Back on Land!

By Annabel Payne, Macquarie University

We’re back! Well, we’re in Fremantle, Western Australia. The past two weeks have flown by, and it feels strange that now it’s all over and we’ll be heading home to our respective cities. Meeting new friends and learning new skills, I think I can safely say we all had an amazing experience.

CAPSTAN students Kaycee, Bella, and Luke join trainers Lisa, James, and CAPSTAN director April for a photo outside at sunset on the last night on RV Investigator for this year's hands-on marine science training voyage
CAPSTAN students and trainers enjoying a little outside time on our last night at sea (photo credit: April Abbott).

I’ve been to sea before, but this was my first time learning about plankton collection, identifying different climate events from microfossils, counting different birds and mammals, understanding CTD measurements… the list goes on! CAPSTAN has been a brilliant learning experience and if you’re thinking about applying for next year, definitely do!

Monkey Island is the upper most deck on RV Investigator and is dedicated to marine mammal and sea bird observations.  From here, trainers and students can keep an eye out from sunrise to sunset.
Ben and April watch for sea birds and marine mammals from Monkey Island (photo credit: Leah Moore)

I decided to work in the wet/dirty sediment lab because I felt like it might complement the work I’ve been doing at university. I’ve been looking at how changes in sediment provenance influence Neodymium, an isotope usually used to track changes in past ocean circulation. A lot of the age models used are derived from oxygen isotopes in foraminifera. Since we had Stephen onboard, our foram expert from Melbourne, it seemed like the perfect opportunity to learn as much as I could. I now know the importance of a certain species for identifying the last glacial maximum in sediment cores from the Southern Ocean, how changes in size and species distribution are influenced by temperature and light!

The Smith-Mac grab, a box-like tool deployed for sampling the seafloor, is deployed over the starboard side of RV Investigator at sunset during CAPSTAN's 2019 hands-on marine science training voyage.  RV Investigator operates around the clock, meaning deployments can happen day or night.
Smith-mac grab sampler is deployed at sunset

My particular mini project while at sea involved sieving samples from the top and bottom of the cores, separating the different fractions out to see how grain size distribution varied down the canyon we were targeting. In these samples we found a huge variety of forams – some look like popcorn, others look like christmas baubles, and others were perfect spheres. The variety of forms within such a small sample gave me a huge appreciation for just how diverse life is at a microscopic scale.

CAPSTAN student uses a metal spatula to scrap off a thin layer of core along the edge to expose a 'clean' surface.
Prepping the kasten core for sampling by cleaning off the smeared edge

The same could be said for in the plankton lab. The tiny jellyfish, starfish, copepods and various other little critters were fascinating, it was certainly a novel experience being able to see what I’m studying for a change!

A tiny amphipod with a huge black eye floats in the view of the microscope.  This amphipod, along with many other microscopic critters, were caught in plankton nets as part of the 2019 CAPSTAN marine science training voyage.
An amphipod we caught in a net tow as viewed down the microscope (Photo Credit: plankton lab)

From the science to dressing up as sea creatures and trivia, we had a great time. Maddie kept us all singing with showtunes, Sian’s whale calls (which may have something to do with the lack of cetaceans – sorry Sian!), movie nights, through to the excellent food and expert crew. A trip on the RV Investigator is one to remember.

End of voyage group photo with CAPSTAN trainers, students, support team, and some of our crew (Photo Credit: Ben Arthur).
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RV Investigator… now that’s what you call a tight ship!

By Angela Russell, University of Adelaide

To conduct the science needed to unravel the mysteries of the ocean and its influence on ecology and climate, you need to take operations up a notch. Some may think it’s simply a matter of dangling a few instruments over the side of a boat but let me tell you…RV Investigator is no ordinary boat!

