Tag Archives: exmouth

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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Adopted

Today was another photo-sorting day- with the wind still high and a lot of data yet to be processed, we camped out on the couches and filtered photos from various sightings into identifiable and non-identifiable categories, then started to draw and match the individuals to the photos. You’d think there would be photo-ID software that could match fins for us, but with this much data on the line and no access to CIA-style facial recognition software (pick out the secret spy from the crowd at the airport using nothing but a few keystrokes and a paperclip!), it’s more accurate to just do it this way. Or so I’m told… Anyways, Kaja and I will soon know the catalogue quite well, and have already begun to recognize many of the more distinctive fins. I’m prioritizing memory space for the identifiable Sousa sahulensis (Australian humpback dolphins), since they’re our main study organism, but several Tursiops aduncus (Spotted bottlenose dolphins) are easy to spot from a hundred meters (hooray, metric system!) away. “There’s Hook!” we’ll yell on the boat. “There’s Steps again, and her juv!”

I wonder if they begin to recognize us, or our boats. They don’t seem that interested, and we don’t seem that easily distinguishable from the water. Humans are weird.

 

Anyways, since it was a day off-water I took off at 5 for the bush, camera in hand and water bottle in my Dr. Seuss backpack. Along the way I was met by a little friend I’d seen wandering about a few days earlier:

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She’s a little dog, and I’ve seen her dwarfed by cars and bikes alike as she trots along behind various passers-by on the street. I didn’t know what she was looking for, besides adventure and I guess a random American to adopt. I whistled to her, and she came running over, tail tucked between her legs and head low. I know, stray dogs can be a risk and I had no guarantee she was friendly, but she looked so nervous. I sat down on the sidewalk and offered her my hand, which she took as a sign to drop the scaredy-dog act and leap into my lap. Little dogs with a lot of personality often can’t contain their feelings inside of their bodies, I’ve learned, and it was no different for her; she spun in circles, sat down, rolled over, leapt up, sat down again, ran around me twice, and then set about washing my face as thoroughly as she possibly could. I named her Baby, and we set off for our bush walk together.

Baby liked going for a walk, but got very nervous when I left the path. Sniffing around in the bush for a few seconds, she wandered back onto the clear dirt and waited for me there. I, however, needed to take a photo of a rotting automobile carcass in the shrubbery (for you, Ryan dear):

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Anyways, with darkness falling she led me back out of the bush, stopping to wait when I fell behind (classic Agent Red Squirrel, watching ants move a dead grasshopper or taking photos of little birdie footprints in the red dirt). I worried about her so close to the street as we left the footpaths, but she listened when I called and followed close to me all the way back to Casa de Sousa, where we had a good scratch and I wondered how to find her home, if indeed she had one. She was a bit too well-fed and trained to be a stray, but she didn’t have a collar nor, it seemed, any inclination to leave what was promising to be a very satisfying rub-down, even with darkness falling. Happily, a jeep passing by came to a sudden stop in front of us, and she wagged happily over to the opening door.

“There you are!” the driver said, stepping out. “Been looking for you. She jumped the fence,” he told me a bit sheepishly. I told him I was glad she’d found her people.

“Cheers for that, mate!” he waved as they headed home.

Thanks for the lovely walk, little friend!

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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

Playing Catch-Up

Marine life can be slow- nudibranchs, jellyfish, sunfish, algae- but can also move at unbelievable speeds. Turtles may seem to take their time, but they whizz by under the boat daily and (I know from personal experience) don’t even have to exert themselves to outpace an intrusive camera-wielding diver. Even motivated dugongs, with their blubbery bulk, can pick up enough speed to evade good photography from a boat. But for the most part if left undisturbed and not on the hunt, marine mammals like dolphins and whales move at a fairly leisurely pace, taking a few shallow dives between breaths and then a longer dive below the surface.

That wasn’t the case at all when we met Pseudorca crassidens, the false killer whale. Somewhere upwards of thirty of them were spotted charging north along the outside reef, slicing through deep water and breaking the scattered whitecaps with seafoam of their own. Coming in relatively close to the boat and staying shallow, they didn’t seem to be disturbed by our presence (they have a reputation for enjoying boat races and wakes) but rather headed somewhere unknown on an urgent errand. At their speed and with spray over their short rostrums at every surfacing, they were near impossible to photograph, but fun to watch as the whole group flew by us. When we were surrounded, they were spread nearly as far as we could see through the swells, and we could turn any direction still expecting to see sleek black bodies in the waves.

