You don’t/can’t pay all undergrads in your lab – are you evil?


This issue comes up a lot in the academic twitter-verse. Usually in the context of internships at conservation NGOs (at least in my world). I generally agree, people should be paid for such internships. They are usually true work or something close to work, even though students gain valuable experience.

The issue also gets discussed in the context of students doing research on campus. The tweet that I saw that set the current round off (and set me off):

Below are some my thoughts on the issue. But first, I’m aware there are students with great financial need, including some that are homeless. I’m strongly supportive of greater inclusion of underrepresented groups in science and in increasing their participation. And I think we all agree, it is crucial to do what we need to do, as individuals and as institutions, to make big changes so that everybody is able to gain research experience (if they want it) regardless of their financial situation, i.e., I totally agree paid internships are invaluable for some people. Dozens of friends and colleagues shared their stories and how important paid internships were to them:

Me too! When I first left high school, I took classes at a local Jr college while working as a waiter, mowing lawns, cleaning boat bottoms, working in a warehouse, etc. In Boston at NU as an undergrad, I worked as a bike messenger and waiter, had a work study position to work for Jon Witman gaining invaluable experience, got financial aid, took out student loans, etc. I hear you. I get it. I experienced this too and I’m supportive. But this isn’t what’s being debated.

I just counted and roughly 47 people tweeted at me version of:

Of course I don’t reject this. (And I note, this debate tactic is nasty, lame, and all too common amongst us lefty twitter peeps. Not cool people).

In my own lab, I’d pay a student out of pocket if that’s what it took to give them time to work with me on science. And finally, no, I am not pro-slavery. So please, if you want to join this discussion, be fair and reasonable and don’t make straw man attacks on me, e.g., claiming as one idiot did, that I support the exploitation of persons of color for their labor. In fact, every single person that’s chimed in to agree with me has immediately been attacked like this, e.g.;

So here is what I think:

1. I do not agree that we should pay all students learning to do research in academic science labs. My rationale is that;

2. Doing so would be practically impossible. Your’e talking about literally millions of students learning to do research in many hundreds of universities across just the U.S. There really isn’t funding to pay them all. Departments certainly don’t have it. And most academic scientists do not have NSF funding. Restricting undergraduate research training to only paid positions would greatly, enormously reduce the number of students, including underrepresented students, learning to do research. Also, as Luiz Rocha pointed out, many people don’t have the $ to pay students working with them and this would also exclude those PIs and that research: 




3. Science can be a powerful tool in righting many societal wrongs. I fully support that. But I don’t agree there should be a litmus test. I think scientists have the right to focus on basic science, conservation, curing cancer, whatever, and frankly ignore solving other ills of the world. I loathe the twitter-view that we all have to simultaneously solve every wrong, every problem, from income inequality, to biodiversity loss, to childhood morbidity, in each and every one of our labs, every single day. People. This is insane. We can’t all do it all. Please give your colleagues a break and let them focus on what they choose to focus on. I see some colleagues doing amazing work with training underrepresented groups in STEM, while others protect endangered sawfishes. Others may disagree, but me, I’m fine with that. Do what you have the time and resources to do, and don’t beat yourself up because some asshole on twitter is berating you for not doing more.

4. I definitely don’t agree anytime a student is “doing” research (i.e., learning to do it via an apprenticeship) in an academic lab they are doing “work” and are thus an “employee”. In most cases, they are not doing anything of value commercially or even to research, so its dumb to call it work. Students come to university to learn. They learn in the classroom and in the lab. This activity, again we call it learning in higher education, generally is clearly distinguishable from actual work. (I recognize that true work does take commonly take place by students, in labs, e.g., if somebody is washing glassware, they probably should get paid to do so, as that seems closer to work than a meaningful research experience). One person argued since I/professors get paid to do science, so should students. First, mostly we don’t get paid to do science! At least in academia. e.g., I rarely get summer salary when I do most my science. In fact, we often PAY TO DO AND PUBLISH science. Second, we are professional scientists. We actually produce published science. (Few grad students get paid to do science either). And an undergraduate student going through the motions in a lab, just learning the ropes, often isn’t doing anything that leads to published science, i.e., its only marginally “research” . It isn’t work. It is learning. (Yes, some students do publishable, awesome research. Many in my lab have and Ive published countless papers with undergraduates. But mostly, UG student research isn’t publishable)

5. At least at my institution, most undergrads (about 500 per semester in my department) get course credit for doing research. And we are greatly expanding CUREs – Course-based Undergraduate Research Experiences, where we merge the lab and classroom, and do research collaboratively as a class. Hopefully, it’s obvious that students getting course credit for learning to do research cannot be paid for it

6. There are many other dimensions that people have brought up. Craig McLain argued paying some but not other students in your lab creates a stigma. I don’t really see how, since that should be privileged information. But I’m not totally rejecting this argument. I think his solution to this (which many people argued for) is to pay all students in labs, even if they don’t need it, even if they’re rich, even if they’re not doing work. I don’t agree. Even if you can, even if you have funding, there are circumstances where there might be better uses of your limited research dollars, e.g., outreach, students with greater need, grad students with low salaries and poor benefits, etc. Fact: it’s a zero-sum-game. A lot of the calls for paying any student in a lab don’t recognize this.

7. I think Terry asked a fair and challenging question about my argument:

I don’t really disagree. Taken in isolation, yeah that is unfair. I agree with everybody we need to work to avoid that situation. My “solution” (greatly oversimplified here) is to find funding so that low-income students can obtain research experiences. Including field courses, which are wildly expensive and from which are nearly always excluded. Yes that is really unfair. It sucks. I just disagree with Terry (and lots of other people it seems) that a practical solution is to pay everybody learning to do research in a lab. In the field course example, that would be like waving tuition, fees, travel costs for every student. But is that reasonable? I never retaught a field course I developed in the Galapagos because UNC Study Abroad is charing ~ 10K for a 6 ch course. Crazy. And that excludes even students from middle income families. But realistically, the course can’t run without income, so I don’t see waiving cost to students as a practical solution. At least at a PI/lab/institutional level. But maybe that could be part of a Bernie Sanders free-college-for all approach (which I’d support, but somebody’s gotta pay).

I guess the exception is a world where there literally were no resources to enable low-income students to participate. In that case, I suppose I agree; there shouldn’t be unpaid internships. I just don’t agree that’s the world we live in. And I think you (Terry) agree, since your “pay everybody” argument requires vast resources (that I don’t think exist).

8. Overall, I think we should all chillax, have trust in each other, and accept each others financial limitations and choices. And Academic Twitter, please stop being so prescriptive and well, just demanding and judgmental. I think Terry could have argued his point without making any broad accusations. And I don’t agree that if you have an undergraduate learning to do research in your lab that your’e not paying – because maybe they have a scholarship, maybe they are getting course credit, maybe their dad is Donald trump… whatever – that you are complicit in a great evil. I just don’t think its that simple and I believe its a mean and unfair accusation.

You can’t know everybody’s goals, situation, etc. We can’t all do it all. Isn’t that obvious? We are all on the same side, fighting many of the same fights. Let’s try to use twitter to spread the love and support amongst our field rather than to tear colleagues that don’t do it exactly as you do down.

Lots of really interesting perspectives coming in on twitter. All kinds of nuances.

