Wednesday, September 10, 2014

Fieldwork in paradise: how does that even work?

It's taken me a while to post anything lately: not because there's nothing to talk about, but because Palmyra is so unlike any place I've ever experienced that I'm kind of at a loss for how to explain it. Intellectually you can think about it, of course: there's this island in the middle of the equatorial Pacific where on average (on average!) 20 people live, none of them for longer than a few months at a time. But actually being there and experiencing a place so remote that Hawaii seems like the center of civilization is something else entirely!

So rather than talking about the science more right now, I thought I'd try and give an impression of what staying on Palmyra is actually like - at least, as a scientist. The staff probably have a completely different experience (and if any of them ever read this... you're awesome!!)

Outside the lagoon: the Zenobia.

As I mentioned earlier, Palmyra is an atoll: that means it's the remnant of an ancient volcano sinking into the sea, or if you like it's a preview of what will eventually happen to Kauai and the other Hawaiian islands. So it's made up of a bunch of different islands, and in between sits the lagoon, where water has filled up the caldera of the volcano. Inside the lagoon the water is incredibly still and quiet, and to get to the open ocean you need to take a decently long boat ride through the channel on the western side of the lagoon.

Right now there is only one boat on Palmyra capable of dealing with open-ocean conditions on a regular basis, and that's the Zenobia. She's named after an ancient queen of Palmyra, Syria (see what they did there?) and is the base of operations for most of the scientific diving that happens on the atoll. So for a lot of the time we were on Palmyra, we spent most of our days on Zenobia motoring around to the various dive sites we needed to find. Conditions varied a lot - but much of the time it was really sunny and calm, and we had some visitors come join us on the ride: 'melon-headed whales', which are technically in the dolphin family I believe and have more rounded faces than the bottlenose dolphins you picture from Seaworld. The pod we saw must have had dozens of whales, and we were able to hop in for a quick snorkel with them one day! Floating in the blue water with nothing around but our team, the Zenobia, and the whales was pretty amazing.

The other thing the Zenobia often does is fishing. There's plenty of fish around Palmyra obviously, and although there are pretty strict limits on how many can be caught, the Zenobia goes out sometimes and gets a fish for the galley. We did this a couple of times, and ended up catching a 22-pound ono (wahoo) on our last day out. I don't have pictures right now but the sashimi the galley staff made from it was definitely "ono"!

The amazing thing to me about fishing on Palmyra was how QUICK you have to be. We put out long lines off the back of the boat that get dragged behind as we go, then if a fish bites the line has to get pulled in right away... because otherwise the fish on the line will get eaten by a shark! The first day of fishing, Dave hooked an ulua and did a really good job hauling in the line. It took maybe 30-45 seconds or so from first bite to pulling the fish close to the boat... but by then we could already see a shark popping up from the deep. The staff showed us videos later of other fishing expeditions where dozens and dozens of reef sharks were gathered around Zenobia trying to join in the fun - so I guess we didn't even get the full experience.


Boating on the lagoon.
"Palmyra, Palmyra, this is Lagoon Boat 2. We have two people on board and are headed to Home Island..."

When you're working on a remote atoll and the nearest hospital is a thousand miles and an emergency charter flight away, you have to be pretty careful. So whenever anyone leaves the camp (and by "leaves" I mean "even walks more than 15 minutes or so away") they bring a radio, and check in with the field station manager before they go and when they come back. That includes people who work on other islands - we didn't need to for our project, but there was a group on Palmyra studying the ecology of how seabirds, geckos, and spiders interact on all the different islands around the atoll and they would take out the smaller "lagoon boats" every day to go and do their work. 


The lagoon boats are quite small, flat-bottomed boats that can fit about 4-5 people comfortably. In the still waters protected by the atoll these types of boats work great for getting around, and we got the chance to ride around in them a bit after finishing all of our instrument deployments. We had something like 3 or 4 days "free" after the CTD/current meter installations, so made sure to hit up some of the amazing snorkeling spots around the atoll. It's just incredible: the coral cover is damn near 100% in a lot of these spots and it's ALL healthy. Then you have every kind of tropical fish you can think of swimming around, with some rays and sharks thrown in, and it pretty much blows every other snorkeling spot I can think of away. Including Hawaii, including the Great Barrier Reef, all of that still can't compete with Palmyra.

video

Crazy Corals, Palmyra: this doesn't even do it justice! More photos hopefully coming soon.

