60 Minutes ran a really great piece on Jardines de la Reina or Gardens of the Queen (GQ), last night. GQ is a spectacular reef off of Cuba’s south coast with abundant predators including goliath and black grouper and Caribbean reef sharks.
My PhD student Abel Valdivia (seen in the video above) is from Cuba and GQ is one of his field sites for his dissertation research on the role of sharks and other predators in the functioning of Caribbean reef ecosystems. Emmett Duffy and I accompanied Abel to GQ in May and it is indeed as spectacular as David Guggenheim describes. All of our coverage of the trip including Emmett’s journal and some cool video is here.
The very few remaining Caribbean reefs like GQ with fish communities that are more or less intact are invaluable. They show reef managers, policy makers and the public how spectacular reef fish can be (when we don’t eat them) and are essential for science. Despite some inaccuracies about the state of the benthos that I’ll outline below, I thought the 60 Minutes piece was great for reef conservation in general. Anderson Cooper did a nice (if imperfect) job explaining how reefs are threatened and why that should matter to us. The storytelling, imagery and editing were superb.
Now, on to the fact checking.
There are a lot of predators at GQ True We have been surveying reefs throughout the Caribbean over the last several years, purposefully looking for reefs with lots of sharks and grouper, and GQ has more than anywhere else we have been. The total fish biomass at GQ is ~600g per square meter, most of which is shark, grouper and snapper. This is 6-8x greater than most Caribbean reefs where, as David Guggenheim correctly points out, large predators have been locally extinct for decades.
The corals at GQ are healthy and abundant False Coral cover (the percentage of the seafloor covered by living corals) is only 18% inside the reserve (in 2005/2006 Pina Amargós et al. 2008). Not bad, but far from the pristine state, in which coral cover would have been well above 50%. In comparison, the Caribbean average was 16% during this period (n = 1547 surveys performed between 2001 and 2005, Schutte et al. 2010). The once-dominant and now ESA threatened Acropora cervicornis or staghorn coral was wiped out regionally in the 1980s by a disease and is functionally extinct in GQ as it is elsewhere in the Caribbean. Some other key species including Montastraea spp. are also in tough shape at GQ.
Another indicator of the poor health of the benthos (seafloor) at GQ is the large amount of macroalgae or seaweed: 45% compared to a Caribbean average of 15% (Schutte et al. 2010). Not surprisingly, coral recruitment (the density of coral babies and a good indicator of reef “resilience”) is very low (~ 1 per square meter Pina Amargós et al. 2008)
Figure 1. Benthic coverage (%) of corals, seaweed (macroalgae including Halimeda spp.) and “other” (e.g., sponges and gorgonians) in and out of the GQ reserve (in which fishing is not allowed) compared to Caribbean averages. GQ data are from Pina Amargós et al. 2008 and the Caribbean averages are from Schutte et al. 2010.
The high predator density at GQ proves that marine reserves work Sort of The reserve certainly receives protection but the remoteness of the reefs combined with the scarcity of boats in Cuba (for obvious reasons) also plays a role. Determining how well marine reserves work is scientifically tricky, and a snapshot picture doesn’t tell you much. Fabulous reefs like GQ are the kinds of places that receive protection, so there is a chicken and egg problem too.
25% of reefs have died off True, but We have not really lost entire reefs the way we lose forests when the trees are cut down, but we have lost a lot of reef-building corals over the last few decades. The best available science indicates that across the Greater Caribbean the value is closer to 75% (loss in relative terms), and the picture isn’t much better in the tropical Pacific.
90% of sharks are gone True Again, if anything, this is an underestimate. It is indeed rare to see a shark on a Caribbean reef and only a few countries – most notably the Bahamas – recognize the ecological and economic value of sharks and protect them nationally. Sadly, marine reserves like the Galapagos Islands are becoming targets for shark fisherman.
Goliath groupers are critically endangered True Goliath groupers are listed on the IUCN red list as critically endangered and are extinct throughout much of their former range across the Greater Caribbean. As David Guggenheim says, it is indeed very rare to see a goliath grouper on a Caribbean reef. However, thanks to 20 years of protection, the species has begun a robust recovery in Florida. This is one of the major success stories of modern fisheries management that could have been mentioned in the piece. Furthermore, it was achieved by a regional scale single species management approach.
GQ is more “resilient” than other reefs due to it’s protection, isolation, abundant predators, etc False Since the state of the benthos at GQ is far from exceptional (in terms of coral and seaweed cover), this argument isn’t justified. In fact Dr. Fabian Pina, the Cuban scientists in the story, has shown that coral cover in the reserve is no higher than it is on neighboring unprotected reefs (Fig. 1)(Pina Amargós et al. 2008). Conserving coral populations is a lot harder than restoring fish: the primary threats to corals cannot be managed locally and fish can’t stop climate change or disease outbreaks from happening.
Corals are being killed by sewage, coastal development and climate change True, but These are indeed coral killers, but in the Caribbean, a majority of coral cover loss was caused by disease outbreaks. Coral diseases like white band and yellow band (or yellow blotch) have decimated once-dominant species. Yellow band outbreaks appear to be exacerbated by ocean warming and both diseases are just as severe on isolated and protected reefs like GQ as they are on reefs in close proximity to people and point source pollution.
GQ is an underwater eden, is largely untouched and illustrates the way a coral reef ecosystems really should look False Although populations of a half dozen predator species are in good shape, coral populations have been devastated, there is an unnaturally large amount of seaweed and invasive lionfish are abundant. (So much for the Grouper-can-naturally-control-invasive-lionfish hypothesis)
Overall, this was a great 60 Minutes segment and reminded us all how vibrant a coral reef can be when the fish aren’t all gone. Ironically, the weaknesses in the reporting illustrate the value of pristine places: without a reference point for what healthy coral populations look like, we forget how lush they can be and we mistakingly consider “natural” to be what remains. The image below was taken in 2003 on an inexplicably resilient reef in Jamaica (with practically no fish) and gives you a sense of what truly robust Caribbean coral populations look like. Unfortunately, I don’t know of anywhere in the Caribbean where both the corals and the fish are pristine.