We are continuing to steam and do regular CTDs along the transect to reach the two northerly stations on either side of the Mid Atlantic Ridge. We have now reached the Charlie Gibbs Fracture Zone (incidentally there was no-one called Charlie Gibbs). Here we are deploying the DOBO Lander Mooring– the Deep Ocean Benthic Observatory. This device is a large titanium frame packed with equipment. DOBO will remain on the sea floor in the CGFZ for one year. It will be recovered by R.R.S. Discovery when she visits the area for further research as part of the ECOMAR project next year. It is designed to collect data on scavenging fish over a period of 12 months by recording the attraction of fish and other animals to bait, in this case mackerel. The frame carries 8 tubes each containing a single mackerel in artificial seawater; the first mackerel is exposed at the start. These are sealed to prevent access by any animals. A stepper motor and controller release a mackerel at predetermined times, i.e. one every 30 days over the period of deployment.

A CCD camera takes photographs illuminated by 2 LED lights. The camera will record for a total of 24 hours over 9 months onto a Hard Drive. It initially records the bait release and then records over varying intervals until the next release in 30 days. The camera records for one minute every 15 minutes for the first 12 hours, then for one minute every 30 minutes for the next 12 hours and finally for one minute every 5 days. The process restarts with the release of the next fish. An ADCP current meter is also fitted to the lander to measure ocean current.

Mounted above the DOBO at a depth of is a MARU pop-up whale listening device. This piece of equipment consists of 2 glass spheres; the bottom one housing a battery and the upper is the recording device and a peizo-hydrophone. It is suspended 42.5m above the seabed and above the DOBO. This is part of an experiment by Henrik Skov a MarEco scientist from Denmark. It will gather data on cetaceans (whales and dolphins) in the CGFZ for one year.

Ballast weights consisting of two iron bars keep the DOBO on the sea floor at a depth of 3688m. In 12 months two releases will be triggered, the weights released and DOBO will float to the surface to be recovered and the data downloaded.

As we were continuing to do CTDs I was assuming that there would not have been a lot of new information to impart. I was not sure when we were to have arrived at the CGFZ so I have prepared a different addition to our life at sea.

Oceanography today relies a lot on new technology, much of which we take for granted and as such we use acronyms for systems we don’t fully understand and which are quite complicated but make our lives easier. Take for example the much-used CTD. We assume that out here in the middle of the Atlantic we can suspend a piece of highly technical and valuable equipment over the side of the ship to a depth of 3700m. That it will reach the bottom of the ocean and be where we want it to be. There are many variables at sea. Wind and ocean currents, which move in different directions and can seriously affect working conditions at sea. If something is suspended over the side the assumption is it will go straight down with a vertical wire. In the past, not so, however, today on ships like the “James Cook” we have “D.P.”

So what is “D.P.” and how does it work?

D.P. stands for Dynamic Positioning- a text book description is ‘ An integration of systems and sub-systems combined that automatically control a vessel’s surge, sway and yaw by means of active thrust’ This means that it controls the vessel’s position and heading using position references by propulsion only.
Most ships, you assume have one or two propellers, the James Cook has 6! There are the two main propellers, which have fixed pitch and variable speed. Also at the rear are two stern thrusters of 800 and 600 KW power. These are mounted across the ship. Forward there are two more propellers, one tunnel thruster of 1200 KW power and a fully retractable azimuth thruster. This one can be lowered below the hull and can turn through 360 degrees. These systems are all designed for maximum quietness, which is also very important for the underwater acoustic systems.
There also 2 High Lift rudders, which improve low speed manoeuverability.

The D.P. system is totally automatic with no hands on control by anyone on the bridge.
All the computer, which controls it needs, is information.
The information it requires is heading input, provided by 2 gyrocompasses;
Position reference provided by gps with differential correction;
Satellite and terrestrial signals
Hydro acoustic position reference
Vertical reference sensor information

With all this information the computer adjusts for pitch and roll and calibrates the ships position to an accuracy of ± 2-3m

There are also wind sensors - sonic anemometers that also provide a live input to the ships positioning.

All in all this sophisticated technology means that equipment that operates on a vertical wire such as CTDs, corers, optical sensors do remain vertically below the ship and if equipment needs to be placed on the sea floor it goes exactly where it should with pinpoint accuracy.

We can do amazing things at sea now but the one element we cannot control is the weather. If it gets too rough to work then we have to heave to and stop.

