Although it would be hard to imagine, you couldn’t have seen a more excited group of adults than when a three-metre rectangular block of muddy sediment was pulled onto the ship. This surreal moment is when you realise you’ve fallen into the rabbit hole and entered a whole new world; the world of a sedimentologist.
This block of muddy sediment is a sediment core taken from
the bottom of the ocean and reveals a whole plethora of wonderful and strange
stories from Earth’s history. These stories relate to how our planet’s
environment, climate, and ocean currents have changed over time. What is truly
amazing is that we know so much about the long and dramatic history of our
planet despite the fact that we have not been part of that history for very
long. This amazement is humbling and is a reminder of the capabilities of the
human race, and the responsibilities we have as stewards of the planet.
Once the core is brought into the lab there is a flurry of activity to open the metal casing, which holds the sediment core, and to see what strange and mysterious tales from the ocean depths have been brought to the surface. With the casing removed heads are bent over to observe the colour, structure and composition of the sediments. Quick, sharp remarks are exchanged between the various parties involved before the processing of the core is started without delay. First, the core is logged which involves documenting the major characteristics of the core. This is important because these observations will underpin the majority of the interpretations which brings the whole story together. From here smear slides and small sediment samples are taken along the core to examine the changes which occur from top to bottom.
Hours will be spent analysing these slides and samples, with more sampling done along areas of interest until the sediment core looks less than pristine. Not to worry however since before the sediment core was scooped, poked and prodded an archive core was taken and stored in the fridge. This archive core is kept with all its structures and features intact as an original record for safekeeping.
There is a certain amount of chaos and untidiness in the lab which may be disconcerting to the casual viewer, but there is a method to the madness with great care being taken to systematically record and sample the sediment core. Furthermore, there are efforts to limit contamination across the core (i.e. avoid mixing sediment from one area of the core to another). In fact, it is quite liberating to be able to conduct science in a lab where things are more practical, and improvisation is encouraged. A day in a life of a sedimentologist will surely shake up the perception of the typical scientist in a lab coat conducting experiments in a clean and well organised laboratory.
Today is the last day of the CAPSTAN research voyage IN2019_T01. My excitement is palpable as CAPSTAN has surpassed my expectations. The training provided in multidisciplines ranging from geology, geophysics, oceanography and microbiology will definitely act as a milestone for stepping into a future marine scientist. Time passes so quickly, I spent almost 12 days in the ocean and during these days I observed nature very closely, clear water, blue sky, sea birds and micro organisms with in the ocean.
This year’s training cruise was targeted on the canyon system on the eastern edge of the Bight Basin, near the outer continental shelf just southeast of Portland, Victoria. This region is unique due to the presence of cool water carbonate turbidite deposits. Such carbonate systems can only be formed with minimal terrestrial input. I was enthusiastic to see these carbonate systems as my masters research project is also related to the carbonates but they are formed in warm and temperate environment.
Carbonate involves limestone and dolomite (rocks) that consists of mineral calcium carbonate (CaCo3) and dolomite CaMg(Co3)2 respectively. The organisms that live with in the water are zooplanktons (animals) and phytoplanktons (plants). They are made up of calcium carbonate and after their death they accumulated with in the water and after cementation and compaction, limestone is formed. It is important to understand carbonates because they can tell us about sea level changes, paleoceanography, paleoclimates, and marine ecosystems. They also holds around 50% of the oil and gas reserves.
A submarine canyon is a steep sided valley that extends from continental shelf to the sea bed. The turbidity currents carry material from the continental shelf passes through the canyon with an immense speed and may deposited with in the canyon and deep ocean floor. There can be many driving forces behind these turbidity deposits. These can be triggered by earthquake, gravity flows and tectonic forces. Due to density contrast between the sediments, the coarser ones will deposit first and finer will remain in suspension and deposited at the end.
Our chief scientist, Dr. Leah Moore selected specific depths for coring after looking at the bathymetry (geophysical) data. The bathymetry data uses acoustic (sound) waves to determine the geomorphological features of the ocean floor. The RV Investigator is equipped with the Kongsberg EM122 multibeam echosounders to retrieve high quality bathymetry maps. The cores were retrieved at 1700m, 2200m, 3700m and 4700m depths. I was working in the sedimentology lab to find out the variations in percentage of the fossils present in the top and bottom of each core. I was exposed to using the microscope to identify different foraminifera.
