Shelf Sea Biogeochemistry blog

Showing posts with label RRS Discovery. Show all posts
Showing posts with label RRS Discovery. Show all posts

Sunday, 15 March 2015

Meet Jo Cox, the first female captain of any NERC owned research vessel.

On Monday we continued our work at sites H and I as well as the spatial survey which we are carrying out between the sites. There will be more about the spatial survey later in the blog, as today’s post is focused on the most important person on the ship.  Jo Cox is the captain of the RRS Discovery, and indeed the first female captain of any NERC (Natural Environment Research Council) owned research vessel.

Jo has always been a keen sailor and spent most of her childhood sailing in circles round a reservoir at weekends, however she took an unconventional path towards a career at sea spending five years training as an engineering apprentice and test engineer with Land Rover. During her apprenticeship she was given the opportunity of sailing on a Tall Ship (Sail training for children and young adults), spending 10 days sailing on the schooner Winston Churchill.


Jo Cox, captain of the RRS Discovery, and the first female captain of any NERC owned research vessel.

After that, she was hooked and she spent most of her annual leave and most weekends sailing offshore. “I loved my job at Land Rover, but my heart was rapidly over-ruling my head, so I took the plunge and quite literally ran away to sea.”

Since running away to sea, Jo has sailed on a variety of ships from a 300,000t tanker, to an old general cargo ship on a round the world trip. One trip stood out above the rest with 6 months spent on the British AntarcticSurvey (BAS) vessel RRS James Clark Ross (JCR). “I loved the science work that the vessel undertook, the range of people that I came across, and of course, the beauty of the Antarctic was also pretty amazing.”

Following this BAS offered her a 3rd mate position on the JCR, and she spent the following 10 years working for BAS on the JCR and the other UK Polar ship the RRS Ernest Shackleton. In 2012 a change of career beckoned and Jo left the open waves to spend three seasons working as the Government officer in an Antarctic base on the island of South Georgia manned by BAS scientists; however with each passing season her desire to return to sea got greater and this lead her to apply for the vacant Masters position on the RRS Discovery.
 “The Masters position on RRS Discovery represented an amazing opportunity to work at the cutting edge of research, on a purpose built vessel with the ability to carry out a fantastic range of scientific activities.”

Coming from an engineering background, Jo has only ever worked in male dominated environments and offered the following advice to other women considering a career at sea. 

"The maritime industry offers a fantastic career opportunity for anyone with the commitment and dedication that is required to pursue it. In doing so there are inevitable sacrifices, but the rewards and job satisfaction more than make up for it. Women at sea are no longer the rarity that they once were, and with each passing year there are a steadily increasing number reaching the ranks of Master and Chief Engineer. It’s certainly not for everyone, but if you’re willing to get stuck in and work hard then the opportunities are out there.”

She also offered the following advice to scientists concerned with making her life at sea a little less stressful – “Be organised and be ready on time…..”

Sound advice I think….

Saturday, 7 March 2015

What is happening in the benthos?

Louis Byrne, British Oceanographic Data Centre, NOC

The seas picked up again on Saturday and unfortunately again a few members of the science crew have been feeling a bit green, however the strong winds left us on Sunday and we had our first days’ proper sunshine of the cruise, complete with the obligatory sunset photograph, but not the fabled green flash!

The focus on this cruise is on processes that are happening in the benthos – meaning the environment above and within the seabed – and how these processes change as the seabed moves from sandy sediment to muddy sediment. To do this we are investigating four sites which are characterised as sand, sandy mud, muddy sand and mud. We managed to complete the NIOZ coring of the sandy site (Site G) over Sunday night, giving our sedimentologists some sandy samples to analyse along with the muddy sediment collected from site A.


A sample of sandy sediment ready to be sliced

Natalie Hicks (SAMS) is using the samples collected by the NIOZ corer to investigate the dynamics of benthic carbon cycling, including how deep and for how long carbon is stored in the different types of marine sediments, and how much is released back into the water column. She is collecting sediment samples from the seabed to a depth of 25 cm and then slicing it into cross sections, with each slice containing sediment from a different depth. These will then be stored in a freezer until the end of the cruise, when they are taken back to the laboratories in the Scottish Association for Marine Science (SAMS) to be analysed.

 


Natalie slicing her core into cross sections

Back at SAMS, the sediments will be analysed for their porosity, which refers to how much space there is for water between the grains in the sediment. Muddy sediment has smaller grains which fit together more tightly than sandy sediment, leaving less space for water between them. This makes it easier for pockets of water deeper in the sediment to be cut off from the sea water above.

Once this happens the water in the pocket will quickly run out of oxygen (there will be more about this later in the blog), making it impossible for aerobic bacteria (they are the ones requiring oxygen for respiration) to consume the organic matter in the water. This organic matter will then be stored in the sediments, unless it is resuspended through physical water movement or animal activity.
 



A NIOZ core about to be dropped into the Celtic Sea

Apart from the porosity and grain size, the carbon (both inorganic and organic) is measured as well as the amount of the lead isotope,
210Pb. The carbon is measured so that we can have an idea of how much biological material is buried within the different sediment types.  210Pb is measured as it can be used as an indicator for how often the sediment at each depth is being resuspended or accumulated. Putting all of these measurements together, can give you a better understanding of benthic carbon cycling, and how this differs between the different sediment types

All of this is important so that we can determine whether each sediment type is a source or a sink of carbon. If we can understand better how deep carbon needs to be buried in the different sediments before it is sequestered (stored permanently in the seabed sediments) and how long it will stay the sediments for, then we can know how much carbon they will absorb over time. This will help us predict how much atmospheric CO2 may be buried in our marine sediments over a certain timescale.