David Shale

Hello. My name’s Will. I’m one of the marine ecologists on this trip and about to start my PhD at Newcastle University. I’m here to examine deep sea food webs on ocean ridge systems. To do this I’m heading to two very remote locations in the world- East Scotia Ridge (ESR) in the Antarctic and to the Mid Atlantic Ridge (MAR). These sites are very different and have been chosen for very special reasons. The sites on the ESR are hydrothermal vents while the stations selected as part of the ECOMAR programme are areas that are believed to contain none or limited hydrothermal activity.

So, my first stop is here over the MAR with my samples approximately 2500 metres below me. That is the equivalent of 25 football pitches or 7.5 Eiffel Towers. Which begs the question how am I going to get at them? Well, I’m going to be collecting material in two different ways. Firstly with the semi-balloon otter trawl (OTSB) during the first three cruises and secondly the UK’s deep sea remotely operated vehicle ISIS on the final cruise in 2009. These two pieces of equipment will allow me to collect different types of animals. The OTSB captures mobile megafauna that live on the sea floor, and has been written about in previous blog instalments, while ISIS will collect suspension feeders that live in areas that the OTSB cannot reach- mainly attached to rocks and steep surfaces. Once the catch is on board and sorted, a small tissue sample is removed from the specimens, which I will take back to Newcastle for biochemical analysis. This will give me an idea of the position or trophic level of each species within the food web. Ultimately, I will compare the food webs of the MAR (non-vent) and the ESR (vent) to determine the relative importance of chemosynthetic and photosynthetic sources of energy at vent sites under strongly seasonal and very productive waters in the Antarctic, and examine the range of influence and incorporation of chemosynthetic energy into the food-webs of ‘non-vent’ ridge fauna at the MAR.

For now we are still on the CTD transect, heading north, which means no sampling for me. But as the blog has already mentioned there a series of scientists who are currently working around the clock. Andy wrote about the work Jane Read from NOC was conducting in relation to the CTD transect yesterday. So today I’m going to write about the work currently being undertaken by the scientists from Plymouth Marine Laboratory (PML). Their current aim is to collect data that will validate ocean colour satellites. Ocean colour is literally the colour of the sea, which is caused by whatever is in the surface layer that absorbs light. In the open ocean the main absorbing particles are phytoplankton (Fig. 1) or in other words the plants of the ocean. There are millions of these in a single droplet of sea water. So in the upper 100 metres you have a dense forest of phytoplankton which collectively are bigger than the tropical rainforest. Phytoplankton forms the base or foundations of the food web. They capture the energy from the sun and use carbon dioxide (CO2) to produce their own food in a process known as photosynthesis. This energy is passed to the next level when they are eaten by zooplankton and so on up to higher levels of the food web to animals like fish and whales.

Fig. 1 As you can see from the above images, phytoplankton comes in many different shapes and sizes.

The phytoplankton can be observed form space by ocean colour satellites. There are currently three ocean colour satellites that orbit the earth. These are SeaWIFS, MODIS and MERIS (Fig 2). When sunlight shines on the sea a proportion is absorbed by the phytoplankton and some of it is reflected back to these satellites. Each satellite carries a radiometer that can detect sunlight reflected from the sea surface. From this signal the scientists are able to get an idea of the amount (or biomass) of plant life in the oceans. They can compare these satellite images of phytoplankton biomass against sea water samples collected by the CTD rosette (mentioned in Colin’s blog). Phytoplankton plays a crucial role in regulating the earth’s atmosphere. Their role can not be understated as they absorb more carbon dioxide (CO2) from the atmosphere than land plants. Therefore, phytoplankton plays an important part in regulating CO2 concentrations and in turn our climate.

Fig 2 Satellite image taken by MODIS-AQUA over the MAR on 30 July 2007 showing chlorophyll concentration of phytoplankton. Our sample sites are marked by the white boxes.

The guys form PML are also conducting experiments on the photosynthesis and carbon fixation by phytoplankton. Using light, phytoplankton biomass and sea surface temperature, which can be derived from satellite data, they are able to produce global maps of carbon fixation by the phytoplankton and compare this with the experiments that are done on board. Satellite measurements of carbon fixation are being used to monitor the health of the oceans and how much CO2 phytoplankton is drawing down from the atmosphere. These measurements are crucial in understanding the seas role in reducing global warming.

So for me I’m going back to reading scientific papers, books and watching DVDs until I get a chance to start fishing once more! And finally a big HELLO to all my friends and family back home. See you all soon.

