Wednesday, June 26, 2013

Belize 2013 | Guest Post From BBC Cinematographer

New England Aquarium coral biologist Randi Rotjan, PhD, and aquarist Joe Masi are in Belize monitoring coral health near Carrie Bow Cay. Tune in here for live updates about their research and animal encounters, and see pictures from previous expeditions herehere and here

Today's entry is a cross-post from the personal blog of BBC cinematographer John Brown. 

A fantastic couple of weeks in a genuine tropical paradise. The crabs did everything that we were told that they would and more. It’s a really incredible behaviour and possibly unique to hermit crabs and humans. We certainly couldn’t think of another species which forms these ‘synchronous vacancy chains’ – individuals queue in order to move up from a limiting resource to a more suitable resource.

Photo: John Brown via

Shells are everything in the world of the hermit crab, and an individual’s ability to grow is limited by the size of the shell it inhabits. Hermit crabs therefore rely on finding a shell slightly bigger and better than their own in order to move up the housing ladder. Sometimes these shells are occupied by another crab, sometimes not, and sometimes a small crab comes across an empty shell that is too big for it to move into. What’s really fascinating is that the crab then ‘knows’ that waiting next to the empty shell is a good strategy as, sooner or later, the presence of that big empty shell will probably set off a chain of ‘house moves’ that will result in an empty shell of a suitable size for it to move in to.

Photo: John Brown via

Within hours a large empty shell can have dozens of crabs patiently waiting next to it, sometimes arranged in neat lines according to size, all biding their time until the right sized crab turns up to unlock the chain – rather like the home owners on a housing ladder, waiting for the family at the top of the ladder to get their mortgage approved.

Sometimes this waiting is orderly, sometimes it disintegrates into a mass brawl, with multiple lines forming and tug-of-war battles developing between rival lines – while tiny crabs rush from the end of one queue to another trying to guess which line is going to win.

Photo: John Brown via

When the move finally happens the speed is incredible. Ten or more crabs can switch up in shell size in a matter of a few seconds, usually leaving a tiny empty shell at the end as everyone has moved up one size. Occasionally the chain would break down as an individual would move up in shell size but be reluctant to let go of his/her old shell and you’ll end up with a nude crab charging around desperately trying to figure out what to do, like the looser in a game of musical chairs. It was great behaviour but surprisingly tricky to film – small and sensitive creatures and a behaviour that can go from nothing to completion in a few seconds, but I think we got a really strong sequence.

We were lucky to be on the island with the nicest bunch of people you could imagine, Randi Rotjan (who discovered the synchronous vacancy chain behaviour [along with Sara Lewis]) was absolutely fantastic, a brilliant advisor and great fun to work with. [Learn more about these vacancy chains in this blog post about Randi's research!]

Photo: John Brown via

The island was so lovely to work on; you wake up at sunrise, pull on swimming shorts, get some coffee brewing, and could be filming within 5 minutes. In addition to the very cool hermit crabs there were pelicans, a pair of ospreys, frigate birds and the bath-warm sea was filled with fantastic marine life.

We got the bulk of the sequence filmed in the first 10 days, which was a good thing as the weather gradually deteriorated to the point that we found ourselves in the midst of the terrifyingly named Hurricane Barry. This resulted in 3 days of intense rain (7.5 inches on night), gale force winds, and huge seas – which somewhat re-moddeled the island. All the crabs climbed the palm trees which was very interesting, a bit unnerving (what did they know that we didn’t?), and behaviour which, in the future, I’ll take more seriously.


There were lots of lovely things to photograph on Carrie Bow Cay, I became rather obsessed with taking pictures of the outhouse, which may herald an exciting new direction for my career ….

Photo: John Brown via

Photo: John Brown via

Many thanks to  John Brown for allowing us to share his pictures and experiences with the readers of the Global Explorers Blog!

Monday, June 17, 2013

Belize 2013 | A trip to the Pelican Cays

New England Aquarium coral biologist Randi Rotjan, PhD, and aquarist Joe Masi are in Belize monitoring coral health near Carrie Bow Cay. Tune in here for live updates about their research and animal encounters, and see pictures from previous expeditions herehere and here

Today's post comes from Joe.