Ocean warming caused most Caribbean coral loss: a review of the evidence


Coral cover on Caribbean reefs has declined precipitously over the last few decades, e.g.; Gardner et al. 2003 (Science PDF here):Screen Shot 2013-09-14 at 8.35.07 AM

and Schutte et al. 2010 (MEPS PDF here):Screen Shot 2013-09-13 at 10.02.04 PM

Also see Hughes 1994Cote et al. 2005, and Jackson et al 2014. There is substantial evidence that human-caused ocean warming is the primary cause of this loss of reef-building corals on most Caribbean reefs:

1) The temporal pattern of decline is concordant with the hypothesis that warming caused most Caribbean coral loss. Modern, human-caused ocean warming started around 1920 and began to accelerate in the late 1960s. Across the Caribbean (as well as globally) regional average coral cover began to decline roughly 10 years later (~ in the late 1970s-early 1980s, sampling is sparse during this period so it’s impossible to be more precise).


The Caribbean has warmed by nearly 1C just since the mid-1980s Chollett et al 2012. The mean trend is 0.29 °C / decade, 1985-2009:

There are also remarkable long-term in situ temperature records for the Florida Keys that document warming over the last century, and a roughy 1C increase in August SST since the mid-1970s (from Kuffner et al 2014):

Although a coarse-grained approach, this is the starting point for climate change attribution based on IPCC criteria, i.e., a 30 year or greater record of temperature and a potential response (in this case coral cover). Although other factors could explain the observed coral loss, we can say with some certainty that it occurred while the region was warming. It is also evident that regional coral cover has been dropping in a somewhat stepwise manner, following temperature-related impacts (from Aronson and Precht 2006):

Moreover, the timing of the primary alternative explanation for Caribbean coral mortality – an increase in macroalgae – suggests the seaweed bloom was a response to and not a cause of the observed mass-coral mortality, i.e., cover cover collapsed several years before the macroalgae increase (see graphic from Schutte et al above).

2) Spatiotemporal coincidence of anomalously high ocean temperatures with coral bleaching and mortality. Hundreds of studies going back decades have documented mass-bleaching and subsequent coral loss on Caribbean reefs. For example, Winter et al 1998 related the timing of extreme SST with mass bleaching in Puerto Rico, initially in 1969 then again in 1987, 1990 and 1995:

By the mid-1990s, there had been enough mass-bleaching events for Winter et al to work out coral bleaching thresholds and their dependence on both the magnitude and duration of the warming anomaly (a concept first developed by Tom Goreau Jr, Peter Glynn and others, that led to the “Degree Heating Week” metric and concept, now widely applied in coral reef science).

McWilliams et al 2005 found that bleaching coincided with warm months and years across the Caribbean between 1983 and 2000:

And that the severity of the anomaly was a good predictor of both the geographic extent of mass-bleaching and the average percentage of coral colonies observed bleached (i.e., local and regional dose responses):

One of most comprehensive accounts of Caribbean mass bleaching is the monograph by Ernest Williams and Lucy Bunkley-Williams (published in the Atoll research bulletin in 1990).  Nobody could read – or even skim – this scholarly masterpiece and still argue warming and bleaching have not been important drivers of Caribbean coral loss.  The account is incrediby detailed and foresaw a lot of the work that was repeated in following decades. For example, they documented which taxa bleached first during events from 1986-1989:

Locations for which coral mortality was observed include The Bahamas, the Florida Keys, Columbia, Puerto Rico, the US Virgin Islands, Turks and Caicos, Panama, Curacao, St. Lucia, and Jamaica. (It made me smile to see the names of so many prominent leaders in the field as the sources of these observation, including Lang, Jaap, Gladfelter, Woodley, Causey, and Hudson. Also see this piece in the NYT about Caribbean bleaching of 1987 – it’s fascinating to read some of the views on the causes of bleaching as the field just started grappling with mass coral mortality, e.g., Nancy Knowlton was already pushing the idea it had more to do with cumulative impacts while Judy Lang pointed out that even corals on remote reefs across the Bahamas had bleached.)

Much of this history is described in the excellent review of coral bleaching by Baker et al 2009, which clearly indicates bleaching was occurring globally, including across the Caribbean:

In 1998 oceans temperatures reached new modern highs, triggering mass bleaching globally, including across the Caribbean; e.g., on the Belizean Barrier Reef (Aronson et al 2002) where SST anomalies of >1C caused coral cover to drop by 40%:

Then in 2005, a massive warm blob sat over the southeastern Caribbean, causing extensive bleaching in the Virgin Islands and numerous other locations:

An event extremely well-documented by Eakin et al (2010) (Also see this):

And again in 2010, another well-documented mass bleaching event hit the region, including Tobago, Puerto Rico, the USVI, and Curacao:

Mass-bleaching of Orbicella annularis in Curacao in 2010, from Vermeij 2012.

This was followed by more localized bleaching events in 2014 and 2015 and 2016 and so on. For example, there was severe bleaching (of what little coral remained) in the Florida Keys in 2014 (Manzello 2015):

There are dozens (and likely hundreds) of published papers, including numerous regional compilations, documenting coral bleaching and it’s impacts across the Caribbean over a 30 year period. This evidence alone supports the inference that ocean warming is an important driver of Caribbean coral bleaching and loss.

3) Coincidence of anomalously high ocean temperatures with coral disease outbreaks. Caribbean reef scientists broadly agree that coral disease outbreaks have been a primary cause of Caribbean coral loss (e.g., Aronson and Precht 2006). Caribbean reefs were dominated by corals in the genera Acropora and Orbicella for thousands of years.  That is until the late 1970s / early 1980s when a regional outbreak of white band disease wiped out Acropora palmata and Acropora cervicornis (Aronson and Precht 2016).  This was followed in the late 1990s by the beginning of the yellow band outbreak in Orbicella, which waned around 2010 after host population density had crashed.  Several studies suggest there is a causal link between temperature, ocean warming, disease severity, and the loss of these two critical reef-building genera. First, based on data collected by Ernesto Weil, Harvell et al 2009 reported that lesion growth rate and prevalence of yellow band disease in Orbicella was related to temperature:

Rogers and Muller (2012) reported that the incidence of white pox and white band disease in Acropora palmata was related to temperature:

Additionally, Randall and van Woesik 2015 found clear links between several aspects of ocean warming and white band outbreaks in both Acropora palmata and Acropora cervicornis. 

Finally, Precht et al 2016 reported a high prevalence outbreak of white plague disease, infecting numerous coral species, that occurred during the record high temperatures of mid-2015 in south Florida:

4) Tank experiments linking temperature with bleaching and mortality. Countless aquarium experiments have mechanistically linked temperatures beyond the thermal optima with bleaching, mortality, reduced calcification rates, and other fitness indicators. This extensive laboratory experimental work provides strong evidence that the observed association between warming and coral mortality could be mechanistic.


5) Species-specific patterns of coral loss suggest warming, bleaching, and disease, rather than macroalgae, are the cause of Caribbean coral loss.

The coral species for which absolute cover has decreased across the region are those that are most susceptible to warming, bleaching, and disease. Principally, Acropora spp., Orbicella spp., and other massive species such as brain corals. One species in particular that hasn’t declined, Siderastrea siderea, is far less sensitive to thermal stress. If macroalgal overgrowth (and not warming, bleaching, and disease) was the primary driver of coral loss, you wouldn’t expect this pattern – and you certainly wouldn’t predict that massive boulder and fast-growing and massive branching colonies would be the most sensitive to macroalgal overgrowth.

