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.

Beginning our 12 hours shifts with some brilliant sunrises over the Celtic sea

Louis Byrne, British Oceanographic Data Centre, NOC

Through Tuesday night and on to Wednesday we were coring the final benthic station H, and by noon we had clear blue skies, a burning sun and had finished the coring at site H, and in doing so finished all the work we needed to complete at all of the four main SSB benthic  sites! The fun doesn’t stop here however, as we still have to do the majority of the spatial survey which we have been performing between the sites and steam to the central Celtic Sea site (called CANDYFLOSS) and then finally the shelf edge. A pretty full programme is being planned for both these sites!

Sunrise over the Celtic Sea

Over the last couple of days we have been working solidly 24 hours a day to get the data we need, with shift changes at 6 PM and 6 AM, and hats off to the SteveWiddicombe (Plymouth Marine Laboratory) and the rest of the night team who have been coring, trawling and fluming in the dead of night to get us towards the finishing line. The day team (led by Dave Sivyer of Cefas) have also been working just as hard, and we have been fortunate to begin our shift with some brilliant sunrises over the Celtic sea.

Vas Kitidis (Plymouth Marine Laboratory) and Natalie Hicks (Scottish
Association for Marine Science)

Morale was high as the sun was out and not before long our benthic scientists had reverted to type and started covering their faces with mud. Through the day and into the night we continued with the spatial survey that we have been doing periodically thus far, and which I will talk about in detail in the next post.

First core of the day for day team

First coring at sunrise

We’re hoping that we have enough time to get the majority of the survey done and have time to do a couple of day’s sampling at CANDYFLOSS, although with just over a week left before we need to be back in Southampton the timing is tight!

Some members of the day team