Some conservationists have expressed their concern over the use of live rock in the aquarium hobby. They see this as denuding the reefs, and, if that were shown to be correct, I for one would have sympathy.
As I understand it, much of the live rock is taken as rubble, that is, it is not part of the actual reef, but rock that lies loose. There is an argument to say that this rock should not be touched as it belongs to the reef. The opposite is that the reef is unchanged if it is taken away. I feel fairly certain that some rock may well be taken from the actual reef in some areas, in the same way that cyanide is/was used to obtain fish. Hopefully the latter practice is now minimal or has ceased altogether.
The amount of live rock that is being used nowadays is substantial. It is probably the most used filtration media in reef aquariums, and is often used in fish only aquariums as well. So it is reasonable that some attention is paid to its source. No-one wants damage to be caused to the reefs because of the aquarium trade.
It was a pleasure therefore to read of the efforts of a commercial concern that is providing live rock but is not taking it from the reefs – well, not from the wet reefs anyway.
What is happening is that land based rock that used to be a coral reef is being mined in quantity and then transported out to sea, around 20 miles off-shore. In the sea it has been left as a coral reef allowing it to develop. The area used is in the Gulf of Mexico.
The commercial concern involved has to be congratulated as the rock had to be left for 4 years to develop naturally, so for that period the company had the investment but no profit. That length of time is quite a commitment.
The reef is being harvested now, but not all of it. Part is left intact without interference, and the remainder is recovered in sections by divers, who fill baskets that are raised to the surface for the waiting boat. The areas that have been harvested are re-seeded with replacement rocks from the land, and in this way a continuous supply is available. The amounts involved are substantial. The quality of the rock is described as ‘premium.’
Of course the mining of the rock from the land could be damaging environmentally. I assume that in order to obtain authority to mine the rock, an agreement to landscape the mining areas would be required.
Separate from the live rock enterprise and in a different area of the world is hard coral production. Divers go down to the reefs and selected mother colonies have a part removed. This part is placed in a small tube which in turn is fastened to a small manufactured standard tile. These tiles are then left in the sea to develop. Again, harvesting is delayed pending development, but after a period a near continuous supply of corals can be obtained. The system means the mother coral remains in situ and continues to provide further corals as long as it continues to be deemed suitable.
Much of the coral programme came about through an education exercise, where local collectors have been taught sustainable methods.
With all the gloom about the potential future of coral reefs at the moment, usually with global warming as a foundation, and the known problems of sedimentation, over fertilization, destruction for building needs etc, it is very pleasant to learn of efforts such as those described. True, in the commercial case it may be simply that a profit source was identified but so what, it is a big step in the right direction. Corals are grown (‘fragged’) by many aquarists, but the majority are still obtained from the wild, so the fact that some are now cultured in the wild and at the same time protect the livelihood of local people can only be good.