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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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!

The Art of Science

By Jess Radford, Deakin University

A very important part of research as a scientist is being able to communicate what you have worked on to a wider audience. The general public have varied knowledge and levels of understanding of science so the simpler, clearer, and more engaging the message, the better. The message can be communicated through blogs, documentaries, podcasts, even art. There has always been an ‘us versus them’ mentality between the arts and the sciences. But at the best of times they come together for a common purpose. From the beautiful natural history illustrations of animal specimens, to Attenborough’s documentaries enthralling young and old with sublime cinematography, it’s all a unification of the two disciplines.

Cartoon of 'Sampling the Abyss' that hangs on the wall of the lounge on RV Investigator.  In the picture, RV Investigator can be seen at the surface and a submersible with 4 people is down below amongst angler fish, octopi, and other creatures of the deep.
Fantastic art work in the lounge of the RV Investigator that I love to look at!

I am learning so much during my CAPSTAN voyage, about so much fantastic science from entirely different disciplines that I had no prior knowledge of. Something that took me by surprise was the use of a fascinating piece of oceanography equipment to create miniature works of art. The CTD (Conductivity, Temperature, Depth) is a carousel that holds 36 bottles and is lowered to the oceans depths. On the way back up to the surface, bottles are closed at particular points to obtain samples from different depths of the ocean. While all of this fantastic ocean water sampling is happening, a mesh bag of polystyrene cups that have been decorated are accompanying the CTD down into the oceans depths and back up again. The magic trick is that the polystyrene cups, that are for the most-part made of air, experience the extreme pressure of the oceans depths and the air is squeezed right out of them. What a fantastic way to demonstrate the immense pressure of the oceans depths than with little pieces of art.

CAPSTAN student Jess wears her hardhat as she stands next to the CTD rosette.  The rosette is taller than Jess, with the top of the niskin bottles lining its edge about even with her head.  The sensors (CTD itself) are at the lower part of the cage.
Myself next to the CTD rosette for scale. The CTD can withstand extreme depths, it all depends on the length of the wire available to lower it. The lowest we took the CTD on the CAPSTAN voyage was 4.5 km (into an underwater canyon!)

The “D” in CTD stands for “Depth” but is more of a representation of hydrostatic pressure, the pressure of the water above (and around). So the deeper into the water, the greater the increase of pressure. The CTD and the polystyrene cups can withstand a lot more pressure than we possibly could, which is evident in the air that is lost from the cups at such great depths and amounts of pressure. I decorated three cups; drawing the phytoplankton that would be sampled in the CTD bottles, the CTD itself, and my personal experiences on RV Investigator.

Phytoplankton are plant and algae that occur in a variety of beautiful shapes ranging in size from a few mm to the very tiniest most microscopic. Phytoplankton is extremely important in our oceans as it is the very first link in the food web, providing food for many animals. They are also an important part of the carbon cycle, storing carbon and producing around 70% of the worlds oxygen. So as you might imagine, measuring and collecting quantities and types of phytoplankton in our oceans is very important in monitoring ecosystem health locally and globally.

My three little artworks: phytoplankton, the CTD, and a view of the foremast that I see from the bird and mammal observation deck every day. All next to a full-sized polystyrene cup for scale.

Phytoplankton appears again on my CTD cup. For that cup I drew the CTD carousel that holds the sampling bottles, and drew the sampling bottles representing the different measurements taken by the CTD; oxygen, conductivity (salinity), temperature, current velocities, nitrate, fluorescence (light), and pressure/depth. Generally people aren’t going to know what all of these things are, so my illustrations attempt to convey these in a more approachable way. For example conductivity/salinity is represented as a salt shaker. Even with my science background, I don’t fully understand the ins and outs of all of the measurements and hydrochemistry involved with the CTD, but I hope I’ve presented it in a way that bridges the gap for most people. It’s not so easy to draw on a polystyrene cup, so these aren’t absolute masterpieces, but I hope they’re a good form of communicating some of the science from onboard RV Investigator!

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!

If you can read this, thank a plankton!

By Anthony Mott, Charles Darwin University

Sure, the bumper sticker says, “If you can read this, then thank a teacher”.  And that is true, you should probably thank a primary school teacher.

But in the six seconds it took you to read to this point you breathed three times, and microscopic plankton produced around two-thirds of the oxygen you breathed into your lungs. In fact, you have been reliant on plankton for much of your oxygen since you were born. This is not to say that the trees, plants and large intact forests such as the Amazon are unimportant, but marine studies since the 1980’s revealed that the tiny microorganisms that photosynthesise like plants and float around in the ocean are much, much more important than anyone realised. Collectively they contribute more oxygen into the atmosphere than any other living species. Plankton matter much more than your science teachers knew when they were trying to pique your interest.

