Diarrhetic Shellfish Toxins in Primorsky Krai, Russia

Mariculture and recreational zones are expanding rapidly along the coast of Primorsky Krai in the Russian Far East, increasing the pressing need for monitoring of toxin-producing algae and seafood poisoning. One poisoning syndrome, diarrhetic shellfish poisoning has not been reported in this region, but its expansion to other subarctic waters has been observed. To our knowledge, the research here shows the first measures of diarrhetic shellfish toxins (DST) on the east coast of Russia. Mussels contained DST concentrations above the recommended regulatory level of 16 mg/100 g shellfish at almost all sites sampled in the Primorsky Krai region, with maximum concentrations of 56.3 mg/100 g. The primary DST isoform was dinophysistoxin-1 (DTX-1; 94%-100%) but minor amounts of okadaic acid (0%-6%) also were detected. Other lipophilic toxins measured in shellfish were yessotoxin , pectenotoxin-2 (PTX-2), and azaspiracid-2; the last two toxins observed in Russian water for the first time. Phytoplankton samples dominated by Dinophysis acuminata contained DST, indicating that it was likely responsible for shellfish toxicity. Particulate seawater samples with Dinophysis contained 2.1–10.2 ng DTX-1/l and 6.5–101.8 ng PTX-2/l, corresponding to cellular concentrations of 3.1–5.6 pg DTX-1/cell and 9.6–46.7 pg PTX-2/cell. These findings provide a foundation for a Federal Monitoring Program for harmful algal blooms and phycotoxin control in seafood in Russia, and suggest that appropriate methods for both rapid screening and regulation of shellfish toxins should be established to ensure safe harvest in Russia.