In the front line What happens when ecosystem services are lost? Just as it is hard to calculate accurately the economic value of different ecosystems, it Is equally difficult to predict the cost to society of losing their various services. It was thought that the bleaching event of 1998 in the Indian Ocean would have a major impact on tourism and fisheries. It was estimated, for example, that Tanzania would potentially suffer a direct loss of US20 million from tourism revenue (Westmacott et at, 2000al. However, neither sector underwent the expected decline: tourism fluctuated but probably more as a result of worldwide political and economic changes; while fisheries are still in decline largely because of overexploitation. Both the 1997 bleaching and the 200i tsunami were single, if acute, events, and reefs and mangroves are expected to recover from damage incurred. A more typical scenario is of reefs and mangroves undergoing steady decline. Ecosystems that can no longer provide their full ecological services have a social and economic 'cost' to humanity, which can be felt in areas or situations many miles away Ultimately, therefore, degradation of coral reefs and mangroves will cause loss of fishing and tourism revenue and other forms of livelihood, loss of export earnings, malnutrition due to lack of protein, increased coastal erosion, and destruction from storms and catastrophic natural events. It is predicted that, for example, over a 20-year period, blast fishing, overfishing and sedimentation in Indonesia and the Philippines could lead to a net economic loss of US26 billion and US25 billion respectively for these two countries (Burke et al, 20021. In the Caribbean, coral reef degradation continuing through to 2050 could reduce benefits from fisheries, dive tourism and shore protection by a predicted total of US350 million to US870 million over that period (Burke and Maidens, 2004). LOSS OF REGULATING SERVICES The impact of the loss of the protective functions of coral reefs and mangroves is already being felt in some countries. Parts of Sri Lanka, India, Indonesia and the Maldives, where coral mining and collection has almost eliminated some reefs, have already seen serious erosion. In Sri Lanka, erosion on the south and west coasts now averages an estimated in cm a year, considered to be partly due to damage to reefs. Some US30 million has already been spent on breakwaters and other constructions to curtail this, and it has been estimated that the cost of replacing the coastal protection provided by these reefs would be US246 000-836 000 per km (Berg et a, 19981. A hotel in West Lombok, Indonesia, spent an average of US125 000 a year over a seven-year period restoring its 250-metre-long beach, which had been eroded largely because of offshore coral mining (Riopelle, 19951. Modelling and predictions of the impact of the loss of natural shore protection provide dire warnings. Modelling of the changes in wave energy striking some island shorelines in the Seychelles (Sheppard et at, 20051 indicates that wave energy has recently doubled as a result of sea level rise, loss of corals from reef flats due to bleaching, and changes in reef crest profiles and wave 21