Just a little blue sky for you, wherever you are. 
Field work ain’t half bad sometimes.
Category Archives: Team Sousa
Ba-Bopsy
“Okay. All my life, I had a lump at the back of my neck, right here. Always, a lump. Then I started menopause and the lump got bigger from the “hormonees.” It started to grow. So I go to the doctor, and he did the bio… the b… the… the bios… the… b… the “ba-bopsy.” Inside the lump he found teeth and a spinal column. Yes. Inside the lump… was my twin.” – Aunt Voula, My Big Fat Greek Wedding
Andrea Martin is a genius, a straight-up acting genius. She was genius on Sesame Street and on Broadway and of course in this movie, and as a result since 2002 I’ve been:
- Terrified of any sort of bodily lump
- Sympathetic to the plight of vegetarians trying to explain themselves
- Aware of the concept of biopsy.
A biopsy is an investigative surgery; it doesn’t kill the subject, but provides information to the doctor or researcher performing the operation. In Aunt Voula’s case, it provided some really unexpected news, and Team Sousa hopes for revelations of the same magnitude (if not the same comedic heights).
That’s right, in addition to our observational data, we’ve started collecting genetic information via dolphin biopsies. Using a special rifle and large, red, sterile, buoyant darts, we (really just Tim, but it’s a team effort) take careful aim at a peduncle (dolphin back, below the fin) and fire, hoping to remove a neat plug of skin and blubber. This sample gets preserved on ice, shipped back to Adelaide, and analyzed to determine the sampled dolphin’s sex and potential genetic relationships.
*This photo shows the whole red dart en route to contact with a Sousa peduncle. The actual sample taken is much smaller (5mm in diameter) and likely couldn’t be seen from this distance.
It does feel like a drastic procedure- I mean, we do actually shoot at the dolphins with a rifle. But the dolphins barely react, generally diving on hearing the noise of the dart hitting skin or water, and then returning to whatever it was they were doing before. (According to Krützen et al., 2002, dolphins react the same way whether they were hit or missed, indicating that it’s really the sound and disturbance of the dart that causes them to duck.) Additionally, the scar created by the biopsy rifle has been observed in several dolphin populations (this method is well-documented and historically proven among people who study cetaceans) to disappear within a month or two. Compared to the gouges and scrapes we see and recognize on Sousa sahulensis and Tursiops aduncus fins, the plug is hardly noticeable.
I don’t advocate shooting anything at dolphins or really bothering them at all (how would you like it?) but short of waiting around for all of our catalogued individuals to turn upside down and wave their genitals through the air, there’s no other way to determine the sex of the various members of our study’s social groups. And the other data (relatedness, genetic distance, etc.) that we will gain will be a fascinating addition to our observations of the fission-fusion groups of mixing dolphins. Do related dolphins spend more time together? How long does a subadult or young adult stay near its mother? Are allied males related to one another?
Most of the time the biopsy rifle stays in its box at the back of the boat. But we’re hoping to collect as many samples as possible to unlock the genetic gold mine that could be present and underlying our Sousa sahulensis’ behavior and environmental needs.
Krützen, M., Barré, L.M., Möller, L.M., Heithaus, M.R., Simms, C., Sherwin, W.B., 2002. A biopsy system for small cetaceans: darting success and wound healing in Tursiops spp. Marine Mammal Science 18, 863–878.
Pretty Birds
It’s amazing what we get used to. Locals keep their eyes forward while passing bloated kangaroo carcasses, spray Raid on redback spiders residing under the handles of the car trunk, and don’t take a second glance at the colorful parrots that beat their wings above street lights and telephone wires. And you’d think after the avian fauna of Costa Rica and India, Nepal and California, I’d be immune to the charms of squawking corellas and squabbling galahs… but of course, though I adjusted rapidly to the climate and the time change, the constant flip-flops and the vague answers to any question (“not bad,” “not long,” “not far,” “not too much,”) I’m still fascinated by the birds.
I think someone must be feeding the galahs. They’re remarkably cavalier about my approach, a slow flip-flop shuffle with a big lens and some muffled cursing as I trip over the tufts of grass that cling to life in the backyard.
