Decarbamoylsaxitoxin coincided with the greater proportions of GTX 2,3 in the sample profiles that exhibited low total toxicities (Table 1, Fig. 6). Accumulation of higher proportion of carbamate toxins (GTX) relative to the other group of PSP toxins (C toxins) was observed in the mussel tissue also by Kwong, Wang, Lam, and Yu (2006). These authors recorded carbamate toxins accounted for 33.4% in Alexandrium species, while the same toxins accounted for 53.0% on average in the mussel samples. Such difference could result in differential retention or biotransforma- tion of PSP toxins.