Finishing the cruise – last CTD station and a glider recovery

by Penny Holliday

We’re presently steaming into Reykjavik, finishing off processing some data, and packing our kit up again. There are minke whales and puffins in the water, and the fog that was surrounding us yesterday has finally lifted. Spirits are high because yesterday we finished all our work – we did a last CTD station to complete the section, and recovered a glider that has been spending the last few months running the same line from Scotland to Iceland.

It’s been another great trip on RRS Discovery – everyone has worked hard and cheerfully together and we have got a fantastic set of data, and some happy memories to take home.

Photos by Penny Holliday

Taking Inspiration from the North Atlantic: A Maiden Voyage

by Jason Salt

Participating in my first oceanographic expedition, I desired to better understand the inner workings of the ship and research taking place within. This cruise is an occupation of Extended Ellett Line, a hydrographic section from Scotland to Iceland over ~70 stations. In recent years, this line has also been surveyed nearly once annually also by a Sea glider. These autonomous vehicles profile the ocean in a saw tooth path by changing their density to move through the water column. Wings allow for pitching at different angles can generate lift which can also drive the glider forwards through the ocean. They can be fitted with a vast array of different sensors to measure parameters such as water column transport, chemical composition & ocean fluorescence. The interest of my PhD at SAMS (Scottish Association of Marine Science) lies in using the oxygen concentrations to make estimates of carbon fixing, which can have implications for carbon storage, cycling & also food chain structure and dynamics.

Over the past 2 weeks I have been involved in and observed just some of many the fascinating scientific equipment and techniques used on research vessel at sea. I feel privileged to have been able to assist with the processing of the data, deep sea “mud” slicing & water sampling of depths up to 2700m for later analysis of salinity, nutrient and oxygen concentrations! Alongside this, I have had the opportunity to experience working/living closely with a group of amazingly dedicated scientists, technicians & crew members on a day to day basis. Despite the team working 3 different watches over 24 hours, rarely has there been a dull moment. Daily activities have evolved over the course of the journey as we found creative ways to entertain ourselves. Endeavours have ranged from intense circuit training on the foredeck to playing an intriguing assortment of games in large groups and in the latter stages, solving trivial daily puzzles & anagrams put up in the main lab.

Although we are nearing the end of this adventure there is still plenty ahead to look forward to, of this including the recovery year’s Ellett Line Sea glider, deployment of a final MET office ARGO float & the glorious sight of Iceland in the closing days. It would be careless to not mention the substantial variety of wildlife that have graced us with their presence, including my personal voyage highlight of being surrounded by as many as 60-70 common dolphins as they circled fish shoals beneath the surface. I’ll value the knowledge and experience I’ve acquired from this expedition to invigorate my enthusiasm for studying the world’s oceans and the life within for countless years to come.

Photos by Jason Salt

Passing Rockall and sending two OSNAP gliders off to work our line

by Penny Holliday

Over the weekend we reached two major milestones; the first was finishing the Rockall Trough part of our section, culminating in a drive-by view of Rockall. Getting that part of the work done always brings some satisfaction because it marks the halfway point (one week into a two-week survey). It’s nice to see this strange little rock as we pass by on our way to the next set of stations to the west. I’ve been here many times since I first saw it in January 1996, but I couldn’t resist taking yet more photos…

The second was sending off two OSNAP gliders to do their work for long after we leave the area. Gliders are ocean-going robots that fly though the upper few hundred metres of the ocean collecting information about temperature, salinity and currents as they go. They transmit their data back to us by satellite and build a very detailed picture of the conditions along our OSNAP line. We waved goodbye to one UK glider (which we call Bellatrix), and one US glider that we have launched for our partners at Woods Hole Oceanographic Institute. Today we found another WHOI glider that has been working out here for a few months and brought it on board; from here it will go back to base for servicing and a battery change, before being sent off again later in the year.

