[Coral-List] Guardian Article on Recent Studies by Cinner, Bruno & Valdivia
pawlikj at uncw.edu
Fri Aug 19 08:19:07 EDT 2016
Just a note for this thread on "local protection," as it relates to Caribbean reefs.
We found that Caribbean MPAs increased abundances of parrotfishes and angelfishes, which decreased abundances of fast-growing, chemically undefended sponges and lowered levels of coral overgrowth and smothering.
Here are the references:
Loh, T.-L., McMurray, S.E., Henkel, T.P., Vicente, J. and Pawlik, J.R. 2015. Indirect effects of overfishing on Caribbean reefs: sponges overgrow reef-building corals. PeerJ, 3: e901 DOI: 10.7717/peerj.901
Loh, T.-L., and Pawlik, J.R. 2014. Chemical defenses and resource trade-offs structure sponge communities on Caribbean coral reefs. Proceedings of the National Academy of Science, 111: 4151-4156.
In a nutshell, Caribbean MPAs are well justified on the basis of their impact on sponges, which are aggressive spatial competitors with the remaining reef-building corals.
Interestingly, our benthic surveys recorded GREATER abundances of seaweeds in MPAs, supporting recent large scale studies suggesting that fishes are unable to control seaweeds on contemporary Caribbean reefs. More about that, and the importance of considering players other than fishes-seaweeds-corals in this reference:
Pawlik, J.R., Burkepile, D.E., Vega Thurber, R. 2016. A vicious circle? Altered carbon and nutrient cycling may explain the low resilience of Caribbean coral reefs. BioScience, 66: 470-476 doi:10.1093/biosci/biw047.
Joseph R. Pawlik, Professor,
Dept. of Biology and Marine Biology
UNCW Center for Marine Science
5600 Marvin K Moss Lane
Wilmington, NC 28409
Video Channel: https://www.youtube.com/user/skndiver011
From: coral-list-bounces at coral.aoml.noaa.gov [mailto:coral-list-bounces at coral.aoml.noaa.gov] On Behalf Of Avigdor Abelson
Sent: Wednesday, August 17, 2016 11:50 AM
To: Bruno, John; coral-list at coral.aoml.noaa.gov
Subject: Re: [Coral-List] Guardian Article on Recent Studies by Cinner et al & Bruno & Valdivia
Thanks for taking the time to respond to my mail.
I would like to emphasize your new assertion as it appears in your reply: “Another way to put it is that LOCAL PROTECTION IS NECESSARY BUT NOT SUFFICIENT”.
I think this take-home message is much safer than the assertions in your Scientific Report paper, and I embrace it together with the tiny “sting” you left for me at the end of your mail :) (“If you think parrotfishes and watershed management can protect corals and other reef inhabitants from that reality, no data I show you is going to change your mind”). This suggests that I am a “local stressor fanatic” who denies the crucial role of climate change and global drivers.
However, quite the opposite is true. I have been a witness to the devastations of El Niño years in the Indian and Pacific Oceans since 1998. Likewise, I have followed with much concern and heartbreak the recent months’ news coming from the GBR, and have seen with my own eyes the sad outcome of this El Niño year in the Philippines. So you don’t have to try convincing me about the importance of countermeasures to global drivers – I am fully aware of the need. However, I have also witnessed for over three decades the harmful local-scale footprint of humans via coastal development, pollution, deforestation and destructive fishing. Therefore, I believe that the battle should be on all spatial scales, and definitely not a battle between us.
My problem, though, is that I don’t see how repetitive statements like “the urgent need to reduce emissions” and other similar ones are making any actual measurable change. I am afraid that we, the listers, ecologists in general and environment advocates, are part of a minority camp, and that the world looks at these issues from a different angle. If this is true, then we should seek new ways to change the trend rather than debate among ourselves. In many countries the political situation and public awareness are not there yet. This is also true for many Foundations’ decision-makers, who find human health more important than the health of the Planet.