In this photo, RV Investigator steams across the ocean.  RV Investigator is a 93.9m long, 18.8m wide ship, powered by three diesel engines and two electric propulsion motors (Figure 1). Purpose built for CSIRO, the RV Investigator puts Australia at the forefront of ocean research globally, conducting oceanography, geoscience, atmospheric and marine science, from the Antarctic ice edge to the tropics.
Figure 1: RV Investigator at full steam (Photo Credit: C. Minness)

RV Investigator is a 93.9m long, 18.8m wide ship, powered by three diesel engines and two electric propulsion motors (Figure 1). Purpose built for CSIRO, RV Investigator puts Australia at the forefront of ocean research globally, conducting oceanography, geoscience, atmospheric and marine science, from the Antarctic ice edge to the tropics. Along with a phenomenal team of engineers, navigational crew (Figure 2), technical crew and IT professionals, the ship’s impressive technical capabilities allow us to enhance our investigations to an advanced level.

The navigational control deck faces a long panel of windows in the bridge of RV Investigator.  Part of the at-sea training on board RV Investigator for CAPSTAN's 2019 voyage included a bridge tour.
Figure 2: The navigational control deck within the ship’s bridge. (Photo Credit: Angela Russell)

The vessel is like a mesocosm of the world! It accommodates 40 scientists and support staff, and twenty crew. RV Investigator generates around nine megawatts of power, enough electricity to power a small suburb! It even completely biodegrades all sewerage onboard, so as not to contaminate the samples. Obviously, there is no room for error here, so engineers work around the clock to maintain the workings of the ship, keeping replacements for every part of the machinery. Engineers are also equipped with a workshop to repair engine parts or scientific units on the fly.

Colored bathymetric map of the Discovery Bay Canyon off of Portland Victoria with deeper water indicated by purples and blues and shallower waters in reds and yellows. The Discovery Bay Canyon has a Y shape and was the study area for the 2019 CAPSTAN voyage.
Figure 3: Bathymetric map of the Discovery Bay Canyon (Photo Credit: J. Daniell)

A brief overview of RV Investigators ‘kit’ includes advanced sonar technology which emits acoustic signals in a 30 km wide beam in water depths to 11.5 km to reveal, in 3D, seafloor features such as deep-sea canyons and mountains. We used this swath data and ArcMap (GIS) software to create a high-resolution bathymetry map of a previously unmapped, deep sea canyon we traversed (Figure 3). A drop keel underneath the ship (Figure 4) can be raised or lowered into the water column. This allows water samples to be recovered without interference from the ship.

A view down to the top of the drop keel meters below from RV Investigator.  In this photo the drop keel has been lowered to be even with the ship's gondola (not pictured).  A tour of the ship, including normally restricted areas such as that around the drop keel, was part of the student experience during their at sea marine science training on CAPSTAN's 2019 voyage.
Figure 4: The drop keel lowered to the water’s surface (Photo Credit: Angela Russell)

The ship is specifically designed to an international maritime classification called DNVSilent-R. This means RV Investigator is one of the quietest vessels in the world. Radiated ship noise interferes with acoustic signals, so by building a quiet ship, the performance of the equipment used to monitor the marine ecosystem, and map the seafloor is maximised. Roll stabilization also improves our use of scientific instruments, such as microscopes and balances, which can be tricky on a moving ship.

CAPSTAN 2019 Chief Scientist and support staff describe the sediment grab sampler on deck while RV Investigator transits to the first station for sampling. On the work deck, all personnel must wear hard hats and steel capped boots.
Figure 5: Chief Scientist Leah Moore discussing the deployment of the Smith MacIntyre sediment grab sampler with the technical support and science team. Photo Credit: Angela Russell

The logistics behind the location of sample sites and each sample collection is a strategic masterpiece and one aspect of our mission I was particularly in awe of. The Chief Scientist works in close collaboration with the Technical Operations Team, Integrated Ratings Crew and Master of the ship, to design each procedure in a way that ensures the safety of the crew and their scientific instruments, to meet the research objectives and to optimise sample quality. It really is a symbiotic relationship, in that each is part of the team that is integral to the other (Figures 5,6,8).

