Alexandrium tamarense has been associated with paralytic shellfish poisoning (PSP) which is potentially the most important shellfish toxin globally. This potentially fatal condition results from the ingestion of shellfish that contain the potent PSP neurotoxins. Alexandrium spp are potent producers of PSP toxins worldwide, with the species Alexandrium tamarense being of particular concern in UK waters. The magnitude and timing of blooms vary widely. The toxicity is not constant but can be related to environmental factors such as nutrient stress. Excystment, subsequent vegetative growth rate and other environmental factors that influenced toxicity may all combine to determine the severity of a PSP event.
The biogeography of the A. tamarense complex is of particular current attention. A. tamarense exists as five, morphologically indistinguishable ribotypes with the toxin producing Group I strain and the non toxic Group III strain present in UK waters. Recent analysis of global molecular records suggests that UK waters are the only location that toxic and non toxic ribotypes coincide. Previous studies have reported the presence of the (benign) Group III strain only in the south of the UK with the (toxic) Group I strain being present only in the north. However, recent surveys undertaken independently by both Marine Scotland and SAMS have observed that this pattern no longer holds true with both Group I and III strains of A. tamarense present in Scottish waters.
The question underlying my PhD study is to establish if any environmental niche differences exist between the two strains. I investigate how environmental conditions influence factors such as excystment, growth and competition and how these affect the different A. tamarense ribotypes.
Supervisors
Project funder
NERC CASE (Marine Scotland)
University
University of the Highlands and Islands / Aberdeen University