Life around camp.


 The camp itself is pretty interesting too - staying there feels a bit like the summer camp you might have gone to as a kid, except of course in the middle of the ocean and full of adults. Also probably not as much archery practice.

Everyone stays in rustic cabins


with electricity but no running water or air conditioning or anything: they're pretty comfortable but can get overrun with ants and other bugs. I think I came back looking like my legs had caught chicken pox. worth it!

Most of the time we were there, the population of the entire atoll was 15:



so we saw a lot of each other. Like living on a ship (or at summer camp) all the meals are served at certain times and everyone eats all together. We were lucky (again) in that the "science season" is ending on the atoll and the "donor season" is starting. That means they bring in the big guns to make insanely fancy meals to impress all the rich people coming in for fundraising trips... and that chef had just gotten there when we arrived. So we got all sorts of treats: chocolate souffle, French pastries, Thai noodles, pasta, polenta, a Thanksgiving dinner at one point... I'm just not going to get on a scale for a little while!

The camp is nice, but it's really small and there are no outdoor lights. That means it gets DARK at night. So you have to carry around your headlamp with you. It's not actually that hard to walk around in the dark since there really aren't that many ways to get lost - but if you don't have a light, you run the risk of smushing all the crabs wandering around! There are something like 11 or 13 different kinds of crabs on Palmyra, including the coconut crab:



named for its ability to CUT OPEN COCONUTS. These things can get to be just enormous; the ones I saw weren't so big, but were definitely weird-looking. But none of the crabs have any interest in pinching you, they run away pretty fast into the bushes.

The places people mostly hang out after dark are at the "Yacht Club" (actually made by people coming to Palmyra in private yachts in the 70s) and by the "manta light". The Yacht Club is where all the party shenanigans happen - safely of course - and the manta light is literally a big light you turn on right next to the dock and then wait for manta rays to show up. It usually works pretty well:

(photo credit: David Slater)


And of course, I wouldn't be doing my job describing Palmyra life if I didn't mention the swimming hole. That's right, by the end of the runway there is a postcard-worthy spot fringed by palm trees where the bottom drops off steeply... so clearly the thing to do was to hang up a climbing rope and a rope swing.



All in all, despite all the hard work Palmyra really is a paradisiacal place and I'm incredibly glad that I got the chance to experience life there.

Wednesday, September 3, 2014

Go time!

After all the work of preparing and calibrating the instruments, we've spent the past few days motoring around the atoll doing the fun part - installing them on the reef! We have five different study locations:



but it took multiple days to do them all. That's because the instruments are pretty big, and each of them is weighted down with 60 pounds of lead, THEN staked into the reef. So with all that equipment, it's dangerous to SCUBA dive with it all. Each installation requires at least two dives, then when you include surface interval time and traveling between sites you end up with only enough time for two installations per day.

On our first day of diving, we headed to the northeastern shore of Palmyra. Here we had a little bit of an issue to figure out, since we're trying to put instruments mostly on the same spots that were used by a team from Stanford. This makes the data a lot more useful in the end since between us we'll end up with very long time series of temperature, salinity, and currents... but we have to be careful, since our sites are popular with a bunch of different groups. In particular, coral ecologists from UC San Diego have set up 'transects', or study regions, where they are monitoring different aspects of coral distribution. So we had to do some snorkeling around to make sure that the exact spot we wanted to use wasn't going to be right in the middle of where someone had spent 5+ years studying things! I think we figured it out properly in the end, but it was a bit stressful for a while there.

Our next site was the 'Channel', which is pretty much exactly what it sounds like: a channel connecting the lagoon to the open ocean. It was dredged by the military during World War II, when Palmyra was being used as a base of operations in the Pacific theater, and has been used by larger boats ever since. Having an instrument in the channel will let us see any influences of water exchange between the lagoon and the open ocean: for example, water might heat up more inside the lagoon than outside, or an abnormally large amount of rain might make the water inside the lagoon fresher than the outside. Either of those things could create changes in the oxygen isotopic ratios near the coral site, and therefore influence El Nino reconstructions. Anyway, we went out in the channel, and had another successful instrument deployment.

