All fieldwork

Did you know, as we float atop the waters of the Subtropical North Atlantic, we also sit on layers and layers of ocean from all over the globe, and that these can be decades old? The ocean here is around 4 kilometres deep, with different layers having originated in different places and made their way here by deep convection – the process by which mixed surface layers of the ocean travel to it’s interior. In this way, a water mass’ ‘age’ refers to the last time it was in conta

Today started as any other; a 2300 alarm, an apple from the galley, and a rendezvous in the main lab to prep our CTD cast (if you missed it, here’s a CTD 101). But today was an exciting CTD as I fired my own bottles! By which I mean, I pressed the button at the correct time at the correct depth 24 times, but it was a big moment for me. I again took all the samples I need - another 50 litres (10 litres per depth from 5 different depths) filtered through 0.2 micron mesh for gen

For me, the most exciting moment of a cruise is the moment the first CTD hits the surface of the water. The second, a few hours later (if you’re lucky!), is the moment the first samples hit the -80 degree Celsius freezer. This means my sampling is well and truly underway, and we’re on our way to answering some of the big questions we have about the ocean and the Earth as a whole. This happened today at 0100 hours. We typically meet in the ship’s main lab about half an hour be

Let’s talk about the triangle of filtering. Just to make sure we’re all on the same page, when we talk about ‘filtering’, we are talking about pushing litres of seawater through a very fine mesh. And what’s key here is that, at least in my case, what I’m interested in is what stays on the filter. The water produced just runs back into the sea, but what doesn’t fit through the pores is what we’re here for: tiny, microscopic phytoplankton that live in seawater (about a million

Today is the day! My fourth research cruise and my first to the Bermuda Atlantic Time Series. After a quick dip in the harbour to make the most of our last opportunity to be in the water for the next week, I packed myself up and boarded the R/V (Research Vessel) Atlantic explorer. After a few last-minute checks and a little unpacking, I headed out to the middeck to wave goodbye to our colleagues on the shore. At 1200 hours we departed, heading out through ferry reach to the w

Saturday morning rolled around, bringing with it a change of scenery as today was the first day I stepped aboard the R/V (Research Vessel) Atlantic Explorer, BIOS’s research ship. I met Rod, chief scientist of this cruise and PI of the Bermuda Atlantic Time Series on board in the morning, and had the pleasure of meeting many of the BATS and AE techs and scientists over a delicious lunch prepared by the ship’s chef, Dexter. Alongside the regular BATS sampling and my own sampli

This week has been exceptionally sunny and calm for a March in Bermuda and so, determined not to let it go to waste, we decided to head out on BIOS’s dive boat, the Rumline, to do a little pilot sampling to test methods ahead of my first cruise aboard the R/V Atlantic Explorer later this weekend. The boat was heading out anyway with a group of undergraduates here for a ‘spring semester’, so another member of Team Microbe and I tagged along, carboys and cool boxes (for sample

With all this snorkelling, boat days and sunset cruises, you must be wondering, when am I actually going to do some work? But fear not, for I have (believe it or not) been working away during the trusty 9-5 to ready everything for our first expedition. This cruise is different from others I’ve been on since I’m going ‘alone’ (ie, not with anybody working on my same project), it’s testing my organisational and experiment planning skills to get everything ready. Doing science a

Well hello there! You’ve stumbled across a special entry to my DPhil (PhD) diary, which is the first time I write to you from the Bermuda Institute of Ocean Sciences , a marine research station nestled in the subtropical North Atlantic, in the middle of the Sargasso Sea, on a little island called Bermuda. If you’re here deliberately, I hope this blog, and subsequent entries, is everything you dreamed of (hi mum!!). If you’re here by accident, then welcome to a glimpse inside

'Drifting over the Lake District in an airship at a height of 3000 metres and trying to drop a rock onto a barn roof. At night' ~ Chief Scientist Professor Jonathan Sharples Those are the words used by the Principal Scientific Officer of research cruise JC275 (CarTRidge) to describe our expedition across the south Atlantic Ocean in the austral summer of 2025. In fact, he is referring not to the terrestrial mountain range in north England, but rather to the divergent plate bou