Another exciting thing was CTD as it was new for me. CTD stands for conductivity, temperature and depth. It consists of a carousel that has 36 niskin bottles with sensors at the bottom. In the operations room, a fluorescence curve that shows the chlorophyll activity with in the ocean and helps to decide the locations for samples. These bottles were closed at designated depths while coming back to surface. The polystyrene cups that were decorated by the students were sent down with the CTD to demonstrate the pressure affect. These polystyrene cups became very small in size after coming back from the ocean. Due to this small experiment, it is very easy to understand that pressure increases with depth.
On the very last day, we had a lot of fun. Our CAPSTAN director, Dr. April Abbott arranged a quiz to entertain all the participants and crew members. Everyone was in a different costume except me to relish those last moments. Our trainer, Stephen is a great geologist but his sense of humour was also amazing. I am obliged to be a part of this exciting opportunity as it not only increased my knowledge related to marine science but also helped me to thick critically, improved my confidence and science communication skills.
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!
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.
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
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.
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.
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!
April Abbott, Macquarie University, Director of CAPSTAN
Last day group photo on the bow. Photo Credit: Marine National Facility/CSIRO
With an incredible crew, wonderful trainers, enthusiastic students, and favourable seas we couldn’t have asked for a more successful CAPSTAN pilot voyage!
Drone in flight at sea. Photo Credit: J Kaempf
The last full day at sea was an appropriate end to an epic 13 days crossing the Great Australian Bight. Students recapped the research results, our sea bird counts soared (# of total individuals increased 4x over the last day), we had regular marine mammals checking us out, and flat seas allowed the drone back into the air! The day was split between observations, presentations, writing, cleaning, and some celebrating!
A seal was snoozing peacefully until we came along!
The morning was busy as students finalised their presentations, trainers cleaned the laboratories, and everyone took some time to enjoy our surroundings! Student groups presented their findings to the science team after lunch- each team a demonstration of the importance of interdisciplinary collaboration! The research completed in a short 4 days on station is incredible, especially considering over-the-side deployments ceased at night.
Students sort the rock dredge. Photo Credit: Marine National Facility
Not only did the students’ ability to relate data across disciplines show, but their science communication skills also got a chance at the spotlight. Elise even broke down the importance of interdisciplinary approaches by relating the benthic ecosystem to by far the most popular board game of the trip, Settlers of Catan (one night after dinner 20% of the people on board were all playing at the same time!) – assigning each resource (wheat, wood, brick, etc) to an important ecosystem component (phytoplankton, benthic organism, sediment composition, etc).
Dolphins riding the bow wave
It is hard to believe we’re back on shore already- we’ll miss our ship family! Who knows, we may even see some of our students back as trainers in the years to come!
The bow of the ship was busy most of the day, as calm seas and our proximity to Tasmania made for a beautiful sight and lots of marine visitors!
Stay tuned to the CAPSTAN website and this page as we start to look ahead to voyage 2019!
Muhammad Rashid Saleem, University of Western Australia
I Muhammad Rashid Salem, from University of Western Australia, express my feelings during Collaborative Australian Postgraduate Sea Training Alliance Network (CAPSTAN) 2017 program and my significant learning and achievement in different aspect such as geophysics, sedimentary geology, paleontology, and oceanography that helped me to get better understanding of marine geoscience processes.
I characterise sediments through the microscope in one of the labs on board
Working on offshore as a petroleum geoscientist was my dream and this dream comes true just because of this uniquely tailored scientific research program. Working as a petroleum geoscientist student from the University of Western Australia in CAPSTAN program gives me an opportunity to work hands on in professional environment and gain actual work experience in the field. This scientific research program gave me an opportunity to interact with researchers from different universities and CSIRO professional staff; and helped me to improve my communication skills in professional environment. Personally, this research has introduced me to a lot of useful resources in my field. I hope the skills, which I achieved during research will be a tool to improve my chances as a job applicant and assist me to become a better employee in my area of interest.
Our chief scientist takes a phone call in the operations room
Visiting the sites! It is very interesting to get on the back deck with other teaching staff and ship members to collect the cores and rock dredge material that come out of the sea floor surface. The study of deep ocean sediments under the microscopes in wet laboratory helped me to recognize different facies and their fossils. Other interesting studies include geophysical data to map the sea floor surface and to know about sub bottom profile and hydrochemistry to know about temperature and salinity of ocean.