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In the wake of these odontocetes (toothed whales), we spotted two different sailfishes. Although they are sometimes said to be traveling with the false killer whales, the orca research boat that pulled up alongside us for a chat informed us that they were more likely scared out of the way by the oncoming pod and are seen at the surface somewhat dazed, tired from avoiding the whales. These didn’t seem at their peak- sailfishes are supposed to be among the fastest in the ocean, but one allowed us to pull the boat (and GoPro) up alongside:

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I was worried I had the little camera (on the end of a long pole, which was catching an alarming amount of drag as we drove through the water) pointed in entirely the wrong direction to catch the big fish, but after looking at the photos, there it was. When the boat got close it dove, but only a little, and hovered around below the water for nearly a minute before disappearing deeper into the blue.

All of this is a big stupid metaphor for the fact that I haven’t blogged as much in the past few days and have a backlog of photos from this fast-paced trip that I just haven’t been able to keep up with. I haven’t even written yet about dingoes (70% on the West Coast here are pure dingo; only 5% on the East Coast can claim that level of genetic isolation from dogs; we almost certainly saw a crystalline example of Canis lupus dingo the other day on the road) or baby emus or sea snakes, and tomorrow we’ll be snorkeling and I’ll have even more to talk about. Life moves fast and even the biggest and most impressive things slip away, but I’m just going to keep moving anyways.

This is Agent Red Squirrel, sprinting off for the next adventure!

 

Boat Days

This post is officially dedicated to my uncle Tom, aunt Kailane, and cousins Liam and Aidan! They have most generously contributed to the Vicky-Has-Internet Fund, in addition to being longtime readers and supporters of Agent Red Squirrel. Their questions were about the lay of the land in Exmouth- I know I’ve skipped a fair bit of background in terms of this project and the area I’m living in.

First of all, I’m living in a town called Exmouth, which is on the North West Cape of Western Australia (state bird: the black swan; state flower: the red and green kangaroo paw). I’m working as part of the North West Cape Dolphin Research Project, NWCDRP for “short.” It’s a small town- about 2,200 people here year-round, and since it’s off-season for school holidays in Australia and the whale sharks have mostly moved on for this year, that’s probably a reasonable estimate for the current population. It borders the Indian ocean and the Exmouth Gulf, clearly a sea-oriented town though it appears surrounded by low striated bluffs, red sandy soil, stunted eucalyptus trees, and myriad other dusty shrubs and grasses that shelter ‘roos, emus, echidnas, and other exotic fauna (cockroaches, spiders, ants… you know, cool stuff).

Every reasonably-sized house in this town of reasonably-sized single-family houses and rentals has a boat parked out front, along with some palm trees and plumerias. The more landscaped ones have sunflowers, and maybe a little bit of lawn. But the rainy season is over here, and despite the 30-year flood that washed out levees and kangaroo corpses in town this winter (northern hemisphere’s summer) the ground is dry again. Green grass may not last long as we edge our way into spring and summer.

I’m cooking dinner tomorrow night, so hopefully I’ll have a few more photos of “normal life” here at the house. But for now, here’s what we’ve done in the past few days on the boat:

Since the weather has turned, we have been out from basically sunrise (or slightly thereafter) until sunset (or slightly thereafter). Smooth seas, light breezes, turquoise water with more than 11m of visibility straight to the bottom… life ain’t bad on the North West Cape right now. We load up the boat in the morning, rubbing sleep out of our eyes and sunscreen on our faces, and truck over to one of three boat ramps with the trailer rattling along behind us. Tantabiddi, Bundegi, and Exmouth Marina are our three points of entry, and we motor along from there to wherever our transects for the morning begin.

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We science away for a few hours- scanning quadrants of the water and horizon for vessels, whales, obviously dolphins (Tursiops aduncus or Sousa sahulensis, our study species), and anything else that catches our eye. Here’s Kaja science-ing:

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Kaja Wierucka

And then we break for a very civilized morning tea.

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Sometimes we also break for some penalty push-ups. They’re extra fun when there are swells.

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Meanwhile, marine life continues around us. We spot dolphins every few hours, which prompt rapid-fire photography and driving a boat in circles amid much cursing and sometimes ooh-ing and aah-ing (especially if there are calves present); sea snakes aren’t uncommon, nor are breaching humpbacks and calves. We saw a dugong yesterday, and a young hammerhead shark! Tim and I saw Pseudorcas, or False Killer Whales, for the first time today as they came flying by our boat on some unknown mission, spooking two 5-foot sailfish into their wake. I’ve been assured there will be no lack of photographic opportunity, and I’m excited to post more photos for you soon.

Amidst all this ocean nonsense, we make time for lunch and water breaks, but for the most part we spend our time with binoculars and clipboards, searching for the elusive fins and short blows of our dolphin buddies/nemeses. Today as the sun was setting and a mother humpback was breaching in front of the rising moon, we cruised back in to the Bundegi boat ramp. Exhausted dinner, spreadsheet entry, hosing down equipment, blogging, and now sleeping. Lots of stored up good stories for the coming days, plus a special guest appearance by an early-morning dingo and THIS ON THE DASHBOARD OF THE TRUCK:

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Yup. This is Australia. Ain’t nobody gonna forget it. Exhausted Agent Red Squirrel signing off- stay happy, readers.

