Assessment of emerging biotoxins (pinnatoxin G and spirolides) at Europe's first marine reserve: Lough Hyne

Abstract

Active and passive sampling methods were employed over a four-month period, at a site off the South-West coast of Ireland, to characterise the occurrence of cyclic imines in the water column. The marine toxins 13-desmethyl-SPXC, 20-methyl SPXG toxins and pinnatoxin G were detected using active sampling from Diaion HP-20 resin. Seven water depths were sampled to determine stratification of the toxins in the water column using Solid Phase Adsorption and Toxin Tracking (SPATT). Both 13-desmethyl-SPXC and pinnatoxin G were detected using two different resin types; Diaion HP-20 and Amberlite XAD761. HP-20 proved more effective at accumulating the toxins, with a higher percentage of positive samples and a higher ratio of toxin adsorbed relative to XAD761. No temporal variation in toxin-quantities was detected, indicating that there was no change in density of causative algal species in the water column. Pinnatoxin G was detected more frequently from surface to 30 m depth, with a similar pattern observed for 13-desmethyl-SPXC occurrence using XAD761. No difference in the occurrence of 13-desmethyl-SPXC was observed between depths using HP-20 resin. This is the first reported incidence of pinnatoxin G in Irish waters and highlights cyclic imines as emerging toxins in European waters.