Photos by Penny Holliday and Angelina Smilenova

Hunting for treasure on the seafloor

by Paola Moffa Sanchez, Cardiff University

One week after setting off from Southampton I am finally able to look at my computer screen for longer than 15min. I found my sea legs!! For someone who gets extremely seasick on the shortest boat rides, this is a huge achievement. My friends can´t comprehend why I would put myself through sailing for three weeks across the North Atlantic in a rocking boat with my terrible motion sickness. I did also wonder last week: Why did I not to choose to study lakes or bogs instead? There is a simple explanation: the ocean is special and no matter how ill you feel, having the opportunity to be on a research cruise like this one is totally worth it, personally and scientifically!

This is my first time on a physical oceanography cruise. So far, I have met incredible people doing very exciting research and I have gotten to see all the gadgets that get used to measure the properties, chemistry, and movement of waters in the ocean. This is a bit different from my research, where I mainly focus on understanding how the ocean changed in the past and how this may have impacted past climate. To do this we use sediments from the bottom of the ocean, which means the cruises I would go on normally are very muddy. My aim on this cruise is to survey the sediments on the seafloor and find the most suitable ones for extending the recent ocean measurements back in time (to 1000´s of years).

Essentially, is a bit like a treasure hunt. To survey the sediments of the seafloor we use a very clever method, which works on the basis of sending sound to the bottom of the ocean and receiving it back on the ship. This, sounds a little bit like a bird chirp and can get annoying whilst trying to sleep in our downstairs cabins. The sound sent is at a specific frequency, which will penetrate up to 100m into the sediment depending on its properties and tell us something about the sediment and hence the processes involved in the deposition of the sediments and their potential for reconstructing past ocean conditions. This allows us to find the best spots and then send the multicorer down to collect these sediments. So far we had a successful recover at a site that we surveyed and it even came up with a starfish! It must be a sign!

I could keep writing for ages but my watch has already started (16-midnight!) and the CTD will be on the deck soon ready to be sampled!

Photos by Paola Moffa Sanchez

Researching #microplastic pollution in the #deepsea

by Winnie Courtene-Jones, Scottish Association for Marine Science

The deep sea conjures up visions of a realm that is deep, dark and devoid of life, however this reputation is not true. The deep sea is the portion of our oceans off the continental shelf and deeper than 200 m, this makes up a large proportion of our planet (around 80 % of the oceans is classified as ‘deep-sea’) and supports a huge diversity of marine life, including many commercially important species.

The deep sea faces a number of anthropogenic threats, including fisheries, mineral exploitation and litter, especially plastics. Plastic is an extremely durable material, meaning that while it breaks up into ever smaller pieces it does not completely vanish. These small plastic particles are termed microplastics and are of particular concern, as they are bioavailable to a wide diversity of organisms which may eat them mistaking them for food. Indeed over 600 different species have been found to ingest microplastics, and microplastic pollution has been identified throughout the natural world: in terrestrial, freshwater and marine systems, and from sea surface to the seafloor.

It is thought that marine plastics and microplastics sink through the water column and ultimately reside on the seafloor. However, limited research has focussed on microplastic pollution in the deep sea and we do not know, as yet, the quantities of microplastics present in the deep ecosystem, how these may interact with organisms, and the pathways and timescales for microplastics to transit to the deep oceans.

My work broadly focusses on researching microplastics in the deep sea environment, attempting to answer some of these unknowns. I have been lucky enough to sail on the Extended Ellett Line both this year and last year to collect data. Participating in these scientific expeditions is a real highlight for me, I gain such amazing personal and professional experiences. Collecting data on microplastics only takes up a proportion of my time; therefore whilst on board I also assist with chemistry sampling and analysis. While I find this work extremely interesting and insightful, to a biologist (me) nothing can beat being out on deck undertaking and sorting through sediment cores!

It was an early start this morning, long before the sun came up, to deploy the megacore; this takes multiple cores of the sediment via long tubes (similar to an ice core). Once the megacore is brought back on deck, the core tubes are carefully removed, and the sediment sliced into depth sections on board. These depth sections equate to different periods in time and can be dated using various analytical techniques. The sediments were preserved for microplastic analysis once back in on land.

