Day 23, 3 September 2017 β€” Manta Rays at Lankan Point, Maldives

Another day off! Seeing that I was sick on my previous days off or spent them in Male trying to finish the medical checkups, finally we went out for a dive to find some manta rays! We took the boat out to Lankan Manta Point, a spot often boasted to be one of the best places to see manta rays in the world. Mantas come to the reef here to be cleaned by small reef fishes such as the blue streaked (Labroides dimidiatus) and bicolour (Labroides bicolor) cleaner wrasses.

I hopped onto the boat trying not to get my hopes up too much, and was joined by two guests, Maxim and Noa. This time, it was Macy who was leading us along and we were both pranked by the boat crew who kept swapping all our equipment and tying my slippers to the zipper of my wetsuit…but all the laughter aside, I was dying of anticipation. Lanka point is a fringing reef that gently slopes down to a depth of around 20m, but it is somewhere along the middle of the slope where we wait for these giants to pass us overhead.

Screen Shot 2017-10-09 at 5.26.03 PMΒ Here’s a rough map of what the dive site looks like courtesy of iDive Maldives.

We loiter around the slope for what feels like forever and I distract myself looking at a school of headband butterflyfish (Chaetodon collare) with their striking red tails, unusually gathered in a small school, hovering above the reef.

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All of a sudden, I hear the sound of Macy’s underwater horn, it sounds like a strange beep and echoes around. I whirl around looking far into the blue but I see nothing. Turning back at Macy again, I see her pointing above me. 5 HUGE MANTA RAYS JUST SWEEPING RIGHT OVER MY HEAD. I almost forgot to breathe, and almost instinctively, I floated up to get nearer. Fumbling around with the camera, I got a badly shot video of the belly of a manta as it swooped by above me. There were so many of them I just couldn’t figure out which to focus on. Rookie’s mistake. One after another, they glided past and I couldn’t believe my eyes. I always knew they were big animals, but having them this close to me really made me understand how majestic they really were.

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I looked out for their eyes, and it was probably my imagination, but somehow there was a small sparkle of curiosity I glimpsed in them. We might have spooked them a little, because two of them glided straight on to a further part of the reef. Another three lingered and circled slowly around the reef, like children playing ring a ring o’ roses. I stared captivated and dumbfounded as their shadows rotated, slightly blurred because of the poorer visibility in the water that day.

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If you look carefully at the photos, you can see little specks of fish coming up to clean the rays. I’ve observed something similar with the thresher sharks in Malapascua when we volunteered with the Thresher Shark Research and Conservation Program. There, they studied two species of wrasses that were commonly involved with the cleaning behavior–the blue streaked cleaner wrasse (Labroides dimidiatus) and moon wrasse (Thalassoma lunare)

Left: Blue streaked cleaner wrasse (Labroides dimidiatus) and Right: Moon wrasse (Thalassoma lunare)

Over here in the Maldives, it seems as though there are quite a few species of fish that were involved in the cleaning. As far as I’m aware of, there aren’t any studies done in the Maldives that look at the cleaning behaviour of reef fish on manta rays. Would be really interesting too to find out how the abundance of these cleaner fish changes as many of parts of the reef were lost to last year’s bleaching event.

We continued the rest of our dive after the rays left the cleaning station and saw more beautiful animals, but my head was still reeling from the experience of seeing wild mantas up close in the wild for the first time.

The badly shot videos I took of my overexcited encounter

Left to right: Me during a safety stop, Noa from Germany, Maxim from Russia and Macy…stretching underwater.

As we did our safety stop during the dive, one of the manta rays glided beneath our fins, a final goodbye before one of the most memorable dives in my life.

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Day 18, 29 August 2017 β€” Night dives at Angsana Ihuru

When night falls, the entire scene underwater shifts dramatically. Butterflyfish and all the brightly coloured reef fish go into hiding, and the nocturnal fish emerge to hunt. I have quite a lot of fun peeking into the dark holes of corals and seeing fish fast asleep.

Parrotfish, wrasses and triggerfish hiding in the coral at night, hoping they don’t get noticed by the predators on the prowl. Most are safe within the rocks and crevices. Some fish even have an added layer of protection. Parrotfish have been observed to secrete a bubble of mucus that they encase themselves within. This purportedly conceals their scent from predators like moray eels, but another interesting theory is that it acts like a sort of mosquito net, preventing them from being fed on by blood-sucking, parasitic isopods. How cute is that. Parrotfish mucus is secreted from glands within the gill cavity and helps them to sleep too, a combination of features that has still not been observed in other animals. Just imagine only being able to sleep when you’ve covered yourself in your own snot.

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White spotted hermit crab (Dardanus megistos)

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Looks like a familiar face, the coral guard crab (Trapezia cymodoce)!
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Very entrancing featherstar (Crinoid) that I couldn’t stop watching as it rolled its tentacles slowly into the mouth.

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Surgeonfish
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Soldierfish
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Crown of thorns starfish (Acanthaster plancii) coming out to gorge itself on coral polyps. 😦
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Lionfish

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Lots of Tubastrea or sun coral…named because I guess they look like the sun. Ironically though, they live in darker places and are more active at night. Unlike most corals, they are not photosynthetic and rely almost exclusively on catching plankton with their tentacles at night.
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Banded coral shrimp

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A very huge, probably pregnant map puffer (Arothron mappa).

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Velvet snail (Coriocella hibyae), a very confusing name because it looks more like a slug or sponge than a snail. This stumped all of us for quite a while and we couldn’t figure out what it was until we got back and checked it up.

Creatures of the night

Lots of marine animals undergo diel vertical migration, especially plankton, where they rise from the depths of the ocean at night to the shallower areas. At night, they are less likely to be hunted by visual predators. Also, the water at night is usually cooler, meaning that it can present a metabolic advantage for organisms to conserve energy. One of my favourite things to do is to just look at the crazy number of strange worms, larvae and plankton zooming around near my flashlight.

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Plankton at night

Some of this plankton can even bioluminesce. So when we switch off our flashlights and are in complete darkness, you can see a glitter of glow-in-the-dark plankton tracing your every movement. It’s hard to capture on camera because it flutters for a second before dissipating quickly again. I could make out the outline of Macy flapping around crazily like a strange octopus, and as I laughed, the bubbles rising from my regulator lit up with plankton as well. It’s almost impossible to capture the biolumniscent plankton in a photo underwater…it’s like trying to take a picture of stars at night, only this time you are moving, the stars are moving and everything is a beautiful surreal blur.

As we ascended slowly towards the end of the dive, I spot a little movement in the sand. Ducking quickly into its burrow, a white mantis shrimp peered back out at me carefully. It edged out slowly, then ducked back inside further.

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The eyes of a white mantis shrimp hidden within its burrow.

 

It’s strange how night dives are now one of my most favourite dives. I remember my first night dive and feeling suffocated because of the darkness, and feeling a sense of dread that something would burst out of the shadows and charge straight at me. Now it’s become one of the most exciting dives and I can’t believe how different the entire underwater world looks when the sun goes down.