The rains and rough weather returned on Sunday, however I think most of us have our sea legs now!
 



Sunset on Saturday

Tuesday, 27 January 2015

Expeditions of Discovery find the secrets of the shelf seas

Shelf Sea Biogeochemistry and the recent pelagic cruise (DY018) were featured in an article 'The secrets of the shelf seas – one of Earth’s most important ecosystems' by The Observer newspaper. 

The sea off our coasts teems with microscopic life that breaks down the carbon dioxide we pump into the air. Now a series of expeditions aims to find out more.


Colony of salps floating under the RRS Discovery during DY018. Underwater photography courtesy of Claire Ostle (University of East Anglia).

Saturday, 29 November 2014

Glorious mud

Ocean research cruise blog of Jonathan Sharples

 

We reached the northern-most station by about 7 pm last night. There was great excitement watching the data from the CTD as it was lowered through the water. If any site was going to have reached the fully mixed winter state by now, it was going to be this one. About a dozen of the scientists were crowded around the CTD computer in the main lab, willing the temperature of the water to stay the same as the CTD went lower. But there was a collective groan as a thermocline appeared at 66 metres below the surface. It’s a bit disappointing that we are not going to be out here to see that final transition to the winter mixed water, but I’m pleased that I appear to have generated so much enthusiasm for shelf sea physics amongst the crowd of biogeochemists on board.

box corer

Matthew Bone, from the University of East Anglia, is interested in the muddy seabed at this site. We collected 4 cores from the seabed using a large “box corer”. This is a large steel cylinder that is lowered down onto the seabed, and then pushed into the seabed by the large weights above it. When it is pulled out, a core of the seabed mud is held within the cylinder and brought on board. Matt has been working on measuring how the mud releases nutrients back into the water. This muddy area of seabed, in an area called the Celtic Deep, is an important fishing ground for a scampi that lives on, and burrows into, the mud. At one point last night the radar was showing 12 fishing vessels around us, within a distance of about 10 miles. One of the cores caught a scampi. It seems happy enough in the lab, busily shifting mud around the top of the core and tending a burrow. The plan is to release it later today when we pass over another area where we have in the past seen scampi on the seabed.

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mephrops


Friday, 21 November 2014

21 November, 2014 09:05

Ocean research cruise blog of Jonathan Sharples

 

We arrived at the central Celtic Sea mooring site yesterday at 0930. Recovering the moorings was delayed a couple of hours while we waited for the wind to drop a little, but we began pulling them out of the sea shortly after lunch.

We have a fairly complex array of instruments on the moorings out here. There’s a weather buoy, provided to our project by the UK Met Office, plus a Cefas Smartbuoy that samples the surface biology and chemistry. The Met Office buoy doesn’t need servicing – they are designed to stay at sea sending back weather information for about 2 years. The Cefas buoy is looked after by Cefas scientists also working on this project. That leaves 3 other components that we need to service. The first mooring is a vertical line of acoustic current meters, anchored to the seabed and stretched upward by large buoys. These current meters are being used to measure turbulence in the sea, which allows us to calculate the supplies of nutrients towards the sea surface and how carbon is being mixed downward.



curretn meter buoy recovery
The second mooring is a relatively simple steel frame containing two acoustic current meters; this frame sits on the seabed, with the current meters looking upward and every 5 minutes measuring the flow of water in a series of 4 metre thick layers throughout the entire depth. Finally, the most complex of the moorings is a line holding about 25 temperature and salt loggers, anchored to the seabed and stretched up towards the sea surface by several buoys. These loggers, sampling every 1 minute, show us how stratified the water is, where in the water the thermocline is, and also if there are any waves running along the thermocline. All 3 moorings came up OK, though the string of loggers popped up about 1 km away from where we expected it to appear, requiring a bit of nifty ship manoeuvring by the captain to grab the mooring before it drifted onto the Cefas buoy. Once everything was on board, the National Marine Facilities engineers, along with Jo Hopkins and Chris Balfour from the Oceanography Centre in Liverpool, downloaded data, re-batteried instruments, and got the new mooring wires wrapped onto the winches ready for deployment.

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bedframe recovery

Tuesday, 18 November 2014

Shelf edge station begins




Ocean research cruise blog of Jonathan Sharples

 

Work at the shelf edge has started well. One big difference between the work here and the work that we did at the first station on the cruise is that we have no moored instruments here. The shelf edge is the most heavily fished part of the seas around NW Europe, so long-term deployments of moored instruments tend to be unsuccessful as the chance of moorings being snagged by fishing gear is very high. For the duration of our work at this site we instead hang a chain of instruments from the ship. Jo Hopkins and Chris Balfour, from the National Oceanography Centre in Liverpool, spent the previous day setting up about 40 temperature, salt and chlorophyll loggers so that their clocks were all synchronised and they all take measurements at the same rate (once per minute). The instruments were then clamped every 2.5 metres on a 200 metre wire lowered over the stern, with a 300 kg ball of lead on the end of the wire keeping it vertical in the water.

Jo with chain instruments

We are using this chain of instruments to track a particular feature of the shelf edge. As the tide moves onto and off the shelf, the steep slope in the seabed causes the tide to push the thermocline up (tide flowing onto the shelf) and down (tide flowing off the shelf). This up and down motion generates waves on the thermocline that move away from the shelf edge, both onto the shelf and away into the deep ocean. These underwater waves can be very large, 100 metres from peak to trough and 15 km long. They are important because they result in a lot of mixing at the shelf edge, bringing nutrients from the deeper water up towards the surface. Our chain of instruments will track this up and down motion of the thermocline wave, so we have a picture of how rapidly the physics of the water below us is changing as we collect all of the biological and chemical samples
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t-chain deployment