RV Investigator sits at the wharf in Hobart, Tasmania before departing on the 2019 CAPSTAN voyage providing 18 students from across Australia hands-on training in marine science
RV Investigator sits at the wharf in Hobart before the voyage

This week eighteen postgraduate University students interested in the marine environment boarded CSIRO’s RV Investigator and sailed from Hobart on a slow trip to Fremantle to better understand Australia’s marine estate, which is actually larger than all the land Australia is responsible for. Along the way they have undertaken studies of plankton at various locations and at various depths, guided by another 20 senior scientists and technicians.  They also filled in some poorly defined spots by mapping the ocean floor, collected and examined samples of often ancient mud, gravel and ooze from undersea canyons, and measured different currents from the surface all the way to the ocean floor. But breathing is important, so arguably the plankton studies matter the most.

CAPSTAN student Anthony Mott stands on one of the outside decks of RV Investigator as the ship departs Hobart for 10 days of at-sea marine science training
Enjoying the deck of RV Investigator

Plankton are a broad category of tiny, often microscopic organisms that live mostly by drifting around in the water and include both plants and animals.  Some generate energy by acting like plants, and others devour other plankton. Plankton exist in both fresh and seawater, but marine plankton outnumber the rest simply by sheer number. The plankton that generate the oxygen we rely on are the plant-like plankton which photosynthesise just like plants on land – taking in CO2 and water, and releasing oxygen. They can have very short life cycles and can reproduce really quickly when conditions are right – often producing massive natural blooms in response to a sudden increase in nutrients, such as runoff from land or agricultural areas following a major storm.  Most marine plankton are made up of single cells and their small size means they are highly efficient and are an important mechanism for soaking up CO2 from the atmosphere, so plankton are an important part of the global carbon cycle.

CTD rosette with 36 niskin bottles is recovered from the ocean on board RV Investigator as part of CAPSTAN's hands-on marine science training
The niskin bottles on the CTD rosette can be seen coming out of the water

Once the RV Investigator neared the Victorian coast near Portland it positioned itself at the head of three undersea canyons to investigate their role in channelling coastal soil and sand down onto the undersea continental slope-looking at how they funnel cool, nutrient rich deeper water up from the depths up onto the continental shelf. This concentrated source of nutrients underpins a broad marine food web – with plankton being the first organisms to capitalise on the nutrient supply.  Very fine nets were dropped to capture the plankton populations at different depths.  Water samples were collected at the top, sides and bottom of the canyon systems. Collecting samples at different depths and locations provided important information on which conditions best suit different species, as well as provided some insights as to how widely certain species are distributed.  Nutrient rich waters close to the surface may contain up to a million microscopic plankton in one litre of water, whereas similar locations can yield completely different results with variations in factors such as temperature or nutrients. The Southern Ocean that circles just above Antarctica seems particularly important. And 40-odd marine scientists and students want to know why because any change in the mix and number of plankton may have significant implications for oxygen supply and the changing climate.

Deployment of the bongo nets for plankton sampling from RV Investigator as part of the CAPSTAN hands-on marine science training program.
RV Investigator’s crew and support staff deploy the Bongo nets to recover a vertical tow plankton sample

The southern Australian coast is home to many marine species not found anywhere else in the world. This region also attracts much travelled species like Southern Bluefin Tuna that spawn south of Indonesia and migrate south down the WA coast and across the Great Australian Bight to SA and Victoria; Southern Right Whales come here t0 breed and calve. The area also attracts rare and endangered marine mammals like Sperm, Killer, Blue, Minke, and Humpback Whales. It’s easy to be distracted by the big things, but they are all dependent on a sustainable food web that starts with the microscopic things that are easily overlooked. And that’s why 40-odd scientists braved forecasts of 12 metre swells and unpredictable weather to head into remote oceans to study the little, poorly understood, strange, but often beautiful creatures that make an under-recognised contribution to global oxygen and carbon cycles.

Never will I look at mud the same..

By Aaron Puckeridge, University of New South Wales

NEVER WILL I LOOK AT MUD THE SAME WAY AGAIN! Did you know that by looking at mud you can find tiny fossilised animals, or even understand past climates? Neither did I. On land, mud has a dark colour from decomposed animal and plant matter, and it is the same in the ocean. In the ocean, dead animals will sink down to the seafloor and accumulate, eventually forming mud. As a marine biologist I have never appreciated how interesting mud can be!

