Here are some of our memories of 2017 in picture form – we hope they reflect what a great year 2017 was for new data (phosphate) and extension of our multi-decadal time series.
Happy holidays from the PAP-SO team!
Here are some of our memories of 2017 in picture form – we hope they reflect what a great year 2017 was for new data (phosphate) and extension of our multi-decadal time series.
Happy holidays from the PAP-SO team!
On the 28th of April the last sampling at the PAP-SO finished with a zooplankton net and then the RRS Discovery set sail back towards the UK.
The cruise was a great success with all of the expedition aims met and 108 stations sampled in 13 days, an impressive amount! Stations are recorded every time a piece of equipment is deployed over the side of the ship with the general rule of ‘if it got wet, it’s a station’. This rule is used as not all deployments are successful but this cruise had a great success rate of more than 95 %. The PAP-1 and PAP-3 moorings were successfully deployed and recovered, the bathysnap frame was successfully deployed and a whole host of other scientific sampling and experiments were carried out as has been detailed on the blog these past few weeks.
The PAP-1 buoy being deployed. It floats on the ocean surface for a year recording data and sends it back to land via satellites
We had to leave the PAP-SO site by the evening of the 28th as the Captain had warned that the weather forecast predicted we were in for a bumpy transit back to land. This meant lashing down boxes and securing all lab equipment for the journey until it was time to start packing up. The transit to Portland took about two and a half days but luckily the large waves and rocky weather was mostly finished by Sunday!
At the end of a research expedition it is tradition that a ‘cruise party’ is organised to allow everyone to have some down-time after working for 2 and a half weeks without a day off and to celebrate a successful cruise. On Saturday evening everyone met in the bar to socialise, have our two drinks and we were treated to a surprise jamming session from Rob, Morten and Richard!
Rob Young (left), Morten Iversen (middle) and Richard Lampitt (right) played Hotel California and other classics, a mix of country songs and Richard sang Wonderful Tonight by Eric Clapton.
Another cruise tradition is to have a team photo at the end of the cruise up on the foredeck with the Captain.
First team photo with the Captain. From left to right: Rob Young, Chelsey Baker, Ken Buesseler, Meg Estapa, Luciana Genio, Corinne Pebody, Katsia Pabortsava, Noelie Benoist, Miguel Charcos Llorens, Sue Hartman, Richard Lampitt, Nick Rundle, Joe the Captain, Kev Saw, Brian Bett, Lenka Nealova, Claire Laguionie-Marchais, Christian Konrad, Morten Iversen and Andrew Gates
Team Photo Round 2 with the addition of Claire Evans, Jessica Song and Jennifer Kenyon
We are now back on dry land in Southampton with lots of unpacking to do, but on a more exciting note, we also have many samples to analyse, data to collate and explore, and many questions about the ocean, such as how processes work and how they are changing, to be answered! The research cruise was great fun, very productive and a resounding success due to hard work from the crew, the scientists, the technicians and engineers, as well as Richard the Principle Investigator, who organised the daily activities and made sure that everyone achieved their research aims during the cruise. A big thanks to everyone on board for making it a great experience and an enjoyable cruise.
Do you want to know more about this cruise, oceanography in general, or life at sea? Leave a comment or tweet us and we will answer your questions.
We hope you have enjoyed the blogs and we’ll be back next year. See you in 2018!
Author: Chelsey Baker
One year ago, I started the project LO3CATed – Larval Occurrences in Open Ocean: Connectivity studies in the East Atlantic and Mediterranean – in the frame of a Trans-National Access to Fixed Point Open Ocean Observatories (FixO3-TNA). This project aims to obtain observations of deep-sea larval distributions and settlement at bathyal and abyssal depths across the North Atlantic biogeographic region, encompassing the Mediterranean Sea. Obtaining direct observations of larval abundances and distributions in the deep sea is extremely challenging due to the small size of larvae coupled with haphazard sampling in space and time of a vast and complex fluid environment. Within FixO3, I am using a network of mooring arrays to obtain long-term samples using a modular sampling device that includes passive larval tube traps attached to a settlement frame containing experimental colonization substrates. We chose three biogenic substrates – wood, bones and shells – that mimic common habitats found in the deep-sea benthos, such as wood and whale falls, and also cold-water corals, which typically have fragmented distributions and potentially serve as steeping stones for species dispersal over wide geographical distances.
Figure 1. LO3CAted modular sampling device.
