On the move again: Dauin

January 24, 2016 / Maarten De Brauwer / 9 Comments

After a few weeks of visiting my family in Belgium and loading up on chocolate, beer and hugs of my little niece, it was time to get going again. Just over a week ago I flew back to Asia and the first stop was a small town in Philippines called Dauin.

Some of you might have already heard about Dauin. You might have heard/read me ranting on about how great the muck diving is, dived there yourself or maybe you’ve seen some of the many underwater photos appearing on various social media. For those of you who haven’t heard of it, Dauin is a small town of about 25000 inhabitants in the south of Negros. The place is close to the city Dumaguete and sometimes the two are used as synonyms in dive circles (they are not). Dauin is a sleepy coastal town where most people used to make a living from fishing or farming. “used to”, because it’s rapidly getting renowned for its awesome muck diving.

In all fairness, the story actually began with coral reef diving. Facing Dauin lies a small island called Apo. The reefs around Apo were the very first MPA (Marine Protect Area) in the Philippines and have been a poster child for MPAs in developing countries ever since. The fame of Apo brought in divers and it did not take too long before people discovered that the shore dives off Dauin were something quite special.

Dauin The beaches of Dauin are mostly made up of volcanic sand, though they are not as black as the ones you find in Lembeh. While there are a few small coral patch reefs, the real treasures are found in the sand. It’s muck diving at its best: you’ll find frogfishes, seahorses, mimic octopuses, flamboyant cuttlefishes, … The fact that most sites are easily reached and that there is a growing muck dive industry makes it an ideal area for me to conduct research.

Last year I spent most of May in Dauin, doing a lot of diving and a lot of running around between divecentres to talk to people about dive tourism. This time I just went back for 5 days to talk to a few more people to fill in some gaps in my data on the socio-economic value of muck dive tourism. So unfortunately no research dives this time. Luckily I did manage to meet up with my good friend Dragos, who uses Dauin as a base to take some pretty sweet underwater photos. The underwater pictures in this post are his. If you want to see more of his (award winning) work, check out his site here.

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The small trip to Dauin was the end of a productive, exhausting and entertaining research trip. I am writing this post in Manila airport, as I’m finally on my way back to Perth. After nearly 8 months of fieldwork and traveling it’ll be great to see my colleagues again and to start writing up some of my results. So keep an eye out on the blog for updates of what is going on. Or if you’re in Singapore in April, come and have a chat at the ADEX Dive expo, I am giving a talk and will be presenting some of my results.

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Want to become a marine biologist?

January 20, 2016September 2, 2016 / Maarten De Brauwer / 2 Comments

Funny read about great and not-so-great reasons to become a marine biologist, text by Dr. Milton Love. This is the link to the full text, but here’s a preview:

“Okay, here’s the bottom line. By federal law, marine biologists have to take a vow of poverty and chastity. Poverty, because you are not going to make squat-j-doodly in this job. And just how squat is the doodly we are talking about? Well, five years after finishing my PhD I was making slightly less than a beginning manager at McDonalds.

And chastity? Well, who’s going to date someone who persistently smells like a thawed haddock with an attitude? Not even a dolphin.

But there are two really, really good reasons to want to become a marine biologist.”

Enjoy the read 🙂

Holiday special – Feeding time!

January 3, 2016January 3, 2016 / Maarten De Brauwer / Leave a comment

Now the main holiday madness is over, we are all starting to take stock of the damage done by the excessive eating and drinking we’ve been doing. Or at least I am doing so… In this time of year, we can all relate to the feeling of being way too full after that unnecessary third helping of dessert. Compared to other animals we’ve got it easy, all we have to do is cook or order our food and start stuffing ourselves. It’s slightly different with the critters we find in the ocean.

Best of Dauin_Lizardfish eating Dragonet

Lizardfish eating a dragonet

While there is a lot of active hunting happening in the ocean, many of the species I study are ambush predators. This means they are even lazier than we are when it comes to getting food. They spend nearly all of their time lying down on the ocean floor, waiting for dinner to swim by and then gulp it down. The plus side of this is they can’t get annoyed with themselves for not ordering the more delicious looking plate their neighbour is wolfing down. The downside is that they sometimes have to wait a long time until dinner swims by.

When you are an ambush predator, being camouflaged is particularly important. If you look like what you really are (a hungry fish), no tasty morsels will be tempted to swim anywhere near your mouth. Camouflage that helps animals hunt is called “aggressive camouflage” and sometimes “aggressive mimicry”. The difference between the two is that camouflage refers to animals pretending to be a plant or dead object like a stone. Mimicry refers to pretending that you (or a part of you) are a harmless or tasty living animal such as a herbivorous fish, worm, …

Aggressive camouflage: Estuarine Stonefish (Synanceia horrida) looking like a rock covered in algae and sponges

Good examples of critters using aggressive camouflage are stonefishes and lizardfishes. They pretend to be rocks or blend in with the sand, waiting for a bite sized morsel to swim by. Aggressive mimicry is used by many species, but it is perfected by frogfishes. They use a modified fin ray as a fishing rod, the bait on top of it (or “esca” if you want to sound all sciencey) has evolved to resemble a small animal like a shrimp or worm. This bait is wiggled around until an unsuspecting fish gets too curious for its own good and ends up as prey. In one species, Antennarius hispidus the esca (=bait) has even been found to contain bioluminescent bacteria, great for luring in snacks at night. Frogfishes are not the only fish using a bait to attract meals, this technique is also used by some flounders and stargazers.

The inside of the mouth of a giant frogfish (A. commersoni)

If you have ever had a fish tank and tried to catch your fish bare handed while cleaning it, you will know that no matter how nearby a fish is, it’s hard to catch one. So ambush predators have a number of adaptations to make this easier. Most of them have a huge mouth that sucks in a lot of water when they open it quickly. This suction feeding causes the fish to get sucked into the predators mouth together with the water. On top of that, the teeth of most of these predators are pointed inward, making it easier to hold slippery prey. Another funky adaptation are “pharyngeal teeth”, small teeth on the inside of the throat that hold the prey when the predator opens its mouth to get a better grip on it. You’ve read that correctly, as if frogfish weren’t weird enough already, they also have teeth in their throat.

While most of us only binge eat on special occasions and then feel guilty about it, frogfishes and other similar predators really don’t care. They eat whenever they can, as much as they can. When you think you’re exaggerating, remember this: the mouth of a frogfish can expand to 12 times its normal size when eating. The equivalent of this would be you fitting an entire chicken in your mouth when eating. Frogfishes can also eat prey that are up to 1,5 times bigger than themselves! For us, this would be roughly the equivalent of eating a whole pig for Christmas, which would make for some interesting scenes around the dinner table…