CAPSTAN students and trainers recover a gravity core
Entirely, I learnt about geoscience in depth and realize how important the data is, which we collected during over fieldwork for petroleum prospective. My favorite times are when everyone including staff gets together during free time and discuss the things in friendly way. Last but not least, I want to say thanks to chefs and kitchen staff for their delicious dishes and their care about my food will always be remembered.
Life in the field is always hard especially when you are working offshore for the very first time, but I am very fortunate to have cooperative teaching staff and student from different universities worked as a team and make this scientific research very easy. Keeping up everyday routine to perform different task are challenging, but in a good way – it pushes me and make me stronger to learn and improve my skills.
A sediment grab is brought on deck
My advice to upcoming CAPSTAN group is that working on this scientific program is very interesting and rewarding but make sure that be prepared to work hard in challenging environmental conditions. If you are adventurous, though this opportunity will be right up you alley!
On Saturday morning, we were told that we, the students, would be planning the next day. By planning, that meant we decided where exactly we would be going and the activities that we would be doing. Basically, it meant we all got to be “chief scientists” for the day (want more on the student led day? click here!). That afternoon, four groups gave pitches on what we thought should be undertaken the next day, which was our last day on site.
The rock dredge being brought back up onto the deck. We were watching anxiously from the 02 deck above!
Having had the last five days on the ship, we have all been able to gain an understanding of what activities are capable in this environment and the time frames which are involved. Using this newly acquired knowledge we were able to make realistic scientific plans, considering all disciplines of people on board. That meant CTD operations, vertical plankton net deployment, Smith Mac sediment grabs, multi-corer, gravity coring and the most exciting piece of equipment for the geologists on board, myself included, the ROCK DREDGE.
After all the groups gave their pitches, one member from each of the groups came together to finalise a plan. Saturday afternoon was spent in the operations planning and prepping for the next day. We choose to undertake gravity cores, CTDs, vertical plankton hauls (see some of the species here), rock dredges, and the multi-corer (weather dependant). The sites for all these operations were chosen– shout out to Stuart in the operations room for his patience and guidance in helping us choose the dredge and coring sites!
Gravity core deployment. The robotic arm holding the gravity core in place is just being pulled away ready for the core to be dropped.
We went to bed, happy with our decisions, leaving two members of the group up on night shift, ready to question Dr Thomas Hubble when he came into the operations room for his shift. The next morning we had a meeting in the chief scientist’s cabin, to discuss the plans for the day. At this point I began to understand the amount of planning and re-planning that is involved in being a chief scientist on a voyage.
The rest of the day we got more of a taste what it would be like to really be in-charge on a voyage. People asking you to make decisions on the spot, looking for certain people and equipment, and things not going exactly to plan. But it was a lot of fun, and I now understand why the chief scientist gets the best view on the ship.
Core processing begins! The core has just been brought back up onto the deck and the students are marking the liner so it can be analysed later in the voyage.
The afternoon was exciting: we retrieved two gravity cores and the most exciting part of the day, the rock dredge. The rock dredge was dropped and then it was an anxious but exciting wait up on the 02 deck, with Bec, Lena, and Karl as we watched the trawl winch pull up the dredge on its long journey back from the deep. At this point, I want to thank all the crew and all the team up on the bridge. This is no easy operation and it was executed extremely well! Following that, thanks to the crew who dealt very well with a group of excited students running around when the rock dredge came back on deck.
A beautiful sunset at the end of the day. The perfect end to the perfect day.
This was the most exciting day for me so far on the ship. I got to watch a gravity core be deployed not once, but twice. Then when the core came back on board we were able to go out on deck, to help process it. We had a successful rock dredge, I got a small window into what it is like as a chief scientist on board a vessel such as the RV Investigator and we managed to get ourselves arms deep in mud. We, the students, have learnt so much on this voyage, and were only half way through. We all like to think we did a pretty good job, though I was very happy to hand my chief scientist hat back to Dr Jochen Kämpf at the end of the day. I want to finish with a quote from Matt Kimber, our voyage manager, and that is:
“If you want to get something done, give the job to the students”.