RV Investigator crew and support team deploy the CTD (conductivity, temperature, depth) rosette surrounded by niskin bottles over the starboard side of the ship.  Students were involved in monitoring the live readouts of the data to give depths to the winch operators and to fire the bottles as part of their at sea marine science training on board the 2019 CAPSTAN voyage.
Figure 6: Deployment of the CTD (conductivity, temperature, depth) rosette. Photo Credit: Angela Russell

One of my highlights of the voyage was in the operational room on the internal communication system during deployment of the CTD unit (Figure 7). It was my job to request the CTD stops required to collect water samples remotely at different depths, up to the Integrated Ratings crew (IR crew) located in the ‘Cat House’. This area is where the winch and boom are managed, and where all the ships cameras are simultaneously viewed. This gives IR crew the ability to visualise the CTD going over the side, while viewing the winches below deck as it descends. Once the unit was in position at its lowest depth (it went down to 4500m), I fired the closing of each of the 24 sample bottles on the return journey with a single mouse click.

CAPSTAN student Angela oversees a CTD deployment from the operations room on board RV Investigator as part of the hands on marine science training.  She monitors live readings transmitted from the rosette and plotted on the computer screen to determine depths for discrete sampling with the niskin bottles and communicates the next depth to winch operators.  Once the rosette reaches a desired depth, she can fire each bottle with the click of a button.
Figure 7: Firing 4500 m deep niskin bottles on the CTD rosette from the operations room (Photo Credit: April Abbott)

As students of the CAPSTAN voyage, we are spoilt with the level of expertise and state-of-the-art technology provided to us. It’s been a once in a lifetime experience that I will be forever grateful for.

RV Investigator crew and technical support staff secure the kasten core to the stern deck following a successful deployment.  4 kasten cores were collected as part of the hands on marine science training on the 2019 CAPSTAN voyage.
Figure 8: Crew and support staff secure the Kasten sediment corer after recovery using the hydraulic A-frame rig (Photo Credit: Angela Russell)

The hunt for cool-water carbonate turbidites

By Mardi McNeil, Queensland University of Technology

Every marine science voyage has a research plan and specific aims and objectives that the science party wants to achieve. Months, or sometimes (usually) years, goes into planning the voyage and targeted survey site selection in order to achieve aims, test a hypothesis, or answer questions which will fill a knowledge gap in our understanding of the marine system we are studying. This is how science works!

Map of the ship track for CAPSTAN's 2019 voyage.  The map shows the eastern part of the Great Australian Bight showing the ship track from Hobart to the canyons off of Portland and then the planned track as the ship begins its transit from the study site to Fremantle.
The CAPSTAN voyage survey area of the Portland Canyons and Otway basin off southern Australia (green and red dots). RV Investigator will then transit across the Great Australian Bight to Fremantle.

The science objectives for our CAPSTAN voyage have been planned out by our Chief Scientist Dr Leah Moore, and the educational objectives by our CAPSTAN Director Dr April Abbott. On this research cruise we are targeting a submarine canyon system which connects the continental shelf margin off Portland Victoria, to the Otway Basin at 5,500 m water depth in the Southern Ocean. We are literally sailing across the abyss!

Our primary geological objective is the search for a cool-water carbonate turbidites, resulting from the funnelling of sediment down the submarine canyon until it is deposited in a submarine fan at the base of the canyon. Cool-water carbonate systems are not as well studied as their sub-tropical and tropical counterparts as there are fewer places in the world where they occur, and they’re typically in deeper water.

Photos of the sediment collected in the third kasten core with a full core image on the left and a inset with a zoomed in photo of the biological hash visible between 165 cm and 182 cm in the core. The core was collected as part of the hands-on marine science training on CAPSTAN's 2019 voyage.
Photomosaic of Core #3 (left) and inset of the 165 to 182 cm section. This close up shows coarse carbonate bioclasts (grains) of bryozoans and forams, referred to as a bryomol/foramol assemblage and considered typical of the cool-water carbonate factory. The coarser grains are embedded in a muddy matrix comprised almost entirely of planktonic forams (visible only under the microscope). Photo Credit: Matt Jeromson and Mardi McNeil.

The term “Carbonates” refers to sediment grains which are comprised of calcium carbonate minerals, commonly calcite and aragonite. Over geological time these sediments lithify to form limestone rock. Most carbonate sediments are biogenic in origin, which means they are produced by biological organisms. The classic example is a coral reef, where the soft coral polyps precipitate their hard skeletons, and coralline algae produces the calcite cement which glues it all together, resulting in hard limestone.

