Cruises

As the cruise draws to a close it is time to reflect on what we have achieved. The observations we have made, described in the preceding blog entries, will allow us, in the fullness of time, to describe far better than has been hitherto possible the downward flux of organic carbon through the twilight zone and the processes responsible for the attenuation of this flux in the NE Atlantic during summer.

However we are a long way from this stage. We now face a period of at least six months data synthesis and sample analysis before we can begin to understand and place in context what we have observed. This is particularly important because a recent US programme known as Vertigo completed similar analyses at two sites in the Pacific. The power of our observations here will therefore be multiplied enormously via comparisons with Vertigo, building on the novel insights they obtained.

On a personal level it has been a great pleasure to sail on this cruise.
The supportive and comradely nature of the scientific party, ships staff and technical support personnel  has given me strength in my hours of need and some of the wildlife sightings have been spectacular.

As we head home through the Irish Sea it remains for me to hope that you have enjoyed the blog entries and that you have gained some insight from them into oceanography as both a career and a lifestyle. Finally many thanks to Jennifer Riley and Charlotte Marcinko who have masterminded the content of the blogs, all those people who wrote them, to Martin Bridger our software expert on the ship who made it all possible. And you would not be reading this if it were not for the Classroom@sea and Eurosites websites who are hosting them.

My name is Ross Holland and I’m the Marine Flow Cytometry technician at the National Oceanography Centre, Southampton. This is my eleventh cruise on the RRS Discovery, and it’s been fun as always! Time is running out for me to write an entry for the blog, as I just finished analysing my last sample of the cruise just before dinner today! I thought it was about time I got involved by telling you a little bit about what I have been doing for the last five weeks.

Flow cytometers, the machines I am responsible for, are instruments used by Marine Microbiologists to study the very smallest forms of life in the oceans, the bacteria, protozoans and the pico-phytoplankton, many of which are less than one thousandth of a millimetre in size. These groups of organisms may be very small, but they are the most abundant life forms in the oceans, and so it is very important to know what they are up to! There may be as many as 3 million of them per millilitre of seawater, don’t let this put you off swimming in the sea though, marine bacteria are perfectly harmless.

During this cruise the focus of our efforts has been on these organisms and their abundance and function at previously little-studied depths.

Our standard flow cytometer works by passing a sample of seawater through a laser beam. Each cell that passes through the laser beam, scatters light and fluoresces in a specific way, and by detecting the exact way in which the particle reacts, we can assign it to a different group of organisms. In addition, the cytometer can actually physically ‘pick out’ groups of cells we are interested in. By incubating them with different labelled substances, we can sort a few tens of thousands of cells out and then measure the rate of uptake of these substances, and get an idea about how active each group of cells is.

Also on this cruise I have been involved in using the sophisticated new size fractionating plankton net developed by Mike Zubkov and Kev Saw. This has been used to catch large numbers of much bigger phytoplankton and zooplankton for us to count on our newest flow cytometer at NOCS, the Flow Cam. This cunning device actually takes a photograph of every cell it counts and can recognise the group of organisms it belongs to just from the photograph. From this we can tell a great deal about the ecology of the waters we are studying around the PAP site!

Ross Holland

Lat 50 26.27 N
Long 11 41.20 W

Radioactive tracers to estimate carbon fluxes

The biological pump is a major component of the global carbon cycle which transports approximately 10 gigatonnes carbon per year from the atmosphere to the oceans interior. For it, to effectively sequester carbon in the deep ocean, it must export organic carbon to depths below that of winter mixing. This occurs via the sinking of organic carbon aggregated into particles, large enough to attain high sinking velocities. The aim of our work in the D341 is to estimate the POC fluxes from the upper layers to the twilight zone in the PAP site using two different and complementary techniques based on the disequilibria of the radioactive pairs ²³⁴Th-²³⁸U and ²¹⁰Po-²¹⁰Pb.

