A month in the life of a marine scientist
Have you ever wondered just what it would be like to be a marine scientist? Lucky for us we have one of our very own who has just returned from a month in the field with her labmates from The Fish Lab catching, tagging and and tracking smooth stingrays and Port Jackson sharks, taking all sorts of genetic and isotope samples from Port Jackson shark skin and blood, as well as shoving nose-plugs in shark noses and gluing magnets to their heads to discover how they navigate, and taking data on their personalities and laterality (yep, sharks are left and right handed.. uhh finned.. too!).
It's been a wild ride!
My name is Joni and over the past 7 years I have earned myself a Bachelors in Marine Science, a Masters of Marine Science and Management and a Masters of Research. Now, I entering into the exciting and terrifying world of a PhD position at Macquarie University studying the biology, ecology and behaviour of smooth stingrays (Bathytoshia brevicaudata). In this post I'd like to give you a little insight into just what our latest field season was like.
The most important lesson I have learned is that no matter how much preparation and planning goes into your fieldwork, you will never come out the other side having done exactly what you set out to do. Most of the time, it's Murphy's Law - what can go wrong, will go wrong. If you aren't prepared for everything to go to shit and still be able to adapt then you probably aren't cut out for the job. That being said, sometimes, somehow you come out the other side having exceeded your expectations. Other times, you reach a compromise between disaster and a rewarding new path. It is such a dynamic process that takes an unwavering persistence, patience... and big ol' balls of steel.
The field season
A typical field season for us involves a bunch of stressed but excited post graduates running about 5 projects concurrently, an always cool, calm and collected supervisor who's done this a million times, about 30 (sometimes up to 50) volunteers on rotation, 3+ cars full to the brim of gear and a boat and canoe headed down to the stunning Jervis Bay on the south coast of NSW, Australia for a solid month of serious science-ing.
We head to Jervis around August-early October each year to target the Port Jackson, or PJ, breeding season. Most of the lab are studying different aspects of PJ biology and ecology and this year we were particularly interested in stable isotopes, stress response and navigation mechanisms (Sherrie Chambers, PhD), intelligence, cognition and navigation (Catarina Vila Pouca, PhD), energy budgets, movements and behaviour (Julianna Kadar, PhD), within- and between-year personality and laterality (Culum Brown, PI), and PJ predation using Baited Remote Underwater Video Stations (BRUVs) (Connor Gervais, PhD).
As for my researh, smooth stingrays are fed fish scraps at a number of boat ramps around the bay and as a result the rays are around most of the year. So it makes sense to tag along and see if we can collect some data on these wonderful giants of the ocean.
Smooth stingrays (aka short-tail stingrays or bullrays) are BIG. Like, 2m wingtip to wingtip big... like up to 350kg at full size big... like up to 3 x 30cm stinging barbs in their tails big. They're also common in coastal habitats around southern Australia, New Zealand, South Africa, Japan and eastern Russia and are often found feeding on fish scraps at boat ramps. In fact, we know very little about most ray species, yet they are more threatened than sharks. That's where I come in. Throughout my PhD I want to fill as many knowledge gaps as possible about this and other species of ray and help rays awareness about their importance in our oceans.
The year, we deployed our first lot of acoustic tags on smooth stingrays in Jervis Bay. The tags we used are Vemco V9 acoustic transmitters, which have a battery life of about 12 months. These tags emit a unique series of 'pings' which help us identify individuals and track their movements. DPI Fisheries have installed an extensive array of 50+ acoustic receivers on rocky reefs throughout Jervis Bay. In addition, there are hundreds of receivers deployed around Australia. If one of our tagged stingrays swims within 400m of any of these receivers, we get data on the location, the time and which individual it was, and we can then use these data to track their movements.
What do you actually need to tag a stingray? Most of it is laid out in the photo below. We primary equipment includes needles and handles, acoustic tags, crimps, monofilament and crimpers, PIT tags (aka microchips, actually exactly the same as those used in cats and dogs) for secondary identification, measuring tape and towels and welding gloves for barb/tail grabbing.
