All samples were collected using standard clean procedures for Hg
analysis. Whole, dried unprocessed shark fins examined in this study
were collected from wild-captured specimens taken from fisheries of
the United States, Sri Lanka, Fiji, and South Africa as part of a separate
study. All fins were sun-dried. Fins were stored at Stony Brook University
in separate plastic bags at room temperature for 12 to 18 months prior to
sampling. A small piece (~10 mm × 10 mm) of the distal portion of each
finwas analyzed for Hg content. Fins originated from one of 13 shark species,
all of which are known to occur in the international dried fin trade
(Table 1).
Bowls of shark fin soupwere purchased for Hg analysis from50 restaurants
located throughout the United States by volunteers in March
and April 2012 (Table S1). Either species or genus of origin of the fin
used tomake each bowl of soupwas assessed using a mini-DNAbarcode
protocol on a single, randomly selected fin needle taken from each bowl
(Fields et al., in review). Subsamples of soup for Hg speciation analysis
were collected in 50-mL polypropylene centrifuge tubes that were
cleaned with a rigorous technique suitable for trace-level Hg analysis