Break Past the Anchor, Waves Come to Conquer

Combine sudden high winds, subpar anchor placement, and a tennis ball as a bilge plug, and what you’re left with is one goodbye to your sunglasses. RIP on the bottom of the bay, my polarized friends.

You served me well

The tragic loss of my optical style occurred yesterday after we finished refreshing the nutrient diffusers for our experiment. During a short but fierce bout of wind and waves, our boat had dragged its anchor loose and had found its way into some very shallow rocks. While attempting to extract it from said rocks, we bumped the drain plug (/tennis ball) and the waves soon swamped our precious craft. In the ensuing mayhem (which occurred only ~50m from shore), we are happy to say that we lost nothing else! Lessons were learned about double-checking anchors, etc., even when close to shore and in a normally calm area.

I regrettably was not able to document our adventure with photographs, but here is a happy picture of our fearless leader

I regrettably was not able to document our adventure with photographs, but here is a happy picture of the fearless leader

But aside from boating lessons, we’ve been learning a bit more about the island’s geography while continuing our studies. Last I blogged, I mentioned that we would be heading to the outer reef. Well, that was indeed what we did the next day:

At some point during our trip, I plan to collect some coral tissue and mucus samples from a variety of coral species. We are planning a project to describe the basic diversity of microbial associates of corals across a wide range of locations and coral types, and I want to do a trial run with samples I take here. Our dive on the outer reef helps me get an idea of the coral diversity on the island so that I can make an educated decision of how to do my sampling.

But the main purpose of the boat trip was to collect water from a number of points on a transect. It extended in a straight line from the shore to the outer reef. Jerome is going to look at how the diversity of viruses in the water changes depending on the distance from shore. We expect it to be quite interesting due to the distinctly changing environments which we encounter along the transect. For example, in the North, there is a distinct ‘fringing reef’ very close to shore, then a deeper channel area with a mostly sandy bottom. On the outer edge of the channel, the ‘barrier reef’ begins – the lagoon side of this reef is flat, shallow, and calm, and we refer to it as the ‘back reef’. The highest point in the barrier reef is the ‘reef crest’ – it is often completely exposed to the air and in some places forms small islets. On the other side of the reef crest is where we find the ‘fore reef’. This reef gets hammered by waves in the shallower parts, but quickly drops off to deeper water. This pattern occurs all around the island, although the zones are sometimes less distinct. The way these reefs form is fascinating – it was actually first described by Charles Darwin based on his observations aboard the Beagle. But I’m going to go over that in detail in a future blog post (after we travel to beautiful coral atoll this weekend!).

Small waves break on the fringing reef in the foreground, while large waves break on the barrier reef in the background

A somewhat undefined sandy channel/backreef area between the two major reef structures on the West side of the island

Waves break just past the exposed reef crest. Backreef structures are just under the water in the foreground.

Over the last few days, we have taken samples from similar transects in the North, South, and West of the island. In the South and West, we took kayaks out to do our sampling.