Publication Abstract

Occurrence of Alexandrium sp. Cysts in Sediments from the North East Coast of Britain

J. Lewis, W.A. Higman, and S. Kuenstner

Outbreaks of paralytic shellfish poisoning (PSP) have occurred along the northeast coast of Britain since 1968. The organism responsible has been documented as Gonyaulax tamarensis (Alexandrium tamarense). Sediment samples collected from Aberdeen to Flamborough head indicated a consistent concentration of Alexandrium cysts within the Firth of Forth, with a possible deposition ground between Aberdeen and St. Andrew's Bay. From Berwick, south to Flamborough Head distribution of Alexandrium cysts is sporadic with concentrations lower than Scottish sediments. Results indicated that Alexandrium cysts are under-represented on the northeast coast in areas with fine sediments and histories of intoxication. It is therefore suggested that increases in the occurrence of the motile stage of this species are seeded by the cyst population within the Firth of Forth, and that these motile populations are subsequently transported along the northeast coast. The northern deposition of Alexandrium cysts between Aberdeen and St Andrews Bay may be caused by a small gyre in the surface current system. Whilst the southerly flow of surface waters from the Firth of Forth to the Wash supports the observed decrease in frequency and occurrence of cysts to the South.

Reference:

J. Lewis, W.A. Higman, and S. Kuenstner, 1995. Occurrence of Alexandrium sp. Cysts in Sediments from the North East Coast of Britain. In: Harmful Marine Algal Blooms. ed. Lassus L., Arzul G., Erard E., Gentien and Marcaillou C., Lavoisier, Intercept. 175-180.