DNA analysis of a large collection of shark fins from a US retail shop: species composition, global extent of trade and conservation - a Technical Report from the Monterey Bay Aquarium

Abstract

19We identified shark fins sampled across the entirety of a shark fin shop that had operated on the west 20 coast of the United States until 2014. From these specimens we obtained 963 species identifications 21 with Cytochrome oxidase (COI) sequencing and 1,720 identifications with control region (CR) 22 48

Coastal sharks supply the global shark fin trade

“…Abundant and widespread species such as blue sharks ( P. glauca ) remain the dominant species in fins from the Hong Kong market hub [ 15 ]. However, even there, genetic barcoding revealed an additional 40 range-restricted coastal species (electronic supplementary material, figures S1 and S2), while studies from other markets [ 13 , 14 , 16 ] show a greater proportion of coastal sharks.…”

“…Figure 2 a plots the probability of occurrence for all species, according to fin identifications in four market studies. The similar geographic pattern of the Hong Kong, Vancouver and San Francisco market sources [ 13 , 15 , 16 ] reflects that China is the established aggregating node that receives, processes and supplies a majority of fins to global markets [ 16 ]. The Brazil-based study [ 14 ] sampled fins in a series of local wet markets and indicates a dominance of fishing activity in coastal Brazil and the Caribbean ( figure 2 a,c ).…”

“…Probability of origin for shark fins sampled from markets ( a ) across the global ocean, ( b ) by EEZ jurisdiction and ( c ) ranked by top sovereign nation contributors. Maps accumulate probability from each species' niche model values, where each species is proportionately rated by the number of fin identifications in four studies [ 13 – 16 ]. Most activity occurs near-shore, within EEZs, and the reported ratio in ( b ) is the relative probability.…”

“…Published studies [13][14][15][16] used cytochrome oxidase (COI) sequencing to provide robust species identifications for 5327 shark fins sampled at markets in Brazil, Canada, China and the United States (electronic supplementary material, table S1 and figure S1). Previous analyses generated SDMs for 51 of these species from open-access occurrence data at Global Biodiversity Information Facility, FishBase and Ocean Biodiversity Information System.…”

“…However, the method was difficult to scale up and provided little information on rare species. A DNA barcoding approach using BOLD and BLAST taxonomy databases [13] with extensive sequence libraries provides an improved ability to identify larger numbers of species. Using this approach, four recent studies [13][14][15][16] revealed the source species of over 5000 individual shark fins from markets in Hong Kong, Vancouver, San Francisco and northern Brazil.…”