Use este identificador para citar ou linkar para este item: https://repositorio.inpa.gov.br/handle/1/14660
Título: Both cetaceans in the Brazilian Amazon show sustained, profound population declines over two decades
Autor: Silva, Vera Maria Ferreira da
Carvalho, Carlos Edwar Freitas de
Dias, Rodrigo L.
Martin, Anthony Richard
Palavras-chave: Ecology
Environment
Geography
Nonhuman
Population Density
Population Growth
Pressure
Survival Rate
Toothed Whale
Animals
Cetacea
Population Dynamics
Statistical Model
Animalss
Cetacea
Models, Statistical
Population Dynamics
Data do documento: 2018
Revista: PLoS ONE
Encontra-se em: Volume 13, Número 5
Abstract: Obligate river dolphins occur only in the rivers of Asia and South America, where they are increasingly subject to damaging pressures such as habitat degradation, food competition and entanglement in fishing gear as human populations expand. The Amazon basin hosts two, very different, dolphins—the boto or Amazon river dolphin (Inia geoffrensis) and the smaller tucuxi (Sotalia fluviatilis). Both species have wide geographical ranges and were once considered to be relatively abundant. Their IUCN Red List conservation status of Data Deficient (DD), due to limited information on threats, ecology, population numbers and trends, did not initially cause alarm. However, the development of dolphin hunting to provide fish bait at around the beginning of this millennium broadly coincided with the onset of a widespread perception that numbers of both species were in decline. Consequently, the need for population trend data to inform conservation advice and measures became urgent. This paper presents a 22-year time series of standardised surveys for both dolphins within the Mamirauá Reserve, Amazonas State, Brazil. Analysis of these data show that both species are in steep decline, with their populations halving every 10 years (botos) and 9 years (tucuxis) at current rates. These results are consistent with published, independent information on survival rates of botos in this area, which demonstrated a substantial drop in annual survival, commencing at around the year 2000. Mamirauá is a protected area, and is subject to fewer environmental pressures than elsewhere in the region, so there is no reason to suspect that the decline in dolphins within the Reserve is more pronounced than outside it. If South America’s freshwater cetaceans are to avoid following their Asian counterparts on the path to a perilous conservation status, effective conservation measures are required immediately. Enforcement of existing fishery laws would greatly assist in achieving this. © 2018 F. da Silva et al. This is an open access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.
DOI: 10.1371/journal.pone.0191304
Aparece nas coleções:Artigos

Arquivos associados a este item:
Arquivo Descrição TamanhoFormato 
artigo-inpa.pdf5,83 MBAdobe PDFThumbnail
Visualizar/Abrir


Este item está licenciada sob uma Licença Creative Commons Creative Commons