Some of the elements that comprise the earth are radioactive. Those natural radionuclides are ideal tracers of a great variety of environmental processes for several reasons. First of all they are ubiquitous in the environment; secondly, their radioactive decay allow us to “easily” measure them (or we can try to measure  1mBq/L of ²¹⁰Po or 6·10^-9 ng/L using other techniques!)

Finally, equilibriums between the activities of the parents and the daughters of the radioactive chains are established in close environmental compartments. As the compartments are rarely close  in the environment, these equilibriums are broken and the measurement of the correspondent desequilibrium allows us to establish different properties of the compartment of interest.

Is this last property the one that we use to estimate carbon fluxes from ²³⁴Th and ²³⁸U and ²¹⁰Po and ²¹⁰Pb disequilibria.

²³⁴Th (T_1/2=24,1d), daughter of ²³⁸U (T_1/2=4,47.109y), can be used to estimate how much POC is exported into the deep ocean. ²³⁸U is conservative in the seawater. But unlike ²³⁸U, ²³⁴Th is particle reactive in the water column. As particles sink through the water column, ²³⁴Th is scavenged with them and the secular equilibrium between ²³⁴Th and ²³⁸U is broken, the subsequent disequilibrium can thus be used to quantify carbon export fluxes.

First, ²³⁴Th export fluxes are calculated. Moreover, if we know the ratio POC/²³⁴Th, PIC/²³⁴Th or BSi/²³⁴Th (that can be measured in the sinking particles using in situ pumps, SAPS), it is possible to estimate the rate of carbon and biominerals export from the surface ocean.

In a similar way, a disequilibrium through the water column it is found between ²¹⁰Pb (T_1/2=22y) and its daughter ²¹⁰Po (T_1/2=138d). However, this disequilibrium has different characteristics than that of the pair ²³⁴Th-²³⁸U. ²³⁴Th is attached to the surface of the particles, however, ²¹⁰Po it is assimilated by the organic matter and incorporated to the cell as a substituent of sulphur. This is an important difference because it is expected that ²¹⁰Po-²¹⁰Pb disequilibrium allow us to better estimate POC fluxes whereas ²³⁴Th will be used to estimate particle scavenging.

Furthermore, the different half lives of ²³⁴Th (days) and ²¹⁰Po (half a year) would allow us to study different timescales, fast changes in fluxes (²³⁴Th) and also seasonal variations (²¹⁰Pb).

During the cruise our aim is to measure ²¹⁰Po, ²¹⁰Pb and ²³⁴Th in the station in as much depths as possible (high resolution profiles if we want to integrate the disequilibrium properly!). For this reason, there where always so many carboys spread around our lab, and some of them flying all around during the storms!

After collecting the water, radionuclides are precipitated following different radiochemical procedures. Afterwards, their radioactive decay will be measured and the concentrations of the radionuclides are obtained.

Maria Villa

Fred Le Moigne

The story of a mass murderer

Zooplankton samples

‘Aren’t they cute?’ – The answers I get to this question vary strongly when I let the people on this ship have a glance through my microscope – from ‘Yuck, they look horrible’ to ‘Aww look, it’s fighting the other one’. I never got a ‘They look really tasty!’ as an answer. But that may be as I never asked a fish, whale or other carnivorous zooplankton. What I am looking at are copepods: small shrimp-like animals that occupy a key role in the marine food web.

To get my sample, I get up at horribly early hours in the morning, because these little shrimp-like creatures know quite well how tasty they are. To avoid predation, they migrate into the deeper waters during daytime, when the sunlight is shining through the upper water layers and fuels the phytoplanktonic photosynthesis. At night time however, in the safety of darkness, copepods and other zooplankton migrate upwards into the food-rich surface layer to feed. They haven’t expected me!