6) Protected areas have not diminished coral loss. Numerous studies have found that effectively managed Caribbean MPAs have not reduced coral loss and warming-related declines are evident regardless of local protections, macroalgae, or parrotfish biomass. A good example is the Florida Keys, where the best-managed reserves in the region still failed to mitigate coral decline (from Toth et al 2014):


Likewise, Jackson et al 2014 found that coral loss was unrelated to macroalgal cover and parrotfish biomass:


It’s also striking how little macroalgae there is in the countless images of coral bleaching across the region. Just look at the pictures above or google “bleached coral Caribbean”. These bleached colonies are not dying because of sponge-microbe interactions, chemicals released from seaweed, and certainly not from macroalgal overgowth (obviously). They’re also not being smothered by sediment from coastal agriculture. That’s not to say these threats aren’t real. But these corals are dying simply because ocean temperatures slowly rose to 0.5-1C greater than recent summertime highs.


7) Reef isolation from local human impacts has not diminished coral loss. If local impacts (e.g., fishing, algae, and pollution) were the cause of coral decline or if they exacerbated bleaching you’d predict that coral loss would be greater on reefs adjacent to larger human populations (where local impacts are greater).  Abel Valdivia and I found that wasn’t the case globally, and Jackson et al reported the same is true for Caribbean reefs:

In the Caribbean, reefs isolated (i.e., not experiencing) the local human impacts described by some to be the main causes of recent coral mortality do not differ in coral cover.  This is evident if you’ve worked on isolated Caribbean reefs and I know its surprising, but its the reality we’re facing.  This is strong evidence that we cannot simply blame land clearing or overfishing by local communities for coral decline.  The most striking Caribbean example I know of is Jardines de la Reina or Gardens of the Queen. Despite amazing, near-pristine predatory fish biomass, and little if any local impacts, coral cover is only 18%.


Epilogue: Why bother reviewing this science? It seems crazy that I just spent my entire Saturday writing a blog post about science that I assume everybody in the field is familiar with. Yet I keep running into statements indicating a lot of our colleagues, including some of the leaders in the field, either don’t believe or aren’t aware of this body of literature. So instead of marching for science today, I blogged for science. Hostility towards science from conservative politicians and business interests is certainly a real threat. But in coral reef science, so is the dismissal of science by scientists.

The three main drivers of degradation are pollution, overfishing, and, increasingly, climate change. I did my PhD at Johns Hopkins University in Baltimore looking at Jamaican coral reefs. Caribbean reefs became degraded much earlier than elsewhere due to runoff following land clearing, mostly for sugar cane, and they are also very heavily fished. So there are few fish left, which means that when the coral die, they are rapidly covered with seaweed rather than with new corals — because there are not enough herbivores, like fish or sea urchins, to eat the seaweed. Tragically, the Great Barrier Reef is rapidly catching up with the Caribbean. But the cause in Australia is different — in our case it is entirely due to the warming water.”Terry Hughes 

First, while coral cover in Caribbean reefs appears to have begun to decline somewhat earlier than on the GBR, the difference is only a few years (if even that; see the update below) (also see this post on the matter). Moreover, the very low sample size (small number of reefs being surveyed annually) means there is great uncertainty about the timing of coral loss before ~ 1985.

Second, its odd to see an explanation for the die off of elkhorn coral around a single island applied to the entire Caribbean. It also doesn’t make sense: how could deforestation cause a well-documented mass coral die off 500 years later? Precisely as ocean temperatures were peaking and the corals had turned white from bleaching or disease? Wouldn’t the scientists have noticed the corals they were studying being buried by sediment? This idea is presumably based on Lewis (1984), who suggest land clearing was one explanation for the mass mortality of elkhorn coral of the shallow fringing reef around Barbados. Yet radiocarbon dating by Macintyre et al. (2007) found that most of the fossil corals on the present day reef crest were killed between 4,500 and 3,000 years ago, likely by storms. (Also see this by Aronson and Precht).  That doesn’t mean early land clearing didn’t have an impact in the Caribbean and elsewhere. But the question at hand is what caused contemporary coral decline. Which the coral trend data indicate happened more or less simultaneously globally (give or take a few years) in the late 1970s and early-to-mid 1980s.

Third, it isn’t true that GBR coral loss is “entirely due to the warming water“. Just as in the Caribbean, there are well-documented impacts of predator outbreaks (e.g., COTS), storms, and disease (see attribution of year and sector-specific loss in the graphic above). Additionally, early land clearing for agriculture is thought to have led to increased sedimentation that buried many coastal reefs of the GBR nearly a century ago (Roff et al 2012). According to De’ath et al (2012), mean GBR coral cover was already only ~ 16% by ~ 2010 and regionally, coral cover “collapsed” roughly 20 years before the mass bleaching of 2016!

Anyway, I really don’t understand it. Global warming didn’t just start impacting coral reefs in 2016 – this has been going on for decades. I was nearly 20 years younger when I first witnessed mass-bleaching in Palau in 1998. It’s not just the GBR being impacted. Hundreds of scientists have witnessed on reefs around the world what Dr. Hughes so powerfully described off northeastern Australia. Why dismiss their observations? And the science described above represents the work of a generation of scientists. I can’t get my head around how or why anyone would summarily deny it, as if it simply doesn’t exist.

Update 1: Here is Fig. 1 from Cote et al 2013:

This is an important graphic.  It emphasizes not only how unique (and unrepresentative) the Jamaica story is in terms of the severity of the cora-algal phase shift, but also in regard to the timing. Hurricane Allan wiped flatted Jamaican reefs in 1980s, greatly reducing coral cover. This has led to the perception that coral cover collapsed across the Caribbean the same year – but the data tell a very different story of a more gradual decline over the subsequent 30 years, really beginning around 1983 or 84ish.

In support of the Biscayne Bay marine reserve

The ongoing battle over the planned marine reserve in Biscayne Bay has scientists and citizens scratching our heads. The impassioned opposition to the proposed protection of a tiny sliver of our shared resource is stunningly out of proportion to what the National Park Service (NPS) has proposed. Moreover, the arguments made by opponents have not been based on science and are mostly illogical. For example, citing a scientific paper I co-authored, Representative Ros-Lehtinen correctly pointed out in an op-ed that a marine reserve in Biscayne Bay National Park wouldn’t protect Florida’s remaining corals from global warming. However, this is analogous to arguing brushing your teeth is unnecessary because it doesn’t prevent cancer. Protecting corals from climate change isn’t the purpose of a marine reserve, although reserves provide countless other benefits. If Rep. Ros-Lehtinen wants to protect corals from climate change, her party and her CORAL bill should support the move to renewable energy, one of the few actions that could in fact protect and restore corals and the reefs they build.

While marine reserves are not a panacea for everything afflicting the ocean, the science indicates, in literally hundreds of case studies, that reserves can greatly benefit fishes, fisherman, and coastal economies based on tourism. This is because the fishes that are allowed to grow large and reproduce within a protected area eventually leave (with their babies) and can then be caught. This is called the “spillover effect” and is the reason why trophy fishes are so often caught adjacent to reserves, like the Merritt Island National Wildlife Refuge.

