Category Archives: Uncategorized

Gerlache Strait

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While many people will continue, for various reasons, to call the above animals “orcas,” I prefer to use the term “killer whale.”

First, it sounds rad. These whales ARE killer, man!

Second, it’s pretty out of the norm for a species* to be referred to by the second part of its two-part name (Orcinus orca, in this case- the first half is genus and the second half is the species designator). You’d never talk about “sapiens” and expect people to understand you meant “humans;” if you referred to “musculus” and expected me to know what animal you were talking about, I’d have to guess if you meant a blue whale (Balaenoptera musculus), or a house mouse (Mus musculus).

Third, and most importantly, I follow the opinion of scientists that I respect greatly in thinking that there’s no way that all of the different types of killer whales across the globe (oh yeah, they’re everywhere, in every ocean, doing their killer thing) are still one species. Just in the Antarctic, there are at least five types of distinguishable killer whales, each of which has a population separate from the others, probably with their own social structure, language, and feeding habits (further study needed). In the Pacific Northwest, where I did a week or two of research with Holly Fearnbach and John Durban (NOAA scientists and generally awesome human beings), three types of killer whales co-habitate but never interact, studiously avoiding contact while passing each other in a narrow strait, consuming different food sources, speaking different languages… Maybe it hasn’t been long enough in evolutionary time (hundreds of thousands of years) for them to have genetically diverged enough to make reproduction between groups impossible, but unless they’re forced (in captivity, for example…), different types of killer whales will never interbreed. In some cases, they’d have to cross continents to do so.

Anyways, these are the “small Type Bs,” also known as “Gerlache Strait killer whales.” They feed (probably) on deep-dwelling toothfish and other large predatory fish in the Antarctic, and are significantly smaller than the “large Type Bs,” which feed on seals. You can see in the photo their yellowish tinge- type Bs and Cs both have diatom (algae) coatings on their skin, which they travel north to shed- and the “cape” of grey around their backs. They can be distinguished from the large Bs by size, and from the Cs by the orientation and shape of their eye patches, and overall can be identified by their presence in their namesake, the Gerlache Strait. Aren’t they beautiful?

Buenos Aires

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Our trip began in Buenos Aires, my first visit to South America. I really can’t claim to have “been there,” since our stop was perhaps twenty-four hours, but we got a little taste of the city. It was very European, actually, many of the buildings French in style, and much of the art in the museum imported from the Old World as well, which made it feel less interestingly new for me as a traveler. But it was summer, and sunny, and the city was beautiful. I got to practice my Spanish, and we got to spend one last night ashore before our transfer to Ushuaia the next day. The mood was chill and the word was “siesta.” Welcome to the adventure! Just wait till it heats up (…figuratively).

About a Wallaby

I think the profession of dentistry must be one of the most-maligned and most-feared in popular media- think of the gleeful sadism of The Dentist from Little Shop of Horrors or the revulsion with which Hermey the Elf is met in Rudolf the Red-Nosed Reindeer. Jennifer Aniston in Horrible Bosses, several horror movies from the 90’s, that uncomfortably pathetic guy from The Hangover… but any list of my favorite horrible dentists must include Mr. P. Sherman, of 42 Wallaby Way, Sydney.

All of this was a tangential way to reference Finding Nemo’s Dr. Sherman’s mid-operation declaration that he needs to “go see a man about a wallaby” as he adjusts his pants and heads for the loo. It’s been a recurring internal joke for me during my time Down Under, anytime anyone needs a bathroom or mentions wallabies- maybe I watch too many kids’ movies? Anyways, as a northern hemisphere-girl I’m fascinated both by the native marsupials and the turns of phrase here in Oz. So we went down to Yardie Creek to see a man named “Boxy” about a wallaby, not in a bathroom kind of way but in a photographic opportunity kind of way.

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The Black-Footed Rock-Wallaby lives in the caves and crannies along the side of Yardie Creek. Though it’s not actually apparently called that (the black-sided wallaby, perhaps?) and doesn’t apparently live in this area, according to Wikipedia… I can attest that they do exist. Scooting out of caves and grooming themselves in the morning sun, squinting into the light and down at the boat passing underneath, these fuzzy little marsupials seemed perfectly at home along the steep rock walls high above the water.

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Yep, perfectly at home. Just letting it all hang out. Right on out there.

I don’t know a lot about marsupial anatomy but I’m pretty sure that is not a lady wallaby. No pouch, no joey (DID YOU KNOW THAT AUSTRALIAN CUB SCOUTS ARE CALLED JOEYS?) and no little pink bow…

Must be a dentist.

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.

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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.

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…

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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.

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Species-ous Allegations

 

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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.

Birthday Sousa

Yes, today was August 22nd over here in Australia-land- it seems I get to experience a virtual 36-hour-long birthday since most of my internet-friends are on the other side of the International Date Line and about 12 hours different in terms of time zones. 1.5 times the fun! And I’d say the day lived up to that billing.