Today was definitely the craziest day we've had so far - and on a Sunday too. Alarms went off at 02:45am, which is feeling pretty normal by now, and we headed down to the main lab to watch the CTD profile as it went down. Whilst my filters were filling (15L per line takes me about 1.5hours), we filtered samples for SEM, which will allow us to visualise, count and identify our plankton to get an idea of their diversity and community changes over physical gradients. Having snap

The first of March brings with it an Aquarius moon (according to my moon journal!), the beginning of  meteorological spring, and, for these eager scientists - our first pre-dawn CTD!! Standing in the main lab at 02:59, we watched the profile as it descended to about 300m (a veritable 'dip' compared to its 6km capability) and returned with its bounty - 24 20L Niskin bottles filled with water from various depths through the profile. Not only this, but we were treated to a displ

Yesterday we transited to our ‘ridge’ site – almost time to test our theory of increased productivity on the mid-Atlantic ridge! We used the afternoon to host another mini-conference of science talks – and today was my turn to present. It was a really supportive and curious atmosphere and, though it was only a 10/15 minute talk, sparked much discussion afterwards. While we’re here, I’ll take the opportunity to tell you a little about my PhD. My focus is marine phytoplankton a

Another dawn CTD, but this time a full run-through, enabled us a dress rehearsal for our long-anticipated pre-dawn. Sampling went off without a hitch (surprisingly there is not a huge amount of competition for sampling at 0400!), and while my samples were running I decided to embark on a DIY project to see if I could optimise my filtering set up. As a minimum I have 12 samples to do at a time, and only 6 lines on my inline peristaltic pump set up, so I wanted to try my hand a

Today brought with it our first CTD! Through we weren’t looking to sample our full smorgasboard of filtering delights, it was very exciting to see that depth profile for the first time on this cruise, and allowed us to do a number of tests through our respective rigs to get a feel for filtering speed and biomass. ‘Filtering’ is not actually as straightforward as it sounds – there are a number of factors at play and it’s important to find a happy medium to get high quality sam

Today was an exciting day because it was the inaugural meeting of ‘espresso club’ – aka, Team Plankton meeting outside the ship’s coffee room at 0400 to begin the gradual shift to our 0300 starts (we still had a couple of time zones to go at this point). Making the most of the bonus hours in our day, we decided to take the opportunity to get our FIRST DATA – even if not from this cruise. The JC273 team had left us a couple of trays of chlorophylls in the hold, which we measur

Today began encouragingly with a rainbow over the back deck, and the first order of business: building deck incubators. A deck incubator is essentially a paddling pool for sample bottles – we cover them with blue light filters (like you might find in a theatre) and pipe through underway water from below the ship – thus maintaining ambient light and temperature conditions you might find a few metres below the water’s surface. With the help of Grant (Chief Petty Officer, Scienc

Not a huge amount of science was done today - everyone gets a day of grace to adjust to the ship's movement, which leaves most feeling at least a little groggy - but let me tell you a little about the experience of leaving port. We headed out to the front deck where we had the optimum view. When you leave a big port like Rio you get a 'Pilot' - someone who knows the way and comes up to the bridge to guide you out. He came on around 0900 and we were off. We sailed past many of

Our containers arrived which means not only do we have equipment but, in our case, we now have a lab. One of my most asked questions is whether the labs are built in to the ship and the answer is yes, many are, but some are also built into shipping containers which can be mixed and matched according to the needs of the specific expedition. That called for a 0500 start today, which was easy due to the excitement we all felt at finally getting going, and all hands on deck (now

Come along with us on our trip from Rio to Namibia via the mid-Atlantic ridge looking at the role microscopic photosynthesisers play in absorbing carbon from our atmosphere and storing it away in the ocean depths. Hello! If you're new here, I'm Ari, a  PhD student  at the University of Oxford, an avid  science communicator   and video reporter/producer for  New Scientist . I'm about to embark on my second research cruise, for the expedition that will provide me with the bulk