All Predators Are Super Scary
They come in all shapes and sizes. Below the Navy Pier (built by Americans here in Exmouth, to support the construction of the lovely VLF, aka Very Low Frequency, radio towers that you may see poking out of photos of the area), there are some big ones. The Big Friendly Grouper, rumored to have been desirous of chin rubs and head pats since the 1960s or so, is perhaps the most obvious of the large predators. Though he lives up to his name with regard to divers, the BFG could still suck down some pretty big fish if he so chose. The Wikipedia page for Queensland groupers, of which he is one, states that they consume a large variety of marine life including “large sharks and juvenile sea turtles.”
Yeah, I dunno. Large sharks? Whatever. We gave his giant green-gray dorsum a good pat on the sand near the pier and moved on- I’ll see if I can get some photos from my dive buddy, because at that point my poor little camera had sucked down a bit too much salt water.
Our next predator, though, was much more colorful, and just a bit smaller:
The photo’s not my best by any means, but these little colorful guys (Harlequin shrimp snacking on an unfortunate sea star) were tucked in among what appeared in low light to be gray-blue-green rocks, and I had to hang a bit upside-down and change my white balance to get it. Perhaps the shrimp don’t seem as intimidating as other predators I’ve mentioned on this blog, but that’s only because you don’t move solely on tube feet. To this sea star, they’re the scariest thing on six legs.
My third and final predator for this post:
The greynurse shark (Carcharius taurus) is known to be non-aggressive… unless provoked. Happily nobody in our dive group was interested in provoking anyone or anything, and for the most part the little sharkies (2-3m, maybe 6-9 feet?) took very little notice of us at all. With the visibility under the pier, maybe 8-10 meters maximum, it was very easy for them to slip out of view, which was a bit disconcerting, but thrilling nonetheless. The most archetypal predator, lurking in the murky depths, gliding without effort through the jumbled wrecks of past and sunken human endeavors… You don’t notice until you get to see one up close, but they’re all fine-tuned muscle, tough cartilage, and suspicious eyes balanced and perfectly buoyant in the water. And you look at them, bubbles spewing from your regulator and pooling against the underside of the rusting beams over your head, bobbing up and down each time you breathe, hands shaking (from cold, of course) and bright plastic fin tips brushing the rubble below you, and you wonder how little soft pink humans ever got to think they were in charge of the world.
You Won’t See It Coming
About once a week, maybe more, I get an email from someone I know (relatives, friends), with a title something like “340 Things That Will Kill You In Australia Without You Knowing” or “54.3 Ways Australia Secretly Wants You Dead” or “How To Get a Job and Stop Being a Drain on Earth’s Resources” (wait crap that last one is unrelated). Anyways, there are apparently lots of poisonous things that want me dead on this continent, though so far they’ve been reluctant to go on the attack. Anyways, part of what freaks people out about Australia I guess is the number of things that are both poisonous and sneaky.
Enter the wobbegong- this Eucrossorhinus dasypogon is considered harmless (I’ll start you off easy) if unprovoked, but certainly startling to come upon. The Navy Pier at Exmouth (dive currently run by the Ningaloo Whale Shark and Dive Company, very fun crew, very cool dive!) hosted at least two different and fairly large wobbegongs, which was excellent- they’ve been on my list of cool fishes since I was a young Agent Red Squirrel, reading books about marine life under the covers late at night. It’s harmless to divers but looks sort of creepy- those white spots aren’t actually the eyes, though. Look closer:
But only because you’re a human- if you were a fish, you wouldn’t want to get that close. That wide mouth creates a lot of suction, and technically that fluffy carpet there IS a shark.
More fun facts about the tasseled wobbegong- its fringe is made of skin, and in the other two species of wobbegongs doesn’t go all the way around the chin. That’s why this name (Eucrossorhinus dasypogon) translates to “well-fringed nose with shaggy beard.”