By Ajinkya (AJ) Koleshwar, University of Western Australia
The Collaborative Australian Postgraduate Sea Training Alliance Network (CAPSTAN), was a spectacular opportunity for myself to broaden my scientific horizons aboard the RV Investigator. Prior to boarding the ship, the day was filled with nervousness, with a hint of excitement in meeting colleagues with similar interests from across Australia. However, upon boarding the ship, my nervousness suddenly transformed itself into being awestruck with an immense excitement by the enormous multi-disciplinary capabilities from the biological to the geological spectrum of the RV Investigator. The voyage briefing provided me with a strong overall understanding of the basic training that was going to be provided during the entire voyage, with a preliminary plan for the main stations and the tests that were going to be performed. A trip down to the hydrochemistry lab introduced the CAPSTAN students to the CTD (conductivity, temperature and depth) instrument. This was completely new to myself. The instrument in reality works towards measuring the complex relationship between pressure and depth involved with water density and compressibility. Furthermore, in the operations room upon the deployment and retrieval of the CTD, a fluorescence indicator helps identify the locations within the water column wherein a higher proportion of chlorophyll activity was present. This helps to deploy plankton nets (see some of the catch here) at the specified depths. Furthermore, the following instruments were introduced, the gravity monitor, a sediment grabber, the gravity core, and the rock dredge (see the mud here).
The best view on the ship is on top of at the observation deck (monkey island-it is that little deck above the blue roof in the photo below) above the bridge. The spot is optimal for bird and mammal watching. As marine birds account for approximately 3% of the proportion of birds, watching the albatross’, the shearwaters, and the gannets adapt to their surrounding in the middle of the ocean is phenomenal to witness. Their unique flight patterns and behaviours helped me appreciate and enhance my knowledge in the area (read more about the birds here).
We made it! Boarding the RV Investigator for our CAPSTAN voyage.
A snapshot of November 18th on the ship was spread out from being able to contribute to each of the instruments in their data retrieval to the data acquisition. The first stop was up to the observation deck, from 08:00 UTC to 09:45 UTC, where mammal activity was not present, however there was an upwards of 20 birds seen with two albatross species, two shearwater species and one gannet species. The previous day was mesmerizing with a sighting of over 100 pilot whales next to the ship. Having never seen whales before, witnessing the behaviour of a large pod was an event I will personally cherish.
The observation deck, was followed by a thorough tour of the engine rooms. To witness first-hand the machinery that operates the ship, was indeed fascinating. I was personally surprised at the intricacies involved in running the engineering aspects of a research vessel and the dynamic changes required to successfully retrieve samples.
Sunset on the night of November 18, 2017
Finally, the students were tasked with the responsibility of being the Chief Scientists to develop a science plan for the following day (check out more stories on how it went here!). The opportunity to be part of the dynamic planning involved in proposing a multi-disciplinary scientific strategy was an enriching experience. Four student groups were responsible for presenting their project plans to the entire science party. To arrive at a mutually agreed upon plan based on the inputs from each group, a delegate was nominated to work with the team of scientists to implement the strategy to enhance the overall training outcomes. The experience was highly interactive and invaluable to being able to understand the thought process involved in the dynamic nature of marine planning. The amount of effort required in planning and pin-pointing locations of interest to retrieve samples in a marine environment was astounding to witness. The CAPSTAN experience has surpassed my expectations and there is still 8 days left on the ship. The training provided on the voyage is definitely the stepping stone for moving into a future as a successful marine scientist.
This program has been a great example of the effectiveness and necessity of integrating many different scientists from many disciplines to paint the best picture of a certain marine environment. This inaugural CAPSTAN program has brought together 9 experienced trainers and 20 aspiring postgraduate students from disciplines ranging between ecology, geology, microbiology, oceanography, geophysics and hydrochemistry. As an early career marine scientist this has been an invaluable experience to hear and learn from people with so much different knowledge and skills.
The underlying scientific objective of our voyage was to explore an area of reported high biomass around the shelf break at the bottom of Western Australia. The key interest around this area is high numbers and diversity of megafauna. Once on site, it became very evident that our large range of expertise complemented each other extremely well.
And we’re off! All types of scientists on board!
Our first task was to improve the resolution and coverage of our knowledge of the shape of the seafloor in this area. Our main study area was made up of three large canyons systems, namely Bremer, Whale, and Hood. This is my area of interest! We used many types of sonar technology to explore the seafloor. First, we used multi-beam sonar to paint a picture of the seafloor. The essence of this technology is that it sprays around 400 pings of sound at a time from the bottom of the vessel and then times the return to a transceiver on the bottom of the vessel. By knowing the speed of sound in water we are able to know the exact depth, and by using many beams we can paint a detailed picture of the seafloor.
