Coral Reefs More Diverse, and Fragile, Than Previously Thought

Even coral that looks the same, new research shows, may be part of a completely different species. Image credit: Wikimedia Commons

Some types of coral are abundant across reefs—turning up in a wide range of depths. Researchers have long assumed that this demonstrated versatility of the species—something that could be useful when rebuilding reefs damaged by pollution, bleaching, and other climatic events.

New research, however, has shown that these corals are not homogeneous. Instead, they consist of a variety of distinct and highly-specialized species—a finding that could have serious implications for the preservation of reefs worldwide.
Image credit: Wikimedia Commons
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Pim Bongaerts, a PhD researcher at the University of Queensland, explained:

However, we demonstrated that there is specialisation of the coral host to particular reef environments, with each strain of coral host associating only with particular types of symbiotic algae...the results also highlight the lack of connectivity between different habitats on a single reef, such as shallow and deep water, which has important implications under future climate change scenarios, as coral reefs will be largely dependent on neighbouring areas for their recovery.

It has long been thought that coral living in deep water could be used to repopulate damaged reefs. Unfortunately, this new research—and a concurrent transplantation project—have shown that this is not the case.

Sophie Dove, The Director of the Coral Reef Ecosystem lab of the Global Change Institute, commented that:

This essentially rules out the idea that corals from deep areas of the reef might act as a source of larvae for repopulating shallow water areas when they get damaged.

Though this is bad news for conservationists, the discovery provides an incredible new insight into how reefs develop such an incredible range of diversity. "Classically, the diversity of corals was thought to have arisen as a result of the geographic separation of populations over time," Dove explained before adding that:

Our data...reveal a compelling case of where genetically distinct populations of corals originated at the one geographic location due to specialisation to particular reef environments.

This ecological speciation is a well known driver of diversity in rainforests but this is the first indication that such a process could also play a role in the "rainforests of the sea."

More than anything, researchers explained, this study shows how little we understand about even the most heavily researched reef systems.

Read more about coral reefs:
6 Steps to Saving the World's Coral Reefs
Coral Reef Loss in Southeast Asia to Reduce Food Supplies 80%: Strong International Action Needed
Transplanting Coral As a Cheap, Easy Way to Restore Reefs?

Tags: Conservation | Coral Reefs