Saxitoxin (STX) concentrations measured by enzyme-linked immunosorbent assay in tissues from seabird carcasses collected during a seabird die-off event in the Bering and Chukchi seas in August–September 2017. Tissue concentrations are reported in µg/100 g STX, except those below method detection limits (BD) or with detectable but not quantifiable values (DBNQ). — = No sample was available for testing