The site I was most excited about was on the "reef terrace", off the western shore of Palmyra past the channel. My collaborator Kim Cobb collected a set of coral cores from this area in 2003, which have since become one of the best-known paleo-reconstructions of the El Nino/Southern Oscillation (ENSO). So I really wanted to have an instrument as close to that location as possible, so we could be sure that the data we were getting reflected the ENSO influence on that coral specifically. It took us a couple of tries since the currents were fairly strong the first day we went out, but now the instruments are happily in place and hopefully getting lots of great data. Plus the reef was pretty amazing there too! (Photos coming soon from our resident photographer, Dave.)

It all went really smoothly considering the amount of preparation and technique required to get these things down in the water. Just goes to show the skill of the UH dive techs! Here they are in action at our last deployment site off Palmyra's south shore:

(photo credit: Dave Slater)


Friday, August 29, 2014

Equipment prep

We spent a total of a day and a half getting all of our instruments ready for installing on the reef. That might sound like a long time, but when you think about what it takes to prepare all these things it makes a lot more sense!

We have five different sites around Palmyra where we'll be putting instruments; together, they'll let us get a sense of the overall circulation changes around the island during the course of the El Nino (or at least, of the winter). At each of those spots, we'll be putting in:

- A "CTD", or Conductivity-Temperature-Depth sensor. This measures the pressure, which can be translated into water depth; the conductivity of the water, which is convertible to the salinity; and the temperature of the surrounding water.

- An "ADCP", or Acoustic Doppler Current Profiler. This instrument sends out regular acoustic "pings" like the sonars you see in movies about submarines. Those pings reflect off plankton, dirt, or other debris in the water and return to the instrument; then the change in the frequency of the ping once it gets back to where it started tells you how fast the current is flowing.

The CTD and ADCPs are attached to each other with clamps, then mounted on metal bars and weighed down with 60 pounds of zinc. Then just to make sure they won't go anywhere, they get staked to the reef! The entire setup looks like this:



Then the other thing we are measuring is the isotopic composition of water: both seawater and rainwater. These measurements are really important, because they tell us the relationship of temperature and salinity changes to changes in water composition... which is what the corals we're using to reconstruct El Nino actually 'care' about. To make it simpler: if you think of the seawater around the reef as a big bucket that's affected by

- rain coming in
- water evaporating from the surface
- ocean currents bringing water with different amounts of oxygen isotopes


(credit for background image: Widlansky et al. 2014)






what we're trying to do is measure how important each of those things are during El Nino events. The data we're collecting will be analyzed on its own, then also incorporated into our new, 'isotope-enabled' version of an ocean model (the Regional Ocean Modeling System, or ROMS) so we can get a complete picture of circulation around all of Palmyra, not just the few spots we'll be able to collect data.

In theory it should be really cool! Now to get started on those measurements...

We made it!

Short post today, but I just wanted to update and say that we made it safely to Palmyra! We got in yesterday morning, and have been busy getting all of our instruments ready ever since (see next post for more).

The trip to Palmyra is just a few hours from Hawaii. To get there, the only way is either by having your own boat or by taking the plane chartered by the Palmyra Atoll Research Consortium, or PARC. PARC is a sort of 'club' that universities join, and by paying their PARC fee they get a certain number of seats on the plane every year. I'm not too clear on all the details, since Mark has been nice enough to deal with all of that for us, but I do know that the plane to Palmyra is easily the nicest flight I've ever been on. It's a Gulfstream II:



I found out later that the reason why they charter such a nice jet is so that the plane can make it from Hawaii to Palmyra and back without needing to be refueled (and therefore the Palmyra staff doesn't have to maintain giant airplane fuel tanks). But this is one of the types of planes used by the super-rich, as we found out by reading all the onboard magazines. Most flights you get Skymall: this time we got to read about luxury resorts, investment real estate, and the best private planes to buy. (According to the magazine, it was the Gulfstream.)

That meant we had excellent views of the atoll when it first came into view!



It was pretty amazing to actually see this island I've been starting at for so long on Google Earth in person. Then the only thing left was to get used to being quite literally in the middle of the Pacific Ocean!



