Article:Reefs in your living room

Saturday April 25, 2009

Stories by MARIA DANIEL

Until recently, only specialists could maintain marine tanks. Now, with a bit of planning and know-how, everyone can enjoy the magic of coral reefs at home.

Garden ponds were a feature in ancient Chinese, Mesopotamian, Greek and Indian homes and palaces. But indoor aquariums are a fairly new invention.

The traditional goldfish bowl is said to have been invented by the gorgeous and vulgar Jeanne-Marie Du Barry who became the mistress of King Louis XV in France in 1768. Aquariums made up of sheets of glass glued onto a metal frame appeared in the early 1800s but early models leaked like mad and had to be supervised night and day.

Sohal fish from the Red Sea swimming around coral.

Today, leak-proof fish tanks are easily available. Freshwater tanks for guppies and goldfish are relatively easy to set up and maintain. But marine tanks are not so easy. This is because reefs are complicated ecosystems that form the background to some of the world's most fascinating underwater wars.

The weird world of reef life

Reefs are created by tiny sea creatures called coral polyps that live in large groups on the ocean floor. A group of these little animals called hard corals produce a rock hard limestone skeleton that protects them from predators.

Coral reefs are a mix of live coral and limestone skeleton leftovers inhabited by other fish and animals. These reefs act like huge apartment complexes. Even though they cover less than 0.2% of the ocean floor, coral reefs are home to more than nine million species. Coral reefs rival tropical rainforests for biodiversity, hence their nickname Rainforests of the Sea.

Coral reefs are incredibly complicated eco-systems. Although scientists have spent years figuring out how they work, our knowledge of reef ecology is still quite limited.

Toadstool leather coral use chemical warfare to kill their neighbours.

As the French pioneer sea explorer Jacques Yves Cousteau pointed, out: "No aquarium, no tank in a marine land, however spacious it may be, can begin to duplicate the conditions of the sea."

Marine biologists are discovering that some of the most common marine tank denizens lead incredibly complicated lives.

The popular toadstool leather coral from Indonesia and Tonga looks pretty and inviting but it is allelopathic, meaning it can harm neighbouring corals through chemical warfare.

Toadstool leather coral eats microscopic algae. When coral feel they have too little space, or too many neighbours, they kill off competitors by leaking poisonous substances into the water.

This coral can also move about. It can detach its bottom from whatever it's stuck to and reattach itself in a place it thinks is a better home.

Luckily, toadstool leather coral isn't aggressive. It is perfectly happy to live in a tank, as long as it has enough space and food.

Spaghetti leather coral from the Indo-Pacific is more aggressive. This gorgeous coral eats algae as well as microscopic animals like zooplankton, baby brine shrimp and phytoplankton. But it considers other coral enemies and will drape itself over neighbours and kill them.

Then there are the fish. In documentaries, there are always shots of angel fish darting in and about the reefs. While they look really pretty, these fish are actually eating the coral. If you put a bunch of these in your tank in the wrong conditions, they will eat up your coral.

In addition, many reef inhabitants use poison as a defence against predators. Box fish are usually quite gentle, but if they are bumped by another fish, or frightened in some way, box fish can release enough poison to kill off a whole reef tank.

Such problems put off the casual fish admirer. But fans contend these challenges are precisely what makes reef tanks such a fantastic hobby.

Source: www.malalaaina.org. The Ocean Eco foundation, www.marinebiology.org

Related stories:
The health benefits of aquariums
Don't let your tanks kill our reefs

This article was taken from: The Star Online: Lifestyle: Living 25 April 2009