Thursday, April 21, 2016

The Doomsday Expedition - Part 1

by Kim Cobb

Every once in a while, the universe reminds you that you are small. Very small.

Several weeks ago, my students and I set out on what was supposed to be a 7-day expedition to Christmas Island, a remote island in the central equatorial Pacific, to document the effects of the current El Niño event on the coral reef there. We could not have known that we would face major ordeal after major ordeal, all while confronting a mass mortality event of staggering proportions on the island’s pristine coral reefs.

The mission’s goals were simple enough:  to revisit sites that we’ve been monitoring for the last two years, service temperature and salinity logging devices, and drill some coral cores that span the bulk of the 2015/2016 El Niño event.

We joined a team from Julia Baum’s lab, who had been diving intensively for two weeks prior to our arrival, taking detailed photographs of the reef and collecting tissue samples from any survivors. The goal of their work is to decipher the recipe for coral resilience to extreme temperature stress, in order to aid the reefs of tomorrow weather future such extremes.

We landed to grim reports of extensive coral mortality, confirming our worst fears that the 9 months of continuous ocean warming associated with the largest El Niño event in history had taken their toll. Of the sites affected by the current global bleaching event, Christmas has been in the grip of extreme temperature stress for the most time, by a long shot.

My first dive was shocking. Above water it looked like the same island I’d been visiting for 18 years. But underwater it was a wasteland. As I descended to depth that day, my eyes would see things that my heart and mind couldn’t yet process.

Algae-coated dead coral on my first dive of the expedition, to 30ft on Christmas Island's south reef, April 2, 2016. In this entire view, there is only one small coral still alive - a half bleached/half dead Porites colony in the lower left. Credit:  Kim Cobb.
The reef was almost completely dead, with all but a few of the hardiest Porites colonies – mostly the smallest size class – coated in red/brown algae. These corals had lost their valiant battle against the elevated ocean temperatures months ago, most likely. I busied myself with the task at hand, retrieving a Conductivity-Temperature-Depth unit off the reef, swapping out the smaller package of sensors we’d co-located with the CTD, taking momentary solace in the fact that the instruments were still intact on the reef. Aside from their huge cost, their memory banks would tell us exactly how warm it had been on the reef in the preceding six months, across the peak of the event. It would have been a crippling loss, scientifically, had they been washed away. We have been swapping in new CTD units at this site since 2014, amassing one the longest, most detailed records of ocean conditions in this region.
The Conductivity-Temperature-Depth sensor after recording ambient 
conditions on the reef from Nov 2015 until April 2016, surrounded by 
dead coral.  Credit:  Kim Cobb.

My mind still reeling from that first dive, I was sure my second dive would be better. We were diving a site that I have visited on every single field expedition I’ve ever conducted, where the largest Porites coral colonies grow. These colonies are decades old, rising 1m or more off the floor of the reef, locking a remarkably accurate history of ocean temperatures in their skeletons. I had drilled one such colony for the TV documentary “Years ofLiving Dangerously”, wielding a huge hydraulic drill in the glare of two underwater cameras.

When I jumped in the water, it was clear my optimism was misplaced. The reef I knew like the back of my hand was unrecognizable. Of the five larger Porites colonies I had tagged and photographed in November – all still alive at that point, if not bleached – four were completely dead, and one was partially dead, hanging on by a thread. I was so overcome with emotion that I shed a few tears into my mask.

I took some time to swim the reef, taking in the destruction. Pocillopora:  all dead. Favia:  all dead. Montipora:  all dead.  In fact, the only things that seemed to be alive and well were, once again, smaller colonies of Porites averaging well under 1ft in diameter. Every good story needs a hero, and these corals were just that. It was as if nobody had told them that a record-breaking El Nino was still underway. My eyes were repeatedly drawn to these small pockets of color on the reef, while my science brain kicked into overdrive planning new science around these stalwart survivors. I would go on to tag and photograph these individuals, and collect small tissues samples that Danielle Claar, from the Baum lab, will sequence in the hopes of uncovering the secret to their unlikely survival.

When we return to the reef later this year, I will take small drill cores from these survivors, in order to document the story of this El Niño event from the perspective of the corals by analyzing the geochemical variations in their newly-laid skeletons. Such samples will allow me to make an apples-to-apples comparison to coral records of past mega-El Niño events, like the 1997/98 event, and to mega-El Niño events of the past centuries to millennia. And by comparing recent El Nino activity in the coral record against a long baseline of natural variability in older coral records, we hope to understand if and how climate change is affecting extremes in the El Niño-Southern Oscillation. Our preliminary results, published before the onset of this winter’s record-breaking event, suggest that El Nino events have become stronger as a result of anthropogenic climate change (see article here).

