‘We sell it in secret, like drugs’: Brazil’s appetite for shark meat puts species under threat

A blue shark is taken into cold storage in Cananéia, a fishing port in São Paulo state. Although they reproduce slowly, at least 80m sharks are killed a year globally Photograph: Avener Prado/The Guardian

The bright blue skies and calm waters of the estuary belie rough conditions at sea, and there is no sign of activity among the colourful fishing boats moored around the harbour of Cananéia, a sleepy fishing town 160 miles south of São Paulo.

On the wharf, however, a delivery of frozen fish from Uruguay has just arrived and a few men in white gumboots are busy unloading pallets of beheaded specimens labelled Galeorhinus galeus – school shark.