May 22, 2013
Volcanoes Responsible For Coral Reef Diversity
Michael Harper for redOrbit.com — Your Universe Online
A new study claims earthquakes and volcanoes are responsible for the diverse nature of the ocean´s coral reefs. With this information, scientists are now becoming even more worried about global warming. If these monumental geological events play a role in coral creation, it may be even more difficult to replace any reef lost to climate change and rising sea temperatures. This study, conducted by scientists from the ARC Centre of Excellence for Coral Reef Studies (CoECRS), is published in the journal Proceedings of the Royal Society B.Lead author Dr. Sally Keith of CoECRS and James Cook University says geological events and the general unease beneath the ocean floor is responsible for the wide variety of coral reefs seen in the Earth´s oceans. This also explains why some species of coral are more prevalent than others.
“There are many theories to explain how coral reefs came to be,” said Dr. Keith in a press statement.
“Traditionally scientists have tested these theories by looking at where species occur. We used a fresh approach that focused on where species stopped occurring and why.”
Dr. Keith and her colleagues were shocked when they analyzed the results of their study. Though it had previously been understood that coral species were at the mercy of environmental factors such as temperature and habitat, the results suggested that geological events from millions of years ago actually determined what species of coral grew and where. The gradual shifting of tectonic plates over millions of years is responsible for creating a diverse species of coral, says Dr. Keith.
“For example, Hawaii is a chain of volcanic islands that has formed as a tectonic plate moves over a ℠hotspot´ of molten rock. The rock repeatedly punches through the Earth´s crust as lava, producing volcanoes that jut out above the ocean surface, eventually forming a chain of volcanic islands,” explains Dr. Keith.
“Over time, corals spread across the island chain using the islands as ℠stepping stones´, while at the same time they (remained) isolated from the rest of the Pacific. As a result, a distinct set of Hawaiian coral reefs arises.”
Additionally, the team also found that older species of coral are better equipped to expand into new territories.
Volcanoes have been known to play a role in the formation of certain types of coral. For instance, coral that grows around a volcanic island as it sinks below the sea surface is called an atoll. These atolls can take millions of years to fully form, a fact which co-author Professor Sean Connolly says should be something to consider when discussing climate change.
“Climate change is leading to the loss of corals throughout the tropics. This study has shown that the diversity of corals we see today is the result of geological processes that occur over millions, even tens of millions, of years,” said professor Connolly.
“If we lose these coral-rich environments the recovery of this biodiversity will take a very long-time, so our results highlight just how critical it is to conserve the coral reefs that exist today.”