Coral-algal Phase Shift

There is no such thing as a pristine coral reef left in the world. All regions show some sign of impact and decline leaving regions impacted with extreme cases fringing on ecological extinction (Pandolfi et al. 2003). Studies estimate a 30% reduction in global coral coverage in the last three decades with projections reaching as high as 60% by 2030 (Wilkinson 2002). Coral reef degradation is matched with an increase in abundance of macroalgae (McCook 1999). Continual stress by such variables as human activity, diseases and natural impacts such as hurricanes may eventually result in a phase shift of the system, going from coral dominated to macroalgae (Hughes et al. 2003). The following footage illustrates a phase shift in the Central Pacific. Neighboring islands within the Line-Islands archipelago. An area previously analogous with high coral coverage was eventually dominated with fleshy macroalgae with the inability to recover.
Credits
Cinematography: Dr. Forest Rohwer
Edited by: Neilan Kuntz
Written by: Neilan Kuntz
Location: Palmyra Atoll, Line Islands, Central Pacific (2005)

Hughes et al. (2003) Climate Change, Human Impacts, and the Resilience of Coral Reefs. Science 301: 929-933.

McCook L.J. (1999). Macroalgae, nutrients and phase shifts on coral reefs: scientific issues and management consequences for the Great Barrier Reef. Coral Reefs 18: 357-367.

Pandolfi J.M. et al. (2003) Global Trajectories of the Long-Term Decline of Coral Reef Ecosystems. Science 301: 955-958.

Wilkinson C. (ed.) 2002 Status of coral reefs of the world: 2002. Australian Institute of Marine Science, Townsville, Australia.

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[sintelin]

LIES!!! All lies!!! Studies estimate that coral-algal phase shifts are a figment of our imagination (i.e. unicorn syndrome) and are not actually a valid threat to coral reef health. (Disclaimer: Except in Jamaica)