Two weeks after crisscrossing the Dominican Republic from one compass extreme to another, the Baseline Caribbean team delivered their collection of reef fossils and modern reef sediments — all 800kg of it — to Santo Domingo’s Las Américas International Airport for shipping to Panama.

In all, the expedition logged about 1,500km on the road, three full field days exploring fossil reefs, 14 dives on modern reefs, two birthdays (Aaron had his b-day, too) — and only a couple of upset tummies from the mystery meat dishes and/or the choppy seas.

The 18 crates of samples include 65 large bulk bags and 130 small ones. “There are a lot of steps you have to go through to get them shipped,” said Erin. “Filling out papers with customs, checking the permits, waiting around, sending the samples through customs where some get randomly opened, and then packing them up nicely.”

If all goes as planned, the samples should arrive for analysis at the lab of STRI staff scientists Aaron O’Dea in the next few days. Then the “real” work begins — finding and identifying all the corals, dermal denticles and other traces of past and modern Caribbean reef in those bulk bags will take many months. But let’s not remind the team of that until everyone gets a much deserved rest after two nonstop weeks on the road!

 

After three days of sampling in Samaná Bay, it’s time to pack up and head back to Santo Domingo with another 90 sediment samples. It was neat to see the differences between the fossil reefs of the Enriquillo Valley and their modern counterparts in Samaná, a bay with a similar form and comparable sheltered fringing reef environment.

While one of our study sites was home to a large thicket of living staghorn coral (Acropora cervicornis), most of the reefs we visited were devoid of this IUCN critically endangered species. All that remained were eroded fragments of their branches covered in algae and encrusting organisms. Instead, algae, sponges, the occasional coral head, soft coral, or gorgonian (sea fan) populated the sandy bottom. Starfish and urchins patrolled the substrate, but we saw few fish.

In contrast, fish were much more abundant at the reef with healthy staghorn coral. We spotted small parrotfish, wrasses, surgeonfish, lizardfish, and territorial damselfish tending their algal gardens amongst the branches of the staghorn coral. We even saw an octopus crawling along a crevice between coral heads. In this shallow habitat, we collected sediment between the living staghorn colonies or in areas containing its rubble. While we encountered large waves and wind during our visit, the bay is normally more quiet. As such, we found the sediment to be fine and silty — exactly what we were looking for.

Deeper on the reefs, the corals were more densely distributed than I had originally expected them to be. As on the fossil reefs, we collected sediment samples between the thickets of coral heads, including brain coral (Diploria), star coral (Orbicella), lettuce coral (Agaricia), and starlet coral (Siderastrea). We even observed some of the same coral species that we had identified a week earlier on the fossil reefs.

While our qualitative observations suggest differences between the mid-Holocene and modern reef communities, the next step is processing the sediment we collected to characterize the microfossils left behind by the inhabitants of these reefs — both common and cryptic. Now we just need to get the samples back to Panama!

—Erin Dillon

 

How much work do you cram into a two-week expedition? As much as possible. But there’s always time to celebrate something important, even on the highway. Happy birthday, Erin Dillon!

And we’re off! After successfully bagging 300 kg of fossil reef, we’re heading to Santo Domingo today. Diving on modern reef for a few hundred kilos of modern sediments starts tomorrow. #BaselineCaribbean

On the North side of Lake Enriquillo there’s a site called Las Clavelinas (or Las Clavellinas, depending on the literature). The problem is finding its exact location….

Salimos esta mañana al Cañon del Buho a recolectar fósiles de un inmenso arrecife coralino. Félix nos explica el pronóstico del día.

 

 

 

This morning the crew headed off to Cañon del Buho, or Owl Canyon, so named for the owls that live in tiny caves in the rock formations. Aaron explained where we’re going (or where we went) in these clips recorded this morning:

We reached the banks of Lake Enriquillo just before nightfall. A new road has been cut through the Holocene fossil reef — to circumvent the steadily rising hypersaline lake, which is 40 meters below sea level — and the spoil of fossils line the road for kilometers.  Acropora cervicornis (staghorn coral) is the dominant species found here, along with a variety of other coral species, snails and clams. Nightfall and a brief rain kept the exploratory visit short. The serious sampling begins tomorrow…