Walkabout

Although Tim laughs at my blogging efforts, I’m sure he’d appreciate this bit of Australiana (that may be a real thing or I may have just made it up… unclear): this evening before we ate dinner, Cindy, Karl, Kaja, and I “went walkabout.”

Walkabout consists of basically wandering with no destination in mind. Of course, I was on my everlasting quest-for-kangaroos (or just ‘roos, if I’m really going Aussie and ignoring my everlasting love of alliteration), but for the most part we just went for a twilight wander. Equipped with cameras and accumulating much red dust on our feet, we examined kangaroo poop, flipped over rocks in search of that poisonous stuff you all keep telling me not to touch, and ambled across the bush in no particular hurry. We felt very authentic, though as a group of people from, respectively, the Netherlands, Poland, and the United States we considered pretending not to understand English should we be stopped by anyone official-looking.  

It’s still so pretty out there. I think these are my favorite flowers so far:

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But I can’t forget my new acquaintance, the Sturt Desert Pea (Swainsona formosa). If memory serves, Tim said these are the representative flower of Southern Australia and aren’t too common:

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I like to give the impression that all of my days are spent in glorious exploration and comfort and a state of unhurried excitement, but to be honest most of today was very tedious. We’ve got one hell of a procedure in terms of cataloguing and sorting and eventually matching dolphin fins in pursuit of tiny data points that hopefully will end up being relevant again someday, and in the process it feels like interminable button-pushing and repetitive typing and generally squinting at a computer screen wishing you could just blow up computers in general and go back to film and physical folders. When we’re “grounded,” like today, as the boat was in for service and the wind was high (seas ranked at Beaufort 4 or higher… on the same scale, 0-3 encompass glass-smooth to scattered whitecaps), we spend eight hours, 9-5, on renaming and copying and cropping and describing and drawing photos. It’s just a necessary part of the work we’re doing, and while it’s significantly less fun than being on the boat, it has to be done in the pursuit of knowledge and understanding.

Anyways, it ought to be clear why I might want to spend less time talking about that stuff than about the neat spiders I saw or the sand dunes we ran around on, which take up far less of my time than this blog might otherwise imply. This isn’t a fairytale, and it isn’t a vacation, but it is an adventure that brings with it both tedium and excitement. The purpose of this blog, much like the eventual purpose of the scientific papers that will be produced from this study, is not to catalogue every moment of the in-between. It’s to find some nuggets of truth and beauty in the world we inhabit and share those with a wider world than just ourselves.

That’s what makes going walkabout special- the magic comes so easy as the sun goes down and the red dirt settles in the cooling air. We can forget any stiff necks and tired eyes in the dimming light and wander without direction, in the company of new friends and the cradle of an unfamiliar place.

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The Myth, the Mystery, the Marsupial

Having seen, since I got here, several road-killed kangaroos and several packages of kangaroo steaks, I decided it was about time I saw a live kangaroo. Armed with the knowledge that they come out around sundown, I slipped on my shoes, grabbed my camera, and headed for the nearest scrubby area.

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As the sun went down I walked out between the low eucalyptus and yellow grasses. It’s winter here, edging perhaps into spring, and many of the plants are in bloom before the heat comes back (as I’m here it will only get warmer, from temperate weather now up into the 90s probably).IMG_0598

I spotted a few birds the other day and finally got a photo today- they’re crested pigeons (Ocyphaps lophotes), commonly seen across mainland Australia except for the very tropical regions. Are they actually more colorful than their northern hemisphere cousins, or am I just used to the other ones?

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Crested pigeon

I don’t think bougainvillea is native here, but along with plumeria and palm trees it makes up the majority of landscaping in the area. At one edge of the scrub I was wandering through, the pink leaves and tiny flowers were visited by what I thought might be a hummingbird, but turned out in fact to be a hummingbird-shaped moth with a plump little body, dark eyes, stubby antennae, and a blur of wings.

Hawk moth at a bougainvillea

Hawk moth at a bougainvillea

By then, the sun had set and I had still seen no ‘roos. The myth, the mystery, the marsupial: they remain elusive to me though I’m not worried. I’ve got three months to find myself some live ones and try not to hit them with cars. Perhaps tomorrow will be my lucky day, as we’ll be headed out across the cape to Tantabiddi and will have to drive back with the boat around sunset.

I snagged a eucalyptus leaf on my way back in. They’re actually native here, but have engrained themselves into the California landscape so ubiquitously that I associate giant striped-bark trunks and the spicy smell of their oil with home. If you’re at home, gentle readers, take a deep breath. Non-native trees may be ecologically questionable in California, but I’m grateful for the familiarity now.

Eucalypts are endemic to Australia... except that they appear to grow very well in California

Eucalypts are endemic to Australia… except that they appear to grow very well in California