New publication: Finding the species that make a muck diver tick

Now that my PhD thesis has been submitted, it is time to start blogging again! In the very near future I will write a new blog about this whole PhD-writing experience, but for now I will tell you about a new paper that has been published recently in the scientific journal Ocean and Coastal Management.

The paper, “Known unknowns: Conservation and research priorities for soft sediment fauna that supports a valuable scuba diving industry“, describes which species are most important to muck dive tourism, and how much research and conservation work has been done on them. I investigated this using a specific method that is pretty new and has not been used in conservation work until now.

Froggie pair_MDB

Who doesn’t like a frogfish (Antennarius pictus)?

Since these the method and the results will be of interest to different people, this blog is split in two parts:

  1. How did I do the research?
  2. What are the results?

If you are a scuba diver, a dive professional, a travel agent or otherwise mostly interested in the cute animals, it’s completely fine to head straight to number two (even though you will be missing out). If you are a resource manager, work for an NGO, are interested in marketing, or conduct research on flagship species, definitely read the first part of this blog as well!

First section: the Best – Worst Scaling method and why everyone should start using it

wwf-logoIt is important to first think about why anyone would care about which species are important to muck dive tourism, or any kind of tourism by extension. The obvious answer would be “marketing”, if you know which species attract the tourists, you can use them in your advertising and that way attract more tourists. If that is too capitalistic for you, remember that dive tourism provides (mostly) sustainable incomes to thousands of people around the world. But there is more, people might not visit a destination, but still care very deeply about certain species. This principle has been used (very successfully) by many conservation organisations to set up fundraising campaigns. The best known example is probably the World Wildlife Fund, which uses the panda bear as a logo, even if they are trying to protect many more species.

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Blue ringed octopus (Hapalochlaena sp.) are popular with divers, maybe because of the cuteness combined with its deadly bite?

With that in mind, how do you find out which are the animals that people care about? You can obviously just ask people what they like, get them to make a list of top 5 animals, rank a number of animals in preferred order, give scores to certain animals, etc. But there are some serious problems with most of these methods such as:

  • They are not always reliable, since some people will be consistently more or less positive, or have cultural biases, throwing off your scaling
  • They can be very labour-intensive (=expensive) to properly design and collect data on
  • Statistical analyses of the results are usually very hard to get right
  • It is very difficult to say how the preferences vary between different groups of people (male-female, age, nationality, etc.)

To overcome these issues, we used the “Best-Worst scaling method” and compared it to a traditional survey. This method has been around for a few years, but is mostly used in food marketing (wine!) and patient care in medical research. The big benefit of Best-Worst scaling is that doing the stats is really easy, and without too much extra effort you can also easily interpret how different groups have different preferences.

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Flamboyant cuttlefish (Metasepia pfefferi) might not be popular with researchers, but divers love them!

Without going into too much detail, the basic design of Best-Worst scaling is that you ask people what they would like MOST and LEAST from a fixed set of animals (or any other thing you are investigating). There are plenty of online platforms (we used Qualtrics) that allow you to design this kind of question, so it’s quick, easy and cheap. Getting results is as simple as subtracting the amount of times an animal was picked as most preferred and the number of times it was least preferred.

Figure 1

Example of a Best-Worst Scaling question

The reason I am describing this method here, is that it is just not known enough in the conservation, or even tourism world. It has the potential to allow all kinds of organisations with limited funding (NGOs, marine parks, or even dive centers) to investigate why people would visit / where they will go / what they care about. Which, eventually, might lead to more research and conservation on those species.

Second section: Which species drive muck dive tourism?

Mimic Octopus

The mimic octopus (Thaumoctopus mimicus), number 1 on many muck divers’ wish list

The results of the surveys won’t come as a shock for avid muck divers or people in dive tourism, but do seem to surprise from people unfamiliar with muck diving. Here is the top 10:

  1. Mimic octopus / wunderpus
  2. Blue ringed octopus
  3. Rhinopias
  4. Flamboyant cuttlefish
  5. Frogfish
  6. Pygmy seahorses
  7. Other octopus species (e.g. Mototi octopus)
  8. Rare crabs (e.g. Boxer crabs)
  9. Harlequin shrimp
  10. Nudibranchs

While other species such as seahorses or ghostpipefishes are also important to muck divers, a dive location that does not offer the potential to see at least a few of the top 10 species is unlikely to attract many divers.

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Nudibranchs (Tambja sp.) are always popular with photographers

Some differences did occur between diver groups of divers. Older and experienced divers seemed more interested in rare shrimp than other groups. The preferences of starting divers was poorly defined, but their dislikes were most pronounced than experienced divers. Photographers in particular are interested in species like the mimic octopus, potentially because of their interesting behaviour, although that would have to be investigated in a follow-up study.

The final step of our study was to look at how much we know about the animals most important for muck dive tourism. The answer is simple: not much. For most species researchers have not yet investigated if they are threatened, or not enough is known about them to assess their risk of extinction. It does not look like this will chance soon either. The combined amount of research conducted on the top 10 species in the last 20 years is less than 15%  of the numbers of papers published on bottlenose dolphins (1 species) in the same time. Which are not threatened by extinction in case you were wondering. To give you another comparison, from 1997 until now, 2 papers have been published on the flamboyant cuttlefish, compared to more than 3000 on bottlenose dolphins.

Don’t get me wrong, I am not saying we should stop researching dolphins, but perhaps it is time that some of the research effort and conservation money is also invested in the critters that make muck divers tick?

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Harlequin shrimp (Hymenocera elegans), popular with divers AND the aquarium trade

Poll: alternative muck diving terms

voteAfter the recent blog about the history of muck diving I received some interesting suggestions about alternative names to describe the activity. Because this is a democratic blog, it’s time for a poll! Tell me (and the rest of the world) which name you prefer and who knows, it might just catch on!

