The coming coral catastrophe

If you had to identify the most popularly cited threats posed by a changing climate, rising sea levels would be a strong contender. While no one would argue that the fate of hundreds of millions of humans who live in low-lying coastal regions is not a good enough reason to put the brakes on global warming, I'd like to see more attention paid to what's happening beneath the ocean surface at its current level. I'm talking about the possibility of mass coral extinction. It's the subject of a new analysis in Science by an impressive list of 39 scientists from an even more impressive list of research institutions around the world.

So impressive is that second list, in fact, that I'm going to reproduce it. Right after a couple of excerpts from the paper itself, which carries the straightforward title of "One-Third of Reef-Building Corals Face Elevated Extinction Risk from Climate Change and Local Impacts." (doi: 10.1126/science.1159196).

The authors selected 845 species of reef-building corals, discarded 141 on which the data were insufficient, and took a look at the conservation status of the rest.

Of the remaining 704 species, 231 are listed in the threatened categories, while 407 are in threatened and Near Threatened categories combined .... The only species that do not fall within threatened categories are those that inhabit deeper, lower reef slopes and those not solely dependent on reef habitats.

That is truly frightening. And before someone objects that the threatened and near-threatened labels are less worrisome than "endangered" or "critically endangered," or that the Earth has seen mass coral extinctions before, the really disturbing trend is not the fact that a third of all corals are in trouble, but the speed at which corals are being added to the lists of species at risk.

Our results indicate that the extinction risk of corals has increased dramatically over the past decade. Using the values from previous reports of the Global Coral Reef Monitoring Network, it is possible to determine extinction risk levels prior to the 1998 massive bleaching events. Before 1998, 671 of the 704 data-sufficient species would have been categorized as of Least Concern, 20 as Near Threatened and only 13 included in threatened categories.

All this is important from a human perspective because coral reefs support food webs that supply protein in the form of fish and invertebrates to hundreds of millions of people who don't have the luxury of switching to an alternative. Among the chief causes of the population declines are warming temperatures and ocean acidification. (And if there was ever a good argument against any climate geo-engineering scheme that doesn't somehow deal with acidification, this is it.)

I also find it scary from a personal point of view. One of my favorite experiences in life was SCUBA diving on the Great Barrier Reef, and ever since my son was born 20 months ago, I've kept alive the hope that I could take him on a similar expedition, if not to Australian waters, then to a Caribbean reef. For that I'll have to wait another decade or so. I fear there may nothing much left to see by then.

Now, here's that list, which perhaps better than anything else in the paper demonstrates the strength of ;;;; dare I say it? ;;;; the consensus on the risks we are running by refusing to take the lead on the climate crisis:

IUCN Species Programme/SSC/Conservation International Global Marine Species Assessment, Biological Sciences, Old Dominion University, Norfolk, VA, USA.
Research Center for Oceanography-Indonesian Institute of Sciences, Jakarta, Indonesia.
Hawaii Institute of Marine Biology, Kaneohe, HI, USA.
Dauphin Island Sea Lab, Dauphin Island, AL, USA.
Charles Darwin Research Station, Puerto-Ayora, Santa-Cruz-Galápagos, Ecuador.
NOAA Fisheries/NOAA Coral Reef Conservation Program, Silver Spring, MD, USA.
Brown University, Providence, RI, USA.
CIMAR, University of Costa Rica, San José, Costa Rica.
Waikiki Aquarium, University of Hawaii at Manoa, Honolulu, HI, USA.
Coral Reef Research, Townsville, Queensland, Australia.
Center for Applied Biodiversity Science, Conservation International, Arlington, VA, USA.; Tasmanian Aquaculture and Fisheries Institute, University of Tasmania, Hobart, Tasmania, Australia.
School of Biology, Newcastle University, Newcastle upon Tyne, UK.
Department of Marine and Wildlife Resources, Pago Pago, American Samoa, USA.
Smithsonian Tropical Research Institute, Balboa, Panama.
National Museum of Natural History Naturalis, Leiden, The Netherlands.
Reef Check Foundation, Pacific Palisades, CA, USA.
Research Center for Aquaculture, Minggu, Jakarta Selatan, Indonesia.
Biology Department and Shields Marine Station, De La Salle University, Manila, Philippines.
School of Marine Studies, University of the South Pacific, Suva, Fiji.
NOAA Fisheries Service, Protected Resources Division, Petersburg, FL, USA.
CORDIO East Africa, Mombasa, Kenya.
Reef Check Philippines, Manila, Philippines.
NOAA, Florida Keys National Marine Sanctuary, Damage Assessment and Restoration Program, Key Largo, FL, USA.
Sulu-Sulawesi Seascape Program, Conservation International - Philippines, Quezon City, Philippines.
Silliman University, Institute of Environmental and Marine Sciences, Bantayan, Dumaguete City, Philippines.
Australian Research Council Centre of Excellence for Coral Reef Studies, James Cook University, Townsville, Queensland, Australia.
Zoological Society of London, Institute of Zoology, London, UK.
Department of Biological Science, University of Warwick, Coventry, UK.
Department of Biological Science, University of Warwick, Coventry,UK.
IUCN/SSC - CI/CABS Biodiversity Assessment Unit, Conservation International, Arlington, VA, USA.
Museum of Tropical Queensland, Townsville, Queensland, Australia.
Department of Marine Sciences, University of Puerto Rico, Lajas, PR, USA.
Marine Conservation Society, Ross-on-Wye, Herefordshire, UK.

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Carpenter, K.E., Abrar, M., Aeby, G., Aronson, R.B., Banks, S., Bruckner, A., Chiriboga, A., Cortes, J., Delbeek, J.C., DeVantier, L., Edgar, G.J., Edwards, A.J., Fenner, D., Guzman, H.M., Hoeksema, B.W., Hodgson, G., Johan, O., Licuanan, W.Y., Livingstone, S.R., Lovell, E.R., Moore, J.A., Obura, D.O., Ochavillo, D., Polidoro, B.A., Precht, W.F., Quibilan, M.C., Reboton, C., Richards, Z.T., Rogers, A.D., Sanciangco, J., Sheppard, A., Sheppard, C., Smith, J., Stuart, S., Turak, E., Veron, J.E., Wallace, C., Weil, E., Wood, E. (2008). One-Third of Reef-Building Corals Face Elevated Extinction Risk from Climate Change and Local Impacts. Science DOI: 10.1126/science.1159196