In a cool-water carbonate system there are definitely no reef building corals. In southern Australia, the main carbonate producers are bryozoans and foraminifera. Bryozoans are colonial, meaning hundreds to thousands of tiny animals called zooids, live together in a colony and collectively produce a hard carbonate skeleton. This skeleton can take many forms, like delicate fan-like nets, or robust upright branching sticks.

Microscope images showing species of calcareous plankton that are being used in the description of the cores collected on the 2019 CAPSTAN marine science training voyage and an image of a smear slide with these species present from one of the cores collected from RV Investigator.
Examples of the micro and nanno fossils we have been using as stratigraphic markers in our sediment cores: A) Scanning Electron Microscope image of planktonic foraminifera Neogloboquadrina pachyderma typical of polar or glacial assemblages (Almond et al., 1993), B) Scanning Electron Microscope image of the coccolithophore Emiliani huxleyi indicating sediments are younger than 80,000 years (www.mikrotax.org), and C) transmitted light microscope image of a sediment smear slide from the current voyage that shows abundant E. huxleyi (photo: Annabel Payne). A and B are not to scale.

Foraminifera (or just “forams”) are single celled organisms similar to an amoeba, but they secrete a calcite “test”, or shell. Foram tests come in an almost endless variety of shapes and sizes, and can be benthic (bottom dwelling) or planktic, meaning they live freely in the water column. Forams have evolved rapidly throughout geological time (hundreds of millions of years), so geologists and micropalaeontologists use foram test shapes to determine the age of the sediments we are looking at. This helps us to quickly “date” our cores in the field, where we don’t have the capacity to use isotope mass-spectroscopy analysis to determine an absolute age. One reason we want to know the age of our cores is to determine whether the sediments we’re looking at were produced during a glacial cold period, or an inter-glacial warm period like today.

Schematic from Passlow 1997 showing a classic turbidite sequence with the coarser grains settling out first (lower in the sediment column) and fining upwards.
A ‘classic’ turbidite sequence showing how sediments are deposited out of suspension after gravitational and hydrodynamical flows (Credit: Passlow, 1997)

On this CAPSTAN voyage we have collected three cores from different water depths within the Portland Canyon, and one from the bottom of the canyon in the fan. We hope to capture evidence of glacial-interglacial cycles, and a cool-water carbonate turbidite system.

In geological speak, a turbidite is a characteristic sedimentary deposit which forms when sediment is transported down-slope in a fluidised (watery) plume under the influence of gravity. Because different sediment grains have different densities and shapes, they settle out of suspension in a characteristic way. The most dense sediments settle first, and the lighter less dense sediments are the last to fall out of suspension. This cycle repeats over and over every time there is a gravity driven turbid flow, resulting in a characteristic cyclical pattern of deposition which we call a turbidite.

Four of the sedimentology team sit around the laboratory bench excited about the preliminary results from the sediment cores and grabs taken as part on marine science training on CAPSTAN's 2019 voyage.
The other heroes of the Sedimentology Lab feeling triumphantly satisfied at the results coming out of the canyon cores. From left to right: Kaycee, Stephen, Jin Sol, and Matthew (missing: Bella and Mikala)

Onboard RV Investigator we have now finished our coring and are working through sampling the cores at 10 cm intervals, looking at the sediments under the microscope to see what carbonate grains we have. Our preliminary results are in, and there is some excitement coming from the Sedimentology lab! We have picked up a glacial – interglacial cycle, and managed to estimate an oldest date based on a nanno-fossil called a coccolith, which we know from the geological record was abundant from about 80,000 years ago, so we now know that our cores cannot be older than 80,000 years.

So the big heroes of the Sedimentology Lab are the tiniest carbonate grains which allow us to read our cores like a history book, and interpret biological and physical processes through geological time. And it turns out that we have indeed, found our cool-water carbonate turbidites, and glacial-interglacial cycles. Science mission accomplished!

Mud, Mud, Glorious Mud

By Mikala Maher, University of Canberra

After what seemed liked forever, and exceeded excitement on Christmas morning, we finally had sediments to explore. Over the last two days we have deployed a total of four Kasten Corers and two sediment grabs from the shallow shelf to the deep marine environment within a Submarine canyon environment.

