In the midst of the Atlantic

by Gadaffi Liswaniso

Almost midway through the 24oS transect from Rio to Walvis Bay onboard the James Cook research vessel on cruise JC159, and by now we don’t need to look at each other’s name tags to know who is who, just some laughter in the corridors signifying friendship. The JC is equipped with one person cabins allowing privacy for each person onboard, no one has to worry about another person’s love for broccoli during sleeping times, ha ha!! Although we are very far from our family and friends, the IT team has made sure we stay connected to the world via the onboard WiFi connection that is available in most spaces on the ship.

As JC159 left Rio, we managed to capture a view of some apartments creeping up the mountains (image: Gadaffi Liswaniso)

Time differences have been a hustle since we left port in Rio as I had to keep up with 3 different clocks: time on onboard, GMT and Namibian time to ensure I don’t call anyone back home at 2 a.m thinking it was right timing.

The RRS JC scientific crew consists of five working groups that sequentially work on the CTD after it has been hauled out, starting out with the CFCs, dissolved oxygen, carbon, nutrients, isotopes, salts and lastly either biological or microplastic sampling. Each group has a designated laboratory where they analyze their samples before arriving at the next station. Each group has 8 hours on shift plus 4 hours standby for post data analysis or any other tasks as required to perform. For sure none of all the scientific analysis would be so efficient without the ship technical crew, bravo to them!

Argo floats are also onboard to ensure continuation of data collection in the S. Atlantic; they are designed with lithium batteries that can last up to 5 years without replacement while collecting important physical data of the ocean, and operate through special missions given by the user. Not only do Argo floats stay on the water surface but they are also able to dive down to 2000 or 6000 m depending on model, thereby giving us a profile of oceanic physical data at various depths according to specific missions.


At least two emergency drills have been done since leaving port to ensure safety out at sea, orienting all aboard on the necessary steps to follow in case of an emergency, where to go, what to bring along, and how to use the safety gear for sea going purposes. We have really settled well onboard, today I even did my first laundry.  We have a resourceful library, a well-equipped gym and sauna, and a lounge with various movie genres and gaming consoles to help us enjoy during rest hours. There is also a bar where we can chat over a beer or wine. The ship’s crew even went the extra mile and made a temporary seawater pool to relax in during warm sunny days out in the midst of the Atlantic.


On the hunt for invisible drifters across the South Atlantic Ocean

by Nina Faure Beaulieu

Everyone aboard the James Cook is on a different mission, and each team is formed of detectives who are gathering clues to solve a wider mystery. Our mystery is rather a big one, in fact it is the biggest one on earth: the ocean.

My role in this group of detectives is to hunt for the near-invisible: microplastics. These are tiny pieces of plastic, the official definition being any plastic smaller than 5 mm. Despite their overwhelming presence in the news lately, we actually know very little of the basic facts about them. How do they form? Where do they come from? How are they transported both across and through aquatic environments? Where are they going? What effects, if any, are they having on marine life? How does their abundance change across different oceans? Hopefully this expedition will bring us a microstep closer to answering some of these questions about microplastics.

The CTD rosette from above, with water samplers at the ready (image: N. Beaulieu)

Our sampling transect crosses the South Atlantic from Rio De Janeiro in Brazil to Walvis Bay in Namibia. I will be attempting to sample microplastics both across and down the water column to understand a little more about their oceanic distribution. This transect is particularly interesting as it crosses the South Atlantic Subtropical Gyre. Gyres are large, circulating oceanic currents driven by the combination of winds and the earth’s Coriolis force (rotation); debris tend to accumulate in the centres of the subtropical gyres.

Along this 6-week transect, the ship stops about every three hours to pick up 24 passengers. These passengers are 20 litre water samples recovered at 24 discrete depths from the sea floor to the surface. Our deepest sample lived at 5697 m and it took about 3 hours for our sampling device to reach it. The device in question is called a CTD– Conductivity, Temperature and Depth– after its principal sensors, and consists of a rosette, or frame, carrying 24 bottles of 20 litres each.