This morning we went back to Mrs. Mac’s, Exmouth’s charity-supporting “ops shop”- a secondhand store, carrying everything from coffee mugs to swimsuits to prom dresses to sewing kits, books, and plastic kiddie toys. People drop their junk off and the cool stuff makes its way onto the shelves. Kaja and I have been keeping tabs on their selection of Australian-flag-related clothing (there’s a pretty fabulous bikini that neither of us really thinks we’ll wear, but admire every time we go to the store) and have so far managed to acquire temporary tattoos, blue shorts that proudly display the name of the country across the rear, two small flags, and an Australian flag baseball cap. Get ready, everyone who might expect a souvenir from me- it’s either gonna be a postcard or a recycled treasure from the give-away heaps of small-town Western Australia. Good gracious I love Mrs. Mac’s.

The next stop, grocery shopping, allowed me to indulge in a family tradition that I wasn’t expecting to celebrate. Long-life noodles, boiled and then fried up in a pan- I improvised a bit, since I’m not exactly sure how they’re normally made. Whatever it was that I did turned out pretty awesome though, or at least I enjoyed them thoroughly. With a little veggie stir-fry in a sauce, it was perfect. Or so I thought before Kaja brought out chocolate chip cupcakes, the recipe for which I will need to steal before long.

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Then in the afternoon, when the wind died down, we headed out for a few transects on the boat. After a good solid Sousa sighting (research never rests! ADVENTURE IS OUT THERE, and so are Arrow and E, a frequently-sighted and very well-photographed mother-juvenile pair) we came back, wiped everything down, entered data, showered, and headed out for some celebrating.

I can’t think of a better day, though of course I miss my family and friends from home/Dartmouth. Rest assured that I thought of you all (even you readers I’ve never met… I thought of you right now… as it occurred to me that I might have readers I’ve never met… hi?) and wouldn’t have enjoyed this day half as much had it not been for you lovely people, your science, your art, your friendship, your pumpkin bread (hi mom!). Coming up- more science, less birthday, hopefully some diving, perhaps some tropical reef ecology, and YOUR QUESTIONS ANSWERED (if you ask them anyways, I’ll do my best).

FOR SCIENCE AND FOR GLORY,

Agent Red Squirrel

 

p.s. I’m still accepting contributions to the Vicky-has-Internet Fund- you can message  if you’d like to help out. Internets are EXPENSIVE here… and I’d like to keep posting photos and terrible jokes to all you virtual folks! Hooray (and thanks)!

The Science of Sousa

Despite all the photos of us smiling and drinking tea on boats, looking at the pretty little dolphins and later playing with baby kangaroos, we are actually here in Exmouth for Scientific Research (note the Important Capitals denoting the Realness of our Science).

Anyways, the research bit is cool too. Out on the boat, we drive transects around the tip of the North West Cape, collecting data on dolphin species, numbers, age classes and groupings, locations, environmental conditions, and the ever-important photographs for identifying individual dolphins from the catalogue Tim’s assembled over the past two years.

We aim for good-quality, zoomed-in, in-focus, and well-lit photographs where the fin is parallel to the plane of focus on the camera and fully out of the water, for maximum potential to identify them. Glare, spray, waves, animal movements, boat lurches, poorly angled light or backlight, focus problems- any of these things and many more can disrupt the camera and leave us with a big pile of crappy photos that we later have to sort through. But occasionally we get a photo like this:

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It’s clear and sharp, all four fins are fully out of the water, the lighting and contrast are good, and the dolphins are nearly exactly at a right angle to the direction of the lens. As a bonus, the two farthest dolphins are surfacing “in position,” meaning that their positioning along with the relative small size of the middle dolphin indicates that they are possibly a mother-juvenile pair (or in boat slang, MJ). From this photo, then, we can identify probably three out of four dolphins in the catalogue, note that the group cohesion is less than 2 meters, observe their traveling behavior, determine likely relationships, and enjoy lovely memories of how blissfully flat the water was that day.

When processing this photo, we first zoom in. Most of our photos (not sure about this one in particular) are shot with the lens fully extended to 400mm. We then have to crop out most of the photo, anything that is just water or unidentifiable parts like flukes or pectoral fins. This photo, since it’s got four good fins in it, will be copied into up to five different files, one for each dolphin and one to demonstrate the MJ pair’s positioning and relationship in the water and in the group.

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The small fin in the middle (a PJ, or potential juvenile) looks fairly unmarked. The edges are smooth, and though there is some spray obscuring a tiny part of the fin, there don’t seem to be any scars that would last from sighting to sighting and allow us to match this dolphin with photos from another time and place. Dolphins heal absurdly fast and absurdly well, sustaining shark attack wounds and other injuries that would seem fatal to a human while continuing to swim around the friggin’ ocean. And their scars often go away really fast, so they can’t regularly be used to tell one fin from another. Therefore, we go mainly on nicks and notches, the unique shapes and textures of a dolphin’s fin. For example:

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In this way-zoomed-in photo, you can see a notch about the middle of the fin, another toward the top, plus two at the tip. By searching the catalogue for a fin with exactly this shape (fairly distinctive, though not nearly the most distinctive fin I’ve seen) we can determine who’s who with relative ease, especially once we get to know the different fins throughout the season. These ones are Tursiops aduncus, Indo-Pacific bottlenose dolphins, not the main study species Sousa sahulensis, and there are more than 250 recognizable individuals in the catalogue, so we probably won’t know all of these really quickly. But there are a few, like “Steps,” that we can recognize immediately.

