Some very rare leisure time while heading into the next week at warp speed

Louis Byrne, British Oceanographic Data Centre, NOC

Over the weekend the weather has picked up a bit and we had couple of glorious days of sunshine complete with great sunsets such as the one pictured a few days ago. We have now moved from sampling the muddy and sandy sites A and G to site I which is the muddy sand site.

Helen Smith, Kirsty Morris, Natalie Hicks and Sarah Reynolds pointing at the location of sites I and H.

By Sunday we had managed to successfully complete all of the coring that we needed to do at site I, leaving only a few samples left to collect before we can move on to station H, the final of the four benthic sites (we are still planning on journeying to the shelf edge to a site called CANDYFLOSS, with the PSO (Principle Scientific Officer) Malcolm Woodward currently working hard on designing the TARDIS that will be taking us there).

Unfortunately there is no such thing as a weekend on a research cruise but some scientists have managed to carve out some very rare leisure time away. There is a film room with an extensive DVD collection (and the centre of RRS Discovery yoga), as well as a bar with a satellite TV where a few of us watched comic relief on Friday. The Kitchen-Galley is spacious and the food has been consistently delicious, indeed it will probably be the thing I miss most about the ship – Thank you Mark and Amy!

Mark, head chef on the RRS Discovery

 

Apart from the coring we also managed to complete most of the trawling that we need to do this trip. Three trawls are conducted per station and Steve Widdicombe of Plymouth Marine Laboratory (PML) will be analysing the animals that are brought up to try and estimate the biomass of marine animals that live on the sea floor. Some of the colourful creatures that we found in our nets have been photographed by Kirsty Morris (National Oceanography Centre).

A cuttlefish (photo by Kirsty Morris)

A shrimp caught in the trawl (photo by Kirsty Morris)

A spider crab (photo by Kirsty Morris)

We’re now heading into the next week at warp speed and are looking forward to completing the work at site I so that we can move to H and then to CANDYFLOSS, where as well as carrying out our usual coring, water sampling and other data collection tasks we will make a short detour to pick up and drop off some sea gliders (more about them later in the blog). 

The trawl net being brought back in (photo by Kirsty Morris)

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….

Oxygen concentration in the sediments and the effects of filter coffee in human behaviour

Louis Byrne, British Oceanographic Data Centre, NOC

Thursday was a quieter day on board the RRS Discovery and we managed to have some time to relax (and catch up on some much needed sleep). In the morning we all learnt a valuable lesson about what happens when you give a certain SAMS research scientist a filtered coffee before noon - it seems to be roughly equivalent to feeding a gremlin after midnight. Luckily Natalie had calmed down enough by the evening to give Steve, the CPO(s) [Chief Petty Officer (science)] a haircut, with the finishing touches being applied by Eva McQuillan, the Irish Observer on this cruise.

Earlier in the blog in the post titled ‘What is happening in the benthos?” we looked at the work of Natalie and SAMS (Scottish Association of Marine Science) in examining carbon cycling and storage in different types of marine sediment. In addition to the measurements outlined in that post, Natalie is also taking separate core samples and measuring them for oxygen consumption and depth in the sediment.

 

Fig. 1: Sediment core being profiled for oxygen

One type of measurement involves using a very fine oxygen probe (microelectrode) to find out how deeply oxygen penetrates into the sediment. This probe is lowered into a sediment core like the one pictured, and as it goes down the core it measures how the oxygen concentration changes as you descend deeper into the sediment.  As you go down deeper into the sediment the oxygen concentration decreases quickly, as the oxygen is being used by bacteria and other organisms living in the sediment quicker than it is being mixed back into the sediment. 

 

This decline is not the same for all types of sediment, as the more sandy a sediment is, the deeper oxygen can penetrate into the sediment. This is for a couple of reasons. The first is that muddy sediments have smaller grains which can fit together more tightly meaning the sediment can hold less water between the grains and the oxygen in that water gets used up quicker.

The second is because muddy sediments can hold more organic matter giving the aerobic bacteria (bacteria that respire using oxygen) in the sediment more organic matter to consume. In consuming the extra food they will use more oxygen in the sediment. The picture below (Fig. 2), shows oxygen profiles from one of the sediment cores collected during this cruise (the sediment type is sandy mud which is mud with a little bit of sand).  By just one centimetre (1000 micro metres =1 mm) below the surface of the sediment, all of the oxygen has been used up. If this was an oxygen profile from sandy sediment, the oxygen would penetrate to depths of five centimetres or more.

 

Fig. 2: Oxygen profile from that sediment core

This particular sediment core also beautifully illustrates how some marine animals have adapted strategies to cope with the low oxygen concentrations. The burrow which you can see in Fig. 3 is that of a polychaete worm, and it creates a flow of oxygen from the surface of the sediment down to a depth of several centimetres by moving its body (this is known as bioirrigation). The process of moving sediment (e.g. to create burrows) is known as ‘bioturbation’. This flow of oxygen from the water above the sediment allows the worm to live in the oxygen poor mud and also allows oxygen to penetrate deeper into the mud than it would normally be able to do. This can then affect the chemistry within the sediments and the overlying water, and alter the oxygen penetration depth.

 

Fig. 3: Polychaete worm in its burrow.