Marine reserves lead to bigger fishes – Florida needs more of them

The resistance of fishing groups and some of our elected officials stems from the “freedom to fish” mentality that considers fishing a right that should not be constrained. To most Floridians, this is preposterous: we can’t drive, hunt, skateboard, smoke, fly a kite or be naked anywhere we’d like. Government places restrictions on all kinds of activities to separate things that don’t belong together, e.g., highways and playgrounds. In marine conservation, this is called spatial planning – working within constraints of the seascape, the local ecology, and the demands of user groups, we zone the oceans to try to keep everybody happy and safe. The NPS is only proposing some much needed zoning to reduce the dangerous (occasionally chaotic) comingling of activities currently taking place throughout the Bay. To me, setting aside 6% of a national park, so people can observe wildlife in a safe, low impact manner is a no-brainer. Recreational fishing would still be allowed in 94% of the parks waters and across thousands of square miles of prime fishing habitat outside the parks boundaries.

I work mainly on the effects of climate change on corals and other marine critters. As Rep. Ros-Lehtinen pointed out, my work shows that marine reserves do little to mitigate those impacts. Yet, as a scientist, I still strongly support the establishment and expansion of marine reserves throughout Florida for their proven benefits for fish populations. If the planned Biscayne Bay reserve has a flaw, it is that it is way too small – a groundbreaking study recently found that to maximize benefits for fish and fisherman, at least 30% of the oceans should be protected (essentially creating nursery grounds that would massively boost the profitability of commercial fishing).

img_0315I also support the planned reserve as a father. Last summer, my family and I spent our vacation in the Florida Keys, which we’ve been doing since the early 1970s. Every day, we snorkeled in the Sombrero Reef Special Protected Area, where, safe from harvesting, the fishes are absolutely stunning. Snorkeling just a mile outside the reserve was a totally different experience; the fish are much smaller, scarce, and afraid.

Scientists, snorkelers, SCUBA divers, reasonable fisherman, and parents don’t have lobbying groups, but if we did, we’d deploy them to convince our representatives to support the Biscayne Bay reserve and the general expansion of protected areas throughout Florida. Instead, we have to rely on public comment periods, during which time 90% of 43,000 pieces of correspondence received were in support the marine reserve. Congress simply hasn’t listened.

Response to Avigdor Abelson

The graphics below are to supplement our response to the criticisms of Avigdor Abelson about our recent paper in Scientific Reports.

Possible Conceptual Figure OK-2


Back to Belize

I arrived in Belize yesterday with three former lab members (Abel Valdivia from CBD, Courtney Cox from the Smithsonian, and Jenny Hughes, a recent graduate from UNC). Although field ecology is really fun (if pretty challenging) we are actually here to work. In 2008 my lab took over a reef monitoring program Melanie McField set up in the mid 1990s to track the state (AKA “health”) of reefs along the Meso-American reef in Belize (we also work in Mexico and Honduras). Most years, we come down in May after classes are over to survey 16-19 sites from the north, just below the Mexican border, all the way down to the far-offsore cays near Honduras.  The sites are all on fore reefs, between 35 and 45 feet, with our transects typically ending just above the drop-off at 6oish feet.  About half the sites are “protected” (to some degree, e.g., from fishing, etc.). The general purpose of the long-term project is to measure and understand changes in the reef ecosystem on what is one of the world largest barrier reefs.  The sites were already pretty degraded when Mel started but there has been further loss of coral cover and fish biomass and a large increase in fleshy macroalgae over the last 20 years.  The causes are numerous including coral diseases, ocean warming, possibly poor water quality due to coastal development that leads to sediment and sewage pollution, and of course overfishing.  Although it’s a really cool place, the reefs are in pretty piss poor shape with few corals and fewer large fishes.


In the past, we’ve also had shorter-term projects to measure the effectiveness of the protected areas in conserving or restoring corals and fishes (not very), the impacts of invasive lionfish on native fish communities (insignificant), and we’ve brought corals back from multiple sites to our coral reef ecosystem lab in Chapel Hill to measure the relative and interactive effects of ocean warming and acidification on coral survival and calcification (the negative effect of warming is far greater).

This year, we are continuing a study of whether the national ban on the catch and sale of any herbivorous fish (including parrotfishes), implemented in 2009, has effectively restored parrotfish populations and herbivory, thereby reducing the cover and biomass of macroalgae.  The last time we checked in 2013, we saw inconclusive hints of increases in the biomass and density of stoplight parrotfishes (a key species here). It has now been 7 years since the law went into effect and if it has been reasonably well-enforced (and our forensic marketplace monitoring suggests that it more or less is), we should see measurable, even large increases in parrotfish biomass.

Basically there are three possible outcomes: 1) no increase in parrotfishes. 2) an increase in parrotfishes but no subsequent decline in seaweed. 3) increased parrotfish biomass and decreased seaweed cover. My money is on scenario 2. Scenario 1 could result from continued harvesting or parrotfishes, to increases in predators (sharks, etc., which is unlikely but we will test for this), or because parrotfishes from the larval source are being over harvested and if local populations are not self-seeding (if all the baby parrotfishes from reefs in Belize migrate to Mexico and if all of Belize’s babies come from Honduras, local protection in Belize won’t have much effect on population density. I’ll report back next week on this.

Are isolated central Pacific reefs really “healthier”?

In a new paper – that got a lot of media coverage – Smith et al 2016 quantified benthic reef composition “across 56 islands spanning five archipelagos in the central Pacific”.

Screen Shot 2016-04-05 at 1.04.47 PM

I think it’s an admirable project and an interesting data set, and there is a lot to like about the paper. However, some of the main interpretations, particularly in the press coverage, are off the mark. Although average coral cover was greater on reefs adjacent to uninhabited islands (24 vs 15%), this difference was non-significant; a key fact ignored or downplayed in the press. More importantly, the average coral cover of the human-dominated reefs Smith et al. surveyed isn’t representative of reefs in the region. Numerous synthesis of large survey and monitoring programs indicate the coral cover average used in Smith et al. for comparison to the uninhabited reef atolls is strangely low. This broader work also indicates the observed coral cover on uninhabited reefs isn’t at all exceptional. For example, mean coral cover across the Indian Ocean was 31% (2001-2005, Ateweberhan et al 2011), and in most subregions, cover was greater than the isolated reef average of 24% reported in Smith et al, e.g., Western Australia: 34%, Mozambique & South Africa: 28%, South Western Indian Ocean Islands: 36%.

The 15% value reported by Smith et al. is even lower than the average across the Caribbean – a highly disturbed and degraded region that lacks plating acroporiid corals (thus the central Pacific baseline is almost certainly 10-20% higher). And the value of 24% for uninhabited central Pacific reefs is a common, nearly universal subregional average these days, e.g., as seen across the Pacific (via Bruno and Selig 2007):



And even across most the Caribbean (Schutte et al 2010):

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Some of the reefs Smith et al. surveyed clearly have very high coral cover:

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But the same is true of the broader Pacific, Indian ocean, and Caribbean, e.g., see this figure.

And I agree, their data indicates there is plenty worth preserving and fighting for and in that sense constitutes good news. But that finding and message is true of every regional synthesis of coral loss I’m familiar with – it isn’t particular to highly isolated reefs and regions. All regions have reefs and areas with especially high coral cover and far more fishes. It isn’t objective to attribute the coral cover values on the reefs in Smith et al. 2016 to isolation and the absence of people given similar observations are made around the word, often adjacent to developed coastlines.

In fact, to me, the lesson of Smith et al. is that even our most remote reefs are highly impacted and sensitive to (and not resilient to) ocean warming and subsequent bleaching, disease and coral loss. Just look what’s happening on the highly isolated northern Great Barrier Reef this week. Although isolated reefs could plausibly recover from bleaching more quickly than locally impacted reefs: 1) Given the growing frequency of mass bleaching I’m starting to question whether this even matters. 2) This doesn’t appear to be the case: if they did recover more quickly, coral cover should on average be greater (assuming the disturbance regime was equivalent). But it isn’t.

