Coral triangle is the global center of marine biodiversity

The coral triangle is universally recognized as the “global center of marine biodiversity” and “the Amazon of the seas.”

It is fair to say that most of the Earth’s saltwater species that exist in today’s oceans owe their ancestry to ancient residents of the triangle. Now part of the South Pacific, the coral triangle was once a landlocked lake that formed during the Ice Age when massive blocks of ice sucked up the surrounding water, and land masses appeared from the ocean bottom. When the ice melted, the land was once again covered by water, and the species of the coral triangle propagated first east and west along the equator and then north and south.

Today, the triangle sits roughly in the tropical marine waters of Indonesia, Malaysia, Papua New Guinea, the Philippines, the Solomon Islands and Timor-Leste. All of it sits directly north of Australia. It covers 5.7 million square kilometers of ocean waters. The triangle is home to at least 500 species of reef-building corals and more than 3,000 species of fish, including the world’s largest fish – the whale shark – and the coelacanth. There are more species of coral, fish and crustaceans in the triangle than there are at any other location in the world.

But perhaps the most interesting thing about the triangle is the multitude of yet undiscovered, or, more accurately, scientifically unclassified wildlife that can still be discovered there today. All one has to do is dip below the surface of the water, and they can feast their eyes on an animal that would leave scientists dumfounded.

“You can see things that you’ve never seen before, and possibly things that are new to science that have never been described before,” said Rudy Whitworth who visited part of the coral triangle at Raja Ampat in Indonesia. He spoke about the coral triangle at this year’s Great Lakes Shipwreck Festival.

Whitworth, a member of The Ford Seahorses Scuba Diving Club, which sponsors the festival, said he filmed eight or nine undescribed species, including two that are likely brand new to science: a triple-fin blenny and a species of nudibranch.

“When I went to my experts, the doctorates that do the assigning, the scientists, they said ‘I have definitely never seen this one before.’ That’s really special.”

The uniqueness of the coral triangle is rooted in its role during the Ice Age. As ice cover grew from north and south polar ice caps, global temperatures dropped, and most warm-water species around the globe died. As the ice converged on the triangle area near the equator, the ice sucked up huge volumes of water and the ocean bottom suddenly became a land mass. The triangle area became land-locked and the warm-water species survived due to their comparatively warm location near the equator. Once the Ice Age ended, the ice melted and that ocean bottom was covered with water once again. But the result was the only warm-water species left were those located in the coral triangle.

“They have had longer to evolve. Therefore, there are more species there. So when the ice melted and the water came up, the species that were contained in this area actually went out and propagated all around the equator. And then they started working up and down. So the further you get away from this coral triangle, the fewer species you have. In terms of evolution, they have had less time to evolve.”