Everyone on board was interested to see the operations and as the night shift drew to an end and the morning shift commenced the fresh faces appeared around the sediment cores offering to assist and curious about the processes involved. The Extended Ellett Line Cruise is such a valuable opportunity to bring together scientists from a range of disciplines, and while everyone’s own research differs, everyone is willing to lend a hand with any task that needs to be done.

A very successful day!

Photos by Antonia Doncila

Rich work and life experiences at sea

by Antonia Doncila, Edinburgh University

Life at sea never ceases to amaze, especially when you are on a research expedition. I am very proud to call the RRS Discovery my home for this month, as we cruise in the subpolar North Atlantic. The Extended Ellett Line transect covers a primary export route of Arctic waters into the North Atlantic and because of that I have joined the team to analyse and quantify the Arctic nutrient exports. In our changing world, the Arctic is warming twice faster than any other region on the planet. This warming translates into melting sea-ice, increasing the freshwater content of the basin and altering the biogeochemical cycles of this ocean. Because the Arctic Ocean modulates the global oceanic nutrient and salt balance, any environmental changes happening here can lead to altered water and nutrient exports into the North Atlantic. These exports exert control on the North Atlantic vertical nutrient profiles, upper ocean mixing regimes and ultimately local primary productivity. That is why I am interested in the nutrient exports from the Arctic into the North Atlantic: to understand how the two oceans are linked and how they will interact in the context of climate change.

But it is not just my work that is exciting. Some of my colleagues deploy devices named moorings across the entire water column in key areas. These will take continuous measurements of water, temperature, salinity and current velocity at regular depth intervals throughout the entire year. After a year, the moorings are recovered and the data collected shows how different water masses travel and interact and how they change their properties on a seasonal basis. Repeating this every year enables scientists to create a timeline which will highlight how the north Atlantic changes over time. The amazing work done on-board doesn’t end here. Some colleagues analyse the oxygenation of the vertical water profile, others look at microplastics abundance in the deep sea while others take sediment cores which are valuable paleoceanographic records. Every day something different happens and even as a scientist, there is so much I have learned during this cruise, simply by interacting with and observing my colleagues doing their work.

Apart from the rich work experiences, this cruise also offers me rich life experiences. Just from gazing at the vast open water and the powerful waves which are rocking our sturdy ship, makes me truly grasp the majestic greatness and strength of the ocean. It is stunning how these cold, restless waters are home to some of the most gracious creatures on earth: the cetaceans. We are now getting to the middle of the expedition and yet I have seen enough whales and dolphins to last me a life-time. It is just mesmerising how they swim so peacefully in the rocky waters, which would be fatal even to the strongest men, in a matter of minutes. Every time we deploy analytical devices in the water, pilot whales or common dolphins come in great numbers close to the ship, surrounding it, curious as to what we are doing. It feels sometimes that they are as much observing us as we are observing them, which can only make one feel honoured.

I wish we had an Ernest Hemingway or a Herman Melville on-board to take onto the impossible task of describing our adventures at sea. Words are simply not enough for me. However, I can certainly say one thing, until we are docking in Reykjavik, in two weeks’ time, it is just us and the open water…and an ocean of questions and lessons to be learned that will refine us both as scientists and as mere human beings.

Photos by Antonia Doncila

Pilot whales …. and we are actually doing some work too!

by Penny Holliday

Since the dolphin extravaganza on Sunday we have actually done a lot of work (and I have the photos to prove it….). Through the days and nights since then we have completed over 20 CTD stations, processing the data from the instruments on the frame, collecting and analysing the water from the bottles.

We’ve had a few hours of down-time due to some high winds and enthusiastic waves, and it looks as though we are in for another break tonight – the pressure is dropping , wind is picking up, the waves are getting bigger. I suspect that very soon it will be too wild for us to continue working, and we will have to heave to for several hours and wait for it to pass.

But the North Atlantic Ocean is treating us to some delightful sights too – a lovely double rainbow this evening, and earlier, a pod of pilot whales came to check us out when we were on station. They spent ages just hanging around and looking at us, and, I imagine, listening to all the clicks and sounds the ship makes.

Photos by Penny Holliday