Top 10 take-home lessons from Dayton 1971


10) Natural communities are enormously complex, often governed by networks of positive and negative indirect interactions. (complexity, indirect effects)

9) Multiple factors and processes interact to influence community assembly, including competition, predation, facilitation, recruitment, disturbance, physiological stress, patch dynamics, and succession. (multifactoralism)

8) The relative importance of various factors is highly context dependent. (AKA it depends…)

7) Recruitment limitation is important! (supply side ecology)

6) Disturbance can prevent competitive exclusion, maintaining diversity.

5) You don’t need R, Github or even a computer to do transformative science.

4) Pattern quantification and experimentation go hand in hand. One without the other doesn’t get you nearly as far as combining them does.

3) Natural history (local knowledge of a system and its inhabitants) is crucial to interpreting empirical results.

2) Experimental ecology is a very powerful tool.

1) Paul Dayton is badass.

Dayton_diving copyThe image above is of Paul, about to dive beneath the ice in McMurdo Sound, Antarctica, I believe in the early 1970s.  The link to Dayton 1971 at the ESA website is here.   


That wild caught shrimp you just ate? It might be from a skanky, destructive farm

Like lots of people, you probably love shrimp. Love to eat them that is. And hopefully you know, shrimp farming is highly destructive. To make a shrimp farm, you first clear out all the mangroves, destroying a critical coastal ecosystem.  Mangrove loss results in greater storm and tsunami impacts, greatly reduced fisheries production (mangrove roots, below the water, act as fish nurseries), and also reduced carbon sequestration. BIG BUMMER.  So you do the right thing and only buy wild caught shrimp. Moreover, you want to supper local fisherman, like the families that have been shrimping in our vast estuaries here in North Carolina for decades. But how do you know what you buy isn’t actually coming from a polluted, destructive shrimp farm in Thailand? You don’t.

You are at the mercy of the vendor.  Yet many seafood vendors don’t know where their product comes from or they are just dishonest about it. A NC food processor (why do we even have “food processors”?) was just busted for mislabeling shrimp:

Federal prosecutors say a Dunn-based seafood processor and distributor used a bit of bait-and-switch when falsely labeling almost 25,000 pounds of farm-raised imported shrimp headed for Louisiana. source

Beyond this, wild caught shrimp is generally highly environmentally destructive too. Usually, shrimp are caught by dragging huge nets across the bottom. This destroys habitat too (like seagrass beds) and also kills countless other critters that get scooped up and die as bycatch. More on that later…

Steller’s sea cow – candidate for de-extinction?

Today in Evolunch, we discussed de-extinction.  One species we evaluated for post-extinction-reintroduction via the magic of genetics is the Steller’s sea cow, extinct in the wild since 1768 (less than 30 years after it was “discovered”) .

Below is an excerpt from The Unnatural History of the Sea by Callum Roberts that describes the discovery and subsequent loss of Steller’s Sea Cow on Bering island in the mid-18th century. Roberts begins with the trials of an expedition led by Captain Vitus Bering and his men, stranded on Bering Island in the frigid north Pacific in 1741/1742. The descriptions of the now extinct Steller’s Sea Cow by German naturalist Georg Steller is particularly poignant.

The except starts here:

By the dawn of the eighteenth century, two hundred years of European exploration had sketched out much of the world’s coastline. But the north pacific, stretching from eastern Russia and Japan to North America, and the Southern Ocean, the name given to the waters  around  Antarctica, remained unknown and thereby enticing to adventures of the day…

As the winter set in, the land disappeared under deep snow. But food remained plentiful in the form of  sea mammals. The naive sea otters could still be approached and clubbed with ease. The otters, wrote Steller,

at all seasons of the year, more, however, during the winter than in the summer, leave the sea in order to sleep, rest, and play all sorts of games with each other…it is a beautiful and pleasing animal, cunning and amusing in its habits, and at the same time ingratiating and amorous. Seen when they are running, the gloss of their hair surpasses the blackest velvet.


Academic-NGO partnerships to optimize and utilize conservation science


Problems: (1) Many academic scientists in conservation biology are isolated from end-users of their work, including policy makers, stakeholders, and conservation NGOs (CNGOs). (2) CNGOs rely on science and scientists, however, a science staff is very expensive to maintain.

Assumptions: (1) Science is valuable and useful to CNGOs. (2) Some academic scientists want to produce conservation-relevant science.

Solution: Link academic scientists with CNGOs via two-way exchanges. These could include short (weeks to months) and long term (years to semi-permanent) placements. For example, CNGOs staff could be based in an academic research group and collaborate on applied research with academic scientists and their students. Academic scientists could work at or collaborate more directly with local CNGOs offices in their area or spend longer periods of time based at CNGO offices or field sites (whole semesters via sabbatical or even years by taking a leave of absence). Joint retreats could facilitate collaborations and linked projects.

Benefits for the NGO include: greatly reduced cost to achieve scientific output1, far greater connectivity with world-class science, staff training, career advancement opportunities, and a conduit for future staff and student interns. NGO’s would also gain access to students (advised, mentored, and managed by academic scientists) that can work on CNGO research projects.

Benefits to academic scientists and institutions include: far greater involvement with conservation, a better sense of what is needed, and inclusion in the conservation community. Academic scientists will also gain a greater understanding of how to communicate science outputs and to achieve real world conservation outcomes.


1Many of the costs associated within maintaining a science group could be absorbed by the academic institution, including office/lab space, IT support (as well as wireless, software, etc.), PI salary and some staff salaries, journal access, proximity to colleagues in many disciplines, and countless other resources available on a college campus.

New tools for science collaboration

The problem with science is email. You all know what I mean.

Nearly everything we do is done via email. On the one hand, email is faster than snail mail and enables me to effortlessly share large amounts of information via attachments, links, etc.  Email – even more than Word, r, and Excel – is the nexus of professional life not just in science, but in business, the arts, politics, everything.

However, one giant, crippling problem with email is the massive volume we all receive (dozens to hundreds of non-SPAM messages a day). Email efficiency (wasn’t that a benefit?) makes it too easy for people to ask for assistance or to generally bug, distract, and grouch at you. I have been steadily moving away from email, feeling less and less guilty about simply not responding. (I use texting with my students and primary collaborators and sometimes google chat. I only check and deal with email a few times a week and never, ever answer my office phone or check my office phone inbox.)

Email is also a pretty lame collaboration tool. We all use email to communicate with partners on our science projects and papers. We email ideas, draft manuscripts and proposals, data, r code, images, ppt presentations, and complain about NSF and journal reviewers.  It works for all this and more, but there are several problems.  It is really hard to keep the correspondence for a project together, especially since many collaborations last years and can encompass hundreds or thousands of emails.  It is hard to track, archive, and find all that correspondence (too many threads, deleted messages, lame university email storage, etc.).  I also don’t like how the project communications are stored separately from other project files (data, code, manuscripts, etc.), which nowadays usually reside in drop box, git hub or similar.

Last week, I was driving home from the field with my collaborator Dr. Laura Moore and she was making pretty much the same points. For our NSF funded project “The role of ecomorphodynamic feedbacks in barrier island response to climate change”, we have three PIs, two post docs, several grad students, undergrad interns, etc. and we all keep losing communication threads in email, have no way to share and view data, images, plans, ideas, calendars, etc.  There has got to be a new tool that would enable all this: simply, affordably, and in one place without any email!

