How Effective are Marine Protected Areas (MPAs) for Coral Reefs?

Coral reefs throughout the world are under severe challenges from acute and chronic environmental factors; these include high Sea Surface Temperatures (SSTs) that induce coral bleaching, ocean acidification, destructive fishing practices and overfishing, run off of pollutants from agriculture, rising sea levels, blooms of algae, increasing development of coastal resorts and fish farms, oil pollution, and cyclone and hurricane damage. Small modifications to environmental parameters (e.g. a change in temperature of just a few degrees) can cause significant (up to 50%) changes in coral growth rates. Often, environmental parameters influencing growth can be multifactorial, and result in complex cellular changes so that high energy and high sedimentation together can reduce growth, while changes in temperature, salinity, and sedimentation can influence not only growth but also diversity and abundance of corals.