Some statistics that probably demonstrates the priorities of our contemporary human society:
The number of papers engaging with ‘coral-reef conservation’ and ‘coral-reef restoration’, since 2000, is 161 and 113, respectively (based on a Google Scholar search for the relevant terms in the title). The same search revealed that the number of papers dealing with Phenylketonuria (PKU), Prader–Willi syndrome and Williams syndrome (three very rare diseases), are 1490, 1610 and 1710, respectively. Checking the number of papers on ‘coral reefs’ in general (again, same search, from 2000 to the present), revealed 6,130 papers. In comparison, widespread diseases, like Malaria and Dengue have received an entirely different scale of number of studies - 44,700 and 15,700, respectively.
If the number of papers can serve as a rough proxy for levels of funding, then we can see what the priorities are and the relative importance (or lack of such) given to coral reefs and other marine ecosystems. At present, as noted, it seems well accepted that human health is a much more important problem for humanity.
Bottom line, I think we share much in common, and we need to combine forces in order to promote a dramatic change in public awareness (and funding allocation) and to search for new creative ways of countermeasures to the real problems (which are on all scales).
Sincere regards ~AV
From: coral-list-bounces at coral.aoml.noaa.gov [mailto:coral-list-bounces at coral.aoml.noaa.gov] On Behalf Of Bruno, John
Sent: Friday, August 12, 2016 8:45 PM
To: coral-list at coral.aoml.noaa.gov
Subject: [Coral-List] Guardian Article on Recent Studies by Cinner et al & Bruno & Valdivia
Thank you for your feedback. We look forward to reading your response in Scientific Reports. Below we respond to some of your comments in an attempt to clarify things for readers of the coral-list. We posted a few graphics and the Lit Cited here: http://theseamonster.net/2016/08/response-to-avigdor-abelson/
1) As we explained in the paper, the reason we and many others (e.g., Williams et al. 2008, 2015, Knowlton and Jackson 2008, Sandin et al. 2008, Mora 2008, Cinner et al. 2013, Jackson et al. 2014, Smith et al. 2016) used human population presence or density as a proxy for the presence or magnitude of local stressors is that actual data on those stressors is non-existent for all but a few locations. We all wish that weren’t the case, but it’s just the reality. Moreover, the fact is that more people generally means a larger human footprint on the landscape and seascape (see Sanderson et al. 2002, Mora et al. 2011), e.g., human population density is a good predictor of fishing intensity and fish biomass (see Warren-Rhodes et al. 2003, Hawkins and Roberts 2004, Newton et al. 2007, Sandin et al. 2008, Stallings 2009, Williams et al. 2011, Nadon et al. 2012, Cinner et al. 2013, Duffy et al. 2016 and many others). Too many people are one of the core problems reefs are facing, and it’s an ultimate, rather than a proximate cause. So in some ways, we believe it’s better that we focus on it, rather than indicators of human overpopulation like overfishing. On the other hand, we acknowledge things can get tricky when management policy, the intensity of economic activity, global trade, etc. decouple population density from local impacts.
Even if you reject the use of human population density as an indicator of local human stressors, you could just focus on the state of the world’s isolated reefs: the logical inferences still hold. If local impacts were generally substantially greater in magnitude or if the effects of local and global impacts were synergistic, isolated reefs with few or no human residents should have more coral and less algae. But they don’t. Therefore, the logical inference is that global warming is a primary if not the primary driver of coral loss around the world. We put a simple graphic on the blog post to illustrate the logic of this test and the inductive inferences and management strategies the results lead to.
2) We’ve reanalyzed the data using the Global Human Influence Index dataset and again found no relationship between coral cover and human transformation of the coastal landscape. This is a comprehensive index created from nine global data layers that takes into account human population density, built-up infrastructure, land use (agriculture), nighttime lights, land cover, and human access such as the amount of coastlines, roads, railroads and navigable rivers. Details and graphics are on the blog.