Sarah and her zooplankton net

So there I stand with a 200 μm-mesh plankton net at 3 am. After I got my sample, I choose the animals I am interested in and sort them according to size and species. This sounds rather simple. In reality though, I pick each animal individually using a microscope and tweezers. The copepods I am looking at are sometimes as small as 0.4 mm and are just about visible with the naked eye. On a ship that is constantly moving, and in a crowded lab with a table that is vibrating from the filtration rig of my neighbour scientist, this can be a rather tough call. But I am young and patient, and so I count myself lucky when I finally got all the animals needed at about 7 am: It is breakfast time!

It is breakfast time for me, and for the copepods, too! I am about to set up my feeding experiment. I am interested in how much and what these little animals eat. As I cannot watch them actively eat like my fellow scientists at the breakfast table, I need to use an indirect approach. Imagine two identical meadows, and assume that the grass is growing at the same rate on both meadows. Now a farmer brings 10 cows onto one of the meadows and leaves them for 24h. If you mow both meadows after those 24 h and weigh the grass, you can see from the difference how much the 10 cows ate in 24 h. This is exactly what I am doing. I put 10 copepods in 2.2 L glass bottles containing phytoplankton-rich water that has been collected for me from about 25m depth using a CTD rosette. Simultaneously, I set up three control bottles without animals. The bottles are screwed onto a plankton wheel, which is slowly rotating the bottles to keep animals and food in suspension. After 24 h, I take water samples from experiment and control bottles, and fix the sample with the preservative Lugol’s iodine. When I am home again, I will count the phytoplankton in each sample and calculate how much these small copepods munched. This information will help us to understand the role of mesozooplankton in the carbon cycle. Even though a single copepod is tiny, the high abundance of these little grazers results in an enormous turn-over of carbon. Because of their high grazing rates and daily vertical migration, copepods may transport high amounts of particles through the water column. Together with the zooplankton sampler ARIES, my feeding experiments will give us a better idea of how much these wee marine beasties contribute to the biological carbon pump.

Sari Giering

So, what happens to the animals after the experiment and all the other animals that I do not use? Yes, you are right: they get flushed down the sink. And yes, I do feel horrible about it even though they are minute. But dear fellow scientists: Imagine how much zooplankton a single 20 tonnes baleen whale eats every day!!!

Lat: 48 55.88N
Long: 16 32.24W

Under pressure…

Our Lab

This is not only the fabulous title of a song but it is also the condition of life for so many organisms inhabiting the Ocean. Indeed, Ocean is deep with a mean depth of 3,800m. Here, in the PAP site, the depth is over 4,500m. As you maybe know, the hydrostatic pressure increases with depth (1 bar every 10 m), that means that at atmospheric pressure (pressure where we are living, ~1 bar), the pressure is equal to ~0.1 kg per centimeter square but at 1,000m-depth the pressure is equivalent to 100 kg/cm²!!

One of the main topics of this cruise is to better understand how the organic matter is consumed by organisms. We focus our attention on bacteria with a special consideration to their environmental condition of life. We are considering two kinds of pressure effects on organic mineralization:

1)     Bacteria attached to particles sinking through the water column. These bacteria coming from the surface waters are submitted to an increase of pressure (and a decrease of temperature) that limits their metabolism and then their degradation of organic particle.

2)     Free-living bacteria in deep-sea environments. These kinds of bacteria are adapted to their environment and then they are more active under pressure than after decompression of the sample.

To study these microscopic organisms, we have developed original (and heavy) high pressure devices together using high pressure bottles (HPBs). These HPBs are used in the first case to simulate the increase of pressure that bacteria attached-to-particles experiences (PASS: PArticles Sinking Simulator) and in the second case to maintain their in situ conditions all the time during our experiments (HPSS: High Pressure Serial Sampler and not French CTD as it is call here!!). On board the RSS Discovery, we are occupying a whole container (and many more…).

During this cruise, we have used particles recovered from PELAGRA (see blog of the 31^st July) in order to estimate their degradation by bacteria simulating a sinking velocity of 200m/day.

