Shelf Sea Biogeochemistry blog

Showing posts with label CANDYFLOSS. Show all posts
Showing posts with label CANDYFLOSS. Show all posts

Monday, 23 March 2015

Picking up the marine glider

Louis Byrne, British Oceanographic Data Centre, NOC

We arrived at CANDYFLOSS early Monday morning and immediately got into the swing of things with some early morning CTD casts and then NIOZ coring. Between the two we briefly left the site to pick up a marine glider, an instrument which is one of the latest developments in marine research.



Marine glider shortly before being picked up after three months at sea.

Once released into the water, marine gliders are controlled remotely by scientists working for Marine Autonomous Robotics Services (MARS) based in Southampton. They are capable of gliding around the ocean for months at a time and thus are very useful for gaining valuable long term data. They can move up and down the water column by changing their volume and are steered either using rudders or by shifting their mass to one side or the other.

Gliders are useful because they can stay out for a lot longer than your average research cruise, and because they transmit their data remotely to land every time they surface the scientists at MARS can inspect the data almost immediately and find areas of the ocean which are of interest, such as the locations of fronts. Gliders can then be programmed to stay in these scientifically interesting areas gathering useful data. They are also able to work in all conditions, whereas ship based research cannot be performed during times when the weather conditions are too rough to be able to safely deploy instruments over the side of the ship. Autonomous instruments such as gliders are not going to replace ship based research, but the hope is that they will be able to further the capabilities of ocean science and remove some ship based tasks from current research programmes.




Dolphin watching on the RRS Discovery
 
As well as having sensors measuring chlorophyll, salinity, temperature and oxygen, these gliders also have acoustic monitoring devices used to listen for calls made by whales or dolphins, with the acoustic data being sent back to scientists at St. Andrews University to analyse. This particular glider appears to have been sent to an excellent location to listen for cetaceans, as we had only been at CANDYFLOSS for a few hours when the ship was surrounded by a pod of 8-16 (uneducated guess) common dolphins. This pod stayed around the ship most of the day, and seemed in their element racing the bow as we moved between stations.



Dolphins! (photo by Malcolm Woodward)

Saturday, 21 March 2015

We've finally made it!


Louis Byrne, British Oceanographic Data Centre, NOC

86 hours of none stop work we have finally finished 57 spatial survey sites and we’re free to head to CANDYFLOSS.  Upon reaching the total there was a massive sense of relief, but I have to say I will miss watching the sky turn from dark blue through to a pastel coloured orange as the sun rises over the first NIOZ core of the day. It has been hard work but it has also been good fun with resident RRS Discovery DJ Dave Sivyer playing the classics while we wallowed in the Celtic mud. We've had sunny days, lots of dancing, and great team work from all concerned has given us an enormous quantity of extremely useful data. 

 

Kirsty Morris, Helen Smith, Natalie Hicks and Dave Sivyer of day team.

There have been ‘pin chicks’, the ‘screwdriver of destiny’ and enough mud to keep even the most voracious sedimentologist in a state of near constant euphoria. Now it’s time to get some rest while we make the 10 hour journey south to CANDYFLOSS, where we’ll be doing it all again and more before we make the 36 hour journey home!


Thursday, 19 March 2015

Deployment of SPI camera to the ocan's seabed.

Louis Byrne, British Oceanographic Data Centre, NOC


Until Saturday when we are scheduled to depart to CANDYFLOSS we are finishing a spatial survey between the four benthic sites which we have been working at thus far. The work which we are doing at the four benthic stations helps us to understand how processes such as nutrient resuspension and carbon storage work in four different types of marine sediment (mud, sandy mud, muddy sand and sand). The purpose of the spatial survey is to put the data which we have been collecting at sites A, I, G and H into context and to look at gradients in sediment type between the main sites. To do this the program has created a network of 70 locations between the four sites. Our task is to sample as many as we can before we run out of time and head to CANDYFLOSS.



Image taken by a SPI camera

At each station we do two NIOZ cores and a SPI camera, which is an instrument that is lowered to the seabed and dropped into the sediment. It contains a prism to reflect the light 90 degrees so that when an image is taken by the camera, you get an image of the sediment and the overlying water. These images are then analysed to get an idea of the sediment type at that location and inspected for any signs of animal life.



Map of Celtic Sea showing four main benthic sites and CANDYFLOSS. Map created by Kirsty Morris (National Oceanography Centre, Southampton)


From the sediment samples brought up by the NIOZ cores, we can find out the sediment type at that particular location, and a variety of measurements are taken including organic carbon, nutrient and chlorophyll concentrations, as well as particle size, porosity (the space between the grains of the sediment) and the oxygen concentrations in the water between the grains of sediment.



Coring while performing the spatial survey

All of these measurements combined will give us a good idea of how carbon and nutrients are being cycled in the shelf seas over a wide area of the Celtic Sea, with the hope that these data can be extrapolated to cover all of the shelf seas around the UK and parts of continental Europe. This will then give us a much better understanding of the nutrient cycle in this area of the world, and we will be able to estimate how much carbon from the atmosphere is being stored in UK sediments.



Kirsty Morris operating the SPI camera just before it hits the seabed.