A view of the sediment grab sampler being deployed off the starboard winch from a few levels above.  The upper deck is a safe spot for CAPSTAN students to stand without being in the way when they want to see the deployment.
The Smith Mac sediment grab sampler is deployed over the side of RV Investigator to collect surface sediments from 500 m below the ocean surface.

With adrenaline kicking in, samples were prepared and while desperately waiting for samples to dry discussions where held proposing suggestive theories as to what secrets the mud will contain, consulting with the new bathymetry and causing a rave in the observations room.  

Emotions were high with the excitement ongoing deployments and exploring the prepared samples and boy do we have some spectacular organisms and some outstanding structures.

Tag lines are put on the kasten core to assist in recovery from the A-frame on the back deck of RV Investigator during the 2019 CAPSTAN marine science training voyage.
The kasten core is recovered after a successful deployment

My research will be looking at exploring a link to Last Glacial Maximum with shelf sediments. Without further ado, and with credit to the Ice Age, I present to you the sedimentology Mud song.

Mud, glorious mud…we’re anxious to dry it

Two cores a day, our favorite deployment!

Just picture a Turbidite, matching the Bouma sequence

Oh, mud, wonderful mud, marvelous mud, glorious mud.

Mud, glorious mud,

Slide smears and wet sieves

Mud made from plankton

Or hemipelagic rain.

Do nothing but sample,

On mud, magical mud, wonderful mud, marvelous,

MMUUDD

Mud, glorious mud

Freshly plucked from the sea floor

A little smelly but filled with beauties

Soon, we’ll hit the jackpot

Just thinking of gravity cores

Puts us in a mood for

Mud, glorious mud, marvelous mud, fabulous mud,

Beautiful mud,

Magical mud,

GLORIOUS MUD.

Once secured to saw horses in the wet-dirty lab, one side of the kasten core is removed to reveal the glorious mud inside.  Once open, scientists 'clean' the core and then describe it before proceeding to take discrete samples.
Beautiful mud, Magical mud, Glorious mud!

Take me down to Plankton City, where the algae is green and the copepods are pretty

By Sophie Dolling, The University of Adelaide

Where is Plankton City you ask? In the mixed layer; the top most layer of the ocean surface where the water column is largely uniform. How do I know where the mixed layer is? An amazing instrument called a CTD.

The CTD (conductivity, temperature, depth) rosette is deployed from the starboard side of the RV Investigator as part of at sea marine science training on the 2019 CAPSTAN voyage
The CTD in action: lowering into the water column to bring us back the goods

The CTD is loaded with bottles that fill up with water at certain depths in the water column. Each bottle will fill at an individually nominated depth, allowing us to see water from all levels of the ocean. We get to sample the deep Antarctic water, the old oxygen depleted water and the nutrient rich mixed layer water all during one deployment!

A small orange colored sea star from the sieved bongo net samples is viewed through a microscope on board RV Investigator as part of the hands on training for marine science students on the 2019 CAPSTAN voyage
Small sea star found in the larger fraction of the sieved sample

Whilst sampling at the Bonney upwelling zone we were given the task of (hopefully) finding some plankton to identify, sort into size classes, and indicate biomass abundance. To do this, we used a bongo net to collect plankton from different points in the water column. These points were predetermined by analysing data from the CTD. We decided to always sample at 100m deep and one other depth depending on what we saw on the CTD profiles. We were looking for the point where the water column exhibits a sharp change in temperature and density; this is known as the mixed layer depth (bottom of the mixed layer). In basic terms, the water column goes from being mixed to more stratified the deeper you go. The mixed layer depth causes a barrier-type density difference, trapping nutrients above or below the boundary. If nutrients are brought into the mixed layer because of upwelling, the water above the mixed layer depth should be Plankton City; full of yummy nutrients allowing plankton growth.