Also, we are measuring deep-sea microbial activity under in situ pressure conditions. Joined with the IODA₆₀₀₀ data (see blog of the 3^rd August), we will expect to better estimate the bacterial carbon demand of bacteria living in the dark ocean.

Christian Tamborini and Mehdi Boutrif

Organic matter processes in the Twilight Zone

Photosynthetic primary production is the basis of much of the oceanic food chain. The energy fixed by phytoplankton is transferred to grazers and to higher consumers. The efficiency of the energy transfer between producer and consumer reflects the state of the ecosystem, for example nutrient replete vs. nutrient deficient. Through sinking, organic particles from surface waters are transferred to the deep sea, where they are an important resource (i.e. food) for deep-dwelling animals, be they living in pelagic (in the water) or benthic (at the sea floor) environments. We know that in the northern Atlantic Ocean at mid- to high latitude, the deposition of organic particles is seasonally driven by the surface water spring bloom.

However, there is considerable variability in the composition, and hence the nutritional quality, of the organic particles, which is driven partly by the nature of the phytoplankton, but also by the organisms that graze on them. Many of the organic particles leaving surface waters are lost or transformed in the so-called twilight zone (i.e. 200 – 1000 m of water depth), but we know virtually nothing about these processes there.

Certain organic chemicals such as fatty acids, sterols, pigments, or amino acids can retain information on their biological origin. These chemical are often called biological markers (or biomarkers). Changes in the distributions of biomarkers and their isotopic composition can shed light on the transformations of the organic material as it sinks through the water column. In addition, biomarkers and their stable isotopic composition are often used to trace the trophic relationships of many marine communities; this will help to determine the trophic transfer efficiency (i.e. the energy transfer) of the pelagic ecosystems of the twilight zone.

SAPS

Collecting particles from the water can be carried out in a variety of ways. Large volume in situ filtration systems (SAPS) and sediment traps have been used routinely for this purpose. SAPS can pump up to 2000 L of water through a filter in a short period of time (usually 1-2 hours). The particles that are collected by SAPS are rather heterogeneous and can sink at variable speeds, whereas material that is collected by sediment traps is usually heavier and sinks at higher speeds. The exchange mechanisms between these two different “pools” of particles are virtually unknown but can potentially affect the export of organic matter at depth. Comparison of the chemical composition between the different pools of particles sampled concurrently (i.e. by SAPS and traps) and at similar water depths may provide a new insight in these processes.

Lat:48 53.755 N
Long:016 06. 08

Wildlife at the Porcupine Abyssal Plain

Despite the name of the place we have not seen any porcupines but we have seen plenty of marine wildlife on the D341 cruise!

Pilot Whales
One of the first sightings we had was of a pod of small long finned pilot whales. These whales grow up to 6 metres in length and can weigh up to 3.5 tonnes. They occur only in the North Atlantic in the northern hemisphere. Although, they can also be spotted in other oceans in the southern hemisphere. Their diet consists of squid, octopus and fish and they are able to dive down to 600 metres. Their population around the world is unknown however sightings are common.

Our picture shows a pod of around 10 pilot whales and from looking in our whale guide we think they are a mixture of males and females. You can tell this because they have different shaped dorsal fines. From the bridge of the ship you could see that the pod consisted of adult and younger whales. The more mature whales appeared to be guiding the young.

Blue Whale
We have been extremely lucky and had a sighting of a huge blue whale. These whales are extremely rare and are officially an endangered species. There are only a few thousand left in the world’s oceans. They are one largest animals to ever exist on earth and they can grow to more than 33 metres in length and weigh up to 190 tonnes. The whale we spotted was approximately 20 metres long and surfaced only 10 metres from the side of the ship.  The blue whale population was almost hunted to extinction through whaling in the 1800 and 1900’s. The mortality rates were so high it is now thought that some populations will never recover. They are found in all areas of the ocean apart from very far north in the Arctic. They dive to depths of 150 metres on average but they are thought to be able to go deeper. They can also swim at speeds up to 19 mph (30 km/h) which means that the ship we are aboard would not be able to keep up with one if it was swimming at its top speed. Considering how large blue whales are it is surprising that they only eat small krill and other crustaceans. However they eat these things in massive quantities.

