Steps taken by five dive centres here to be part of the United Nations' Green Fins project would be described as being environmentally conscious. It is, of course, in the interests of dive operators to preserve the natural assets they depend on. But many of them are concerned for legacy reasons as well, as over a million new divers are drawn to coral reefs each year - peering in awe at the beauty, reaching out to touch marine life, and kicking fragile structures in the process. It is a case of being admired to death, as is the fate of Venice, according to conservationists. The hordes of visitors there, up to 20 million a year, have driven up prices and driven out many Venetians - half its population has left over the past 30 years.

Coral reefs are far more fragile and face threats far worse than snaking queues and selfie sticks in the narrow streets of the sinking city. Climate change is bad enough for corals, turning them white as temperatures rise and causing water to become more acidic. But there's more to contend with: the destruction caused by anchors dropped on reefs, blight of overfishing, pollution flowing into oceans and relentless coastal development.

The Green Fins effort to raise awareness of harmful practices among divers is a modest but necessary initiative to help preserve mankind's sunken treasures, so to speak. It helps to counter what is the bane of the environmental movement. That is the notion that the impact of climate change is beyond anyone's control by now, and that an individual's puny contribution to conservation will not amount to much - a mere drop in the ocean. But that is precisely how great tides of change come into being, growing one ripple at a time, till their momentum becomes unstoppable. That ought to be the way to view global efforts like Green Fins as well as home-grown projects that focus on small habitats. In and of itself, an undertaking might not save the world, but it holds the possibility of enlightening and inspiring others. It is the potential of the ripple effect that makes even the smallest green effort valuable, aside from its localised benefits.

Alongside threats like pollution and reclamation, Singapore's marine biodiversity also suffers from the woeful lack of awareness among people of its range and uniqueness. Acting together, these have led to the loss of over 60 per cent of the nation's coral reefs. Surveys have shown the presence of 250 species of hard coral, 28 species of seaweed, sea cucumbers, sand dollars, anemones, multi-coloured sponges, crabs, shrimps and nudibranch. Gratifyingly, efforts are now made to relocate coral colonies that are deemed vulnerable, like those moved from the Sultan Shoal to sites at St John's and Sisters' Islands, in order to protect them from the impact of Tuas Terminal development. Every project, big or small, helps to preserve such treasures for future generations.