Will

PS Did you know that a cod cannot hear the James Cook when she passes 20 metres above it!

We have spent much of today in fog, edging to the northwest, making vertical profiles every 15 miles as we go. The focus for the time being is on ocean circulation. We will gradually be crossing the Subpolar Front, a major boundary between warm southern waters and cool northern waters. Along this boundary flows the North Atlantic Current, a continuation of the Gulf Stream and the supplier of the warm water that keeps the climate of Western Europe relatively mild. The Subpolar Front crosses the Mid-Atlantic Ridge close to the twin east-west gashes of the Charlie-Gibbs Fracture Zone. The valleys also provides a deep connection between the eastern and western basins of the North Atlantic via which deep water of Arctic origin seeps to the west. So the topography of this area makes it a crossroads of the North Atlantic circulation.

Our present route follows the track of an orbiting satellite, TOPEX/POSEIDON, which carries an altimeter able to accurately measure the elevation of the ocean surface. At first glance, it appears that the ocean’s surface is flat – at least, if you look beyond the effect of waves and tides. Of course the ocean is curved because the planet is curved, but this can still be regarded as flat if the surface is not tilted when compared with the direction of gravity. In fact the ocean is not flat and the shape of its topography tells us about ocean currents in just the same way that a pressure chart of the atmosphere tells us about winds and weather systems. When the ocean surface is elevated, the weight of this extra water creates high pressure about which currents at the surface flow in a clockwise direction (in the Northern Hemisphere). As our ship track takes us across the North Atlantic Current, the ocean surface will drop by about half a meter. It’s not much! We can neither see nor measure this directly, but by making our shipboard measurements of currents and profiles of density we can infer the slope of the surface and compare this with the satellite measurements. We will also see the deeper structure that is invisible to the satellite. This comparison is the research focus for Jane Read of NOC, Southampton who is leading this aspect of our work

So for now it’s one profile after another as we slowly piece together a transect revealing the structure of the currents and differing water types of this region. There’s not much to be seen as we push forward into the fog.

Andy Dale
SAMS, Oban

Midnight Position N48º 51.5’ W029º 35.3’

We are now heading towards the northern sites. On the way we will be working a hydrographic section comprising 26 CTD stations. The first station on the section was back inboard at 0142. The section is just over 400 nautical miles long. The casts are roughly an hour and a half apart and the average water depth is 3500m. Terry, Darren, Paul, Jane, Andy, Ian and myself make up the CTD team. We are split into three shifts working four hours on and eight hours off. I’m fortunate, I’m working the 8>12 & 20>24, so I can have a normal nights sleep. The other two watches are more disruptive to normal sleeping patterns and it takes your body clock a while to readjust.
There was a torrential downpour around 5 o’clock just before the 2nd CTD of the day. The working pattern for the next 5 days has now been set, each watch will have a single CTD cast. The St Andrews team have also gone onto a watch system to monitor the EK60 during the transit between CTD stations. Monty, Jessica & Rhys are working on the CTD whilst it’s aboard to prepare a mounting for one of the Oceanlab cameras.
Victor and Gavin have taken extra water from the first CTD after breakfast and performed an optical cast at the same time.
Steve is working on the after deck preparing all the ropes and various other components which make up the two northern moorings. These will be full depth moorings with far more instrumentation than the two moorings deployed at the southern sites. Terry and I will be working on setting up the instruments in between the CTD casts over the next couple of days. In total we have 27 instruments to prepare for the two moorings, an assortment of current meters, temperature/salinity loggers, acoustic releases, sediment traps, beacons & lights.
Nikki & Ben are preparing one of the Oceanlab landers which will be deployed before the end of the section. This lander, as well as all four moorings, will be recovered during next summer’s ECOMAR trip aboard
RRS Discovery.
Mick is not having much success today with the binoculars, all in all a miserable day, no sun at all and visibility is very poor indeed.
Highlight of the day, dinner, even more so on a Saturday, it’s curry night. The ship operates a self service cafeteria system, great restraint must be shown, otherwise it’s down to the gym for payback time.
The late CTD watch passes without incident and then it’s time for bed.

CTD cast displayed in real time on one of the monitors in the main laboratory. Water bottles are closed during the upcast as required for subsequent nutrient, chlorophyll, oxygen & salinity analyses.

The CTD at the start of a cast. The package is lowered on an armoured cable with a central conducting core. The instrument is powered from the ship and the data is sent back to the ship in real time.