Voyage participants watch as the two half meter diameter bongo nets are deployed over the starboard side of RV Investigator to collect plankton as part of the hands on marine science training of the 2019 CAPSTAN voyage
The bongo nets on their way down while the team anxiously waited, hoping for plankton to analyse

The Bonney upwelling zone is theoretically a ‘hotspot’ for plankton growth because of the nutrient rich bottom water moving up the water column to the surface through a range of mechanical processes. As we soon figured out, science and the ocean don’t care how far you’ve come to see them; they just do their own thing. The upwelling was not happening, in fact there was most likely downwelling occurring while we were on site. The expected abundance of plankton was largely unknown. What would we see? Would we see anything? Would we see lots?

A small bioluminescent organism is visible in one of the bongo net samples collected by CAPSTAN students on board RV Investigator as part of their hands on marine science training
Sparkly Boy, winner of Plankton Cities Most Beautiful

The bongo net tows did not disappoint. Whilst we do not have the final results of biomass abundance or size class just yet, we do know that Plankton City is an exciting and diverse place. Each of the tow samples were passed through a sieve, separating the plankton into size classes: larger than 100 microns and smaller than 100 microns. Among the inhabitants of Plankton City were a couple of tiny juvenile squids, hundreds upon hundreds of copepods, the spiky tennis balls of the water column (otherwise known as radiolarians), a squishy sea star, and many more wild and wonderful things*. There were two specimens in particular that were voted ‘Plankton Cities Most Beautiful’; Mr Fabulous and The Sparkly Boy. This pair of bioluminescent pretty boys were the talk of the lab**. Mr Fabulous was voted Most Beautiful for his sparkling eyes; eyes that would make Mrs Fabulous swoon. The Sparkly Boy took this one step further, showing off his sparkles all over his body.

Tiny squid is seen through the microscope on board RV Investigator along with other organisms trapped by the bongo nets during the 2019 CAPSTAN voyage.
A small squid found in the larger fraction of the sieved samples.

While on site we were only able to do a handful of bongo net tows. We were able to see some pretty amazing stuff from such a tiny sample size. Can you imagine what else we could find down there? I don’t know about you, but Plankton City is certainly somewhere I want to visit again.

*No squid, sea stars or sparkly boys were harmed in the making of this blog (we let them go back to Plankton City).

Check out my group’s hydrochemistry & oceanography blog on AGU’s The Field!

Sampling Seawater 101

By Jessica Bolin, University of the Sunshine Coast

Time is flying by – it’s day six of CAPSTAN Voyage #2, and we’ve now had the chance to explore different fields of oceanographic research during our group rotations: hydrochemistry, birds and mammals, plankton, geophysics, and sedimentology. Because we all have diverse backgrounds and areas of research, we’ve started to decide what our favourite stations are. My favourite, so far, is hydrochemistry, because we get to work with the CTD!

The CTD (conductivity, temperature, depth) rosette containing the CTD sensors and surrounded by 36 niskin bottles for discrete water sampling is deployed over the side of RV Investigator as part of the hands-on marine science training on RV Investigator through the CAPSTAN program
The CTD being lowered over the side

CTD stands for conductivity, temperature, and depth, and is one of the main pieces of scientific equipment that oceanographers use, because it measures changes in water properties throughout the water column. The CTD we’re using on board the RV Investigator holds 36 ‘Niskin’ bottles in a circular rosette frame, which is lowered from a huge boom on the starboard side of the ship, into the depths below. Upon deployment, each bottle’s plug is held open under tension by a spring-loaded metal hook. It’s an impressive piece of gear – the frame is taller than me (1.8 m), and each bottle can hold up to 12 L of seawater.

Bathymetric map showing the submarine shelf break canyons near Portland, Victoria in the Great Australian Bight.  Four major canyons are visible, one shaped like a Y is the main focus of our study.  The image shows shallower depths in red and greater depths in blue.  Bathymetric data was collected along with sediment and water sampling as part of the hands-on marine science training on RV Investigator through the CAPSTAN program.
Bathymetric map of our study area. Our site is the Y shaped canyon (third from the left). We’ve deployed the CTD at various depths along the canyon.

Our target site is a submarine canyon near Portland, Victoria, and we’re dropping the CTD at various sections along the canyon to further understand the circulation and other physical processes occurring within. As the CTD descends through the water column, sensors attached to the bottom of the frame sample the water’s properties, including temperature, oxygen, and conductivity; the latter which is used to calculate salinity. The data are pinged back to the ship’s operations room, where we all watch the vertical profiles of these parameters developing in real-time.