CTD sampling at sunset (image: N. Beaulieu)

Every team gets to collect some water from each bottle; my role is to filter my allocated water through 55 µm (0.055 mm) stainless steel meshes and sometimes onto 1 µm (0.001 mm!) polycarbonate meshes, so that I can measure the microplastics left behind.

However, there’s a catch. Microplastics are everywhere. They come in the form of fibres, fragments, airborne particles, and so on.  Look at the composition of your clothes right now and it is highly likely they are a mixture of cotton and plastic or even 100% synthetic material, and are constantly shedding fibres. This is a problem when sampling for microplastics: how do you know that what you find comes from the water and not your t-shirt?

CTD microplastic sampling (part 1): The 55µm mesh is enclosed in the cylinder at the end of the tube, and gravity pulls water through into the carboy (image: N. Beaulieu)

For the 55 µm filtering step, it is easier to protect my sample from contamination. All I need to do is connect a tube to the 20 L bottle and let the water flow through an enclosed casing which contains my 55 µm mesh. The pore size of the mesh is large enough to then let gravity do most of the work and pull the water through. The water coming out is collected in containers so that I can calculate the exact volume filtered.

Unfortunately, gravity stops being a sufficient ally when it comes to pulling water through a 1 µm mesh. The pore size is simply too small for it to work and I need a vacuum pump to force the water through. This is when it becomes tricky. Usually, the water collected would be poured from the container into an open beaker which is connected to the vacuum pump via my 1 µm mesh. This just won’t do for microplastics as pouring and open containers means airborne particles could very easily accumulate on the water’s surface and skew my results.

CTD microplastic sampling (part 2): The water is pulled out of the carboy by a vacuum pump (not in picture) into the beaker (orange cap) via 1µm mesh. The waste funnel in the back corner is to calculate volume (image: N. Beaulieu)

This is when I switch from being a detective to an engineer. Or in my case, ask Howard the engineer to come to the rescue! He helped me construct a system where I can connect my container directly to the filtering pump. No exposure to air required!

There are many additional precautions that need to be taken too. When I packed for this cruise I made sure to only take 100% cotton clothing. My equipment needs to be kept inside a laminar flow hood ,which is a semi enclosed unit with filtered air flowing through it. And filters, petridishes, filtering equipment, tubes, etc. need to be regularly acid washed.

So that’s a brief description of my job on the ship; by the end I’ll have filtered over 2 thousand litres of water!  The next step of detective work will come back in the lab on dry land. I will examine my filters under a fancy infra-red microscope (Fourier Transform Infra-Red (FTIR) Spectroscope) and hopefully bring the invisible into the spotlight.

Sunrise watch

by Yvonne Firing

Pre-sunrise CTD water sampling, with Olga ready to log the samples as a bit of colour appears in the sky (image: Y. Firing).

Now that we’re two weeks into the cruise, we’ve all settled into the routines that go with round-the-clock CTD stations.  Part of conducting science at sea is deciding on the watch rota: who will be principally responsible for each aspect of data collection at different times throughout the day.  Cruises generally mean 12 hours at work each day (with breaks, of course!).  Some groups prefer straightforward 12-hour watches, others an 8-on, 4-off, 4-on, 8-off schedule, while others organise three 8-hour watches with flexibility in the remaining hours to make it easier to overlap with personnel on different schedules.  The physics team on JC159 has adopted the last approach, and as a morning watchstander, I have to admit that waking in the early hours to start work at 4 am takes a little getting used to–and then a little more each time we shift the clocks forward to keep up with our eastward progress.  But the sunrises more than make up for the early start!

Even the CTD rosette is taking on sunrise hues … (image: Y. Firing)
… and finally, the sun! (image: O. Sato)
Between CTDs it can be easy to forget to look up from the computer screen, unless a strange glow through the portholes catches your attention … (image: Y. Firing)
… a glance outside revealing pink sky, and pink sea, and pink ship (image: Y. Firing)



