So there we were, scooting across the bay towards the mangroves with clams sitting in our tummies. Gradually, the line of trees on the horizon drew nearer until our guide maneuvered us into a rare wide waterway running among the trees.
Mangroves are unique in that they can live directly in salt water, forming very solid, impenetrable clumps that are rooted deep on the bottom. Roots catch detritous and mud and prevent it from washing away as well as provide habitat for all manners of species, from large fish to fish larvae.
Since the water they uptake is full of ions like sodium and chloride, their cells would normally burst, as water would want to rush in via osmosis to balance out the high concentrations of these ions. However, mangroves can exude salts out of their leaves, thus ridding themselves of any problems.
Crystalized salts on the leaves of a mangrove
The silty depths…
As the motor cut off, we donned snorkeling gear (and in my case, two swimsuits under a 2 mm short wetsuit–brrr!) and slid into the water. The first lucky few got to see large fish that subsequent splashes scared back into the tree roots. Of course, the adventurous ones among us swam up to the edge of the trees, grabbed a breath, and pulled ourselves in among the tangle of the roots, eyes scanning for any movement in the muddy, murky water.
Most terrifyingly, it took a few seconds for your eyes to adjust to the darkness after poking your head into this unknown, plus the space between roots was tight and fins made maneuvering difficult. I caught a flash of something large, and one of my professors saw a few barracuda, but I quickly realized I was happy to leave the rest of the dark mangroves in Mexico unexplored.
Paddling over to the other side of the waterway made me wish I was holding hands with my night snorkeling buddy again (night snorkeling is a whole other scary experience, especially when your light dies and you don’t know which direction the beach is).
The current was quick, so I ended up a few hundred feet downstream of where I had started, and the middle of this psuedo-river was too deep to see anything but brown silt floating in the water column. Still, the trip was most definitely worth it. Within a few minutes, I found myself again against the trees, but here the sun shone into the first couple feet of roots.
While examining some barnacles, I grabbed a partially submerged branch to keep from being tugged away by the current. Before I chose to move further down, however, I noticed a few small orangey blobs right in front of my mask. Focusing my eyes, I realized these were the guts of clear fish and shrimp larvae, and as I scanned around me, I realized thousands of these babies had surrounded me. They faced into the current below me, in front of me, to both sides of me, completely accepting my presence. The fifteen minutes I spent there hanging on that branch are some of the most peaceful moments of my life.
Leaving these guys behind, I explored a bit more before we all hauled our drippy selves back into the boats.
Fantail pipefish. I think this is my favorite animal from the whole trip!
They’re related to sea horses! The resemblance is striking, right? I spent a good five minutes chasing this poor guy around, snapping pics.
Codium sp., aka dead man’s fingers aka a large hunkin’ piece of algae! It’s unusual since it’s made of one cell with many, many nuclei.
To the bay
Down to dune
Following the bends and curves of the waterway back in our boats, our guides eventually brought us to solid land–in the form of sand dunes. Here, we munched on mangoes and pb&j sandwiches (a staple of the trip; on these camping trips, we would have them for breakfast, lunch, dinner, and dessert). There was also some time to get ourselves completely dirty again.
Squishy sand at the bottom, thank goodness
Setting back out, we began to make our way back to the open bay.
Up next: birds, snails, and whales, oh my!