Fellow CAPSTAN student Sian sites in the operations room on board RV Investigator in front of several computer monitors to operate the CTD deployment.  She is watching the CTD parameters (temperature, depth, conductivity, oxygen, and chlorophyll) read out in real time to determine the depths at which to fire the niskin bottles and communicating with the winch operators as part of hands-on marine science training through the CAPSTAN program.
Sian sits in the operation room viewing the different CTD parameters in real time, and getting ready to fire the niskin bottles as the CTD ascends through the water column.

Once the CTD has nearly reached the bottom and starts ascending to the surface, each bottle is remotely ‘fired’ by an observer in the operations room at regular depth intervals. ‘Firing’ a bottle relays a signal to the CTD to release the hook on the target bottle’s plug, closing the bottle and trapping the water at that depth inside. After we have fired every bottle, the CTD is carefully retrieved by the crew and prepped for subsampling on deck… and the real fun begins!

CAPSTAN trainer Veronica Tamsitt samples a niskin bottle on the CTD rosette on board RV Investigator as part of the 2019 CAPSTAN voyage
Veronica sampling (very cold) seawater from a Niskin bottle

From each bottle, we’ll take three subsamples of water for further testing: one to test for nutrients, one for salinity, and one for dissolved oxygen, whilst also recording water temperature. From these subsamples, we can calculate the density of the seawater, which is a primary driving force for major ocean currents. It blows my mind to think that the water we’re working with has come from up to 2200 m within a submarine canyon, which in turn, has travelled along ocean currents all over the world!

CAPSTAN students Jessie, Imbi, and Jin Sol stop between sampling the niskin bottles on the CTD rosette for a selfie in front of the CTD on board RV Investigator with CAPSTAN trainer Veronica as part of hands-on marine science training
CTD selfie! The green team (Jessie, Imbi, and Jin-Sol) with trainer Veronica (far left)

It is safe to say that I’ve developed a new-found love for physical oceanography and all things ocean currents. The ocean is inherently dynamic, and constantly changes in real-time. Teasing apart the mechanisms underpinning the circulation within our site is both challenging and fascinating. Once we start processing and analysing our data, we’ll hopefully be able to pick up the signature of the Flinders Current that flows west along the Great Australian Bight, and perhaps internal waves from within the canyon. Also, with a bit of luck, *fingers crossed* we can pick up the signature of a deep-water ocean current, that Veronica Tamsitt – our token physical oceanographer on board – recently discovered in the Bight, and collect some much needed data to ground-truth the current’s existence. In short, we are discovering SUPER exciting stuff this voyage, so stay tuned!

Check out my group’s blog on The Field!

Jessica is a PhD student at the University of the Sunshine Coast. Follow her on Twitter @JessieABolin

Learning to Become Ship-Shape: An Explanation in Photographs

By Imbi Simpson, University of Tasmania

For many of us this is our first long voyage at sea, and our first time aboard a research vessel. After arriving onboard on Sunday afternoon, and spending a pleasant and rather relaxed evening, unpacking and getting settled in on the ship, we ventured off on Monday morning. We woke early hoping to hear the sounds of the ship’s emergency siren, but not because we wish to sink in the Derwent River before we have left, but because it is a sign of our time starting on the ship, and one of the many safety inductions we would have ahead of us.

Sunset over the city of Hobart, Tasmania as viewed from RV Investigator parked at the CSIRO wharf the night before the ship departed for the CAPSTAN 2019 voyage with 18 students for 10 days of hands-on marine science training.
The last sunset in Hobart before we depart for our adventure!

One of the many things on the ship that we all had to get used to, now that we are on board, is finding our way around! The doors, passageways and staircases all begin to look the same, and it can be rather easy to get lost! One area that people always know the location of is the dining mess area, (but this could just be because of the amazing food and ice-cream fridge!) and the lounge area, which is always nice to relax in when there is some downtime. We have currently started our 12-hour shift rotations, where half of the student cohort is working from 2am-2pm, and the other half 2pm-2am. For some it was a great shock to the body clock, and for others it fitted in well with the poor sleep patterns of young academics!