Turns out, there are many of them. Dozens at least. I’ve explored about a ten and read several posts about various next gen communications and project management apps and below I’ve summarized what I’ve learned so far about a few of the options. Doing this has helped me refine what exactly I was looking for.  I’ll be testing these over the coming months and will update this periodically.

These tools are not meant to replace a shared document, like a Word file in drop box or a google doc or ether pad. They are fine for collecting notes, ideas, links, for collaboratively writing a paper, etc. But they are poor communications tools and are not a good way to share other project files or manage a team or broader collaboration.

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There many apps designed for project managers in the business world such as Asana. This is what my asana looks like:

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These online tools seem focused on tracking fairly discrete jobs and managing teams. To me they seem designed to assign tasks, track work products, deadlines, and other things that business folk do. This could be transferable to science, especially in hierarchical labs, however, many of my collaborations are with pers and my grad students and assigning tasks isn’t really how we do things. But on the other hand, teams of scientists are terrible at clarifying who is doing what, setting and sticking to deadlines, and generally making and communicating about work plans. So maybe this kind of tool could increase productivity.

What caught my eye initially about asana was the tagline “teamwork without email” – the point of my quest. And I really like the To Do list capacity. This could be useful for tracking what your students and collaborators are doing.

The next class of collaboration platforms are somewhat simpler tools like flow dock (built by vikings!), slack (the much-buzzed-about new kid on the block) and basecamp. They (and many similar tools) are designed for email-free communications, project / team organization and integration, and file sharing. Check out this cool example of how basecamp was used to manage the development of retail headquarters for Keen.

These three examples, asana, and their competitors all integrate surprisingly easily with many related and supporting tools. Integration with drop box and google drive makes file sharing a breeze.

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There is social media integration, as well as github, other code sharing tools, and project and team management tools like working on (basically, you use it to notify your team and boss about what you are working on in a simple, twitter-like manner) and Breeze (essentially a drag-n-drop To Do list for individuals or groups.)

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One of the many cool features of slack is the way it handles code sharing via different built in formats, that enable you to add a longer, formatted “post” and code snipers in addition to the traditional simple message:

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The key to normal people actually using these tools is simplicity. (Remember Google Wave?) Developers seems to have finally figured this out. Nearly every tool I looked at had very clean, modern designs and font, simple interface and great support via pop ups, videos, etc. You don’t need to read the instruction manual for any of these, although some seem simpler and more intuitive than others.

Another of my favorites (so far) is HipChat, which seems more focused on simple communications than flowdock and slack. Hipchat, like Campfire and others is an “instant messaging service” (see comparisons and reviews here and here). You can share files with HipChat and it also has powerful integration with GitHub, etc. And Laura will love this: you can set up notification of new messages via email, SMS, bouncy icon, sound alert, etc.

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The basic plan is free and you can upgrade for $2 per month per user (to get video chat, etc).

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Unlike some of the other options, HipChat can be downloaded onto your computer (a desktop client) or used online. I think I prefer online programs these days.


I’ve invited a few of my students and collaborators to try a few of these out with me this summer. If you want to join in, let me know, by email:) Ironic, I know. But this is what email should be for. Necessary but infrequent communication. External, rather than internal communication. In the 1980s you wouldn’t have mailed a letter to your coworker down the hall. And you shouldn’t send them an email in 2014.

So more on this soon. And let us all know (via the comments section) if you have other suggestions or views of these tools.

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Living Shorelines

dfsa Jared Brumbaugh of the eastern NC NPR affiliate did a great piece and interview with Rachel Gittman (a 5th year PhD student in my lab) about her work on salt marsh conservation and living shorelines. Protecting shorelines with natural, vegetative barriers is not only better for the ecosystem, it’s a more effective means of slowing shoreline erosion.  We speak to a local researcher about her work with “living shorelines.”

A new way of keeping water at bay is taking hold not only in eastern North Carolina but up and down the East Coast and local research is helping spread the word on living shorelines.  In high wave action areas, manmade bulkheads make the most sense, but for low to medium wave areas, such as rivers, estuaries, and soundside properties, living shorelines can be more cost effective and better for the environment. Bulkheads are a common sight along waterways in eastern North Carolina.  The wood or concrete structures protect the shoreline from erosion and keep water from encroaching on homes and businesses. But bulkheads can have negative impacts to the ecosystem.  A more environmentally beneficial way of stabilization is living shorelines, whereby stone, gravel or oyster shell filled bags are placed one on top of the other creating a sill. Read the rest and listen to the interview here.

Threatened staghorn coral invades Fort Lauderdale!

Last week I was visiting FIU and talking with Lionfish guru Zack Judd when the topic of the Acropora range shift came up.  He and Laura Bhatti wanted to take me to do something fun on my last day in Miami.  So we decided on snorkeling off the beach on the world famous Fort Lauderdale strip to see one of the local coral reefs.  Seriously.  I was skeptical. First, because this is what the shoreline looks like:


Close up of a typical coastal habitat: 2007573-Elbo_Room_Fort_Lauderdale


I had heard from my buddy Bill Precht that Acropora cervicornis (AKA staghorn coral) is moving northward along the Florida reef track in response to global warming. Precht and Aronson have a great paper in FEE (2004) “Climate flickers and range shifts of reef corals” that outlines all of this.


Though now rare throughout their Caribbean range (mainly due to white band disease), staghorn corals appear to be moving northward into Palm Beach County:


But still, I didn’t think these new populations would be, literally, right off the strip, in pretty shallow water (3-5 m depth). And I didn’t imagine how massive they would be. They were huge and the thickets were fairly thick, even though hurricane Sandy recently rolled over them. Check out these photos Zack took:




I know of other persisting or new staghorn thickets elsewhere in Caribbean (Bill and I documented one such example in Jamaica in 2003) but nothing quite this large. This is really good news. And it is in agreement with my growing sense that climate change is going to be more about change (range shifts, altered composition, new players, etc.) than outright destruction and extinction. We will have some of that, but the science to date suggests that species are changing their distribution and phenological timing in response to warming much more than they are simply dying out and going extinct.  They aren’t giving up quite yet.

The case study also emphasizes the over-dispersion of many marine species and the huge role of abiotic factors, like temperature, in limiting distributions. (I think in general, we are way to concerned about connectivity in the ocean – there seems to be plenty of that.)

Listen, Acropora cervicornis and palmata for thousands of years were two of the dominant reef-building corals  in the Caribbean. Their populations were decimated regionally in the 1980s and their loss radically changed countless aspects of coral reef communities. Their expansion into South Florida does not mitigate that regional loss. It also does not mean future threats won’t wipe them out. And they can’t keep moving forever; there is no shallow water hard bottom habitat to settle on too far north of Florida and other environmental factors, like water sediment and nutrient load, would probably prevent colonization anyway. Range shifts will not save all species. Many, like Australia seaweeds will range shift into oblivion (e.g., the southern ocean). But I think it is still pretty cool to see species like this continue to bounce back. It gives me hope. And I think it should be teaching us some broader lessons.

One is that local impacts and local human population density in general has very little to do with the loss of corals. Look at the shoreline these corals are colonizing! There is nowhere in the Caribbean with such high urbanization and yet here they come. The presence of people per se is not driving coral loss or limiting recovery.

When sponges take over

Below is a guest post by UNC student Kati Moore:

Overfishing, pollution, and most of all, climate change, are destroying corals, causing the collapse of ecosystems and fishing industries around the world.

