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

Studying radium concentrations in the muddy sendiments off the north west coast of Cornwall.

On Tuesday we continued with our coring as well as performing a few more CTDs.  Amber Annett (Edinburgh University) is taking water column samples from the CTD and sediment samples from an instrument called a megacorer, in order to study radium concentrations in the sediment and the overlying water, and she has written the following blog piece about her work.

Naturally occurring radium is a very useful element for studying many different shelf sea processes. This is because it is radioactive (no, not that dangerous sort of radioactive!), and we know the rate at which radium naturally decays. This means that radium can act as a kind of internal clock for a parcel of water, telling us how fast things happen.

Luckily, radium is also extremely rare in seawater, so even though it is a radioactive element it is present at concentrations thousands of times lower than anything we would need to worry about. Even though I use extremely sensitive detectors to measure radium (photo), because it is so rare I still need to sample a very large amount of water  to collect enough for a useful measurement– up to 150 litres for just one sample.

Amber's radium detectors on board the RRS Discovery

Radium comes from rocks, and there is plenty of lithogenic (rock) material in the sandy, muddy sediments on the UK continental shelf here off the north west coast of Cornwall. I am using a megacorer to collect pore water (water from in between the sand and mud particles inside marine sediments) and samples from the sediment-water interface, as well as a CTD to measure radium in the water column above. This lets me look at how much radium diffuses out of the sediments and into the sea, as well as how quickly this process occurs. This work is part of the trace metal group (SSB Work package 3), who are ultimately looking at how shelf seas can act as a source of iron, an essential nutrient for marine plant life, that is very scarce in many areas of the ocean. 

We will be using radium concentrations to help track iron that comes from sediments, where it goes and how fast it gets there.