JC159 Week 1: RRS James Cook visits Rio

by Jack Giddings

Berthed right next to the stunning tropical scenery of Rio de Janeiro, the crew and scientists onboard the RRS James Cook were busy preparing for the next 6-week cruise across the South Atlantic. There was no time to waste. Shortly after stepping off the plane, heavy boxes were unloaded, lab equipment set up and computer fans whirled into life, ready for the hundreds of samples that would be collected across the width of the Atlantic down to its deepest depths. For the nutrients, CFCs, carbon and oxygen teams, a lab’s worth of equipment had to be connected and calibrated ready for the influx of new samples. For the Argo float team, all eight floats were tested to guarantee sufficient satellite communications and functioning external oil and air bladders. For micro-plastic research, creating a zone free from air-borne contaminants was no easy task; it turns out there are plastic fibres everywhere in our environment. To ensure the airborne plastic doesn’t contaminate the sea water samples, all surrounding surfaces were cleaned, static plastic sheets were draped around a work space to attract synthetic fibres from the air, and scientists must wear all-cotton clothes.

Rio from on high (image: Jack Giddings)

But it wasn’t all frantic preparation or last-minute sensor calibrations. The science party managed to venture into the sun-soaked sweat-box that was Rio, exploring the must-visit sights the city has to offer. Of course Copacabana was on the check-list, with some eagerly swimming in the warm(ish) waters of the Atlantic. Some ventured up to Christ the Redeemer, which provided breath-taking panoramic views over the city from Ipanema to Downtown Rio. And obviously one couldn’t resist a refreshing cocktail on the beach to end the day, soaking up samba music and the local hubbub.

The Museum of Tomorrow and downtown Rio (image: Jack Giddings)

Before we set sail, all scientists were invited by the Ambassador of the UK to Brazil and the President Director of the Museum of Tomorrow to attend a cocktail party. The event, celebrating the pre-launch of the UK-Brazil Year of Science and Innovation 2018-2019 was held in the futuristic Museum of Tomorrow. Several speeches were made during the event, from the Brazilian Minister for Science and Technology to the UK Ambassador for Brazil himself, many reiterating the importance of scientific research and international collaboration. It was a reminder for all the scientists onboard the ship that the measurements recorded during this cruise will play a vital role in climate simulations that will improve future projections of a warming world. This motivation will spur future expeditions across the South Atlantic within the next decade, gradually building a picture of how sensitive this part of the ocean is to our changing climate.

As we steamed out to sea we caught a last glimpse through the clouds of Rio’s famous statue of Christ the Redeemer (image: Yvonne Firing)

A couple of days into the cruise, the first several stations have been sampled across the shelf edge off the coast of Brazil. After a very chaotic round of water sampling from the test CTD on day one, everyone is finding their feet and settling comfortably into their shift patterns. More updates will follow.


JC159 is a UK GO-SHIP cruise on the RRS James Cook, from Rio de Janeiro, BR to Cape Town, SA. This research cruise is contributing to the ORCHESTRA and TICTOC research projects, which aim to improve our understanding of how the ocean absorbs, moves, and stores heat and carbon in order to better predict its role in the global climate. To do this, we will measure ocean properties (hydrography) through the full ocean depth along latitude 24S across the Atlantic. These properties include ocean temperature and salinity, which themselves drive ocean currents; dissolved gases, nutrients, and carbon that interact with ocean biology; and tracers such as CFCs and carbon isotopes that tell us where the water came from and how long it has been since it was exposed to the atmosphere.

Dissolved oxygen content on the 2009 occupation of the 24S section (graphic: D. Stephenson)

Our team, led by the National Oceanography Centre (NOC), and including scientists from the British Geological Survey, University of Exeter, Imperial College London, University of Namibia, University of Sao Paolo, University of East Anglia, Autonomous University of Baja California, and Roscoff Biological Station, will be repeating a set of measurements last made here on cruise JC32 in 2009.  By combining the JC159 observations with three other sections (SR1b, ANDREX, and I6S) bounding the South Atlantic that will be occupied over the next year, we will be able to quantify the inventories of heat and carbon in the South Atlantic; how they relate to ocean transports into and out of the region and to exchanges between the ocean and atmosphere; and how they are changing over time.

This blog will feature posts by a number of people involved in JC159.  If you have questions about the science or how we do our science at sea, please email  You can also follow us on twitter: @jc159_24s.