We also use sub-bottom profiling to understand the sediments and water column bioacoustics to understand the biomass in the water column. This creates the basis of our sampling design. From here we handball the data on to the others groups such as our geologists, biologists, climate scientists, and hydrochemists.
Scientist’s version of a movie night. Introducing everyone to the wonderful world of drop cameras.
So onto our friends the geologists. As a biologist, these are a very interesting species of human to observe. I have never experienced people that get so excited over something as seemingly simple as a rock or some mud. I must be missing some of the details! These guys use our multibeam and sub bottom data to locate areas of interest where they sample the rocks and sediments. From this, they are able to infer what past situations were like and help paint another aspect of the picture.
From the geomorphology found in our multibeam data, as well as an understanding of oceanography, we are able to track areas of high productivity and nutrients. This is also compared with constant fluorometry readings indicating nutrient rich water. Here our hydrochemists will deploy the CTD (Conductivity (salinity), Temperature, Depth) as well as taking water samples from various depths. From these samples, they will measure nutrients throughout the water column. This data is then coupled with vertical nets that collect plankton samples. In the grand scheme of things, it is thought that this might tell us where there will be food for the megafauna and thus hint to where the megafauna (including whales) are most likely to be.
All in all this collaborative approach has allowed us to understand a great deal about the structures of this area and the interaction between the bathymetry, chemistry, and biology. In turn, our expertise has allowed people from the other fields to further their efficiency and understanding of what is being sampled.
Let me share with you a tale from the high seas; a story of adventure, discovery and uncertainty. Our intrepid explorers are a motley band of 20 eager, young students, 9 wise trainers, and a crew chirpier than a nest full of songbirds. They have united under the CAPSTAN banner onboard the RV Investigator; a stunning ship built for the sole purpose of researching the azure depths of Australia’s oceans, all in the name of marine science!
Hosing the vertical plankton net while the ship is stationary
Our story begins not at the start of the CAPSTAN voyage, but rather, at the end of the first phase of the programme. The Investigator has spent the first few days collecting data around the western shelf area of the Great Australian Bight. These explorers seek neither diamonds nor gold; they hunt to uncover the jewels of biology, geology, and hydrochemistry that have not been revealed before in this area.
With the data collected and samples onboard, the Investigator begins her journey across the open ocean of the Great Australian Bight towards Hobart. Explorers and crew alike celebrate the success of their efforts, for the data is had and the processing can now begin. The excitement calms and our explorers can focus on analysing the samples.
Or so I thought; an overexcitable student onboard, starting her first night shift of the voyage. For this explorer, the secrets of the Great Australian Bight were not yet finished revealing themselves. Tales from the other students had left the impression in my mind that the night shift was an uneventful time, spent periodically logging the ship’s location and other information such as wind speed and temperature.
One overly-excited explorer
Shortly after beginning my watch, my scientific interest in phytoplankton brought my attention to look at the fluorescence data recorded by the ship as she moved (learn more about the ship’s underway data here). Fluorescence – a measure of phytoplankton abundance in the water – had been consistently low throughout the voyage. However, at this precise moment, my eyes began to see a rapid increase in the fluorescence reading, as well as a drop in the temperature of the ocean over the space of a few minutes.
Such a stark rise in fluorescence had not been seen on the voyage and my curious mind urged me to rally the other explorers so that we could capture this fluorescence peak in an underway plankton net. After running around the ship and rousing the explorers, we succeeded in sampling this peak in fluorescence. My heart was pounding at the sheer unexpectedness of such an event, but on-shift or off-shift, science waits for no one, especially on a research voyage.
Ceratium, a type of dinoflagellate phytoplankton that I love!
With the end of my watch fast approaching, I feel lethargic and spent from the excitement of the day. However, my longing for sleep is dashed when our control room receives a call from the bridge. An enormous shoal of squid has crossed the path of the Investigator and the bridge have never seen anything like it! The three of us in the Operations Room drop everything and run up the 4 flights of stairs to the bridge to catch a glimpse of this incredible phenomenon happening around us. The spotlight is aimed off the port bow and we can see hundreds of ghostly, translucent shapes flashing in view as the ship continues her course. I am transfixed on the size of the aggregation we have just arrived at and I cannot believe my eyes are seeing such an event.
