emmasimon20's Journal

After only three flights and two full days of travel, I arrived jetlagged in Thailand from California on January 22 to conduct marine fieldwork with a team of students. None of us had any idea what to expect. A lot can change in a month.
We stayed three days in Phuket, over a week in the National Park of Mu Ko Surin, a few days in Trang, and a week on Koh Adang, another National Park island. In a few days, we will be flying to Indonesia to observe more coastal ecosystems.
Our primary focus is tracking the growth of fringing coral reef ecosystems. We are using GPS coordinates to replicate photographs of specific coral heads over the years, and using transects to document the changing frequency of coral and invertebrates on the reefs.

This is a brief summary of the organisms observed on the reefs and what I've learned about them so far.

Stony or reef-building corals (Class Anthozoa, Order Scleractinia) were unsurprisingly the stars of the show, most notably massive corals (Genus /Porites/) and branching corals (Genus /Acrapora). Off of Koh Adang, playful bubble coral (/Plerogyra sinuosa/) and the potato-chip-reminiscent foliose coral were present as well. One of my favorite stony corals is the single-polyp mushroom coral (/Fungia fungites/). They range in size from a few centimeters to almost a meter and are usually light pink or purple.
Additionally, some beautiful soft coral (Anthozoa, subclass octocoral) communities existed off of Koh Adang, including sea whips, gorgonians (known informally as sea fans), and leather corals. The soft corals grow faster than the stony corals of Scleractinia and receive much less research attention, which I find to be a shame.
Other Cnidarians (my favorite marine Phylum) presented themselves in abundance. At Mu Ko Surin, the entire team was stung numerous times by what we erroneously assumed to be a jellyfish. After days of painful dives and research, we identified the stinging culprit as a member of the Class Hydrozoan, Order Siphonophore, Family Rhizo-Physidae. Known informally as the "flying spaghetti monster", it appeared pink, with a small bell-shaped center and long tentacles, but I was unable to capture it on camera. As frustrating as the Siphonophores were, I enjoyed observing related jellyfish from afar, including multiple /Marivagia stellata/.

From the phylum Ctenephores, we saw comb jellies. (I don't know a lot about these guys, except that they aren't really jellyfish. Weird.)

The Christmas tree worms (Genus /Spirobranchtus/)poking out of the /Porites/ coral were abundant and oh-so-colorful colorful. They are of the phylum annelids, class Polychaetes, segmented worms, but their bodies are hidden within holes in the coral. I also observed feather duster worms, which just looked like larger, less colorful Christmas tree worms.

Echinoderms are my second favorite marine Phylum.
Linckia sea stars (/Linckia laevigata/) hung out on most Andaman reefs, usually blue in color but occasionally patterned white or light pink.
The crown of thorns sea star (/Acanthasar planci/), which eats coral, was also present on most reefs, but never in high abundance.
Long-spined urchins were all over the Andaman Sea reefs but were most abundant in the reefs near Koh Adang, where I'd see tens of them all crowded together. At what point do urchins go from helping out coral reefs by feeding on algae to bioeroding?

Crinoids (Class Crinoidea), known informally as feather stars or sea lilies, were most common in areas friendly to soft corals, and would even attach themselves to the extended fans of gorgonians.
I only ever saw brittle stars peeking out of /Acrapora/ coral, but never a full-bodied organism— a shame, because I think they are very fun to watch move around.
Sea cucumbers have poop that is really important for marine ecosystems. They can also discharge their internal organs. (That would be cool to witness). There were a lot of sand-covered /Holothuria (Halodeima) atra/ in Phuket, and I saw /Pearsonothuria graeffei/ only off of Koh Adang. It was orangeish and had lively black feeding appendages.

We found giant clams (Genus /Tridacna/) at nearly every reef visited in the Andaman Sea, ranging in size from smaller than the palm of my hand to bigger than my duffel bag. Identifiable by their scalloped clam shell and bright, cool, colors, and are usually observed with massive (Genus /Porites/) coral. Similarly, coral scallops were abundant and burrowed into /Porites/.

I was happy to have spotted multiple nudibranchs, my favorite marine invertebrate! My coolest find was the blue dragon (Genus /Pteraeolidia/) off the coast of Phuket, observed on January 24. Off Mu Ko Surin National Park, I spotted the Genera /Phyllisiopsis/, /Phyllidia/, and /Phyllidiella/.
Off the coast of Amphoe Skao, near Trang, I observed a flatworm of Genus /Acanthozoon/, which I originally misidentified as a nudibranch.