All right, now that you’re nice and comfy down there under the pier, keeping a close eye on where the beams and columns are relative to your head but making plenty of time to listen to the humpback whales singing in the distance and look at the schools of silvery fish drifting through the beams of light in the cloudy water, take a look just off to the north:
Stonefish, like this Synanceia horrida (see, aren’t Latin names fun?) can kill a grown man with one stab of their venomous and invisible spines. Happily, I’m no grown man and can therefore get a lot closer in… just kidding, Mom. We kept our distance and used the zoom on our cameras, but I was terribly impressed by our dive guide, Wes (who is moving to London and had a touching farewell with another lovely friend under the pier, who I’ll tell you more about later) for spotting this guy in the first place. Even pointed out, photo-enhanced and zoomed in, the fish still looks like nothing much. That was the part of the dive when I was happy that all of my various dive instructors and buddies and wise old advisors had taught me to keep my arms in close, away from stingy and bitey hidden bottom-dwellers.
I love diving- even without my favorite dive buddy, I had a happy and safe (though a bit chilly) time under the man-made and ocean-encrusted pier that we see so often from our transects. Warning to photographers, though- don’t take your favorite camera, even in a fancy and expensive housing, underwater with you unless you’re very cavalier or very insured, as my little old faithful G11 has now probably closed its little lens for the last time. But so it goes. If it could think, I hope it would have enjoyed the quality of light down there under the concrete and coral, and the sleep of electronic death. I hope it dreams of nurse sharks and giant groupers, mantis shrimp and harlequin shrimp and hundreds of nudibranchs. I hope it remembers Nepal and India, Little Cayman, Costa Rica, New Hampshire, and California. And I hope it remembers Australia fondly, less in listicles of violent and painful deaths and more in images of red dirt and teal water.
Goodnight from a sleepy Agent Red Squirrel- we’ll be on the boat at 7 am tomorrow, dodging the migrating humpbacks and searching for some more Sousa, as we do. From the boat, I’ll salute my new pier friends below the waves and try not to yawn too much before morning tea.
Good Signs
The weather this week looks lovely! But that’s not really why I made this awful joke title. Road signs in Australia are really fun- I’m used to deer crossings and on a really good day in New Hampshire, a moose crossing, but for the most part road signs in my area just blend in to the background unless I’m looking for directions or speed limits. Here, though:
Knobble-kneed emus, kangaroos poised to leap in front of cars, blue signs indicating “tourist ways” and “coral viewing.”
I’m sure they aren’t interesting to the people who live here, but I love me a goofy animal silhouette.
They’re not kidding, though- emus and kangaroos are all over the road en route to our launch sites at Tantabiddi and Bundegi boat ramps. Even better than the signs are the mirrored looks of surprise on the faces of car drivers and passengers and the animals they come across.
The Others
This town is small, and the marine mammal research world is somehow even smaller. Yet right here on the North West Cape we are not alone. (Sound dramatic enough? Good.)
We’re here (me, Tim, Kaja, and soon Natalie, our new compatriot who will arrive tomorrow), but so are several other groups of researchers. A woman doing research on humpback whale body condition, a group of Danish scientists working on tagging humpback calves and “singers”- male humpbacks, isn’t that cute- and another guy who is just now transitioning from research on killer whale predation on humpback calves to biopsy of humpback calves, mothers, and “escorts” (third whales traveling with the mother-calf pairs) to determine potential genetic relationships. It’s not that the town got bigger: whale shark outfits are closing shop for the season, and as the weather heats up the caravan parks and hotels empty out as “gray nomads” and vacationers head back south.
There’s a research community here- isn’t that cool? Research can’t happen in a vacuum, we stand on the shoulders of giants, and we are here for our own purposes but we are a community. We gather for barbecues and spend the whole time talking about whales, showing photos and complaining about grant applications. It’s a bit of a trap- people do this work because they love it, but that basically means there’s no escape. It’s cetaceans day in and day out, above and below the water- they follow us onto the land and we wouldn’t have it any other way.
Of Sponges and Bananas and Romance
Marine biology is hard. We (scientists!) literally cannot know what our subjects are doing all the time- we (Tim and Team Sousa) are lucky enough to have marine subjects that have to breathe air and come to the surface fairly frequently, but in a rather neat and frustrating exchange they also have a wide home range and can only be spotted effectively during the day, and really only days with good weather. So much of what they’re doing goes unnoticed or unseen, underwater or under cover of darkness or simply when we’re not looking directly at them. Sousa sahulensis has never, to my knowledge, been kept in captivity, nor could we ever say we’d seen them behaving “normally” and/or with a complete range of behaviors if they were to be so kept. Marine biology- it’s like detective work, following incomplete bits of information to try to piece together a whole story. It’s constructing specific questions, ones that we can answer given the limited observations we can get.