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Her scarring is even more distinctive from the other side, and we’ve spotted her a fair number of times since I’ve been in Exmouth. That’s part of the benefit of photo-ID though- we recognize her every time we see her and her juvenile, but just because the other dolphins in her ever-changing group aren’t as obvious, they can still be recorded and identified at a later and more leisurely (sort of…) time.

So there it is- the first part of the Science! All the analysis and breakdowns of data will come later, as we get even more sightings and process the backlog of photos from past boat days. As a reward for reading all that and hopefully understanding a bit more about why all that foolin’ around on boats and such is important to this study, for you my dear readers I present a really freaking cute photo of a baby bottlenose:

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Birthday Bommies

 

 

 

Today was Tim’s birthday- we had a gathering last night, a communal meal with some of the best hummus I’ve ever had (thanks Cindy!), beetroot on burgers, happy and then sleepy baby, and a birthday present from the whole of Team Sousa 2014. Kaja emailed every member, present and departed from Exmouth, and added his or her photo to a collage- we took ours on the boat without Tim noticing a thing. Well, okay, he got vaguely suspicious that we were up to something after a while, but forgot soon enough and never saw the signs we’d prepared. Janine, Tim’s wife, and David, his father, took care of printing and laminating, and we surprised him after dinner. Here’s the final collage:

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This morning we baked cupcakes and headed for the Cape Range National Park, driving out across more miles (kilometers, sorry) of shrubs and termite mounds and red soil. It’s still fairly green after the rainy season, but the hills are beginning to brown and animals are on the lookout for water.

At Oyster Stacks, a well-known snorkel spot, we suited up and jumped in. I’ve never seen plate corals and healthy staghorn and elkhorn formations like those, nor such a diversity of fishes. The Caribbean, or more specifically the Cayman Islands, which were my last dive destination, has lost nearly all of its staghorn corals and much of its coral health due to human activity and development in the area. In Hawaii, where I’ve done most of my diving, the coral and fish populations are impoverished due to the extreme distance between the islands and any other major coral reef masses. The corals that made it out across the Pacific to those newly-formed volcanoes in the sea were rare and mostly boulder-type structures, growing in bulbous mounds across the seafloor and creating nooks and crannies for the fish that made the crossing too. The number of species in the Hawaiian Islands is therefore much lower than those supported by the Great Barrier Reef and the chains of islands and barrier reefs connecting the whole of the South Pacific. That’s not to say it isn’t a lovely place, plenty of color and interesting fauna, and I’ve loved every minute of every dive there, but the reef architecture of Ningaloo is fascinating.

Purple boulder corals mixed with giant orange plates, surrounded by interlocking horns of bright green polyps, all filled with darting crowds of blue and yellow and red fishes. Big coral heads, nearing the surface of the water or even breaking through it, are referred to here as “bommies,” etymology still unclear. It’s a useful term, though, as we’re often sampling around or in shallow coral communities and need to be watching out lest our propeller should take issue and start a fight with one of the more prominent examples of the phenomenon.

Giant clams nestle in on the reef, showing striped colored mantles. They flinch away from shadows but seem so impenetrably large. I don’t know why they don’t live in the Hawaiian chain- possibly temperature, nutrients, or similar reef structural issues, though distance is likely not the issue. Small clams and other bivalves (two-shelled mollusks like scallops, mussels, and oysters) float as plankton on ocean currents until they grow large enough to settle onto the substrate and develop fully, so a giant clam larva could probably span the ocean to the islands if no other factors impeded its spread.

Anyways, I’ve never seen them before and they’re gorgeous. Their thick-walled shells are impressive on their own, and the exposed inner surfaces ripple with blues and greens created by symbiotic communities of algae that provide the clams with solar energy in the form of sugars while taking shelter in its skin.

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Kaja, talented marine photographer of all of this post’s photos, nearly backed into this black-tip reef shark when it rounded a bommie at her back. About 5 feet long and intriguingly deep-chested (possibly pregnant? Later in the season I hope to visit the blacktip nursery out by the mangroves), it is easily identifiable by a layer of black over a mostly-white fin on a gray body. It didn’t seem at all perturbed to see us, nor did it have to work hard at all to outdistance us over the reef when it decided it had had a good enough look.

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I’m so glad to have finally made it into the water. We stayed out until we got cold and tired of getting tossed around in the shallow surf, but I’m confident that we’ll have plenty more opportunity to explore. There’s so much to see, and so many questions to ask and answer out on the reef! #SCIENCE