As I joined the Porcupine Abyssal Plain cruise DY077, I had great expectations because I was going to collect samples from the first year deployment. During the PAP cruise DY050 in 2016, the LO3CAted frames were clamped to the PAP3 mooring and placed at 2997m and 4777m depths, the latter being approximately 55m above the bottom, above the acoustic release. This release is placed at the bottom of the mooring and an acoustic signal is sent when we want to recover the mooring, detaching the cable from the anchor. Therefore, the traps and other sensors have to be placed within a safe distance above it. Because the PAP3 mooring is used as a continuous time-series study of particle flux into the ocean, a new mooring had to be assembled and deployed before the old one was recovered. So my first tasks onboard were to prepare the substrates to put inside the settlement frame, and the solution that is used as a DNA-fixative in the larval traps (salt-saturated Dimethyl sulfoxide, DMSO). Since I started this project I gained a wealth of other skills and experiences, some of them most people wouldn’t think are part of a marine biology job. This includes building PVC prototypes in a workshop and sewing net baskets with bones inside!
Figure 2. Sewing bone baskets
PAP3 mooring was successfully deployed with two sets of LO3CAted frames attached at 2960 m and 4730 m depth, similar to the mooring array deployed one year ago. A few days later, I finally recovered the frames from the old mooring. At a first glance the substrates looked very clean and intact, and I couldn’t see any signs of animals (metazoans) colonizing the substrates. But as in other fields of oceanographic research, we don’t get to see the data until were are back in land. The substrates were preserved in various different ways (ethanol, formalin and frozen at -80˚C), so when I go back to the lab I can analyze them under the light and scanning electron microscopes and use genetic tools to investigate the microbial community forming biofilms on the substrate surfaces. Also the DMSO-fixed larval samples will be sorted under a stereomicroscope to search for minute (less than 300 micrometers) invertebrate larvae and other zooplankton.
Figure 3. Recovering colonization substrates
Although these results felt slightly disappointing, it’s still premature to draw any conclusions from a single-point collection. We know that several benthic deep-sea species develop through an upper ocean larval stage, but we don’t know where in the water column most of these larvae live, for how long and at what depths. And we also suspect that many of them may stay closer to the sea bottom where they can more easily find their natural habitat. So during the PAP cruise this year, we also deployed larval traps and wood substrates attached to the Bathysnap camera frame that will stay at the seafloor for the same period as PAP3. With these experiments we’ll be able to compare samples from just a few meters above bottom (ab) to the ones in the water column (50-100m and 1890m ab). Also, PAP moorings are equipped with a series of other sensors that will provide us with data on various physical ocean parameters, such as salinity, temperature and current flows, which will help us understand the environmental conditions driving different microbial and metazoan communities.
Figure 4. Bathysnap with the larval trap attached
The results obtained from PAP Sustained Observatory will be compared with data collected from three other FixO3 sites (ESTOC, CVOO and PYLOS), and the Nazaré Canyon mooring (MONICAN01). LO3CAted results will provide new insights into spatial and temporal patterns of larval assemblages across geographic and depth gradients, advancing the existing knowledge of biogeographic distributions and connectivity of deep-sea metapopulations. This information will be useful to comprehend the resilience of marine organisms and habitats to natural and anthropogenic disturbances, and to inform stakeholders and decision-makers on science-based options for management and conservation.
I am extremely thankful for the opportunity to join the PAP DY077 cruise and work directly with such an experienced team of scientists and technicians that were so supportive and insightful throughout the whole trip. In addition to the work on my project, I had an amazing time with the benthic team processing megacore and trawl samples, and I also learned from many other activities onboard with various instruments for studying the water column. I couldn’t be more pleased to be part of this incredible research environment contributing to the global understanding of our oceans.
Author: Luciana Genio
One of my highlights at the PAP-SO is net sampling. We use the WP2 net to capture meso-zooplankton at midnight and at noon. Zooplankton are small drifting animals that prey apon the tiny phytoplankton, (small plants) that also drift in the shallow waters of the world. We collect at noon and midnight because we see different animals and different numbers of animals at opposite ends of the day. Many zooplankton swim up to shallow water at night to feed, then sink down to deeper water at dawn. In this way they avoid many of the visual predators that can see them in daylight.
We lower the net to 200m and haul it up again to take a vertical profile of the zooplankton. The metal ring holds the net open and allows the water containing the plankton flow through to the collection device on the bottom (called a cod end) and a weight underneath helps the net to sink down and hang straight and open on the way up. The net needs to be hauled up at a steady rate so the zooplankton don’t swim away and avoid being caught, but not so quickly that it damages the animals caught in the cod end.