We were able to identify the whale as a blue whale from the small stubby looking dorsal fin which was a long way down its body. We have also had the sighting confirmed by the Sea Mammal Research Unit in St Andrews. The pictures that we were able to take do not do the experience of seeing one of these beautiful creatures justice. It really was an amazing and unforgettable experience.

Dolphins
As well as seeing whales we have also had a number of sightings of common dolphins. Common dolphins are extremely energetic and acrobatic. We have seen them riding the bow wave of the ship as we were steaming along as well as surfing the waves and fully breaching out of the water. We were lucky enough to get a picture of this. Dolphins are also very inquisitive and we saw three of them swimming around one of the PELAGRA’s as it was being recovered one night. They are often found in large active schools and they are highly vocal and sometimes their squealing can be heard above the surface. The common dolphin can grow up to 2.4 metres in length and have a weight of up to 110 kg. Their diet is mainly fish, squid and octopus. This species is threatened by entanglement in fishing nets, hunting and whaling, pollution and other human disturbance.

Jellyfish
During the trip we have seen quite a lot of jelly fish. They have been mainly spotted at night time when we have been taking water from the CTD and the deck lights have been shining into the water. They occur in large swarms of 1000’s and make the water look a brown/red colour. We have also inadvertently captured some in the PELAGRA traps. We assume this is happening because the PELAGRAS are drifting through the swarms of jellyfish during the four days they are deployed. This allows the jellyfish to swim into the pots which are spiked with poison and then get trapped.

The photograph shows some jellyfish which have been caught in the PELAGRA pots.

Barnacles
Finally, we have also seen some barnacles attached to one of the moorings which were recovered. The mooring had been in the ocean for 2 months and during this time the barnacles had grown all over it. We think that these are a type of stalk barnacle which when they reach maturity can often attach themselves to ships and moorings.  The French research team onboard identified these as goose barnacles and said that they were good to eat. However, we decided that they smelt horribly bad and were not interested in cooking them up.

Jen and Charlotte

PAP – Moorings: Many things lurk beneath

Since 1989 the PAP site in the North East Atlantic (49^o N, 16⁰ W), has been one of the most frequently studied deep ocean sites. The main reason is that the PAP site is reasonably close to the shore yet it is a deep open ocean site (4840 m) allowing studying oceanic processes along the water column without coastal interferences. The PAP site is currently one of the nine Deep Ocean/Sea observatories which are under the EuroSITES project.

Moorings can be equipped with instruments that are able to operate over long periods and produce time series data sets. At the PAP site there are traditionally two mooring sites.

The first one is a subsurface mooring (traditionally called PAP3) extending from 3000 m down to the seabed (mooring length: approx. 1800 m). The mooring is equipped with three sediment traps (McLane parflux model: two deployed at 3000m and one 100 meters above the seabed) and two current meters (Aandera RCM) deployed below the first and third sediment trap. The main objective is to collect time series records of sinking particles over a year’s period.

The second mooring is the PAP 1 Deep Ocean Mooring System (DOMS). Its main purpose is to sustain a suit of sensors, analyzers and samplers. Most of the sensors are deployed at approx. 30 m.  Below the sensors frame and down to 1000 m, are a series of Conductivity, Temperature and Depth sensors (Seabird Microcat CTD) installed at various depths. An important feature is that the mooring is equipped with real time telemetry, enabling the monitoring/recording of the deployed sensors. This mooring has had many “interesting” experiences over the past years (e.g. in 2005 the subsurface mooring was lost and there were strong evident supporting that it was “fished”).  Recently (23^rd May 2009 during cruise JC34T) a surface buoy mooring was deployed bearing a heavily instrumented sensors frame and the telemetry system, which has provided real time high frequency records of nitrates, chlorophyll, temperature – salinity –  depth (30, 100, 1000 m).