However, we’re out on the water as much as we possibly can be- every relatively windless day, five to ten hours at a time- and we see a lot of interesting behavior. For example, “banana pose,” in which a dolphin arches its back, rostrum (nose) and dorsal fin in the air. It’s a goofy-looking behavior, potentially adopted by males as a social or courtship display. Another example is one that I’ve heard about but haven’t yet seen- “sponging,” which in this case* is another potential courtship behavior, in which a male dolphin selects a sponge on the reef (quite a large one, too) and presents it (at the surface, presumably, since Tim’s seen it) to a female. He then adopts a banana pose. How romantic.
I don’t know that I’d consider any of this to be weirder than human courtship behavior, though. If you liked it, then you should have put a sponge on it- what’s the difference? After actually having visited a bar last Friday on my birthday (WHO AM I) I really could not argue for any sort of logic in the ways that young humans choose to behave (and I’m including myself here, don’t get me wrong). Presenting alcoholic beverages to other individuals or groups, rhythmic full-body movements to pre-recorded vocalizations, displays of colors and other physical attributes… Sponges seem more straightforward. Take note, lads.
*”Sponging” can also refer to another really cool dolphin thing- down in Shark Bay, where some other dolphin researchers have been conducting exhaustive focal follows and continuous analysis of several individuals’ behavior, Tursiops aduncus have been seen with sponges over their rostrums, using the squishy animals as shields against anything poky they might encounter while searching the benthos (the bottom, in this case sandy) for food. They actually teach this technique through generations, demonstrating cultural inheritance and general braininess. Ahh, I remember the days when my mom taught me how to forage successfully and keep my nose out of trouble. As far as I recall, grocery store watermelons are supposed to sound hollow, cantaloupes are supposed to be heavy (as is corn on the cob) and most everything else is just supposed to be unbruised. Put my hand under cold water if it gets burned, and while traveling on airplanes, always wear a scarf. Thanks Mom!
Why
So the new official species name Sousa sahulensis has supplied me with sibilant alliterative opportunities, but has also changed the nature of the research we’re doing here on the North West Cape. There has been some research done on Indo-Pacific humpback dolphins, but the humpback dolphins that live their lives around the continent of Australia (and maybe Papua New Guinea?) may have less in common with their relatives than we had previously thought.
According to Science News (shame on me for not reading the actual paper yet…), skull morphology and DNA sequencing were used to determine the separation of S. sahulensis from their northern cousins, S. chinensis. Our dolphins cannot cross Wallace’s Line, a deep ocean barrier separating Australia from the rest of the world and, incidentally, explaining in part why Australia and its waters contain so many endemic (local only) species- as the Line formed, these coastal dolphins could no longer cross between the home waters of S. chinensis and the Australian continental shelf. Those on the southern side of the barrier evolved through genetic drift and natural selection such that they are significantly different from the northern side, and have now been recognized as their own unique group. But why does that matter?
Well, first of all Tim has to change all the abbreviations we’ve been using on spreadsheets (Sc to Ss) and the title of his PhD…
Okay, the real reason why it matters is that, having proven significantly different from their relatives Up Above, S. sahulensis is now virtually unknown. We can’t assume they behave the same, use space in the same way, or require the same resources or protection as S. chinensis, nor can we rely on the larger population size of both species combined to buffer any human-caused losses or stresses. As oil, gas, and mining operations descend upon Australia’s coastal waters, coral reefs begin to feel the impacts of global climate change, and fishing and ocean recreation continue to increase, we need as much knowledge as we can get about these animals. Their impact on coral reefs and surrounding ecosystems could be a key part of healthy seas around Australia, and we don’t even have a good population estimate, nor any indication of whether the population is growing, shrinking, or neither. Tim’s working hard to break open the wealth of information that the North West Cape dolphins have to offer, but they’re elusive and research requires a lot of time and patience.