Wednesday, August 27, 2014

Destination Palmyra

Today our small team of scientists from the University of Hawaii heads out to one of the most unique destinations in the world: Palmyra Atoll. Palmyra is a tiny string of islands surrounding a lagoon, and has less than 5 square miles of land surface. It's also incredibly remote: 1000 miles south of Hawaii, or almost a 3 hour plane ride.



Haven't heard of Palmyra before? That's probably because no one lives there, at least not all the time - Palmyra is a "US Affiliated Pacific Island" managed by The Nature Conservancy, and is 'inhabited' by a rotating crew of TNC staff, US Fish and Wildlife Service personnel, and visiting scientists.

Even though Palmyra has never been permanently settled by humans, it has a very cool history: it's named for an American sailing ship, the USS Palmyra, which ran aground there in 1802. Throughout the 1800s it was annexed a variety of times: by the US government, by the Kingdom of Hawaii, then by the US again (when the US took over Hawaii - for a while there Palmyra was actually part of Hawaii!). Then in the early 1900s it was bought by a wealthy judge, and has been privately owned ever since... with the exception of a few years during World War II when it was used as a naval base by the US. The Nature Conservancy bought Palmyra in 2000 and sold part of it to the Fish and Wildlife service, and now it's maintained as a wildlife refuge.

Palmyra has an amazing variety of marine life, and one of the healthiest coral reef ecosystems in the world. It's common to see all sorts of sharks, rays, whales, and (it seems like) any other tropical fish you can think of - this makes it a very valuable destination for marine ecologists, who can actually study the ecosystem there without worrying about all the ways people have screwed it up! But none of that is the reason why we're headed out there. No, we are a physical oceanography team, and we'll be deploying instruments on Palmyra's reefs to measure the temperature, salinity, and currents around the island - and the isotopic composition (relative amounts of oxygen-18 and oxygen-16) of the sea and rain waters as well.


Why are we doing this? Well, to explain that I need to explain something else: El Nino. Not this one:

This one:

That last picture is a satellite image of sea surface temperature (SST) anomalies during the last really big El Nino event, in 1997-98.

El Nino events (and their sisters the La Ninas) happen when the trade winds that blow from east to west along the equator become either much weaker or much stronger than normal. When that happens, all the warm water that sits along the equator either 'sloshes' over to the east (El Nino) or gets pushed over into the west (La Nina). They both have dramatic impacts around the world, on weather, fisheries, and many other things: so we'd like to have an idea of how often they happen and how strong they tend to be, not to mention figuring out how they might change in the future! But the problem is that we've only been observing the oceans in enough detail for about 30 years, and El Nino/La Ninas only happen every 3-4 years, and that adds up to not enough events to get a good sense of what 'normal' is like.

One way we can get around this problem is using paleoclimate data to reconstruct what past El Nino/La Nina events were like. Paleoclimate data is basically any naturally occurring object that is sensitive to climate and accumulates fast enough to record changes in climate. On land, people use tree rings, ice cores and other things... but in the tropical oceans, coral reefs are the name of the game. Corals grow very quickly, like trees, and changes in the seawater around them affect the proportion of isotopes of oxygen that get incorporated into their skeletons. Islands in the central Pacific, like Palmyra and its neighbor Christmas Island, are excellent sites for collecting coral data since they're right where we expect the biggest effects of El Nino to be. But we still don't have good measurements of exactly how you translate between isotopes of oxygen in corals and what a particular set of El Nino events looked like, since there aren't very many measurements from right next to the reefs during their entire 'life cycle'. I've been working on using model simulations to understand the physics of how you go from El Nino to coral isotopes, but of course having more data would always be helpful.

Cue the 2014 El Nino! ...hopefully... Earlier this year, it looked like we might be in for the biggest El Nino since the one that inspired the Chris Farley video above. So my collaborators (Kim Cobb, Mark Merrifield, and Brian Powell) and I put in for a small grant to actually go down and put instruments near the reefs at Palmyra so we could watch how the event affected conditions near the shore! In a companion grant, Kim is also collaborating with coral ecologists to look at the impacts of this El Nino on coral ecology. She has a blog here:

Coral reef impacts of the 2014/15 El Nino event

Since we received our funding, the El Nino forecast got downgraded a bit, and it looks like any event we get won't be nearly as big as the 1997-98 one. But regardless of how big this El Nino turns out to be, the data we gather in the next week or so will be critical for understanding how these events are recorded by corals.