In Koh Adang, I saw lots of crabs, and lots of spiny lobster antennae poking out from underneath rocks. I never saw a full-bodied spiny lobster.

As expected, all fish families that co-evolved with coral reefs were well-represented throughout the Andaman Sea.
One of my favorite fish to see on the reef is the anemone fish, part of the damselfish Family Pomacentridae. Damselfish were the most common, small, and numerous fish to see on the reefs. In protected waters, anemone fish, including the false clown anemonefish /Amphiprion ocellaris/ and red saddleback anemonefish /Amphiprion ephippium/ were abundant. Indo-pacific sergeant majors (Abudefduf viagiensis), a common damselfish, were seen most frequently by mooring lines when diving off the boat.
Surgeon fish (Family Acanthuridae) have crescent tails and armored caudal blades. The most common species I was able to identify was the powder blue tang (/Acanthurus leucosternon/).
Moorish idols (/Zanclus cornutus/) are the only species in the Family Zanclidae.
Butterflyfish (Family Caetodontidae) are brightly colored and have a stripe through their eye. The family includes the bannerfish, which looks like a poor disguise of a Moorish Idol.
Angelfish (Family Pomacanthidae) are bigger than butterflyfish and have less of a pronounced mouth, but otherwise, I have a hard time differentiating between the two.
Rabbitfish (also co-evolved with coral reefs) have big lips and venomous spines on their dorsal fins.
Parrotfish (Family Scaridae), while not co-evolved with reefs, were most prevalent. I'm not sure how many parrotfish species exist in this area, but I observed the green blotch parrotfish (/Scarus quoyi/). The "super males" (males that transitioned after being born female) were easiest to spot due to their large and brightly colored bodies. Some massive coral (Genus /Porites/) had damage from parrot fish beaks feeding on algae.
Technically, parrotfishes should be part of the wrasses Family Labridae. Wrasses, including bird wrasses, sling-jaw wrasses, and cleaner wrasses, were common.
Another one of my favorite fish species to see was a juvenile yellow boxfish (/Ostracion cubicum/). Grace said that if I were a reef fish, I'd be that one. I disagree, but I still take it as a compliment.
More often, I observed black-spotted puffers (/Arothron nigropunctatus/). I saw one huge porcupine fish with big eyes.
I only saw Scorpionfish (Genus /Scorpaenopsis/) in Koh Adang, and they were so well camouflaged I almost touched them, which would have been very bad. A quote from Chris: "the scorpionfish sting is so painful you die". I'm not sure if that's true but I'd rather not find out. I saw a lionfish, which is another species of scorpionfish, but they were definitely around because everyone else on the team seemed to see them quite often.
A couple of huge schools of yellow barracuda hung out around Koh Surin reefs, often pursued by trevally.
I saw a couple of ginormous groupers, always out of the open and looking grumpy.
Triggerfish are identifiable by a retractable forehead blade. Aggressive and territorial, they eat snails and other tough invertebrates.
Goatfish rake through the sand with their barbels.
Lizard fish look like lizards.
Fusiliers, identifiable by their forked caudal fins, are more pelagic, but we still saw them on the reefs.
We also saw batfish, sweepers/hatchet fish, and snappers.

The only eel we saw on the reefs was the giant moray, (/Gymnothorax javanicus/), and we saw multiple. At Koh Adang, I saw the largest eel of my life! That thing could have bitten my hand off, and he looked like he wanted to.

I don't know much about identifying sponges, but I definitely enjoyed their diversity of texture and colors. The barrel sponges in Koh Adang grew to enormous sizes, even to a few square meters.

Twice, I saw black-tipped reef sharks, and once I saw a hawksbill sea turtle, which eats sponges.

If anyone is reading this (unlikely, as my primary goal in writing this is to solidify my own understanding of marine taxonomy), please do share any comments or further information on the topics above! And for anyone curious, here's a link to a very crude estimation of some of the data collected on coral abundance following a local bleaching event in 2010: https://docs.google.com/presentation/d/1PVK7EuFTXdBkQRRsaR6tl_MeeE7sS6or5ec2IXacAzo/edit?usp=sharing.