[MARMAM] New publication: Use of boto and tucuxi for bait
Dear MARMAMERS, I am pleased to announce the following publication: Iriarte, V. Marmontel, M. (2013). Insights on the use of dolphins (boto,* Inia geoffrensis* and tucuxi, *Sotalia fluviatilis*) for bait in the piracatinga (*Calophysus macropterus*) fishery in the western Brazilian Amazon. J. Cet. Res. Manage. 13(2):163-173. ABSTRACT: In the Amazon Basin the use of the pink dolphin or boto (*Inia geoffrensis*) for bait in the piracatinga (*Calophysus macropterus*) fishery was first detected in the year 2000. Since then, this artisanal fishery has become more prevalent as it requires only a few hours of work per night and provides immediate cash earnings. It is thus an attractive addition to (or replacement for) traditional fishing. Previous reports have noted the use of botos as bait, but stated that the most common bait used are caimans (*Melanosuchus niger*, *Caiman crocodilus*). Estimates of the number of dolphins killed based on fish landings have been proposed and an apparent decrease in sighting/survival of an artificially-marked boto population was observed. Although stocks/population estimates, trends, and actual numbers of hunted dolphins are unknown, the conservation impacts of this activity are of concern. Between October 2010 and November 2011, research was conducted within an area with serious conflicts between dolphins and fishermen as well as intense fishing for piracatinga, i.e. in the lower Japurá River, on the border with the Mamirauá and Amanã Sustainable Development Reserves, where both boto and tucuxi (*Sotalia fluviatilis*) are used for bait. One-hundred and fifty-seven monitoring surveys were carried out in eight key communities, confirming 114 piracatinga fishing events through direct monitoring and incognito surveys of fishing gear (*gaiolas*). Empirical evidence of the activity in *gaiolas*comprised pieces of bait, carcass remains, piracatinga provoked vomits and dolphin fished carcasses. Of those, 31.2% (*n*=35) involved cetacean bait (91.4% *I. geoffrensis*, 8.58% *S. fluviatilis*), 68.7% (*n*=77) caiman bait (96% *M. niger, *4% *C. crocodilus*), and two fishing events used both types. These percentages may be higher/lower in other areas within and outside the Reserves. Given the increasing trend of the piracatinga fishery, the authors believe that precautionary measures for the conservation of Amazonian dolphins are urgently needed. Development of practical short-term solutions (e.g. offal-baited fish traps) and multispecies management together with law enforcement, incentives, and educational programmes could allow the future transition of riverine communities from the piracatinga fishery to sustainable, higher income activities. KEY WORDS: BOTO; TUCUXI; DIRECT CAPTURE; FISHERIES; CONSERVATION; MANAGEMENT; SUSTAINABILITY; REGULATIONS Pdf copies can be requested to verorci...@gmail.com Sincerely, Verónica -- Verónica Iriarte, MSc Calles 25 y 26 Edif. Club del Mar ss104 CP: 20100 Punta del Este Uruguay ___ MARMAM mailing list MARMAM@lists.uvic.ca https://lists.uvic.ca/mailman/listinfo/marmam
[MARMAM] New Publication: River dolphin mortality events in the Amazon
Dear MARMAMERS, We are pleased to announce the following publication in Aquatic Mammals: Iriarte, V. Marmontel, M. (2013). *River dolphin (Inia geoffrensis, Sotalia fluviatilis) mortality events attributed to artisanal fisheries in the Western Brazilian Amazon.Aquatic Mammals, 39(2): 116-124. DOI: 10.1578/AM.39.2.2013.116.* *ABSTRACT:* In the Western Brazilian Amazon, interactions of boto (*Inia geoffrensis*) and tucuxi (*Sotalia fluviatilis*) dolphins with fishing activities are common, but the prevalence of incidental/intentional catches is not known. This article describes incidental mortality events and intentional killing of *I. geoffrensis* and *S. fluviatilis* entangled in artisanal fishing gear and the opportunistic use of carcasses as bait. Between October 2010 and November 2011, surveys were conducted in waters of the lower Japurá River, between the Mamirauá and Amanã sustainable development reserves. In order to obtain information on interactions and to try to establish a stranding/entanglement response program (SERP), informal conversations were exchanged with local inhabitants (n = 174). Intense carcass-search surveys (n = 171) along the river in the four hydrological seasons (e.g., low, rising, high, and falling waters) were conducted, comprising a total of 1,197 h of sampling effort. Twenty-five dolphin–fishing interaction events were recorded (11* I. geoffrensis* and 14 *S. fluviatilis*), 19 in 2011 and six in 2012 (through SERP). A total of 11 necropsies (three *I. geoffrensis* and eight *S. fluviatilis*) were performed. Four individuals (two* I. geoffrensis* and two *S. fluviatilis*) exhibited evidence of physical violence before death, and two (one* I. geoffrensis* and one *S. fluviatilis*) died in abandoned gillnets. Two intentional killing events of* I. geoffrensis* incidentally entangled for bait use in the piracatinga (*Calophysus macropterus*) fishery were reported by fishermen, while three carcasses (two* I. geoffrensis* and one *S. fluviatilis*) with gillnet marks were also used in that activity. At least six of the *S. fluviatilis *entanglement events occurred in fishing gear used for tambaqui (*Colossoma macropomum*) and pirapitinga (*Piaractus brachypomus*) (90/100-mm mesh-size gillnet), two of the most important commercial fish species in the Amazon Basin. As seasonal fishing constitutes the main income for riverine human populations, the negative reactions that cetacean presence causes to people could have a catalyst effect for the transition from “incidental capture” to “intentional capture and competitor removal.” Law enforcement and precautionary measures through good fishing practices inside dolphin critical foraging areas should be taken together with fisheries’ managers and fishermen to start to develop multiple-species management and ensure sustainable fishing practices. The article is available at: http://www.aquaticmammalsjournal.org PDF copies can be requested to: verorci...@gmail.com -- Verónica Iriarte Grupo de Pesquisa em Mamíferos Aquáticos Amazônicos Instituto de Desenvolvimento Sustentável Mamirauá Estrada do Bexiga 2584, Bairro Fonte Boa CEP:69470-000 Tefé, Amazonas Brasil ___ MARMAM mailing list MARMAM@lists.uvic.ca https://lists.uvic.ca/mailman/listinfo/marmam