One of the main objectives of cruise D341 on the PAP site is to turn around both PAP3 and PAP1. Especially for PAP 1, more sensors will be added on the frame (CO₂, O₂, Radiance – Irradiance, Currents), providing a detailed biogeochemical and physical image of the PAP site over extended time periods.

Apart from these moorings, during cruise D341 a subsurface mooring extending from 50m down to the seabed was deployed. On the mooring line there are five In situ Oxygen Dynamic Autosamplers– IODA (deployment depths: 50, 300, 600, 1000, 2000 m), which are able to measure oxygen in situ and oxygen dynamics. IODA is a custom made system designed and manufactured in France (collaboration between LMGEM and CPPM in Marseille). On the mooring there are also a zooplankton time series sampler (McLane ZPS), four Microcat CTDs and three Nortek current meters. All the above are deliverables within the EuroSites project.

Mooring design, deployment and recovery is a demanding job, which requires a lot of preparation and experience in order for the structure to survive the harsh conditions during its deployment period. The gain though is very valuable as successful moorings provide the base/platform for successful deployment of long term operating instruments.

Thanos Gkritzalis – Terry Edwards – Peter Keen – Dominique Lefevre.

Mastering the oxygen dynamics in the open ocean : IODA6000.

Oxygen maintains life on earth as we know it. In the ocean the oxygen is present at various concentrations at all depths, although there is few oceanic areas deprive of oxygen. Oxygen dynamics is mostly depending on the thermodynamics parameters (temperature and salinity of the seawater) and oceanic circulation, and to a lesser extend on biological activity (photosynthesis and respiration).
It is one reason why we are measuring O2 concentration and its dynamics at the ocean surface, where light is available, as well as the whole deep water column (the dark side of the ocean).
On board of the ship, we are studying the biological oxygen fluxes linked to marine micro-organisms activities. We are sampling from the CTD rosette for in situ oxygen concentration determination, but also we are taking samples in little glass bottles to incubate at sea on a drifting line (“The drifter”) for 24 hours, equipped with an Argos® transmitter and a flash and a bright pink flag for day and night positioning and visibility. This mooring line allows reproducing the in situ temperature and light conditions to respect physiological requirement of the sample taken from the CTD-Rosette.
Then we measure the difference of oxygen concentration between the reference sample (pickled at the start of the incubation) and either dark incubated sample, to derive respiration rate, or the “light” incubated sample to derive photosynthetic rate of the marine micro-organisms. This approach, although very accurate, is time consuming and fastidious, constraining the number of samples which can be analysed.

The great novelty for us of this cruise is to deploy a new “toy”, the so called IODA6000 (In Situ Oxygen Dynamic Autosampler). This equipment has been developed through a tight collaboration between our laboratory (Laboratoire de Microbiologie Geochimie Ecologie Marine de Marseille) and the CPPM (Centre de physique des particules de Marseille). The IODA6000 is made of a 5 litres incubation chamber, auto sampling water at its depth of immersion. Every 3 minutes, temperature and oxygen concentration are recorded in and out the chamber. After each cycle (incubation time), the chamber opens for an hour and then close again for a new incubation. The incubation time varies according to the immersion depth, i.e. the expected oxygen drift related to the in situ biological activity. The deeper we are the lower rate we expect, which is a first order assumption. Some of the IODA6000 are equipped with a light sensor to discriminate day and night period at the surface ocean; nevertheless the IODA6000 is able to reach 6000m. The combination of these measured parameters enables us to derive both the in situ photosynthetic and respiration rates in the upper ocean and the respiration rates in the dark ocean.

