisturbed area. Key observations in the disturbed area were: highly turbid water overlying a destabilized lagoon seabed, complete loss of sediment infauna, and dramatic dry weight biomass declines (e.g. 72 and 65% in S. isoetifolium and H. uninervis, respectively). Such disruptions draw-down resilience rendering the marine habitats less robust and more vulnerable to environmental change and extreme events, with higher risks of chaos and ecological collapse, and constitute a major threat to the industry itself.