Natural habitat

With my husband, Carl, on a deco stop in Bonaire. Photo
by Megan Applegate. 

"I am currently on vacation in my natural habitat - underwater on a rebreather."

- my automatic email responder over the past couple weeks

About 2000 miles due south of my home in Massachusetts, there is a small desert island. The dry landscape is inhabited by tall cacti, feral donkeys, and blue-tailed lizards. Below water, the biodiversity is much greater - corals and snails and fishes abound. Historical relics of harsher times are visible above and below the waves, but now, the island's economy depends on tourism. This seemingly make-believe place is called Bonaire. 

I've been to Bonaire several times, always for dive vacations. This year, my 2-week trip served a dual purpose. As a vacation, it allowed me time away from normal routines to reset and decompress. As a dive trip, it reinforced my technical diving skills and got me back up-to-date for scientific work underwater. 

Showing off my new skill (DPV diving) at a shallow site.
Photo by Douwe Mursch.

I have a lot to look forward to in the next few months. As I have mentioned before on this blog, my team will establish a time-series on the world's largest artificial reef, SS United States, as soon as it sinks offshore of Destin, Florida. We have raised enough funding to cover the field work for the first two years, and I am beyond excited for this once-in-a-career opportunity. The planned sinking location for SSUS is 60 m deep, so I need to be in shape for some pretty deep dives to sample the lower sections of the ship. I got the practice I needed in Bonaire - and I got to do some pretty epic dives along the way. 

Diving deep on a coral reef means observing change in the community. Most times, Carl and I descended straight to 60 m (you want to do the deepest part of the dive first) and then worked our way slowly back up the reef slope, decompressing as we went. At 60 m, there are very few corals. Only one species, Montastrea cavernosa, stood out to me, and the remainder of the invertebrates were sponges and sea fans. The density of fauna increased as we climbed back up to 50 m, then 40 m. One by one, species of corals became apparent on the reef - primarily mounding and plating corals that could capture the dim sunlight. At 30 m, the reef felt like itself again, and at 20 m, it was a thriving, diverse community. I loved observing the cline in diversity every time we dove. 

Bonaire has undergone an unfortunate twist of fate since the last time I was there: Stony Coral Tissue Loss Disease (SCTLD) reached the island. Carl and I could tell - the cover of living coral on the reef was dramatically lower than it had been just a few years ago. Fleshy algae took over in its place. 

The ecologist in me is always observing, always thinking. That fleshy algae is going to make it very hard for corals to settle and recolonize the reefs, so reef restoration requires algal removal. Sea urchins used to munch on all the fleshy algae and keep it in check, but the long-spined urchins died off in the 1980s because of a bacterial pathogen. What if we could bring the urchins back? We'll see if that idea turns into my next research proposal...