A reefscape from the Great Barrier Reef. (Photo credit: AIMS LTMP)
Starting next Monday I will begin making regular posts, excerpting a modified version of an article I published last year on the Earth Portal about Coral Reefs and Climate Change. The complete original article is archived here in the Coral Reefs Collection of the Encyclopedia of Earth. Ill cover global patterns of coral loss and several of the mechanisms through which anthropogenic climate change is contributing to this trend including coral bleaching, disease and ocean acidification. I will also include links to lots of further reading. Let me know if there are particular topics you want to hear about.
Research on the current and future impacts of climate change on reef-building corals is causing scientists and managers to become increasingly concerned about the future of coral reefs. A healthy reef ecosystem literally buzzes with sounds, activity and colors and is populated by incredibly dense aggregations of fish and invertebrates. In this respect, tropical reefs are more reminiscent of the African Serengeti than of the tropical rainforest they are often compared to, where the resident birds and mammals can be secretive and difficult to see. A coral reef can contain tens of thousands of species and some of the world’s most dense and diverse communities of vertebrate animals. Unfortunately, very few remaining coral reefs resemble this pristine condition; on most, corals and fishes are much less abundant than they were only a few decades ago.
The role of corals on coral reefs
Healthy coral reefs are dominated by various forms of reef-building corals, which fill the role of trees in a forest, by generating the physical framework of the reef, benefiting thousands of associated plants and animals. Ecologists refer to corals, trees, and other organisms (e.g., kelp, oysters, etc.) that literally create habitats as “foundation species” and recognize that their loss can be catastrophic for the community and ecosystem that is built around them. The structure built up by corals over thousands of years provides complex refuges in which animals can hide from predators. When corals die, the abundance of reef fish quickly decreases, mainly due to the lack of places for larval (baby) fish to settle as they leave the open water and settle on the reef where they will spend their adult lives. For example, in Papua New Guinea reef fish communities were greatly impacted by coral loss due to ocean warming and sedimentation run-off from the conversion of forest to oil palm plantations.
Declines in coral and fish populations in Papua New Guinea. (Source: Jones et al. 2004)
Jones, G. P. et al. 2004. Coral decline threatens fish biodiversity in marine reserves. Proc Natl Acad Sci USA 101:8251-8253.
Dr. John Bruno is a marine ecologist and conservation biologist. He's also an associate professor in the Department of Marine Science at the University of North Carolina at Chapel Hill . His research is focused on understanding and conserving the structure and dynamics of marine communities. Dr. Bruno works in a variety of marine habitats including coral reefs, coastal wetland and sand dune plant communities, oyster reefs and seagrass beds. Read more of his work on The Climate Shifts blog, and check out the Bruno lab home page.