Colin Griffiths
Scottish Association for Marine Science, Oban.

The PERG researchers saw an early but exciting morning, the first of two catches hitting the deck shortly before midnight. The faunal profile differed distinctly from the OTSB benthic trawls, the biomass dominated by decapods, but there were also a number cnidarians, a siphonore, minute copepods, amphipods, euphausids (krill), pteropods, cephalopods, and diverse fishes including Argyropelecus hemigymnus (hatchetfish) and Stomias boa (dragonfish). The unhappy face of a recent meal could be clearly seen through the side of one dramatic Stomias specimen!

A few of the fish and an octopus survived the journey to the wet lab, and the most intact individuals were borrowed by freelance photographer David Shale to create some amazing images like those above.

Each catch was sorted into appropriate taxa, weighed, and sub-samples placed in ethanol for genetic and isotopic studies.

The focus on pelagic ecology was continued by the Plymouth scientists, who, after an optical survey, were busy in the chemistry lab and radiation room. Victor used 0.2 micron filter paper to collect phytoplankton from water samples, the pigments and carbon of which will be used in their studies of this region’s primary production.

After filtration, the phytoplankton is further sorted. One method for identifying large phytoplankton ( > 20 microns) is with a flow cam, which is essentially a microscope observed by a computer programmed to record the passage of specific plankton through the image.

Smaller planktonic functional types (grouped by similar ecological characteristics, rather than as species) are identified using a flow cytometer. This machine, commonly used in medicine for studying leukaemia and other cancers, fires one wavelength of light into a fluid mixture and classifies the suspended particles based upon how the light is scattered and which wavelengths, if any, are emitted.

The hydrophone is back in the water, and though today did not produce many cetaceans, there was some interesting offshore bird behaviour observed. Some northern fulmars (Fulmarus glacialis) were seen feeding on a group of octopi at the surface, and an artic skua (Stercorarius parasiticus) was photographed harassing a flock of great shearwaters (Puffinus gravis). The skua does this to provoke other seabirds to regurgitate ingested food that the skua then consumes with less effort than hunting for itself would require.

Earlier, Mick also spotted a small shark as the CTD was hoisted aboard in the morning, from the dorsal fin to the tail measuring not much more than a metre.

Jeff Mashburn
Durham University
27/07/07

Last night the weather was still too rough for pelagic fishing, so we were not able to get the samples we hoped for. Nevertheless we were able to get some nice acoustic results using the EK60 mentioned in the last blog, logging data until 0600 this morning.
The PAL Lander was successfully recovered, with new information and pictures from the ridge. The lander is a baited tripod with a downward facing camera (the casing along costs ₤ 30000,- ), taking picture (see photo) every minutes for 12/24 hours. The oceanlab team is currently analysing the pictures. This concluded the work on the SE station.

We then steamed to the SW station, which was today’s study site. Since the weather has cleared up, the Plymouth crew (Gavin Tilstone and Victor Martinez) were able to collect satellite imagery of the western ridge (see previous posted cross-section). Two US satellites and one European are currently detecting the reflectance of sunlight from the surface of the sea. A part of the light is reflected or absorbed by phytoplankton. The PML optic group compare these images to data from CTD transects (the CTD rosette, which measures salinity, temperature, and depth, was sent to 1600 m and took two hours to get back to the surface!) and from the optic profiler. The optic profiler measures the absorption, backscatter, attenuance of light by phytoplankton. There is also a sensor at the bow of the ship that is taking optical measurements to validate the satellite data. This knowledge is used by PML to map primary productivity over the globe.

At 1644 a permanent mooring, consisting of two sediment traps, a current meter and an acoustic release, was deployed at 2500 m, and will for the next year record data on deep sea currents and the contribution of surface productivity to the sea floor.

At 1830 the acoustics team will start another EK60 survey, in order to prepare for this night’s fishing. The weather will hopefully be calm enough for us to fish with a RMT (rectangular midtwater trawl), which is designed to open and close, in order to sample a discrete depth range. Combining this technique with the information collected with the EK60, we will thus be able to describe the main proponents of the pelagic realm. The Perg team is waiting in anticipation for the chance to get some samples!

Tom Bech Letessier, PhD student,
PERG, St Andrews

Last night we were in some big seas, so the ship was pointed into the weather to ride out the storm. This morning, because of the storm, we had moved out of the study site. After breakfast the ship was skilfully manoeuvred through the waves so that we could head back east. The steam back to the study site gave us the chance to once again sample the water column using the EK-60 scientific echo-sounder.

