Saturday, January 31, 2009

Cave Sponges: critical to the coral reef's food chain

I'm sure you have heard about the challenges faced by our coral reefs. Researchers are saying that from 25% to 50% and more of our corals reefs are showing definite decline due to pollution, changes in water temperature, and other effects that can be attributed to man-made activities.

Because of the low level of nutrients in tropical waters, coral reefs have often been described as oases in the desert. And we are still learning just how they are able to survive in such a beautiful but harsh environment.

A recent report explores one component that contributes to the delicate web of a healthy reef: cave sponges. Marine biologist Jasper de Goeij has been studying the role that these basic multi-celled animals play in maintaining the nutritional cycle of the coral reef. His studies show that corals and algae dispense organic compounds that few creatures can use as food. The sponges, however, filter this particulate matter as part of its normal process in filtering vast amounts of water to extract what little nutrients are available.

To protect and sustain itself against this intake of organic material (that can include viruses, bacteria, and other poisons) the sponge is continually rejuvenating cells and the dead cells it sheds form an organic material that can be utilized by many organisms on the reef. In this way, a cycle of mutual dependence is formed.

While our attention is often focused on the most colorful of the basic reef builders, the coral, we must always remember that a coral reef is a complex system with many organisms, plant and animal, playing important roles - sometimes behind the scenes and out of view - in maintaining a healthy tropical ecosystem.

Read article from Insciences Organisation.

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