Once on deck, the contents of the net are emptied into a bucket, so we can examine the catch. We rinse down the net and then empty the rinsed animals in too. Some of the animals are so big we can see them with the naked eye, some are so small that we need a microscope to see them.
We then use sieves to sort the animals into size groups. This picture is of the 2mm sieve where we can see some of the larger animals.
Black square – A copepod with bright orange colouring.
Black circle – An amphipod can be clearly seen.
This is a picture of Clio pyramidata which we caught in the net. It is a very beautiful snail with a transparent shell and it swims in the near surface waters. You can see the soft body parts inside and the wings that it uses to swim through the water (although they have retracted inside the shell on capture). These amazing molluscs are just one of the intriguing animals that we come across. We are still learning lots about how they feed and move through the water.
Critically, we are studying how they are a part of the biological carbon pump that enable the oceans to absorb much of the carbon dioxide in the atmosphere. Getting to look at both the actual animals and their important contribution to our planet, is to me, a summary of our cruise; the beauty and utility of our oceans continues to amaze me.
Author: Corinne Pebody
In 1983 Professor Richard Lampitt, the Principal Scientist on this expedition, published a scientific paper in the journal Deep-Sea Research about a new camera system for observing the seabed. That camera system was called “Bathysnap”. It was a time-lapse camera complete with current meter that could be deployed in deep water. It provided new insights into deep-sea ecology from the very start; the foraging behaviour of a species of deep-sea shrimp was reported in that first paper. Soon afterwards David Billett and Richard used bathysnap photography to show accumulation of organic detrital material (phytodetritus) on the seabed. This demonstrated the significant flux of carbon to the seabed – an important moment in increasing our understanding of carbon cycling and deep-sea ecology. Subsequently, such accumulations were shown to enable large increases in the abundance of a number of seafloor animals, in particular a sea cucumber called Amperima.
Bathysnap has been in use ever since. In normal service it takes an image of the seabed at the Porcupine Abyssal Plain every eight hours between the expeditions to PAP. Each expedition it is recovered to the surface, the data downloaded, and it is returned to continue its work. Over the years Bathysnap has changed to keep up with technology. Today Richard looked on as we deployed the latest incarnation of Bathysnap to continue its important role in the Porcupine Abyssal Plain Sustained Observatory time-series monitoring of the seabed.
As I write this post Bathysnap is sinking to the seabed 4850 m below RRS Discovery. We eagerly await its recovery this time next year and the new insights into life and processes on the deep-sea floor at PAP that we hope it will bring to the surface.
Blog post by Andrew Gates.
It’s our second to last night on the Discovery and we are all racing to finalize our sample collections, write our end-of-expedition reports, and pack up our equipment to leave the ship. Now that the Discovery has started to feel like home, the rush to wrap things up certainly feels strange!
Along with my sea-bag containing my oldest, crustiest t-shirts and my foul weather gear (the real essentials!), I will be sending home a set of samples that I hope will yield a trove of information in the months to come.
During our expedition my colleagues and I deployed three different types of sediment traps to sample the particles that sink out of the surface ocean to feed the life on the seafloor. Kev already described the PELAGRA traps in detail as well as the US-designed neutrally-buoyant sediment traps (NBSTs). We used these traps to gently catch sinking particles in jars full of a syrupy gel that preserves the shapes and sizes of the particles. After returning home, I will take close-up images of the particles in the gel in the hopes of estimating the size, identity, and carbon content of those particles.
While they are many thousands of times larger than the particles were are catching in our gel collectors, the leaves that fall from deciduous trees in autumn are a nice analogy for the sinking “marine snow” particles of interest here. Imagine that you are taking a walk through the woods during the autumn – after fallen leaves are blown about by the wind and pile up on the ground, it can be difficult to tell what kind of trees they came from, where they might have blown from, or how old they are. In the ocean, gel collectors carried about by PELAGRA traps or NBSTs, in effect, gently snag those “leaves” before they become an unrecognizable mess. When we look at them, we can more easily tie the particles back to their biological and physical origins. Pretty neat!
All the pictures below show particles that are a few millimeters across!
Aggregates of sinking material like the one shown to the right can be created in the water when sticky biological particles “bump into” and adhere to one another. Gel collectors are nice because they keep new aggregates from forming or breaking apart after they fall into the sediment trap.