Although my watch ended, and I eventually retired to the world of sleep after the shoal of squid left the spotlight, my dreams took me to a world filled with wonder and a wealth of knowledge to learn. Daylight brought about the news that we passed through the shoal of squid for over 2 hours! How lucky was I to witness this event while most of my fellow explorers were sleeping, and our beloved Investigator was at the right place at the right time?
Sunset before my night watch begins.
Which brings the tale of this intrepid explorer to an end; after a night of emergency plankton sampling and an impromptu visit from some marine wildlife.
I complete this log with two nuggets of gold; plans never go the way we imagine, and the world is filled with so much to explore, if we only take the plunge!
Natural systems, processes, and environments rarely fall into a single scientific discipline. Yet often in our fields of expertise we attempt to approach our understanding of them and analysis of them through a narrow singular discipline methodology. The CAPSTAN programme breaks this mould with a multidisciplinary approach to a multidisciplinary problem.
A sediment grab sample teeming with life
I joined the voyage with an ecology background and an interest in fisheries and sustainable livelihoods. But I soon had handfuls of mud, seawater filled sample bottles, self-made plankton slides, newly acquired mapping skills, a pair of binoculars strapped around by neck, and was launching velocity probes 1000 m into the depths.
Me preparing for the launch of the XBT (eXpendable BathyThermograph) to measure the sound velocity of seawater down to a depth of 1000 m
On our first sampling day, I found prime position on deck to watch the Smith Mac Grab and gravity corer in action then waited for my shift in the lab to start to explore what had been collected. I learnt geologists and sedimentologists are possibly some of the most enthusiastic people out there and that it is contagious. Learning what sediments contain and what they can tell us about the environment past and present was extremely interesting and is an important piece in the larger oceanic picture.
The gravity corer being deployed to collect sediment from the seafloor in 530 meters of water
Our first session in the sedimentology lab included an introductory lesson on identifying and classifying sediments collected by the Smith Mac Grab from 1100 m water depth
Adding to this picture, is the physical form of the seafloor. I have often looked at bathymetric images without much thought as to how mapping the seafloor is actually an immense task. Seeing the sonar mapping in action put into perspective the scale of task at hand, and the vast reaches of ocean floor yet to be explored.
Seafloor imaging using sonar from the operations room of the RV Investigator. Displayed here, the shelf edge in East Bremer Canyon which was an area mapped during the inaugural CAPSTAN voyage.
Understanding the ocean floor characteristics and sedimentation is still only a small part of a very big picture. The days following involved hydrochemistry with CTD deployments and nutrient testing and vertical plankton net hauls. I filled slides with zooplankton and chased them around with a microscope while they tried to swim out of view. Through the microscope you get a glimpse at a whole other world and some of the most unusual creatures imaginable.
Plankton sample collected from the vertical plankton tow. The plankton net was dropped to 100 m, and on the way up the plankton funnels through the net into the plastic cob (closed PVC section pictured here).
One of the microscopes in the lab that we used both for getting a closer look at plankton and at the sediments!
Next was a task more in my field. Typically, my subjects swim, often they crawl, climb and slither, and occasionally they hop. But bird survey are quite different. These flying subjects have speed and agility and an endless blue ocean surface to seamlessly disappear over. Trying to distinguish bill colour on a seabird flying past at high speeds through binoculars takes a keen eye, steady hands and patience. I am interested to see how the observations of these top ocean predators aligns with our understood models of ocean productivity or if new drivers of sea bird aggregations and distribution are uncovered. This highest tropic level adds to the bigger picture, helping tie the biological to the oceans physical processes.
A Gibson’s Wandering Albatross observed during our voyage across the Great Australian Bight. Photo Credit E. Woehler
At any stage of the day through the ship’s intranet you have at your fingertips is biological data, underway seawater data, operational information, and a range of cameras to watch equipment deployment, keep track of activities, and generally run your phone battery flat very quickly.
Only part way through the voyage and gaining new knowledge and skills daily, I already have gained a much broader and comprehensive knowledge of oceanographic process, systems and characteristics. Apart from coming home with a note book full of lists titled ‘things to learn more about’ and ‘look this up’ which will undoubtedly turn my Christmas study break into less of a study break and more of a self-guided research unit. I am also coming home with an appreciation on the linkages and cooperation required from a vast range of scientific disciplines in understand environments, essential to answer the questions they pose.