I hope that the reefs at Christmas Island have the time they need to recover before the next big El Niño hits. It will take ten years or more for the reef to crawl back to even a shadow of its former self. Over this period, we will document its recovery in detail, as an opportunity to learn more about life after death for a reef crippled by temperature stress.

Wednesday, February 10, 2016

A day in the life of a Sci-Mom

by Kim Cobb

Upon hearing that I have four kids ages 5-8 and a job as a climate scientist and Professor at Georgia Tech, people often ask me "How on Earth do you manage it all?"

There are many ways of answering that, including the following stock responses that I often rotate through:
1) I don't. It's a complete mess all the time but somehow everyone has survived thus far.
2) I have a great husband and we share our parental duties 50:50.
3) I spend lots and lots of money on childcare and support at home.

All true, but too vague to be of much use.

So here's a random weekday in my life - in this case, Monday February 8, 2016. To make it interesting, my husband split for Texas early that morning (he's a scientist too).

5:30am - wakeup
I usually beat my alarm to the punch, and spend 30min or so getting a jump on the day. I review my day's schedule, check e-mail and social media, and if I'm lucky, read the headlines of the New York Times.

6:00-6:30am - get dressed
I take this part of my day very seriously, as I like to dress up for work. I put on jewelry, makeup, and perfume every day. By the time I'm done I feel invincible, and ready for anything the day might throw at me.

6:30am-7:30am - morning routine for kids
In order to wake up the house, I blast some female pop-power-songs beginning at 6:30am (Katy Perry, Beyonce, Taylor Swift, Avril Lavigne, etc), and call to the kids to get up and dressed. Nobody is allowed at the breakfast table without clothes and shoes on, and they have to do it all by themselves (our systems are resilient to a 1-parent model as one of us is traveling ~50% of the time). During this time I make breakfast for everyone, and then while they eat it I'm making lunches for the big kids, combing/braiding hair for everyone, and feeding the dogs.

7:30am - everyone out the door to school
This is probably the most chaotic point of my day, unavoidably so. Nobody ever wants to wear a proper jacket, hats and gloves are scattered, the ballet bag isn't packed with the favorite outfit, it's "Bring-A-3-Eyed-Zebra-Toy-to-School Day" in one of the kid's class - you get the picture. And the clock is ticking.

8:30am - to coffee shop for warm-up exercises
Most days I enjoy a buffer between the kid drop-offs and my office, and a donut and coffee hit the spot. This morning I was frantically finishing lecture prep for my 10am class.

9:30am - park minivan and bike across campus to class (much faster than campus shuttles)

9:45am - meet prospective undergraduate research assistant (she was great!)

10am - "Sustainable Communities" class begins
Sit through a very intriguing and substantive guided discussion exercise by my co-instructor, which ends up running into my time and bumping my lecture to a later date. Lost sleep of previous night internally labelled collateral damage.

11am - bike back and enjoy 30 min in office
Work on NSF budget, stress about high costs of my funding request relative to coPIs. Update crowdfunding campaign. Feel guilty for not tweeting enough as @realscientists curator this week.

11:45am - postdoc and graduate student meet to discuss coral project
We review science strategies for new coral radiocarbon dates for postdoc's project. Decide we need more undergraduate research assistants in the lab asap to help her prepare samples.

12:45pm - chat with another postdoc about stalagmite project
Review science strategies for getting a thin section of our stalagmite across the horizon of the Toba super-eruption, hoping to find the petrographic signature of the ash layer.

1:30pm - meet with engineering undergrad who wants to add an Energy Minor to his degree
Talk about GT's offerings in the Energy space, including the two classes I teach, as well as the Energy on the Hill internship program that I direct.

2-2:45 - prep lecture for Energy, the Environment, and Society course

3-4:30pm - teach class on climate change science (probably my favorite topic)

4:30pm - surrounded by 5 eager young women who would like to join my lab, after I announce that we're looking for new undergraduate research assistants

4:45pm - leave to pick up 5-yr-old twins at on-campus daycare

5pm - drop twins at house with nanny, who helps them with their preK homework (really???)

5:15pm - pick up 6-yr-old son at aftercare

5:30pm - pick up 8-yr-old daughter at aftercare

5:45pm - finally home
House is spotless because I have my cleaning lady come twice per week, and she came today. Check dinner progress (nanny cooked a vegan meal of fried tofu, coconut rice, and roasted veggies), check mail, check homework for kids, argue with oldest daughter about the merits of a timed computer-based reading comprehension assignment she has to do (we agree it's pretty useless, but homework is homework...)  Son is playing math games on computer, and twins are wrecking havoc around the house.