We are using the echo-sounder to look at groups of small animals that live in the water column. Eventually the acoustic data, collected with the echo-sounder will be used in conjunction with data from samples caught in a net to estimate the abundance of different animals across the mid-Atlantic ridge.

During the steam back towards the study site Birkir, Tom and myself , the team onboard from the Pelagic Ecology Research Group at the University of St Andrews, have been running the echo-sounder. We need to ensure that echo-sounder data are being recorded from the echo-sounder transducers, on the hull of the ship, all the way to the seabed. We also have to make sure that the data the ship doesn’t go too fast, because if this happens we will not be able to detect animals at deeper depths.

This morning we have seen some interesting patterns of animals on the echo-sounder display. For the first time we saw two dense aggregations of animals that were strongly reflecting acoustic energy on the 120 and 200 KHz echo-sounder frequencies. After the cruise we will analyse the acoustic data to see if the presence of these so far rare observations can be explained by, for example, changes in water temperature or seabed depth.

When we arrive back at the study site we will use the mega-corer. We got one perfect sample and five slighting disturbed sample the perfect sample was sectioned and preserved for the study of single celled animals. The distributed cores were sieved and the residue was preserved to study the slightly larger animals, such as polychaete worms, crustaceans and molluscs.

Because of the storm, we had a pause in the science programme, so I thought this would be a good time to find out what scientists enjoy most about being at sea. Perhaps this wasn’t a good question to ask just after a storm, but here are some of some of their answers:

“I get excited about what comes up in the net.”
“Because normally when I go to sea people buy me new clothes.”
“I get to do the things I enjoy.”
“The excitement of new discoveries.”
“The food.”
“There is something very special about being at sea”
“Because of the interesting people you meet.”
“Being in an unexplored, dynamic environment.”
“The camaraderie.”
“Witnessing the raw energy of nature.”

Tonight, if weather permits, we may be fishing with a net to catch the animals that we see using the echo-sounder. Fingers crossed……

Martin Cox
Pelagic Ecology Research Group, University of St Andrews.

The day today has been a reminder of the fact that we are as much off shore as possible in the North Atlantic Ocean.

Here we are (red arrow):

(Map from encarta.msn.com.)

We planed to do OTSB benthic trawling from 8pm (yesterday) to 2 am, however the weather changed last night and we were unable to trawl. Even though RRS James Cook is a huge research ship designed for off shore cruising, we have to adopt our operation plans in harmony with weather conditions.

So instead, we set out on a passage to work a transect of CTD’s to measure the characteristics of the seawater in the deep valley in the middle of the Mid-Atlantic Ridge (see topographic profile). From these measurements we can estimate the type\origin of the water masses in the valley and further predict on the nature of flow of seawater in the valley.

A topographic profile showing east-west transect going across the ridge:

(Made with Olex software)

We started the first CTD’s at 3 am and sampled to depth of nearly 4000 meters (for an example it takes about 4 hours just to heave the CTD equipment from such depths). We continued doing CTD’s until 2:30 pm when primary production was measured. At this point the weather was to sever to deploy the optics profile and in continuance all deployments were stopped because of the heavy swells. To day there has been a strong gale as wind speed has been gusting up to 45 m\s. Air temperature has been from 14.2-15.5 C.

Also affected by the bad weather are the acoustic measurements. In bad weather the ship is slamming against the heavy swells, hence air bubbles go below the transceivers and interfere with the measurements. As described in earlier blogs, there are several types of acoustic equipment mounted on the ships hull. The Multibeam echosounder maps the topography of the bottom, the EK60 echosounder estimates biomass and distribution of animals in the water column, the ADCP measures current beneath the ship. All these devices generate a sound beam down into the sea and measure very precisely the backscattered sound waves.

The multibeam echosounder maps the 3D tophography of the bottom:

(Modified from Olex software)

Echogram from the EK60 echosounder, shows the distribution of fish and zooplankton in the water column as scattering layers (bottom is red) and then we use Rectangular Midwater Trawl (RMT) to identify what species we are seeing on the echograms:

(Echogram from EK60 software)

Around 13:30 we saw a pot of 10 pilot whales poking about nearby. They didn’t seem to mind the weather at all.

Now we are how to with occasional waves crashing over the back of the stern, waiting for the weather to calm down, so we can continue our research.

