
White beach sand
by Parrot Fish

Yes, and it not a joke!! But if at the moment you find yourself on one of these beaches, like Saona or Catalina islands in Dominican Republic and barefoot, you don’t have to rush for your sandals! Now that you know that the sand you are walking on is made up of minute excrements of this fish, here’s the explanation why you shouldn’t feel sick or be put off.
So, why doesn’t it smell?
Well, the truth is that the excrement is really small pieces of coral which the parrot fish spend their time nibbling during the day. It doesn’t feed off the coral, it eats seaweed and polyps from the surface but, at the same time and because of its beaked mouth, it gets a ‘plus’ of hard coral which it breaks up with the teeth in its throat.
The parrot fish can’t metabolise this coral so it ‘throws it overboard’ in the form of grains. The existence of this species of fish is essential to the survival of the coral as it acts as a ‘natural cleaner’ of parasites, etc. that grow on it, so without the help of the parrot fish the coral would die. If you find yourself near one of these fish you will find them munching and making crunching sounds with every bite.
Another reason is that they need to do this constantly in order to keep their beaks clean and that they (the beaks) don’t grow too much. We’re talking about an insatiable fish that spends the whole day eating and ‘discharging’ without a break and that’s why just one parrot fish can produce 100 kg of white sand every year!! Thinking about this then, to those of us who adore paradisiacal beaches, it’s obviously important that there is an abundance of the parrot fish.
Just imagine, 100 kg of white sand a year for every year of the life of the fish… taking into account that it is one of the most abundant in the coral reefs.. and after thousands upon thousands of years of existence….. imagine the amount of white sand these colorful fish have produced.
Of course, this doesn’t mean that all the white sand to be found on tropical beaches comes from the back end of this fish: scientists confirm that these fish are responsible for about 70 per cent of all the sand on the tropical beaches. I have magnified the photo of the sand about 30 times and you can see it on the right: together with other sediments dragged along by the rivers into the sea, among the grains of sand you can see tiny fragments of shells that get crushed by aggressive waves from the sea, especially during storms. All of this ‘paints’ our beaches a little so that they aren’t as white as talcum powder…..
With 100 kg of white sand a year it’s a pity that the currents aren’t strong enough to carry some of these grains of sand to the coasts of the colder countries in the world, don’t you think that this would brighten up their beaches!
However, thank god we have parrot fishes in our desert islands!