Dolphin harpooning off the coast of Bahia, Brazil

D Danilewicz,E M Costa-Neto,M L V Barbosa-Filho

doi:10.1186/s41200-016-0046-1

Abstract

Hundreds of thousands of cetaceans die each year due to commercial fishing catches, which is the main threat to global populations of these animals. Mortality by fishing gets disastrous proportions mainly in developing countries, for which effective fisheries management programs, as well as monitoring, environmental education or analysis of the catches impact on cetacean populations are scarce. The aim of this study was to record and describe the intentional catching of dolphins by artisanal fishermen in southern Bahia, Brazil, a region located in the Southwest Atlantic Ocean. In 2012, semi-structured interviews were conducted with 65 commercial fishermen from 13 communities in the region. Catches have been occurring for a long time by the use of harpoons and the pieces of dead animals are used as bait in longline shark fishing, whose fins have a high sale value. Although 81.5 % (n = 53) of respondents know the dolphins use, 24.2 % (n = 16) reported having used them as bait and only eight (12.1 %) of them admitted to have already killed these marine mammals. It is urgent that these catches are monitored in order to provide baseline information for future conservation actions.

Highlights

Interactions between fisheries and marine mammals may be classified as operational, when animals interact directly with fishing gear and operations, or biological, when it occurs on an ecosystemic level (Beverton 1985; Northridge & Hofman 1999)
The animals directly caught are used as bait in the fishery or consumed (Mangel et al, 2010; Read 2008; Van Waerebeek et al 1997)
Siciliano (1994) documented that dolphin harpooning and direct catches may be relatively common in Pará, north Brazil, and reported several sites along the Brazilian coast where the blubber of bycaught dolphins were opportunistically used as bait in shark fishery

Summary

Introduction

Interactions between fisheries and marine mammals may be classified as operational, when animals interact directly with fishing gear and operations (e.g. entanglements, bait depredation), or biological, when it occurs on an ecosystemic level (e.g. competition for resources) (Beverton 1985; Northridge & Hofman 1999). In the former, the distinction between its subcategories is sometimes subtle. Siciliano (1994) documented that dolphin harpooning and direct catches may be relatively common in Pará, north Brazil, and reported several sites along the Brazilian coast where the blubber of bycaught dolphins were opportunistically used as bait in shark fishery. The boto Inia geoffrensis (de Blainville 1817) and tucuxi Sotalia fluviatilis (Gervais and Deville 1853) have been directly caught and used as bait in the fishery of piracatinga Calophysus macropterus (Lichtenstein, 1819)

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