Cruising the Clyde
12 November 2015
SAMS PhD student, Ruth Paterson, gives an account of the recent sampling expedition around the Firth of Clyde.
I met the ShellEye team in a car park in Oban on a cold and misty September morning. It was still dark and the town was very quiet. We began our drive to Tarbert on Loch Fyne where we would meet RV Seol Mara, its crew and a collaborating scientist from the Marine Institute, Ireland. Setting sail from Tarbert at 8am (after a cheeky bacon roll) we sailed south to begin our first transect. We were hunting for toxic dinoflagellates Azadinium spinosum and Dinophysis sp. to ground-truth satellite data in these coastal areas.
At station 1 the wind was blowing a gusty force 4-5 and we were apprehensive about sailing further south into the exposed Firth of Clyde. At station 2 the waves were worse and made sampling a real challenge. When lowering a Secchi disk, a large wave came up from below and snapped it in half and all I could do was watch the pieces sink out of sight! As the morning progressed, however, the wind steadily dropped and the sun showed its face.
After sampling a few more stations we stopped for a quick lunch (cruises are hungry work after all) and the waves only lapped against the hull gently as the sun got brighter. As we moved into the afternoon sampling, we saw pods of porpoise, diving gannets, guillemots and swimming shags. We also saw the Trident submarines being escorted into the Clyde by patrol boats and a helicopter, as well as a glimpse of Minke whales in the distance! At our final sampling station of the day, between Troon and Lamlash bay, the water was ghostly calm and there was no wind. The plankton net brought up millions of Copepods and the (broken) secchi depth was 11m.
The next day the weather wasn’t so good, with a stiff breeze in a moody sky and battleship grey water. We did our stations quickly as my fingers froze in the wind and cold seawater. Our Conductivity Temperature Depth (CTD) plots showed beautifully distinct chlorophyll maximums and everything went off without a hitch. We made it to Inveraray to do our uppermost station in Loch Fyne and managed a final one outside Ardrishaig before entering the Crinan basin.
When monitoring toxic species by satellite the pixel resolution of data is too large to measure narrow sealochs and in complex costal environments (the west coast of Scotland being a prime example). These data will contribute essential ground-truthing for ShellEye satellite data in coastal regions and test whether what is being shown matches the field data. The combination of measurements taken will tell us whether harmful algae is present, if there is any associated toxicity, what the phytoplankton community looks like, what the corresponding environmental factors are if we detect a bloom of algae, and also contribute to the first Scottish field survey of new species Azadinium spinosum abundance and distribution.