Author: Meg Estapa
Hi reader, I’m Jen—a first year graduate student from Woods Hole Oceanographic Institution in the US. This is my second research expedition and my first time ever visiting the UK! I came on this expedition as an extra set of hands, but also so that I could become immersed in the fascinating world of Thorium chemistry. As Morten, a fellow scientist onboard, says to me every day, “Are you excited yet? You get to do Thorium chemistry today!” Coming into this expedition I knew very little about Thorium chemistry, but leaving this expedition I feel that I know enough to briefly explain to you what “Thorium chemistry” actually is (after all, I’ve had to help process roughly 200 samples).
Why we sample
Our team looks specifically at Thorium-234 (234Th), a radioactive isotope of Thorium with a 24.1 day half-life that is produced as a daughter product of Uranium-238 (238U) decay. Thorium is particle reactive, and “sticks” to particles as they sink down in the water column. Using 234Th’s half-life, we are able to calculate how much and how fast particles are moving in the water column—or in other words, we can measure the flux of particles into the seafloor.
Measuring 234Th throughout the water column can give us insights into ocean processes, such as biological uptake of nutrients, remineralization of Carbon, and more. However, if you’ve been keeping up with the blog you will have figured out by now that the use of sediment traps is an important part of this expedition. Using 234Th measurements, we can calculate the efficiencies of different sediment trap types—which is our main purpose for Th sampling during this expedition.
How we sample
We collected 234Th in a variety of different ways. The bulk of our samples are collected through a CTD rosette (pictured above). Through in-lab chemistry, we can add a precipitate to the collected water samples. 234Th sticks to this precipitate and allows us to extract it from the water sample. We then filter the samples, dry them, and process them through beta detectors (see picture below). We do this at regular increments throughout the water column in order to develop a 234Th profile (see graph). In equilibrium, the activity of 234Th (dpm/L) is equal to that of its parent isotope, 238U. If these values are not equal, we can deduce whether or not 234Th is sinking down to the seafloor. 238U is a conservative element, which means that its value does not change throughout the water column.
We also collect Thorium samples from the PELAGRAs, NBSTs (neutrally-buoyant sediment traps), surface-tethered traps, and in-situ pumps. These samples do not require chemical processing, but are similarly dried and measured using beta detectors. For more information on the aforementioned sediment traps, please see Kevin’s previous blog post on PELAGRA or stay tuned for Meg’s blog post tomorrow on gel traps.
Although the expedition is coming to its end, our Th story is just beginning to unfold. Now that data collection is over, we can begin to analyze and interpret what our data shows us.
From my perspective, this expedition was an awesome experience to learn—not only from the new world of Thorium that I have entered, but from the diverse array of hard-working and thoughtful scientists on this vessel.
Author: Jen Kenyon
Pelagra sediment traps carry out a similar role to the moored sediment traps that Corinne has described earlier. They differ though in that they drift freely with the ocean currents whilst catching falling sediments for just a few days rather than being moored in a fixed position for a year.
A potential issue with a moored sediment trap that is static in the water column is turbulence caused by ocean currents that flow horizontally across the trap opening. This turbulence is thought to lead to sampling biases that may prevent some particles of certain sizes or densities from ever entering the trap. The Pelagra traps overcome this by drifting along with the ocean currents and thereby eliminating any horizontal flow over the openings.
The name ‘Pelagra’ is an acronym derived from the full title ‘Particle Export measurement using a LAGRAngian trap’.
The Pelagra traps are carefully ballasted such that their density matches the in situ density of the water column at the depth of interest. This depth can be anything up to 1000 m deep. They are deployed from the ship using an on-board crane and released to sink freely to the intended depth where they stabilise to become neutrally buoyant. Any deviations from the intended depth are countered by small incremental adjustments of the buoyancy engine. The buoyancy engine pumps oil in and out of a flexible bladder and by so doing alters the volume of the trap and hence its density.
Each Pelagra trap carries four particle collection funnels and under each funnel is a collection cup that can be moved in and out of position below the funnels at pre-programmed times during the mission, thus the precise collection period for each funnel is known. Once stable, the collection cups open and the traps drift freely for a programmed period of a few days or so collecting falling sediment or ‘marine snow’ as they go. At the end of the deployment the cups are closed, an abort weight is dropped and the traps ascend to the surface for recovery. Recovery is aided by GPS positions sent to the ship via satellite, a flashing light for spotting at night and a high-visibility flag for daylight hours.
One objective of this trip is to carry out comparisons with similar neutrally buoyant sediment traps (NBSTs) that a team from Woods Hole Oceanographic Institute in the US have brought along with them. The first deployment of all four Pelagras that we have brought with us was less than perfect with two of the traps failing to descend to the required depth of 200 m and re-surfacing early, thus collecting no samples. The failure was due to an error in ballasting that meant the traps were too light. This came as a sharp reminder of how tricky it can be to ballast a 150 kg instrument to within a few grams. The other two did manage to stabilise at their programmed depth of 350 m and some good samples were collected.