3) All three studies that have tested this hypothesis (that isolated reefs have more coral and less macroalgae) have failed to reject the null of no relationship, i.e., ours, Smith et al. (2016) and Jackson et al. (2014). No published study (with a reasonable sample size) has found that in general, isolated reefs have higher coral cover. Some clearly do. But so do many reefs adjacent to overpopulated, intensively developed coasts where presumably local impacts are substantial.
4) We don’t agree that our argument that warming is a major cause of coral loss is somehow untested or unsupported. In an earlier paper (Selig, Casey & Bruno 2012) , we clearly showed using an extended version of this database (same sites, more years) that ocean warming caused a major decline in coral cover over the last several decades on these reefs. So we did examine the putative global driver (temperature anomalies) and showed it was a likely cause of the observed pattern. We explained this in the paper. And there are of course countless smaller-scale studies demonstrating the effects of thermal extremes on coral cover.
5) It’s true that science is often used and misinterpreted by the media and others to advance policy positions. But this is true of any science. For example, climate change denier blogs like CO2Science frequently use studies demonstrating local threats to reefs (e.g., sunscreen studies) to argue ocean warming doesn’t matter and that carbon emissions don’t need to be limited. Similarly, the “parrotfish restoration can buy reefs time” argument could be used to delay policies to reduce greenhouse gas emissions. All of our science is both used and abused by advocates for the environment, big oil, etc. We have been very clear that we strongly support local management to mitigate local problems, including threats to corals, to human health and well-being, and to improve fisheries management. If it were up to us, we’d ban fishing from 30-50% of the oceans; but to protect and restore biodiversity (e.g., of large vertebrates), not to conserve corals. Bottom line; yes, scientists have to be cautious, but they also have to report their results unapologetically.
6) We neither found nor said (as you implied) that that there is no evidence of local impacts. There clearly is. They clearly matter. Instead, our results suggest that either local impacts are swamped by warming or that local and global threats have antagonistic effects (our results do not distinguish between the two alternative explanations). Local protection is important. But as warming progresses, it’s becoming more and more obvious that reducing emissions is crucial. Another way to put it is that local protection is necessary but not sufficient.
7) This finding is neither novel nor radical. Dozens of studies indicate local fisheries restrictions (and other local management actions) do not protect corals from ocean warming and acidification. Many people have been saying this on the coral-list for many years. And numerous reef scientists have argued more eloquently and forcefully than us that the only effective solution to mitigating the impact of warming on reefs is to radically reduce carbon emissions (Jameson et al. 2002, Aronson and Precht 2006, Côté and Darling 2010, Mora and Sale 2011). Moreover, to quote Rich Aronson “another way radical, unacceptable ideas can become acceptable is if they turn out to be correct”. Given the mountains of evidence, this idea should be widely embraced by our field, policy makers, and reef managers. We need to stop kidding ourselves: to protect and restore coral populations we need to immediately reduce carbon emissions. In the short term, local threats are certainly important. As many people have said, it’s not either or – it’s all of the above. But the fact is, in the long run, local management won’t matter at all if we fail to limit warming. There literally won’t be any corals left to manage. The perfect example is the Florida Keys reef track, where, after decades of intensive management, coral cover is still less than 5% (and declining). We have only a few decades or a human lifetime at most. IPCC models indicate that under the business as usual emissions scenarios (A2/RCP 8.5), tropical oceans will have warmed by nearly 3ºC (beyond the nearly 1ºC of warming to date) by the end of this century. That means normal summertime temperatures on most reefs of ~32ºC or 33ºC and peak anomalies of 35ºC or greater – well beyond the physiological limits of most coral species and of many other reef inhabitants. If you think parrotfishes and watershed management can protect corals and other reef inhabitants from that reality, no data I show you is going to change your mind.
John and Abel
Literature Cited are here: http://theseamonster.net/2016/08/response-to-avigdor-abelson/
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