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Cruising the Clyde: new publication

11 December 2017
Prof. Keith Davidson, from the Scottish Association for Marine Science (SAMS), provides an update on the Scottish Clyde Sea sampling cruise.
In September 2015 researchers from the SAMS and the Marine Institute (Ireland) cruised the Clyde Sea in southwest Scotland. We sampled 12 stations that stretched from the very top of Loch Fyne to the central Clyde Sea, approximately level with Prestwick Airport. At the same time Food Standards Scotland (FSS) was taking samples from active shellfish harvesting sites for their on-going regulatory monitoring for shellfish flesh biotoxins.

We detected a bloom of Dinophysis acuta which appeared to have accumulated against a thermal front at the mouth of Loch Fyne. The location of the front could be detected in directly sampled CTD contour plots, in satellite images of sea surface temperature (Dr Peter Miller, PML) and through particle tracking modelling (Dr Thomas Adams, SAMS). The maximum cell density of D. acuta at the front was 2840 cells/L, much higher than Dinophysis acuminata (max. 200 cells/L) in the same samples. At the same time, FSS was able to detect diarrhetic shellfish poisoning (DSP) toxins within shellfish at concentrations high enough to close harvesting (max. 601 ±237 mg OA eq/kg shellfish flesh). We also detected other potentially harmful diatom blooms in the area but without reported effects to local aquaculture operations.

In Scottish waters D. acuminata is usually the most abundant species, however, in this instance D. acuta dominated. Increased abundance of D. acuta has been previously linked with physical cell aggregation and increases in surface water temperatures. Furthermore, D. acuta is linked with the production of Dinophysis-2 toxin, which is thought to remain inside shellfish for longer than the types of toxin produced by D. acuminata. This could pose a considerable threat to shellfish aquaculture especially in a time of climate change and its effects, such as rapidly warming sea surface temperatures.

Related Information:

The associated paper was published in Harmful Algae Journal in Summer 2017:
Paterson, R.F., McNeill, S., Mitchell, E., Adams, T., Swan, S., Clarke, D., Miller, P.I., Bresnan, E., Davidson, K. (2017) Environmental control of harmful dinoflagellates and diatoms in a fjordic system. Harmful Algae. 69: 1-17. 

Previous articles on the Clyde cruises were November 2015 and August 2016.