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Giant Tritons eat Crown-of-thorns Starfish which in turn eat Corals. Shell-collecting is therefore contributing to the worldwide destruction of Coral Reefs.
The Giant Triton (Charonia tritonis) is a very large mollusc with an attractive shell. Cutting off the tip of the spire turns it into a musical instrument, and it has been used as a trumpet since ancient times. (The sea-god Neptune is often depicted with a Triton in his hand.) Tritons are now very popular with shell collectors, and over-collection has meant that Tritons have become rather scarce. This is unfortunate because the Giant Triton is one of the few natural enemies of the Crown-of-thorns Starfish (Acanthaster planci). Along with many other factors – most attributable directly to man’s activities – the increasing numbers Crown-of-thorns Starfish is responsible for causing much damage to Coral Reefs around the world, including the Great Barrier Reef in Australia. This starfish is a specialist predator of corals, and its numbers have increased enormously in recent years. Part of this increase might be natural, and some is due to the decline of the Giant Triton, but it also seems that run-off from agricultural land might be having an effect. The link between agricultural activities on land and the increase in Crown-of-thorns Starfish on Coral Reefs is not an obvious one. The water that flows from fertilised areas adds nutrients to the sea-water. Coral polyps are able to use these nutrients, and they then ‘cut-down’ on their intake of live food from the water. This allows more of the eggs and planktonic larvae of the starfish to survive – so you get more starfish. Since the larvae of the starfish can drift many miles in the ocean currents this means that Coral Reefs distant from the areas of pollution can be adversely affected. Aware of the problem with the Crown-of-thorns Starfish helpful fishermen often chop up any starfish they accidentally catch and throw the bits back into the sea. This appears to be a good idea at first – but when you realise that starfish are capable of regeneration it seems less so! Many of the bits simply grow into new adult starfish. The Crown-of-thorns Starfish is an ancient inhabitant of the Coral Reefs. It is well adapted to life on the reefs, and is essential to the long-term well-being of the whole reef. By clearing away patches of coral it opens the way for new settlement and allows reefs to change gradually over time. The problem (as usual) is man! Our activities, from shell-collecting to fertilising agricultural land, have upset a natural balance that has existed for millennia. There are now simply too many Crown-of-thorns Starfish and they are ‘clearing’ patches of coral faster than the reefs can regenerate. Shell-collecting is just one of the many ways in which man is damaging Coral Reefs. Like this? – see what else I have written.
The copyright of the article The Giant Triton in Marine Life is owned by John Blatchford. Permission to republish The Giant Triton in print or online must be granted by the author in writing.
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