And lets not forget the ever-stylish, ultra-versatile, incredibly-sciencey bum bag for carrying this lot around.
There will be some point during fieldwork where you have to Macgyver, or re-purpose, something to solve a problem. This year, we used a stick as a signpost, a spoon as a sinker, plumbing parts for a bait box, a water bottle and fishing rod as a salinity sampler and, my favourite, teddy bear buttons for visual ID and tag attachment for the stingrays. We wanted to tag the rays in such a way that we could identify individuals by sight as well as acoustically, with something that would stop the monofilament cutting into the skin of the stingray. These large, brightly coloured, plastic buttons worked a treat.
Setting out, we had 18 tags to deploy. Optimistically, I thought we would maybe get 10 of those out, which is still a good starting point and will provide us with HUGE amounts of data.
This was our first year tagging the stingrays, so there was some trial and error. We planned to entice them with baits, catch them in a sling, beach them, tag them, measure them and release them. Simple, right?
As it turns out, a 200-300 kilo stingray is a bit tougher to handle than we first thought. But in no time, we mastered the process and had stingrays captured, tagged and released within 3 minutes. The stingrays exhibited no trauma from the whole process, with many not even swimming off when released. They just hung around waiting for some more fish!
The (perfected) workup
In science, a 'workup' in what is done to an animal from its capture to its release. So what does the workup for a giant stingray involve exactly? The most important parts aren't even about the stingray - everyone needs to understand their role, have good communication, work well as a team... and a tonne of upper body strength. Ok, the last one might have something to do with the stingray.
The rest of the work-up is a piece of kelp!
To catch the stingrays we target boat ramps where they are regularly seen feeding off fish scraps discarded by fishermen. This increases our chances of seeing the rays, as well as catching them. Because they are used to feeding on fish carcasses in shallow water, we can use this to entice them into shallow enough water to be able to come around behind them with a large sling.
We use the sling to pull the ray up to the waters edge. To keep the ray calm, we orientate them so their mouths and gills are still in the water. Once beached, we need to disable their use of their tail and barb. To do this, we throw two very heavy, wet towels over the tail to weigh it down, then someone in welding gloves grabs the tail at the barb and uses their body weight to stop them from moving it.
The next step to to attach the tags. To do this, we have the tags ready to go with the tag, top button and monofilament. I use a very sharp, hollow needle to make a hole through the pelvic fin through which I thread the monofilament through and out the other side of the fin. On the underside of the fin I then thread the second button and the crimp. We pull the tails of the monofilament tight so the buttons sit flush with the skin and we crimp it together.
Once the acoustic tag was attached, I then implant a Passive Integrated Transponder, or PIT tag. These tags are exactly the same as those used to microchip your cat or dog. We then measure their disc width and disc length, determine their sex, and then send them on their way!
So how did it all go?
This year we managed to exceed our expectations and tagged 15 female smooth stingrays at 3 different sites within Jervis Bay. For the next 12 months every time one of these rays swims within range of a receiver we will be getting more and more data. The hard part... waiting 12 months to find out!
Check out the video below for some more highlights.
Want to learn more about our research?
How to get involved
One of the biggest struggles of research is securing funding. So The Fish Lab and Elasmo partnered up to design some sick lab t-shirts. We are selling these shirts for $30 each and not only will you look awesome and make all the other research labs jelly, but all proceeds go towards funding our research.
You can also Adopt A Port Jackson! A donation of $500 buys us another shark tag to tag a new Port Jackson shark that you get to name. You can then follow the movements of your adult Port Jackson shark.
Want to volunteer with us?
We are always looking for hard-working and passionate people to help us out during the field season and the rest of the year too! We have a lot of experiments running throughout the year at Macquarie University and Sydney Institute of Marine Science (SIMS), as well as a heap of other field trips around Sydney and beyond sampling all sorts of species. If you're interested and have a background in marine science or are just passionate about marine research, get in touch with us via our website or on Facebook and Twitter.