“Corals are the backbone of the entire ecosystem,” said Emily Darling, a marine and climate change researcher at the University of North Carolina at Chapel Hill.

When corals die, sponges often take over the reefs, which causes drastic changes in reef ecosystem dynamics.

Think of an ecosystem like a city. Some cities are lively and diverse, have great restaurants and an eclectic music scene. Reefs with corals at their base are like this. Corals are colorful and vibrant, and most importantly, support a diverse group of plants and animals, including fish people eat.

Some cities are dull. Life in these cities is monotonous, there is little diversity, and there is absolutely nothing to do on a Friday night. These are reefs without corals. When corals die, other organisms such as sponges take over. Corals are “really critical for biodiversity,” said Elizabeth McLeod, climate adaptation scientist for The Nature Conservancy.

Global warming is making the oceans hotter and saltier, which destroys the tiny algae that live inside corals and give corals their bright colors. Without these algae, corals die. This process is called coral bleaching because killing the algae removes all color from the corals, leaving them white and “bleached.” Coral bleaching is “one of the most critical climate change impacts,” McLeod said.

Bleached coral on the Great Barrier Reef. Image by J. Roff (CC BY-SA 3.0). 

Human actions that release carbon dioxide into the air, such as burning fossil fuels, also release carbon dioxide into the oceans. More carbon dioxide lowers the water’s pH, making it more acidic, a stressful state for most corals. More carbon dioxide in the water also means less carbonate, which corals need to build their skeletons.

Overfishing is another important threat to corals, McLeod said. Overfishing removes fish at the top of the food chains in coral reefs. Without these fish to eat organisms further down the chain, the food chain breaks down, and the reef ecosystem, including the corals, collapses.

When corals die, they leave behind open space for other organisms such as sponges, urchins and certain species of algae. Most marine researchers once thought algae to be the most likely contender for taking over when corals die. New research shows sponges may have a better chance than previously thought.

In a paper published in the May 2013 issue of Global Change Biology, James Bell, marine ecologist at Victoria University of Wellington, cited cases in Belize, Puerto Rico, Indonesia and at Palmyra Atoll in the Central Pacific Ocean where the area covered by coral had decreased while the number of sponges increased.

One sponge whose takeover has been better documented than most is a brown, bulbous sponge called the chicken liver sponge. In 1998, oceans reached record temperatures, destroying a record number of corals through coral bleaching. Some types of corals experienced greater than 90-percent mortality. Scientists refer to this as the mass bleaching event of 1998.

The chicken liver sponge, Chondrilla nucula. Image by Esculapio (CC BY-SA 3.0). 

Richard Aronson, professor and head of biological sciences at the Florida Institute of Technology, conducted research in Belize around this time and found the chicken liver sponge almost completely covered the sea floor which had once been dominated by corals. The chicken liver sponge’s success was due to how fast it grows (many times the rate of most corals), and the smelly toxins it produces to ward off predators.

Researchers have documented similar takeovers by sponges across the Caribbean and Pacific Ocean where corals have died as oceans got hotter, more acidic and more polluted. Sponges have survived these changes mainly because they are less sensitive than corals.

When sponges take over, the ecosystem becomes a dull city. “It’s not like it’s a wasteland,” said John Bruno, marine ecologist at the University of North Carolina at Chapel Hill, “but I doubt that [sponges] are going to support fish populations in the way that corals will.” This means lower diversity overall as well as fewer edible fish.

“It’s hard to see any real benefits either ecologically or economically” when sponges take over, said Bell, author of the journal article on sponge dominance.

Interview with Abel Valdivia about lionfish and biotic resistance

I LOVE this interview PeerJ just posted (and excerpted below) with Bruno lab PhD student Abel Valdivia about our new paper on lionfish and biotic resistance.  

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PJ: What were your motivations for undertaking this research?

AV: The invasion of lionfish into the Caribbean basin over the past ten years provides a unique possibility to study marine species invasion at a large geographical scale. Species invasion is one of the major threats the oceans face today, and can be closely related to issues such as fishing and climate change. With rising temperatures due to global warming, several marine species are shifting their geographical range; occupying new environments; establishing new ecological interactions with established residents, and therefore changing the community structure and composition of the invaded systems. Marine invasions due to human introductions or ocean warming are important to understand at a large spatial scale since it will be a very common phenomenon in the near future.

Lionfish have spread to every shallow and deep habitat of the Western Atlantic and the Caribbean, including coral reefs environments, seagrass meadows, mangrove root systems, estuarine habitats, and even depths over 90 meters. Lionfish have even been reported in the colder waters near Boston, Massachusetts. We are still investigating the negative impacts of this invader on all of these already disturbed ecosystems, but one thing is clear – their voracious appetite threatens small fish and juveniles of depleted fish populations including commercially and ecologically important species such as groupers, snappers, and herbivores.  The failure of the Caribbean region to constrain invasion success may be partially associated with the lack of native predatory capacity due to overfishing, or simply to weak biotic resistance by native predators and competitors to a novel predator.

PJ: How would you say your study is controversial?

AV: Over the past few years some studies have hinted that native groupers could potentially prey on invasive lionfish and therefore act as natural bio-control of the invader. There is one study that reported lionfish in the stomachs of at least two species of large groupers. However, it was not clear if the lionfishes were already dead when the groupers ate them. Another study found a negative relationship between the biomass of native Nassau grouper and lionfish at a relative small spatial scale in the Exuma Cays Land and Sea Park in the Bahamas. In fact, we were excited to test the generality of this negative relationship in a paper published last year. Unfortunately, we did not find any evidence that grouper or any other predators (including sharks) or competitors (same size native predators) were negatively related to lionfish and concluded that other physical environmental variables and culling were the main drivers of lionfish distribution and abundance.

Our current study expands on those findings by adding new factors that are known to affect fish abundance (e.g., fishing and reef structural complexity). We also tested whether lack of native predatory capacity was an issue across the Caribbean. While some reefs actually had a low abundance of native predators due to overfishing, other well-protected reefs with high abundances of sharks, groupers and snappers exhibited a high abundance of lionfish. Therefore, the lack of predatory capacity does not limit the control of the invader. In general there is actually little to no evidence that abundant native predators can constrain the distribution and abundance of invasive predators. For example, the expansion and proliferation of the invasive Burmese python in the Florida Everglades was never constrained by the abundant native American alligator.

Read the rest here

Coral reef resilience: a biogeographic perspective

GBR_corals-590x400Coral reefs are affected by a large range of disturbances including disease, bleaching, storms, and Acanthaster planci, also known as crown of thorn starfish (COTS) outbreaks.  There appears to be a lot of variation of how much coral cover is affected by physical and biological disturbances and in how quickly coral communities recover from it.  Those two ecological processes, resistance to and recovery from disturbance, make up “resilience” (although in some corners of coral reef science, the recovery component is emphasized and nearly synonymous with resilience).  Resistance and recovery (and the disturbance regime they are linked to) control ecological “stability” or the degree to which population or community state varies with time.

People have been quantifying coral community resilience in the field for many decades. Stoddart (1974) studied the effects of hurricane hattie on the near-pristine reefs of Belize in 1961 (when it was still part of the British Empire and called “British Honduras”) and Endean and Stablum (1973) documented the effects of the first of many COTS outbreaks on the Great Barrier Reef.

