Dinophysis acuta in Scottish Coastal Waters and Its Influence on Diarrhetic Shellfish Toxin Profiles.

Sarah Swan,Andrew Turner,Keith Davidson,Elaine Mitchell,Ruth Paterson,Callum Whyte,Eileen Bresnan,Sharon Mcneill

doi:10.3390/toxins10100399

Abstract

Diarrhetic shellfish toxins produced by the dinoflagellate genus Dinophysis are a major problem for the shellfish industry worldwide. Separate species of the genus have been associated with the production of different analogues of the okadaic acid group of toxins. To evaluate the spatial and temporal variability of Dinophysis species and toxins in the important shellfish-harvesting region of the Scottish west coast, we analysed data collected from 1996 to 2017 in two contrasting locations: Loch Ewe and the Clyde Sea. Seasonal studies were also undertaken, in Loch Ewe in both 2001 and 2002, and in the Clyde in 2015. Dinophysis acuminata was present throughout the growing season during every year of the study, with blooms typically occurring between May and September at both locations. The appearance of D. acuta was interannually sporadic and, when present, was most abundant in the late summer and autumn. The Clyde field study in 2015 indicated the importance of a temperature front in the formation of a D. acuta bloom. A shift in toxin profiles of common mussels (Mytilus edulis) tested during regulatory monitoring was evident, with a proportional decrease in okadaic acid (OA) and dinophysistoxin-1 (DTX1) and an increase in dinophysistoxin-2 (DTX2) occurring when D. acuta became dominant. Routine enumeration of Dinophysis to species level could provide early warning of potential contamination of shellfish with DTX2 and thus determine the choice of the most suitable kit for effective end-product testing.

Highlights

Occurring harmful algal blooms (HABs) are known to have an adverse effect on shellfish industries worldwide, with toxic contamination of shellfish from these events potentially resulting in both human illness and a detrimental impact on the often-fragile economies of rural areas [1]
Dinophysis acuminata was recorded during the phytoplankton and Dinophysis acuminata was recorded during phytoplankton growing season
We found no significant correlation between strong positive as both D. acuminata and D. acuta were present at the same time throughout most of the summer, it correlation was identified between D. acuta and okadaic acid (OA) throughout the bloom period but as both D

Summary

Introduction

Occurring harmful algal blooms (HABs) are known to have an adverse effect on shellfish industries worldwide, with toxic contamination of shellfish from these events potentially resulting in both human illness and a detrimental impact on the often-fragile economies of rural areas [1]. Common (blue) mussels harvested in Scotland were linked to 159 cases of DSP in 2006 [8,9] and a further 70 reported cases in 2013 [10]. While these events are relatively few in number, their impact on consumer confidence and industry sustainability is significant. To mitigate the risk of human illness caused by the consumption of contaminated shellfish, European Union regulations require EU Member States to have regulatory programmes in place to monitor the presence of both marine biotoxins in shellfish production areas and the causative phytoplankton [11]. In Scotland, this information is used by the aquaculture industry to make informed decisions, following guidance issued to harvesters by Food Standards Scotland (FSS) in

Methods

Results

Conclusion