Dr. Nancy Knowlton is a coral reef scientist who studies their ecology and evolution, including the impact of climate change. The founding director of the Center for Marine Biodiversity and Conservation at the University of California, San Diego, she is also a professor at Scripps Institute of Oceanography. Her contributions have been crucial to the advancement of coral reef science.
Today, Knowlton holds the Sant Chair in Marine Science, recently awarded by the Smithsonian Institute's National Museum of Natural History in Washington D.C. Occupying the museum's first funded chair in marine sciences, Knowlton will provide leadership to the Smithsonian's Ocean Initiative, an interdisciplinary move to foster greater public understanding of ocean issues.
A chat with Knowlton is like opening a trunk of coral knowledge. The conversation revolved around a recently released article Knowlton co-authored in the journal Science entitled "Coral Reefs under Rapid Climate Change and Ocean Acidification." The piece presented a dire scenario of increasing decline and loss of coral reefs, based on the best available scientific information and the most positive climate change and carbon emission scenarios of the UN's Intergovernmental Panel on Climate Change (IPCC).
"Ocean acidification" is a recently introduced term for an observed reduction in seawater pH. It is triggered by the absorption of atmospheric carbon dioxide (CO2), which reacts with naturally occurring carbonate ions in the ocean, to produce carbonic acid. The change in chemical conditions affects corals and other organisms that need carbonates to build their calcium carbonate skeletons. The phenomenon, together with climate change, increases ocean temperatures and more frequent bleaching events might be too much for coral reefs to handle.
E Magazine: The just released Science paper, which you coauthored with 16 of your colleagues from around the world, points to an almost inevitable coming disaster for our reefs.
Knowlton: If we don't do something to limit CO2 emissions, yes.
How do you see the status of coral reefs in the U.S. in particular? We're having all these problems globally with bleaching and acidification, but how are our U.S. resources?
Well, the situation in the U.S. isn't really much better. Some of the reefs in the Florida Keys and the main Hawaiian Islands aren't in particularly good shape, nor are they all that good in the U.S. Virgin Islands and Puerto Rico. They're about average for the planet, which is not good. The exceptions are some of the isolated coral reef Atolls that the U.S. has jurisdiction over, such as Palmyra Atoll and Kingman Atoll and Jarvis and Howland, the main islands in the Central Pacific. These are really far away from people and therefore haven't been fished. The northwest Hawaiian Islands also, for that matter, haven't really been fished and they're protected. The Northwest Hawaiian Islands are now part of a very large Marine Protected Area, and the other places I just mentioned are protected by the U.S. Fish and Wildlife Service.
You can go dive in those places and the reefs are in very good shape as are the fish populations. So, in some of the far corners of the planet where the U.S. has jurisdiction, reefs are in good shape. But anywhere where there's substantial human use in the U.S., reefs are in bad shape.
These coral reef areas you mention don't have a lot of protection, do they? I was reading in another Science paper that in the Florida Keys and the main Hawaiian Islands, the government hasn't supported programs to increase protection levels.
The Northwest Hawaiian Islands are actually well protected because they're part of a new largely not-take Marine Protected Area. The Florida Keys have a whole series of different levels of protection but the amount of actual no-take protection, where fishing is prohibited, is relatively small. There's also water-quality issues; particularly in the Florida Keys. The combined effects for most of the Florida Keys are not good.
Yes, I was talking to someone doing coral reef...