A serving table in the mess of the RV Investigator after dinner has a fruit bowl, some nuts, and chocolate eclairs with a selection of cereal below.
Some of the food options on board the ship!

We sometimes still get a bit lost on our way to the labs, but we sure won’t in the next few days!  We are currently on our way to our first station, or data collection point. Until we reach this point we are having safety demonstrations, tours around the ship and labs, and starting our shifts. Once we arrive onsite at 700 am, data collection will begin, and not only will the labs become full with rich data to observe and understand, but also our brains will become very full from the next 24-48 hours of data heavy work!

Black and white image of the view from one of the outer decks of the RV Investigator including a life raft and an outside staircase taken on a cloudy day on the Great Australian Bight during the 2019 CAPSTAN student marine science training voyage.
The ship has beauty hidden in secret places.

In trying to get a hang of my sea legs, I’ve been exploring the ship trying to find the lesser known areas (that aren’t off limits!) and discover more of what is onboard. Although we haven’t been able to view land for a large majority of the time we have been at sea, it hasn’t been a scary or isolating feeling. This could be due to the ship being approximately 100 metres long and feeling like its own city out on the sea.

Indoor staircase leading from the bridge up to Monkey Island, the observational deck on RV Investigator is lit by red lights as to not interfere with night vision.
Favourite place at night: the spooky stairs to Monkey Island.

From the moment we left Hobart, the ship has been collecting bathymetry data and mapping the seafloor, which is very exciting as only 5% of the total seafloor has been mapped!

CAPSTAN students and trainers gather in front of the large tv screen in one of the lounges on RV Investigator for a presentation on the kasten core before over-the-side operations began.
Informational meeting about the Kasten core with trainers prior to the safety ‘toolbox’ with the ship’s crew

As the sun rose on Wednesday morning, it was the beginning of an exciting day ahead (and a sleep in for some), as it was day one of two of operations. Operation days are the times in which we deploy equipment into the ocean. This equipment includes:

  • CTD (a device that measures conductivity, temperature and depth of the ocean, as well as collecting seawater samples)
  • Kasten core (collecting cores of sediment samples)
  • Bongo Nets (collecting plankton at shallow depths over the side of the ship)
  • Smith Mac grab (a mouse trap-like device that collects sediment from the sea floor)
Decorated styrofoam cups - on the left a full sized cup with an Ode to Drake's "In my Feelings" with "In my Sediments" written on the side.  On the right, 6 shrunken decorated cups (each about the size of a shot glass) in stacks next to a coffee mug for scale
Styrofoam cups: A full-size cup decorated as an Ode to Drake’s “In my feelings” (left) and a demonstration of the power of pressure with the shrunken cups next to a coffee cup for scale (right)

Before getting to station and while we have been acclimatising to ship life, we have been decorating Styrofoam cups to send down with the CTD, so we can have a hard analogue of the amount of pressure in the ocean. The cups were placed in an onion bag and sent down at the first station, attached to the CTD. With a smile and a swipe of a sharpie, they were on their way to 1700 m below sea level.

The sedimentology laboratory on RV Investigator is full of people once the first kasten core is brought inside.  CAPSTAN trainers and students look on as the core is secured and opened as part on the on board marine science training.
First sediment core brought into the lab!

The rest of Wednesday was a packed day, where we had our first sediment core (from 1700 m) arrive into the lab, and analysis began! We took the time to carefully log the core, drawing and writing comments about what we saw in the mud/sediment before we began to sample it. Wednesday evening lead into the deployment of the Smith Mac grab, just as the sun was setting over the sea, and seals were millings around the ship. Before we knew it, the popcorn and beanbags were out to view the live stream video from the camera that was placed down into the ocean.

A cluster of crustaceans is visible in this screen shot of the live feed from the vertical drop camera lowered 500 m through the water column off the RV Investigator as part of CAPSTAN's at sea marine science training.
A live view of the ocean!

Ending the day in the operations lab, seeing the seafloor bathymetry progress, the promise of a new exciting day of science lies ahead!

Sunset over the ocean taken from the deck of RV Investigator
Beautiful sunset on Wednesday evening.