This is my second time at PAP, and the excitement and challenges are always driving me towards new discoveries and appreciation for my work. As part of the benthic team, we all got our hands (and faces) very muddy. The last blog article about the megacore sampling is a good example. Nevertheless, this is not much in comparison to all the mud we recovered from the trawl net.
Last Saturday evening, a wide Otter Trawl Semi-Balloon was launched over the RRS Discovery for a few hours of bottom trawling in the abyssal plain, almost 5000 m below the surface of the ocean. The net was tied to the vessel with about 14 km of cable wire. Once it reached the seafloor, the ship slowly steamed from west to east for roughly 4 hours to collect large specimen living on the seafloor. The whole process lasted for approximatively 12 hours, including the descent and ascent of the sampling gear. The net was recovered the next morning. Curiosity, and a bit of anxiety, started to rise among scientists, technicians, and the crew. After all, we cannot be sure about the quality or quantity of the catch.
After a rich breakfast to keep our strength up, we gathered on deck to witness the recovery of the trawl net. It took quite some time to bring the gear on board, when it finally slowly appeared from the surface of the ocean. It did look like a giant ball of mud, where several specimens were caught. Once stabilised on board, scientists made use of the fire hose to remove as much mud as possible before opening the net to release the catch in numerous crates. The whole deck was covered in mud, moving back and forth following the rocking of the ship. Specimens were then washed above a large sieving table, and sorted, before being preserved in buckets filled with formalin or ethanol. This is a hard and long process as it involves washing hundreds of muddy animals with filtered seawater, but it was sunny and warm outside, which made it easier.
Similarly as last year, I selected a few animals that I brought inside the lab so I could photograph them, and record their fresh body mass and volume. Later on, I will analyse the photographs to measure the pictured specimen using a computer software, and will convert those measurement into biomass. Then I will compare the photographic results to those recorded on board of the Discovery. Thus, once again, collecting these data is a great opportunity for me to complete my PhD at the University of Southampton, National Oceanography Centre, Southampton.
The specimen collected are well known in the area; NOC scientists come to PAP every year to carry out similar trawling operations for assessing any change in the benthic megafauna community. Specimen collected are mainly see cucumbers, anemones, starfish, sea spiders, squat lobsters, etc. They come in varied shapes, colours, and sizes; the smallest I recorded was a thin spider (0.5 g) while the biggest was the famous purple cucumber Psychropotes longicauda (1220 g). On the other hand, among the animal collected we found several pieces of clinker (on which anemones are sometimes found attached) and garbage including one big shoe, a few glass bottles including an old Listerine mouthwash, plastic bags, etc. A second trawl is scheduled this Thursday evening. Maybe we’ll get to catch different species?!
We have only 2 days of science left on board of the RRS Discovery. Once again, this scientific mission was accompanied by magical moments, such as tremendous sunrises and sunsets, and lots of fun!
by Noëlie Benoist
We know very little about animals living at the abyssal seafloor. However, they are part of important biogeochemical cycles, including carbon cycle. We need to increase our understanding of their functions and temporal variability to predict their fate in the future and how it can influence carbon processes at seafloor.
Larger animals can be collected by trawls or directly observed with cameras. However, most fauna comprises smaller organisms living within the upper most centimetres of sediments on the sea floor. The only way to learn about them is to collect a portion of the seafloor. To do that, we use a megacorer, that consists of height 10 cm tubes and two 7 cm tubes.
Each tube is used for a different analysis: macrofauna (1 to 0.3 mm), meiofauna (< 0.15 mm), foraminifera (protists), environmental DNA (microbes), biomarkers and microplastic contents. We use different protocols to get each of these data. On board, we sliced the cores and preserved it accordingly to what is studied.
Then back in laboratory, scientists analyse the samples. Most laboratory work will consist of observing animals under microscope in order to identify them, to estimate how many species are present in samples collected and how densely they are distributed. Similar data have been collected from Porcupine Abyssal Plain for 30 years now. Therefore data from this year’s cruise will be added to the long-term time series, to assess changes in macrofaunal diversity, density and composition over the time.
The cruise and sample collection is only the beginning…..now the laborious process of sample analysis (which can take several years!) can begin.
Lenka Neal (Nekton Foundation and the Natural History Museum in London)
Claire Laguionie Marchais (National University of Ireland, Galway)