Much has been written about the importance of coral reefs for economic and environmental reasons, and much has been written about wildlife in general having inherent importance to humanity. I support all those reasons, and can give you pages and pages of arguments on why it’s important to maintain diverse and stable ecosystems of all types. However, I also think simply that we humans, as a species (yes, one global and multiplying species), ought to tread lightly on the world.
Yes, it’s important to understand and preserve the world around us because without diversity we and our world will be more easily overcome by change, because reefs and mangroves and wetlands provide storm shelter and water filtration to human habitations, because icy tundras and redwood forests and tigers and whales and tiny colorful fishes inspire us and make us wonder. But that all presupposes that it’s our right to choose to destroy or save those wonderful things. We approach the world assuming that we can manipulate it at will, but we are just students of systems much larger and more complex than the ones we have created.
Species-ous Allegations
As I’ve mentioned before, our focal animal, Sousa sahulensis or the Australian humpback dolphin, has only recently entered the official rolls of described species. In a recent report, scientists named this newly-identified species and thus spake Science- a species was born. Does that sound sort of arbitrary to you? Good, it probably ought to.
Let’s talk about species definitions for a second:
I love species names. I love using those distinct descriptions to identify the organism I’m looking at, and I love the way the fake-Latin words (so science! Very officialness) feel in my mouth. There’s a pleasing elegance to the system through which you can categorize groups of related species, like nested folders or bags-within-bags (kingdom, phylum, class, order, family, genus, species, subspecies). But do I trust species boundaries as absolutes? No, I do not.
A “species” can be defined quite a few different ways, is part of the problem. For example, the biological definition states that for a species to be valid, the population that makes it up must not be able (for reasons of geography, genetic change, or physical incompatibility, among other potential reasons) to produce viable, or fertile, offspring with the group from which it is being separated. Several issues arise with this definition.
First, we consider many animals to be part of one species despite the fact that they’re almost certainly never going to meet and exchange genetic material without the aid of humans. For example, northern and southern hemisphere killer whales in all oceans are still listed officially as Orcinus orca, which is absurd. They can reproduce in captivity, probably, but even groups of killer whales (for example, Southern Residents and the area’s Transients) that live in the exact same bays and straits avoid each other completely in the wild, and probably haven’t exchanged genes for tens of thousands of years. I could go on and on about killer whales and species definitions but I will spare you (for now, mwa-ha-ha) and move on to the next problem.
Second, some domestic animals like farmed turkeys, certain cows, and many dogs cannot reproduce without human assistance. Are they species? They can’t reproduce at all, in reality, so they don’t pass the “fertile offspring” test unless people intervene quite a bit (artificial insemination, cesarean section, etc.).
Some people don’t hold with the biological definition. They prefer to define a species based on the percentage of functional genes that are different between two groups (which varies wildly depending on the age and genetic purity of a presumed species), or physical characteristics that show distance between populations. There isn’t really a definition that captures the flawed system we have (understandably) superimposed on the natural world, and the flawed system doesn’t even capture the nuance that the evolutionary process constantly creates and changes.
Meanwhile, what do you do with mushrooms and plants that can self-fertilize, or other less-identifiable organisms like bacteria, constantly passing genes from one individual to another. How about viruses, just tiny packets of DNA and self-replication machines? People think of things in groups that feel natural (haha, biology = natural…) but that’s not very scientific. It is, however, very convenient and intuitive. We group things to make them study-able, understandable, explainable, referable. For the most part, the species definition really does work to distinguish different types of organisms. We just can’t explain exactly why.
So anyways, it’s a bit tricky to explain why Sousa sahulensis has been officially designated a new group within that system. In this case, a combination of geographic separation, physical characteristics, and genetic difference added up to the split of the Australian humpback dolphins from Sousa chinensis, the Indo-Pacific humpback dolphin. Tomorrow’s post will explain exactly how our Sousa have earned their species stripes- this is likely enough of a biology-nerd’s rant for today.
Stay posted, dearest readers! I’m going to go track down some more cute photos of our resident charismatic megafauna and then turn in- today was long, but wonderful. I’ll dream of manta rays and humpback whales and leaping dolphins- I hope you do too.
Agent Red Squirrel 
