Mangroves

The rhythm of the sea
Pulses through the trees
While the leafy canopy
Rustles in the breeze

The fish and crabs are feeding
Among the mangrove roots
While birds and bats are breeding
In their leafy roosts

But now the trees are dying

In a smelly stagnant pond
Because their roots need drying
And they’ve lost their tidal bond

 Mangroves are marvellous! A productive tidal forest adapted to the rhythm of the sea. But to conquer this niche they had to first overcome the challenges of salt and waterlogging. Salt is excluded at the roots but also accumulates in the leaves which shed and in turn support a detritus food chain feeding crabs, prawns and fish. The tidal pulses on the other hand provide regular respite from waterlogging.

Marvellously adapted they may be but like many organisms living on the edge they are close to their upper tolerance limits. They are hence vulnerable to both waterlogging and hyper-salinity should the tidal flushing be inhibited. Great care is therefore necessary in the construction of causeways and other tidal barriers to ensure adequate flushing and complete drainage which in turn will prevent the death of mangroves and the loss of fish, crabs and prawns. It is very sad to see a marvel of nature transformed into a stagnant, foul smelling and mosquito infested swamp dotted with dead skeleton trees.