An AGW skeptic organization “The Center for the Study of Carbon Dioxide and Global Change” just posted a summary of a recent paper I was lead author on (Bruno et al. 2009 – Jez blogged about it here) on their website CO2 science: “Corals vs. Macroalgae in a CO2-Enriched and Warmer World: Which is destined to predominate?”
“Slimed” is probably an exaggeration or inaccurate description. They didn’t criticize me or the work. And they got much of the science right. But they subtly ignore a key take home message (i.e., we didn’t say there was NO problem, we said that the macroalgae problem is being exaggerated) and incorrectly imply the paper has something to do with coral-seaweed competition in the future (it doesn’t).
Background: The authors write that one of the great concerns of marine scientists is that “coral reefs are moving toward or are locked into a seaweed-dominated state,” based on observations of what occurred on several Jamaican reefs during the 1980s, which concerns are often parroted by climate alarmists such as Al Gore (An Inconvenient Truth) and Michael Mann and Lee Kump (Dire Predictions).
True. But did Al Gore and Michael Mann really address coral reef phase shifts and macroalgae in their movies about climate change? Haven’t seen them…
What was done: To assess the generality of these claims, Bruno et al. “analyzed 3,581 quantitative surveys of 1,851 reefs performed between 1996 and 2006 to determine the frequency, geographical extent, and degree of macroalgal dominance of coral reefs and of coral to macroalgal phase shifts around the world.”
What was learned: The five marine researchers found that “the replacement of corals by macroalgae as the dominant benthic functional group is less common and less geographically extensive than assumed,” noting that “only 4% of reefs were dominated by macroalgae (i.e., >50% cover).” In fact, across the Indo-Pacific, where regional averages of macroalgal cover were 9-12%, they found that “macroalgae only dominated 1% of the surveyed reefs.” In addition, they learned that “between 1996 and 2006, phase shift severity decreased in the Caribbean, did not change in the Florida Keys and Indo-Pacific, and increased slightly on the Great Barrier Reef.”
What it means: Bruno et al. state that “coral reef ecosystems appear to be more resistant to macroalgal blooms than assumed,” and that “the mismatch between descriptions of reef degradation in the literature and patterns in nature was caused by the generalization of a relatively small number of examples,” concluding that their analysis suggests that “the macroalgae problem has been exaggerated,” and that “overall,” there has been “no general recent trend (i.e., post-1995) toward macroalgal dominance.” In fact, they say that “macroalgal cover may currently be close to the historical baseline across most of the world.”
Well, we did say that, but we also said:
“Coral abundance on reefs around the world began to decline several decades ago (Gardner et al. 2003, Bruno and Selig 2007) due to a variety of factors including predator and disease outbreaks, poor land use practices, destructive fishing techniques, and ocean warming (Glynn 1993, McManus et al. 1997, Aronson and Precht 2001, Hughes et al. 2003).”
Point being, that we didn’t say reefs haven’t been degraded and I think we made it pretty clear that the point was that corals themselves, and the factors causing coral mortality, should be the target of reef conservation and management, instead of indirectly addressing what we see as the underlying problem by locally managing herbivores and seaweed.
Isn’t that pretty pretty obvious from the quote from the paper below?
“The current paradigm of reef management and ‘‘resilience’’ is based in large part on the perception that most of the world’s reefs are being overrun by seaweed (Szmant 2001, Precht and Aronson 2006, Knowlton 2008). This belief led to the argument that reef managers should focus primarily on conserving herbivores or water quality (Szmant 2002, Pandolfi et al. 2003, Bellwood et al. 2004). While these are clearly important objectives of management, our analysis suggests that the macroalgae problem has been exaggerated. Overfishing and poor land use practices may trigger widespread coral to macroalgal phase shifts in the future, but to date, the principal form of coral reef degradation has been the loss of reef-building corals, with only limited and localized increases in macroalgae. Therefore, the primary goal for reef managers and policy makers should be the conservation of coral populations, without which the entire system would collapse.”
Several colleagues and reviewers warned us about publishing a “good news” (sort of) story, arguing it would give ammo to skeptics, etc. Frankly, I don’t care. And I doubt many scientists would. If we see conditions improve, we are going to publish that fact. And I really hope we do (see things improve). I am comfortable being an environmental advocate, but I think scientific advocacy should stem from the science, not the other way around.
BTW, who are these people? The Center for the Study of Carbon Dioxide and Global Change mission statement says:
The Center for the Study of Carbon Dioxide and Global Change was created to disseminate factual reports and sound commentary on new developments in the world-wide scientific quest to determine the climatic and biological consequences of the ongoing rise in the air’s CO2 content. It meets this objective through weekly online publication of its CO2 Science magazine, which contains editorials on topics of current concern and mini-reviews of recently published peer-reviewed scientific journal articles, books, and other educational materials. In this endeavor, the Center attempts to separate reality from rhetoric in the emotionally-charged debate that swirls around the subject of carbon dioxide and global change…