Today we've decided to take a break from our transect work and head south to the Pelican Cays.  About an hour by boat, The Pelicans are an interesting ecosystem where coral reef, mangrove and seagrass habitat occur in extremely close proximity; even together at times.

What looks like a typical mangrove ecosystem from the top is really a mangrove/seagrass/reef below!

Tiny schooling fish dart in and out of mangrove roots and gorgonians in the Pelican Cays

A seafan amidst the mangrove roots provides the perfect perch for an arrow crab
The mustard hill coral (Porites astreoides) has a mushroom-like formation on this mangrove root,
surrounded by seagrass.

Unfortunately, what we saw was rather sad. Come to find out this area is a perfect example of how delicate these ecosystems truly are. In 1986, a disease called "white band" spread through the Caribbean causing massive mortality, primarily in Acropora coral species. In this particular area, most of the Acropora cervicornis died. Next, in 1998, a major coral bleaching event occurred because of extremely high water temperatures. In 2001 Hurricane Iris, a category 4, blew through Belizean waters and dropped a great deal of sediment on the reef and another drop in coral numbers was observed.  Finally, just as coral numbers started to ever-so-slowly recover, an earthquake in the Honduras Sea damaged the reef system again -- destroying what little coral recruitment and recovery had taken place (Aronson et al. 2012). This series of events has been well-documented by Aronson, Precht, McIntyre, and Toth over the years, and the most recent paper reported exactly what we saw with our own eyes: huge rubble fields (formerly Acropora cervicornis and Agaricia tenufolia), and very little coral growth.

A close-up of the Acropora rubble exposed by the 2009 earthquake

The rubble extends all the way down the slope (to the right)
It will be nice to be back on the barrier reef doing transects again, where there are hopeful signs of a recovering reef -- we've met many locals who believe "the reef is coming back, slowly."  Patience will be an important value on the road to recovery. These ecosystems took millions of years to form and will probably take many lifetimes to recover -- but I believe that if we succeed, it will have been worth the effort and the wait.

One of our monitoring transects on the Belize Barrier Reef, showing small but healthy corals amidst healthy reef fishes.

Pelican Cays history summarized from: Aronson, R. B., Precht, W.F., Macintyre, I.G., and Toth, L.T.  2012. Catastrophe and the life span of coral reefs. Ecological Society of America

Thursday, June 13, 2013

Belize 2013 | A sharky surprise!

New England Aquarium coral biologist Randi Rotjan, PhD, and aquarist Joe Masi are in Belize monitoring coral health near Carrie Bow Cay. Tune in here for live updates about their research and animal encounters, and see pictures from previous expeditions herehere and here

Today's post comes from Randi.

I headed out to the shallows this afternoon to search for some relatively rare parrotfish species—mainly the rainbow parrotfish (Scarus guacamaia)—that are no longer typically seen on the reef. A year or so ago, I saw a pair of adults while snorkeling at this site, and I wanted to check in and see how they were doing. I found one, and also found an initial phase blue parrotfish! This is a hopeful sign. Big parrotfish used to be much more common here, and sighting them in the no-take marine reserve (new as of 2010) gives me hope that they will grow to be reproductive adults. [Learn about some of Randi's parrotfish research here.]

Rare rainbow parrotfish spotted in the shallows – a sign of hope for a recovering reef.
Blue parrotfish seen by Randi

There are lots of familiar things to love about a coral reef, but it’s also nice to be surprised. Some surprises, however, really get your heart pumping! Ian Gray (BBC film producer) and I came face-to-face with a rather large lemon shark (approx. 6 feet long) in water less than 6 feet deep. Perhaps it was just the shallow setting, perhaps it was because the shark came by us twice, perhaps because I am just not used to seeing big sharks in the water here… but I was definitely taken by surprise and certainly was on high alert. Luckily, my inner shutterbug was still working and I got a photo (proof of our encounter!).

A 6-foot lemon shark surprises Ian and Randi on their snorkel

Though we were looking for parrotfish, we found quite a lot of elasmobranchs on that snorkel. In addition to the lemon shark, we saw a sleeping nurse shark, the baby blacktips that have been living on the backreef, and some rays. Not too bad for a quick swim amidst the long hours of hermit-crabbing. ☺ Speaking of which, the crabs beckon.