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And of course Joe Connell studied the waxing and waning of shallow water coral cover (and species richness) in response to disturbance on Heron Island, GBR for decades (and probably still is).  Connell (1997) was also the first person I know of to synthesize this literature, although exhaustive, he employed pre-meta-analysis “vote counting” and his effort wasn’t exactly quantitatively sophisticated:

Screen Shot 2014-03-28 at 7.02.28 PMGraham et al. 2011 sort of picked up where Connell left off with a meta-analysis of the recovery of coral communities around the world.  Surprisingly, they found that disturbance type, e.g., “physical” vs. “biological” disturbances, and other reef characteristics including connectivity had little effect on recovery rate.  Region did seem to affect recovery, with it being fastest in the western Pacific, i.e., the most diverse place:Screen Shot 2014-03-28 at 10.32.01 PM Human population density and management status also appeared to effect recovery rates, but not in ways that you would have expected! 

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Reefs with lower post-disturbance coral cover tended to recover more quickly:

Screen Shot 2014-03-28 at 10.40.48 PM I recently taught an undergraduate seminar class in which for a class project, we expanded on the Graham et al study and asked: Is coral species richness related to resistance to and recovery from disturbances?

More diverse communities are thought to be more stable—the diversity–stability hypothesis—due to increased resistance to and recovery from disturbances. For example, high diversity can make the presence of resilient or fast growing species and key facilitations among species more likely. How natural, geographic biodiversity patterns and changes in biodiversity due to human activities mediate community-level disturbance dynamics is largely unknown, especially in diverse systems. For example, few studies have explored the role of diversity in tropical marine communities, especially at large scales.

We contacted Dr. Nick Graham, he shared his database with us (thanks Nick!)(which you can download here). We synthesized the results of 41 field studies conducted on 82 reefs, documenting changes in coral cover due to disturbance, across a global gradient of coral richness. The students added the resistance / coral loss data (the original study just looked at recovery) and we used Veron’s coral richness maps to estimate local richness (at the sites of the disturbance studies). 

Our results (Zhang et al. 2014) indicate that coral reefs in more species-rich regions were marginally less resistant to disturbance and did not recover more quickly.  

Screen Shot 2014-03-28 at 6.40.00 PMCoral community resistance was also highly dependent on pre-disturbance coral cover, probably due in part to the sensitivity of fast-growing and often dominant plating acroporid corals to disturbance. Our results suggest that coral communities in biodiverse regions, such as the western Pacific, may not be more resistant and resilient to natural and anthropogenic disturbances. Further analyses controlling for disturbance intensity and other drivers of coral loss and recovery could improve our understanding of the influence of diversity on community stability in coral reef ecosystems. Read more here at PeerJ: Zhang et al. 2014.

Literature Cited

Connell, J.H. (1997). Disturbance and recovery of coral assemblages. Coral Reefs, 16, S101–S113.

Endean, R. & Stablum, W. (1973). The apparent extent of recovery of reefs of Australia’s Great Barrier Reef devastated by the crown-of-thorns starfish. Atoll Research Bulletin, 168, 1–41.

Stoddart, D.R., 1974. Post-hurricane changes on the British Honduras reefs: resurvey of 1972. In: Proceedings of the Second International Coral Reef Symposium, vol. 2, pp. 473–483

Recent and future impacts of ocean warming on marine biodiversity

I am a (relatively junior) member of an NCEAS/NSF funded international working group that is assessing how climate change is affecting ocean ecosystems.  Today, we published our third major paper (in Nature; Burrows et al. 2014), that predicts how ocean warming will affect global patterns of Biodiversity. Read a nice non-technical summary here and a nice summary by the editor:

To survive in a changing climate, a species may need to move in order to stay in an area with a constant average temperature. Such mobility would depend on an ability to keep pace with a moving climate — and on the absence of physical barriers to migration. These authors use the velocity of climate change to construct a global map of how ecological climate niches have shifted in recent decades and go on to predict changes in species distribution to the end of this century. The map indicates areas that will act as climate sources and sinks, and geographical barriers likely to impede species migration. The data show that geographical connections and physical barriers — mostly coasts — have profound effects on the expected ability of organisms to track their preferred climate. This work underlines the importance of migration corridors linking warmer and cooler areas as a means of maintaining biodiversity.

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Our first major paper came out in Science in 2012 (Burrows et al. 2012) in which we described the “velocity” of warming of the planet at relatively fine grains.

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Our second paper “Global imprint of climate change on marine life” – and really the primary output of our working group – was published last year in Nature Climate Change. Read my summary here at Skeptical Science and less technical summaries here and here.

We synthesized all available studies of the consistency of marine ecological observations with expectations under climate change. This yielded ametadatabase of 1,735 marine biological responses for which either regional or global climate change was considered as a driver. Included were instances of marine taxa responding as expected, in a manner inconsistent with expectations, and taxa demonstrating no response. From this database, 81–83% of all observations for distribution, phenology, community composition, abundance, demography and calcification across taxa and ocean basins were consistent with the expected impacts of climate change. Of the species responding to climate change, rates of distribution shifts were, on average, consistent with those required to track ocean surface temperature changes. Conversely, we did not find a relationship between regional shifts in spring phenology and the seasonality of temperature. Rates of observed shifts in species’ distributions and phenology are comparable to, or greater, than those for terrestrial systems.

Working group leader Mike Burrows and I (with Chris Harley) also summarized the output of our team and other literature in a new book chapter (Bruno et al. 2014) which I serialized here.

Top 5 Things I Learned at The Benthic Ecology Meeting 2014

Justin Baumann has a very nice piece on his first experience at the Benthic Ecology Meeting here.

I was really impressed by his insight and the general maturity of his post. I am on Justin’s committee but I haven’t interacted with him enough to get this clear a sense of what he is doing and thinking.  Like so many newish grad students, Justin is really into blogging and science outreach.  I worry sometimes about students putting time into outreach, but one clear benefit is that it enables them to communicate ideas and opinions with their mentors and community.  So go check out his piece and some of his other posts at his website or the superb grad-student-run Under-The-C-Blog.

1) Benthic Ecology Meeting is incredibly student friendly!

According to the official conference booklet, 67% of all oral and poster presentations were given by students. As a conference attendee, I would say that it was safe to assume that students outnumbered faculty by at least 2:1, if not more. There were students everywhere. I’ve never been to so many student talks. This conference is not ASLO Ocean Sciences, it’s smaller, more personal, and less overwhelming. It offers students (both undergraduate and graduate) a great platform for being introduced to a conference and for giving a presentation to a large group of peers without feeling extremely overwhelmed. As someone who gave their first major research presentation in front of a room of the most well known faculty in my field (International Coral Reef Symposium), I would say that coming to Benthics first would have been dramatically better. Plus, since most of the attendees are students, it is a great way to meet colleagues in the field and discuss ideas without being overly intimidated. If you are a marine science student and you have never presented at a conference or want to work on your presentation skills, I suggest that you give Benthics a try!

Read the rest here

NOAA to close key fisheries lab in Beaufort, NC

The excellent Fisheries Blog has a great piece on the proposed closing of the facility on Pivers Island.  I was shocked when I first heard this news.  Duke/UNC organized a congressional visit to the facility that could change minds.

Despite the incredible work done by the approximately 100 NOAA Beaufort Laboratory employees (see page 8), the recently proposed Fiscal Year 2015 budget by President Barack Obama surprisingly proposes closing the facility. That is right, it proposes closing shop on more than a century of research.

Read the rest here

Graph of the day: projected coral bleaching under different RCPs

From van Hooidonk et al. 2013 PDF. Learn about RCPs here.