title: Trends in the exploitation of South Atlantic shark populations.
abstract: Approximately 25% of globally reported shark catches occur in Atlantic pelagic longline fisheries. Strong declines in shark populations have been detected in the North Atlantic, whereas in the South Atlantic the situation is less clear, although fishing effort has been increasing in this region since the late 1970s. We synthesized information on shark catch rates (based on 871,177 sharks caught on 86,492 longline sets) for the major species caught by multiple fleets in the South Atlantic between 1979 and 2011. We complied records from fishing logbooks of fishing companies, fishers, and onboard observers that were supplied to Brazilian institutions. By using exploratory data analysis and literature sources, we identified 3 phases of exploitation in these data (Supporting Information). From 1979 to 1997 (phase A), 5 fleets (40 vessels) fished mainly for tunas. From 1998 to 2008 (phase B), 20 fleets (100 vessels) fished for tunas, swordfishes, and sharks. From 2008 to 2011 (phase C), 3 fleets (30 vessels) fished for multiple species, but restrictive measures were implemented. We used generalized linear models to standardize catch rates and identify trends in each of these phases. Shark catch rates increased from 1979 to 1997, when fishing effort was low, decreased from 1998 to 2008, when fishing effort increased substantially, and remained stable or increased from 2008 to 2011, when fishing effort was again low. Our results indicate that most shark populations affected by longlines in the South Atlantic are currently depleted, but these populations may recover if fishing effort is reduced accordingly. In this context, it is problematic that comprehensive data collection, monitoring, and management of these fisheries ceased after 2012. Concurrently with the fact that Brazil is newly identified by FAO among the largest (and in fastest expansion) shark sub-products consumer market worldwide.
authors.affiliation: Departamento de Pesca e Aquicultura (DEPAq), Av. Dom Manoel de Medeiros, Universidade Federal Rural de Pernambuco (UFRPE), S/N, Recife, PE, 52171-900, Brazil.
authors.forename: Rodrigo
authors.initials: R
authors.lastname: Barreto
authors.affiliation: Hopkins Marine Station, Stanford University, Pacific Grove, CA, 93950, U.S.A.
authors.forename: Francesco
authors.initials: F
authors.lastname: Ferretti
authors.affiliation: Department of Mathematics and Statistics, Dalhousie University, Halifax, NS, B3H 4R2, Canada.
authors.forename: Joanna M
authors.initials: JM
authors.lastname: Flemming
authors.affiliation: Instituto de Pesca, Agência Paulista de Tecnologia dos Agronegócios da Secretaria de Agricultura e Abastecimento do Estado de São Paulo (APTA), Avenida Bartolomeu de Gusmão, 192, Santos, SP, 11045-401, Brazil.
authors.forename: Alberto
authors.initials: A
authors.lastname: Amorim
authors.affiliation: Departamento de Pesca e Aquicultura (DEPAq), Av. Dom Manoel de Medeiros, Universidade Federal Rural de Pernambuco (UFRPE), S/N, Recife, PE, 52171-900, Brazil.
authors.forename: Humber
authors.initials: H
authors.lastname: Andrade
authors.affiliation: Biology Department, Dalhousie University, Halifax, NS, B3H 4R2, Canada.
authors.forename: Boris
authors.initials: B
authors.lastname: Worm
authors.affiliation: Departamento de Pesca e Aquicultura (DEPAq), Av. Dom Manoel de Medeiros, Universidade Federal Rural de Pernambuco (UFRPE), S/N, Recife, PE, 52171-900, Brazil.
authors.forename: Rosangela
authors.initials: R
authors.lastname: Lessa
mesh_terms: D000818:Animals; D001267:Atlantic Ocean; D001938:Brazil; D003247:Conservation of Natural Resources; D005398:Fisheries; D011157:Population Dynamics; D012754:Sharks; D014413:Tuna
keywords: Océano Atlántico Sur; South Atlantic Ocean; bitácoras de pesca; especies amenazadas; fishing logbooks; longline fisheries; pelagic sharks; pesqueras de palangre; threatened species; tiburones pelágicos