6:30pm - family dinner
Partly in response to aforementioned foot dragging, I introduce the Cupcake Party Incentive Plan, whereby those who do their homework each night for the entire week get a fancy, over-the-top cupcake with a  50:50 frosting-to-cupcake ratio the following weekend.

7:00pm - bath night commences
I bathe twins while nanny cleans kitchen. Then twins get PJs on & brush teeth while I bathe my son. Eldest is lost in a spontaneous urge to make valentines cards for my entire extended family.

7:30pm - read to twins; twins 'read' to me
I read two books to the twins, and then they read their books to me and we practice sight words for the week. This is the longest phase of the evening routine (~30min), because there are two of them in this phase.

8pm - read to son, son reads to me; nanny leaves after reviewing plan for tomorrow
I silently curse the inventor of the Valentine's Day school tradition that has me overseeing the preparation of >100 Valentines by Thursday morning.

8:30pm - root through garbage because cleaning lady threw away makeshift envelope with my son's first lost tooth in it. Mission impossible. And pretty revolting. Aborted after 5min, with apologies to tooth fairy. He actually does OK - go figure.

8:45pm - spend a few minutes chatting with my eldest while she settles down with her Kindle in bed.

9pm - I head to bed, where I knock off small but urgent work items for a couple hours.

11pm - I try to sleep, unsuccessfully. Write blog post on my day instead.

Overview of support structures:

1) full-time nanny/house manager
hours worked:  M-Th 3-8pm; F 7:30-5:30pm; and one 4-hr weekend slot/date night
duties: run errands, go food shopping, menu plan, cook 2-3 times/week, homeschool 1 day/week, kid transportation, and most importantly, take care of the laundry from start to finish (I went on a permanent laundry strike about 2yrs ago now).

2) part-time house-keeper (comes Monday or Tuesday for 5hrs, and 10hrs on Fridays)

3) all kids in aftercare/daycare until 5:30pm

So there you have it. How do I make it work? All of the above, with a good husband and a good salary especially critical.

Monday, February 8, 2016

What influences coral survival through an extreme bleaching event?

By Sean McNally and Jessica Carilli, UMass Boston

Reefscape of diverse corals on the south side of Kiritimati (pronounced "Christmas") Island. 
Hard corals are animals that host symbiotic algae in their tissues called zooxanthellae. Corals obtain most of their food from algal photosynthesis – the algae make sugars from carbon dioxide, water, and sunlight, and some of this gets leaked to the coral hosts, feeding them. Despite this effective relationship in which a heterotrophic animal benefits from photosynthesis of microscopic algae, additional nutrients such as nitrogen and phosphorus are necessary for plant and animal growth, and must be attained by the coral ingesting zooplankton, particulate matter, or dissolved compounds. In a perfect system the corals provide shelter and nutrients like nitrogen and phosphorus to the algae, and the algae provide the corals with sufficient food to grow. This symbiotic relationship allows corals to create hard skeletons. Over long periods of time, corals can grow into reefs large enough to view from space. However, chronic or episodic stress can push this relationship out of whack, leading to the coral host expelling its symbionts and becoming “bleached.”
This white Acroporid coral colony is completely 
bleached, with its white skeleton
now visible through clear tissues. If
it has enough fat stores or is able to
feed on zooplankton, it might survive this
bleaching episode. 


The main environmental stressor that causes large-scale coral bleaching is increased sea surface temperature. But why do corals bleach? That’s an important question. Bleaching is not as straightforward as it might seem, particularly because different colonies of corals of the same species—even ones that live right next to each other—might have very different responses to the same stress.

First, let’s get a little technical: The current theory is that increased light and temperatures cause direct damage to the photosystem II portion of the photosynthetic pathway in coral symbionts. Excess oxygen radicals are produced that build up and eventually become toxic to the coral host. This “oxidative stress” results in the degradation and eventual expulsion of symbionts from host tissue. Interestingly, corals can host different types of zooxanthellae, and these can differ in their thermal and light tolerance. One theory suggests that stressed corals bleach to swap out less tolerant for more tolerant symbionts.

However, once symbionts are expelled, corals can starve or become more susceptible to disease. Corals that bleach and survive might either eat enough zooplankton, or live off stored-up fat, to survive these lean times. Increasing seawater temperatures associated with global climate change are likely to result in more frequent bleaching events.