During the D341 PAP cruise, 5 IODA6000s are being deployed at 25, 150, 500, 1000 and 2000m depth, for 20 days, focusing our effort on the “twighlight” zone of the Ocean. When the mooring will be retrieved, it will have remained at sea for 20 days, representing 18 cycles of 24 hours for the surface IODA6000, opening and closing time being set in relation to the sunset, 9 cycles of 48 hours at 150 m, 7 cycles of 60 hours at 500 m, 6 cycles of 72 hours at 1000m, and 4 cycles of 96 hours at 2000m.
In parallel of this in situ work some work on microbial activity respecting the in situ hydrostatic pressure is being carried out to enable us constraining the effect of this controlling factor may have on the oxygen dynamics.

Energy provider for trophic network, Oxygen is.
The dark side, Carbon is Master IODA6000, his Jedi and young Padawan.

How I’ve ended up in the middle of the Atlantic with a bunch of crazy Oceanographers???

What am I doing on the RRS DISCOVERY?
I work for USL (Underwater Systems Laboratory) as a Mechanical Design Technician. The main reason I am here is to support my boss Kevin in the deployment and safe recovery of the PELAGRA drifting sediment traps (the other reason me and my boss are here is because the scientists have been known to deploy and not recover the PELAGRAs!).

O

How did I become a Mechanical Design Technician?
I went to college and did a NVQ level 2 (National Vocational Qualification). This led me to doing a Modern Apprenticeship in Mechanical Engineering, NVQ level 3 in Marine Design and a B-TEC National Certificate. This was a great career route for me as it was “hands on” learning and at the time University wasn’t my cup of tea. By doing a Modern Apprenticeship I also gained a full time job with USL and avoided leaving college in debt. Since finishing my apprenticeship I have also completed a HNC (Higher National Certificate) in Mechanical Engineering which has allowed me to a register as a Mechanical Engineering Technician with the engineering council.

O

So what does my job involve when I’m not on the ship?
My job is to supply the science community with the technology they need to carry out Oceanography i.e. designing, making and testing oceanographic equipment. A great example of what type of equipment USL has produced is the PELAGRA sediment traps which my boss Kevin Saw designed.

A scientist will come to us with a specification for an oceanographic project. This is normally a piece of equipment which will allow them to carry out their research. We then have to break down and simplify their ideas because there’s only so much that’s physically possible (this point is sometimes very hard to get through to some scientists!).

I will then start the design process using INVENTOR which is a CAD (Computer Aided Design) system. INVENTOR allows me to create working assemblies on my computer of the parts needed for the proposed equipment. By creating a working assembly using CAD technology it saves a lot of time and money as I can ensure the design is working correctly before the parts and components are made. It also allows me to show a working assembly to the scientists to see if they are happy with the design (Scientists are very hard people to please!!!).

Once the scientists have given the thumbs-up I can then get all the parts made. This is normally done by our highly skilled machinists in the USL machine workshop but we also give local engineering companies parts to make as we are normally busy working on more than one project at a time.

Once the parts are made I can then begin assembling the equipment in the fitting workshop. When I have assembled the equipment I can then begin the testing to ensure the equipment will work before it is handed over to the scientists to start using at sea for their research.

In USL we have a pressure testing chamber which allows us to test our equipment to depths of up to 6000 meters below the sea’s surface. We put the equipment in the pressure testing chamber to see if anything leaks or implodes. We also have a test tank in the workshop which we can use to trial our equipment in.

Once we are happy that the equipment is ready to be used we will then either hand it over to the scientists (if we think its user friendly enough for them to handle) or take it to sea on one of our research ships for testing. This ensures that we have fulfilled the scientist’s ever increasing high expectations.

O

My Conclusion of D341 so far

Me at work

This is my first cruise on the Discovery and even though the weather hasn’t been great for this time of year the crazed scientists and crew have made working life on board in these “extreme” conditions so much easier. I think in different circumstances these last few weeks could have dragged but time has flown by and it’s been quality seeing what goes on day and night on the Disco. It’s certainly been a learning experience!

Sam Ward
(Mechanical Engineering Technician)