A bar jack hopes to catch a snack when this ray forages in the sand

A sleeping nurse shark hides from the mid-day sun

Tuesday, June 11, 2013

Belize 2013 | The BBC at CBC

New England Aquarium coral biologist Randi Rotjan, PhD, and aquarist Joe Masi are in Belize monitoring coral health near Carrie Bow Caye. Stay tuned for live updates about their research and animal encounters, and see pictures from previous expeditions herehere and here.

Today's post comes from Randi.

In this fast-paced, over-hurried world of email and cell phones and NOW NOW NOW, it is rare when an email graces your desk that just forces you to sit back for a moment, say “wow”, and re-read it. Last fall, I received just such an email. It was from a producer at the BBC about our hermit crab vacancy chain work (detailing how crabs switch shells in very quick succession). The producer explained that they are shooting a new film series and wanted to include a sequence on our work. Wow!

The luggage of the BBC film crew – all for hermit crabs!

Fast forward a bit, and here we are—several months later—at Carrie Bow Caye (CBC) with the BBC, deep into filming these amazing hermit crab behaviors. When we arrived on-island, my jaw dropped at the sheer amount of film gear they had transported. These hermit crabs were truly going to be movie stars!

The stars of the show: Coenobita clypeatus hermit crabs

It’s been great fun so far – I’ve learned a ton about the film-making process, and have also had several new research insights thanks to the ability to see my study animals with better camera equipment than I ever could have imagined. Stay tuned—hermit crabs will be on the big screen (Discovery Channel and BBC) in about a year or so. I promise, the hermit crabs will be the stars of the show.

Happy Oceans Day, everyone!

The producer’s hat, hanging on a tripod: I can’t give away too many of the BBC’s secrets, but this hat has certainly traveled the world. If only it could talk, oh the stories it would tell!!

Monday, June 10, 2013

Belize 2013 | Some place new, some place blue

New England Aquarium coral biologist Randi Rotjan, PhD, and aquarist Joe Masi are in Belize monitoring coral health near Carrie Bow Caye. Stay tuned for live updates about their research and animal encounters, and see pictures from previous expeditions here, here and here.

Getting to Carrie Bow Cay is pretty standard: flight to Miami, on to Belize City, enjoy a smoothie in Belize City while you wait for quick flight to Dangriga, jump on a boat to Carrie Bow. It’s been done numerous times by Randi and New England Aquarium staff before me. This is my first trip to the island, so everything is an eye opening experience. Imagine how big my eyes got when our flight to Dangriga was called and the airline attendant said, "Your private flight has arrived!" Yes, we took a 3-seater—Randi and I literally climbed aboard a Cessna to Dangriga and what an amazing experience.

Randi and Joe on a private plane from Belize City to Dangriga
Joe, the co-pilot!!
Storms on the horizon seen from the plane. The pilot, Jose, kept Joe and Randi safe!

Finally we arrive on Carrie Bow Cay and, as I get acquainted with the island, I see a few things that remind me of home and  summers in New England - great blue herons, nesting osprey, ruddy turnstones, terns, waves crashing and tons of mosquitoes.

Great blue heron fishing from the reef crest
Osprey with the wind on his wings
Ruddy turnstones searching for food on the wrack line

The similar sights and sounds pretty much end there. Carrie Bow is a truly amazing place with a rich tradition of field studies. Currently, the station is sleeping 10 people, which is crowded—the typical population is 8. In addition to the humans, there are thousands of hermit crabs (Coenobita clypeatus), anoles and geckos, and a pair of black tip reef shark pups circling in the lagoon.

Hermit crabs being social
A baby blacktip shark lurks in the seagrass meadows

The best part: surrounding the island are 24 transects that our team will be monitoring over the next two weeks for coral health, coral and fish diversity, corallivory and several more odds and ends that we’ve blogged about in the past. It’s a very exciting project, a great crew and I am thrilled to be a part of it all.

Smithsonian and New England Aquarium divers monitoring coral reef health in Belize