We are joining the Cobb and Baum labs on Kiritimati Island in March to help answer the questions: 
What factors influence coral survival through an extreme bleaching event? 
Are there characteristics we can identify that might predict coral survival in future events?  Understanding why some corals resist or better recover from bleaching is crucial to better protecting reefs into the future.

Wednesday, February 3, 2016

Going "All In" for Science

by Kim Cobb

This spring, my lab will mortgage our scientific future to collect a once-in-a-lifetime dataset on the heels of the largest El Niño event on record. We'll document the effects of this climate extreme on coral reefs in the middle of the Pacific Ocean, where peak El Nino-related coral bleaching and mortality took place. Or at least that's what we infer from the exceedingly warm temperatures relayed back to our screens from buoys near our research site.
Map of current coral bleaching alert, from NOAA's Coral Reef Watch, showing Christmas Island (center of blue circle) in Alert Level 2 status ("mortality likely", according to the legend on the web-page). 
In order to make this field expedition happen, myself and my collaborators are pooling what scant discretionary funding we can find into a collective pot of sorts. We hope that it will go far enough to ensure the participation of the key team members - each of whom brings irreplaceable expertise to the project.

You see, we've been working together as an interdisciplinary team of physical oceanographers (ocean circulation gurus), coral ecologists, climate modelers, and geochemists since August 2014, thanks to two RAPID grants from the National Science Foundation. We got one year of funding to study the effects of the 2014-2015 El Nino event on coral reefs at my long-term research site, Christmas Island. But wait, you're saying to yourself. There wasn't a large El Nino event in 2014/2015, was there?

Before (or while) you have a good chuckle at our expense, consider the following. For one, we were not alone in thinking that a major El Nino event was in the making during spring of 2014, when we submitted our proposals. And more importantly, our datasets ended up providing an incredibly rich dataset to document conditions before and during the birth of this year's record El Niño. In a way, we couldn't have planned it better - what good are experimental data on this El Nino without an appropriate baseline?

We approached the NSF with precisely this argument in early fall, 2015, as our RAPID funding was expiring, to seek an extension that would enable us to study what was shaping up to be a mega-El Niño. We were denied, on the grounds that it was time to let other research groups have a crack at an El Niño RAPID this winter. Fair enough, even though I find it scientifically short-sighted (totally unbiased opinion). Here is a list of El Niño RAPID awards made this winter.

Running on fumes, funding-wise, we sent a skeleton crew to Christmas Island in the November, 2015 to make some early observations of coral bleaching and mortality levels (summarized here). We also serviced environmental loggers that have been collecting data continuously from August 2014 until now, took hundreds of seawater and rainfall samples for geochemical analyses, and tagged coral colonies ranging from minor to 100% bleached, for follow-up tissue sampling, drilling, and geochemical analyses.
 
A partially bleached Porites colony tagged for future
analyses by our team in November, 2015.
It’s been over three months of scorching ocean temperatures since our last trip, and we know that a large majority of the island’s reefs are bleached, if not completely dead. But we won’t know the full extent of the damage unless we can get back out there. And this time, a skeleton screw will not suffice:  we need to systematically survey the reefs at Christmas, from the leeward to the windward side, from shallow to deep. We need to deploy multiple boats per day, filled with teams of science divers, to have a prayer of collecting the comprehensive data and samples we need to answer the big questions about El Nino, climate change, and coral reefs. The resulting data and samples will be analyzed from the perspective of coral genomics & physiology, trace metal and isotopic geochemistry, ocean mixing and circulation, and coral reef ecology. None of these investigations will be conducted in isolation, but rather in our team’s collaborative playground, pushing questions at the intersections between our disciplinary expertise.

So how can we afford to launch a major expedition with no funding? It’s simple really. We cannot afford not to. We could wait 20 more years for an event of this magnitude to open the door to our most ambitious scientific questions – questions that we have been pursuing as independent scientists for our entire careers. By putting our hearts, our heads, and our labs’ very modest pocketbooks on the line this spring, we are absolutely certain that we will deliver some fundamental new insights about the fate of coral reefs under climate change, and the role of climate change in fueling monster El Nino events.

What is happening to the corals reef at Christmas Island this winter is a tragedy. But the bigger tragedy would be to let it go completely undocumented, thus robbing future generations of ecologists and climate scientists of the data and samples they need to study this climate extreme, together with its long-term effects and implications. 

So, are you with us? If so, please consider supporting our spring expedition here. Any contribution brings a smile to our face and a bounce to our step. Thanks for valuing science.