While less talked about than the term “muck diving”, a few people suggested the world needs a fitting name for muck dive enthusiasts (maniacs?).  In bird watching the most fanatic bird watchers are called “twitchers“. I reckon finding an appropriate term for those divers that love nothing more than finding new critters could be interesting.

I have been offered some suggestions, but feel free to add others. For the sake of inspiration, the name “twitcher” actually stems from the nervous behaviour of a well-known bird watcher in the 50s and 60s. So feel free to make fun of your photograph happy critter-enthousiast dive buddies 😉

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Muck-enthusiast in action (can you see the black hairy frogfish?

Fluo time

If this isn’t the first time you’ve read this blog, you probably know I am interested in the phenomenon of biofluorescence. I’ve previously talked written about what it is and what it might be used for. In the near future I’ll be tell you all about the details what I was actually doing. But I realized I haven’t shared any pictures recently that show just how beautiful and otherworldly it can be. So here is a random selection of fluo shots I took over the last two years. Enjoy!

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A bubble snail (Hydatina physis) photographed in Lembeh Strait, Indonesia

 

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Thorny seahorse (Hippocampus histrix) in Bima Bay, Indonesia

 

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West Australian Seahorse (Hippocampus subelongatus) in Perth, Australia

 

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Amazing coral in Raja Ampat, Indonesia

 

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Reptilian Snake Eel (Brachysomophis henshawi) in Amed, Indonesia

 

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Lizardfish (Synodus sp.) in Lembeh Strait, Indonesia

 

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Cockatoo Waspfish (Ablabys sp.) in Lembeh Strait, Indonesia

 

picnogonid

Sea spider (Pycnogonid sp.) in Tulamben, Indonesia

 

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Painted frogfish (Antennarius pictus) in Lembeh Strait, Indonesia

 

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Juvenile Painted frogfish (Antennarius pictus) in Dauin, Philippines)

 

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Barred moray (Echidna polyzona) in Nusa Kode, Indonesia

 

Flamboyant Cuttlefish

It’s been a long time since I put a critter in the spotlights, so it’s time for one of my personal favourites: the Flamboyant Cuttlefish! I am definitely not the only one to like this amazing little animal, for most divers it is high in the top 10 of critters to see. With good reason as well, Flamboyant Cuttlefish are one of the most beautiful and intriguing inhabitants of sandy dive sites.

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Flamboyant Cuttlefish (Metasepia pfefferi) striking a pose

The small cephalopod many divers call “Flamboyant Cuttlefish” are in fact two species: the Flamboyant Cuttlefish (Metasepia pfefferi) and the Paintpot Cuttlefish (Metasepia tullbergi). The first one lives in Malaysia, Indonesia, Papua New Guinea and the north of Australia. The Paintpot Cuttlefish is found further north, from the Gulf of Thailand all the way up to southern Japan. Both species are classic muck dive critters, they only occur on muddy or sandy bottoms, so you will have to move away from coral reef to encounter them.

flamboyant-cuttlefish3So why does this animal deserve the effort of searching sandy plains for days on end, in the hope catching a glimpse of it? To start with (the name is a bit of a give-away) they are very flamboyant critters. We are talking yellows, pinks, blacks and whites, all at once! If that wasn’t enough, they often change their colours into “traveling waves”, even more so than normal cuttlefish or octopuses. From my experience, smaller Flamboyant Cuttlefishes have the brightest colours and make the most extravagant displays. When I write small, I do mean really small: adults do not grow much bigger than 8cm. They ideally sized Flamboyant Cuttlefish for the best colour-show  would be around 3-5 cm!

If finding an animal that size seems difficult, you might also want to consider the following. When they are not disturbed, hunting, or mating, Flamboyant Cuttlefish are anything but flamboyant. In their “standard” state, they blend in perfectly with their background, so they will be a mottled grey, brown, or black. For this reason some divers or photographers are tempted to disturb the animal to better see its colours. It is obvious that this is a bad idea, as it will stress out the cuttlefish. Be patient  instead, observe it for a while and you might even be rewarded by seeing it hunt small shrimp, lay eggs, or even mate!

Another thing that is special about them is that they do not swim, but walk across the bottom. To do so they use two of their arms and an adaptation of their mantle. They can swim, but only do so when they’re startled and over short distances. I could easily spend an entire dive watching these guys wander across the seafloor, little blobs of colour on a quest to eat as many shrimp as possible. It might be because of the awkward way they walk, but I always imagine them to be mildly grumpy animals. A bit like an old man with stiff joints who can’t walk that well, grumbling to himself about how the terrible weather…

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A juvenile Flamboyant cuttlefish (M. pfefferi) walking across the rubble

An interesting mystery surrounding these animals is whether or not they are toxic. Their colours would suggest some form of aposematic colouration, in the same way nudibranchs advertise their toxicity with bright colours. Some authors have even suggested flamboyant cuttlefish might mimic nudibranchs such as the Ocellate Phyllidia (Phyllidia ocellata). I have however, not read a single bit of conclusive evidence of this. It seems to be one of these “facts” people have assumed, written about and then it just got copied. To date there seem to be no papers out their describing whether or not Flamboyant Cuttlefish really are toxic, and which toxin they would produce. If anyone would have come across that information, I would be very grateful if you could share it with me and the rest of the world.

As is often the case with small critters, we don’t know very much about them. But that doesn’t have to stop us enjoying looking at them. Which is why I couldn’t resist adding a video of one of these guys. The title is a bit too sensational, but the footage is great, enjoy!