CAPSTAN student samples the mud from the end of the kasten core on RV Investigator as part of his at-sea marine science training
I sample the core catcher of the Kasten core on the stern deck of RV Investigator

Over the last two days onboard RV Investigator, we have been sampling a deep-sea trench in the Great Australian Bight. The seafloor here sits undisturbed by overhead currents, allowing dead animals to accumulate over thousands of years and form mud. Sampling this mud, up to 3000 metres below the surface of the ocean is where the amazing technology onboard the RV Investigator comes into play. High-resolution sonar gives us a 3D image of the seafloor, helping us to select a site to study. Then we lower a large tube to the seafloor and into the seabed to collect a vertical tube of mud, with young mud at the top and old mud deeper down. At a glance, this looks like any old mud, but under the microscope it is almost entirely tiny animals called plankton.

microfossils and biological debris down a microscope observed by CAPSTAN students as part of their at-sea marine science training
Microfossils and other biological debris in the sediments under the microscope.

Over the coming days we will be looking at these tiny plankton fossils to understand how the ocean above the deep-sea trench has changed the in past. Fingers crossed we won’t get seasick while looking down the microscope!

Initial data and sample collection

By Nathan Teder, Flinders University

The first two days at sea were mainly used to steam ahead to our study area off the coast of Portland, and due to this, the main thing that had occurred was seafloor mapping. We used a single beam sonar system to take data ranging between 5 m per sample to 50 m per sample depending on the depth of the location, and how flat the sea floor is, with topographic structures (i.e. canyons) being taken at a smaller resolution. This method of data acquisition does require some manual cleaning however (figure 1) due to the sonar system being susceptible to noise, especially on the edges of its pulses. This will be running throughout the voyage, but will be especially focused on a set of four canyons in the Otway Basin as these canyons could either be funnelling cold water turbidites to the submarine fan, or potentially playing a role in upwelling depending on if a low or high pressure system is present in the bight.

Bathymetric data displayed with a rainbow color scale.  Red represents the shallowest depths and blue indicates deeper waters.  CAPSTAN students on board RV Investigator learned how to do quality control to process this data as it was collected as part of their at-sea marine science training
Figure 1: The output of a small section of recently measured bathymetry in a 2D wave (top) and a 3D model (bottom). This screen allows the user to manually delete data points that are anomalous (noise).

Day three saw the first deployment of the CTD, plankton nets and coring samples from the sea floor. The plankton nets, and CTD both had samples which could be used to count marine life present at that depth. For the CTD, samples of 10 m, 40 m and 100 m were used with the amount of life decreasing as the depth increased, to the point the 100 m sample didn’t have any life present that was above 100 μm. This was an expected result, due to being at a depth which is deeper than the photic zone which would reduce the amount of life present, due to insufficient light. That said one of the more unsettling parts of this observational work was the amount of plastic present as the 100 m sample had ~ 49 blue fibres of >100 μm present in it, which was from 6 L of water. Switching to a horizontal tow of a phytoplankton net ended up getting a much better result life wise, with ~ 150 various forms of copepods, massive clumps of biomass, as well as a crustacean larvae at a ~ size of 1-2 μm (figure 2).

CAPSTAN students collected plankton from the Great Australian Bight/Bonney Upwelling Region using Bongo nets as part of their at-sea marine science training.  Here is a dead crustacean larvae under the microscope from one of the tow collections.
Figure 2: A dead crustacean larvae present in the towed net sample.

The first core was taken from a ~ depth of 1727 m, and from that, a 2.16 m section of the sea floor was obtained. This whole section was a homogenous olive coloured mud (figure 3) which was firstly split up into an archived, and a working core. The working core was then sampled at a rate of 1 per 10 cm, and each 10 cm block was sampled four time. There was also a point around the 1.73 m to 1.75 m section which was also sampled 3 times due to the presence of a broken shell at the surface. These samples will be analysed later on during the trip, once we move away from our study area.

Figure 3: The kasten core after initial sampling in the wet-dirty lab on RV Investigator

Once that was completed, smear slides were created using mud from the 1 m mark of that sample. These smear slides showed up some air pockets, and biotite in this sample (figure 4). We also saw foraminifera within the smear slides, which are a component of the cool carbonates we are focused on this trip. Our goals include trying to measure if they do descend down to the abyssal plane, and if a canyon system influences the amount that flows down.

Microscope view of sediments from a kasten core collected by CAPSTAN students on RV Investigator as part of their at-sea marine science training.  A variety of micro-organisms can be seen along with record or donut shaped air bubbles.
A smear slide made from sediment from 1 m depth in the Kasten core. Air bubbles are the ‘record’ looking circular objects and the black dots are biotite.