THE RELEVANCE OF REEF RESTORATION IN THE CONTINUALLY CHANGING MARINE ENVIRONMENT OF SINGAPORE

Singapore’s marine environment has changed significantly over the past five decades through coastal modification and intense human activities. More than 60% of its coral reefs have been lost to land reclamation and the remaining reefs remain exposed to increased sedimentation. Reef restoration to address habitat loss and degradation is considered viable under the changing environmental conditions based on the persisting annual coral mass spawning events, active recruitment, high species diversity and recovery from mass bleaching impacts. These ecological attributes indicate that reef ecosystem integrity is still functioning and restoration measures are relevant. An analysis of past and ongoing restoration initiatives indicates their effectiveness in improving degraded reefs as well as establishing new reef communities on modified coasts.

Beach sediment budgets and coastal modification

In recent years a start has been made in developing the concept of the coastal sediment compartment because of a growing interest in the question of sediment budgets. In many ways the coastal compartment is the equivalent of the drainage basin in terrestrial geomorphology-a unit within which it is theoretically possible to compute sediment gains and losses and so arrive at a quantitative budget statement. On coasts of relatively free transport where natural 'sediment-tight' compartments do not exist it is necessary to define notional compartments or longshore drift cells, the boundaries of which may be placed where transport rates are reduced, change significantly or are more easily measured. Hierarchies of compartments may be identified where large exclusive compartments may contain smaller non-exclusive subcompartments. Again the analogy is with different orders of drainage basins in the terrestrial situation (Davies, 1979).