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.

Deploying the Cefas Lander and the SmartBuoy

Louis Byrne, British Oceanographic Data Centre, NOC

Wednesday saw the deployment of two moored instrument suites owned by Cefas. The first deployment was a lander similar to the NOC-L (National Oceanography Centre, Liverpool) Mini-STABLE lander deployed earlier in the cruise, although the instruments attached to the Cefas minilander are very different.

The Cefas lander has an ADCP (Acoustic Doppler Current Profiler), which uses the Doppler affect to measure current speed and direction through the water column. As well as the ADCP there is a water sampler collecting a sample of water in a plastic bag (to be analysed for nutrients on land after the mooring is retrieved) and other instruments measuring a variety of parameters including temperature, chlorophyll fluorescence and optical backscatter (a way of measuring how many particles are in the water, which is useful for determining how much sediment any storm events may mix into the water column).

 

A Cefas SmartBuoy on deck

The second one was a Cefas SmartBuoy which was deployed at the same location as the lander but instead of resting on the seabed it floats on the surface. The SmartBuoy has all the same instruments that are on the lander as well as a water sampler which will collect one sample of water each day for analysis back at the lab.

The Lander and the SmartBuoy are useful because they can provide long term high resolution background data. The overall UK SSB programme is a seasonal project, lasting one year, and repeatedly sampling the same sites to see how the processes affecting the carbon and nitrogen cycles vary between the seasons.

The seasonal changes in the Celtic Sea primarily revolve around the development of water column temperature stratification in spring, through to when it breaks down in late summer to early autumn (see the previous blog post for an explanation to  this process and the resulting phytoplankton blooms).

A Cefas SmartBuoy after being deployed in the Cetic Sea

The data collected by the SmartBuoy and minilander provide very useful data on the timing and magnitude of the development of stratification and the phytoplankton blooms. The chlorophyll fluorescence and oxygen sensors attached to the SmartBuoy on the sea surface can detect the start of the phytoplankton bloom as phytoplankton use chlorophyll to photosynthesise, a process which produces oxygen as a by-product.

Meanwhile on the seabed, when stratification develops there will be a decrease in oxygen. This is because aerobic bacteria and the countless other marine organisms which require oxygen will continue to use it, however, as this layer has now been cut off from the surface (by the thermocline) the oxygen diffusing into the  surface water from the atmosphere does not make it down to the water below the thermocline quick enough to replenish it. This decrease in oxygen will be picked up by the oxygen sensor attached to the Cefas minilander. The minilander is also able to detect when the phytoplankton bloom dies off, as the large influx of dead phytoplankton cells falling down through the water column (also known as Marine Snow) will cause a peak in chlorophyll and later a further decrease in oxygen, as the phytoplankton are consumed.

Large amount of marine particles or marine snow in suspension just above the sea floor. Image credit:
 https://phys.org/news/2013-07-marine-scientists-explore-biodiversity-ecosystems.html

By measuring the biogeochemical changes which revolve around the development and breakdown of stratification, the data from the Cefas minilander and SmartBuoy can help put the rest of the data collected during SSB into context, by placing the measurements taken during this cruise within the seasonal cycle that this region experiences.