Birkir Bardarson

Pelagic Ecology Research Group,
Gatty Marine Laboratory,
St Andrews

On Monday we sampled the benthic megafauna using the Semi-Ballon Otter trawl (OTSB) (see diary entry for 21/07/07). This was the second trawl station at the South Eastern station. The sampling was quite successful. Many phyla were represented. In terms of abundance and wet weight holothurians; fish, porcellanasterid, pterasterid and brisingid starfishes, madreporarian corals and alcyonarians dominated. The other groups in the catch were pennatularians, decapod crustaceans, barnacles, sponges, hydroids, polychaetes, pycnogonids and others. Many specimens were in very good condition.

At least 16 holothurian species were recognised, the group of organisms I am particularly interested in. The most abundant were Abyssocucumis abyssorum, Benthodytes sp., Amperima rosea, two species of Peniagone and Molpadia, Bathyplotes sp. Some of the holothurian species are probably new to science. One of dominant species, the holothurian Amperima rosea, is known as an opportunistic species which responds to episodic fluxes of organic matter. The catch was also notable for the number of fish, especially Halosauropsis macrochir and Coryphaenoides brevibarbis.

The fauna was sorted to the lowest reasonable taxonomical level. Samples were preserved in 4% buffered formaldehyde. Selected specimens were fixed in absolute alcohol for genetic studies.

Following this trawl, an echo-sounder transect was carried out to examine the zooplankton. We then carried out the second Megacorer deployment at this station, which returned 6 perfect cores. One of these contained an individual of the holothurian Kolga nana, the second opportunistic species that we have found at this site. Due to worsening sea conditions, we were not able to deploy the OTSB again this evening, so work proceeded with a series of CTD deployments.

Antonina Rogacheva
P.P. Shirshov Institute of Oceanology
Moscow, Russia

We have had rougher weather today than at any time during the previous week with winds up to Force 7, but work goes on around the clock regardless.

The early hours of the morning saw another attempt at a multifrequency acoustic survey using the EK60. Better results were obtained than the previous afternoon, simply because we were going in the opposite direction. Steaming tail to wind instead of head on makes a big difference to the volume of bubbles beneath the hull. The bubbles affect all the acoustic instruments, confusing the return signals. Reducing the bubbles allows a much better signal, and this time, a deep scattering layer was observed. We hope we can put nets into it sometime soon to find out exactly what animals the layer consists of.

By breakfast time we were back at the south east work site and the megacorer was put to good use, bringing back 5 out of 6 good quality cores. A thick layer of “fluff”, gungy-green phytodetrital material, capped each core and in some cases had been worked into the top layer of the sediment. There was plenty of evidence of bioactivity in the sandy sediment. The cores were rushed off to the cold room for closer inspection.

With breakfast over we set out to the mooring area to re-deploy the PAL Lander. This was done despite the deteriorating weather and increasing seas. Afterwards we headed south of west, back to the shallow (800m) seamount on the other side of the axial rift to recover the ISIT Lander deployed yesterday. Our course took us beam on to the sea, and for the first time we experienced a significant amount of movement. There were one or two crashes, but everything had been tied down well at the beginning of the cruise, so there were no problems, and it was fun having to walk up the deck that was sloping down only seconds previously. Fortunately we’ve got excellent quality “sticky” mats in the saloon to help keep our lunch in front of us while eating.

The ISIT lander was popped up late afternoon, to be followed immediately by a CTD cast. We were anxious that the CTD went without delay, because it was important to gather water in daylight for primary productivity experiments. The CTD had other ideas. Put in the water at about 6pm after a hasty dinner, it had descended to only 400 m when the alarm went off. The CTD was brought back on board and quickly discovered to have water in the cable termination. This was re-made while the scientist gathered in the conference room to review the situation and consider how to cram a further 10 days of work into four, with bad weather forecast for late Tuesday and Wednesday.

Since a window of good weather was forecast for Monday, the CTD was abandoned. It was too late for primary productivity work anyway and CTD’s can be done in bad weather. Good weather brings more urgent priorities and the ship is now heading back to the south east work site for an overnight trawl.

At least the catering department have ensured that our centres of gravity remain low. As well as the usual a la carte menu for lunch, there was green potage soup with fresh bread rolls, and a choice of all or any of curry, Cornish pasty, rice and chips – or salad if you prefer. Dinner included the traditional Sunday offering of steak, served with roast potatoes, peas and sweet corn. It could be preceded by cheese bruschetta and followed by pecan pie with cream – plus ice cream if you were man enough!

Jane Read,
National Oceanography Centre, Southampton