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Local ecological knowledge of fishers from southern and southeastern Brazil about the franciscana dolphin Pontoporia blainvillei: Strategies for conservation

Abstract

This study compares local ecological knowledge (LEK) of fishers from the Southwest Atlantic Ocean (SWAO), Brazil, related to the franciscana dolphin (Pontoporia blainvillei). We conducted 330 ethnographic interviews in ten fishing communities in southern and southeastern Brazil between 2012 and 2018. Boolean or Classic Logic was used to identify 95 fishers who were able to recognize the franciscana dolphin accordingly to the taxonomic entity P. blainvillei: 23 in northern Espírito Santo state, one in southern Espírito Santo, 20 in northern Rio de Janeiro state, and 51 in northern Paraná state. Among these 95 fishers, 87.4% (n = 83) reported incidental captures in fishing nets. Among these, 52 (54.7%) did not know any solution to this problem. Interviews revealed that the fishers usually discard carcasses in the sea after fat and muscle tissue are removed so that they can be used as bait for shark fishing or as food. In Southeastern Brazil, fishers LEK related to their ability to identify franciscana dolphin varied from ‘no identification’ and ‘extremely low identification’ to ‘partial’ and ‘good identification,’ while in southern Brazil, fishers mainly presented a ‘good identification’ of the dolphins. We propose comanagement actions to conserve the franciscana dolphin in the SWAO.

Key words
dolphin; local ecological knowledge; incidental capture; Southwest Atlantic Ocean

INTRODUCTION

The franciscana dolphin, Pontoporia blainvillei (Gervais & d’Orbigny, 1844) is a small coastal marine mammal found in shallow waters up to 50 meters in depth between the northern Espírito Santo state (ES) (18°25’S-39o42’W, southeastern Brazil) and the San Matías Gulf (43°18’S-65o06’W, Argentina) (Praderi et al. 1989PRADERI R, PINEDO MC & CRESPO EA. 1989. Conservation and management of Pontoporia blainvillei in Uruguay, Brazil and Argentina. In: Perrin WF, Brownell RL, Zhou K & Liu J (Eds), Biology and Conservation of the River Dolphins. Occasional Papers-IUCN-SSC, Hong Kong, p. 52-56., Siciliano 1994SICILIANO S. 1994. Review of small cetaceans and fishery interactions in coastal waters of Brazil. Rep Internat Whal Comm 15: 241-250., Crespo et al. 2010CRESPO EA, PEDRAZA SN, GRANDI MF, DANS SL & GARAFFO GV. 2010. Abundance and distribution of endangered franciscanas (Pontoporia blainvillei) in Argentine waters and conservation implications. Mar Mam Sci 26: 17-35., Danilewicz et al. 2010DANILEWICZ D, MORENO IB, OTT PH, TAVARES M, AZEVEDO AF, SECCHI ER & ANDRIOLO A. 2010. Abundance estimate for a threatened population of franciscanas in southern coastal Brazil: uncertainties and management implications. J Mar Biol Assoc UK 90: 1649-1657.). There are distribution gaps in southeastern Brazil, with very few records in recent decades (Cunha et al. 2014CUNHA HA, MEDEIROS BV, BARBOSA LA, CREMER MJ, MARIGO J, LAILSON-BRITO J, AZEVEDO AF & SOLÉ-CAVA AM. 2014. Population structure of the endangered franciscana (Pontoporia blainvillei): reassessing management units. PLoS ONE 9: e8563., Amaral et al. 2018AMARAL KB ET AL. 2018. Reassessment of the franciscana Pontoporia blainvillei (Gervais & d’Orbigny, 1844) distribution and niche characteristics in Brazil. J Exp Mar Biol Ecol 508: 1-12., Mayorga et al. 2020MAYORGA LFSP ET AL. 2020. Strandings of cetaceans on the Espírito Santo coast, southeast Brazil, 1975–2015. ZooKeys 948: 129-152.). The first record includes the coastal area between the Piraquê-Açu River mouth, ES (19°57’S-40º08’W), and Barra de Itabapoana, Rio de Janeiro state (RJ) (21°18’S-40o54’W). The second gap extends from Armação dos Búzios (22°44’S-41o53’W) to Piraquara de Dentro (22°59’S-44o26’W), both of which are located in RJ (Siciliano et al. 2002SICILIANO S, DI BENEDITTO APM & RAMOS RMA. 2002. A toninha, Pontoporia blainvillei (Gervais & d´Orbigny, 1844) (Mammalia, Cetacea, Pontoporiidae), nos estados do Rio de Janeiro e Espírito Santo, costa sudeste do Brasil: Caracterizações dos hábitats e fatores de isolamento das populações. Boletim do Museu Nacional–Nova Série Zoologia 146: 1-15, Amaral et al. 2018AMARAL KB ET AL. 2018. Reassessment of the franciscana Pontoporia blainvillei (Gervais & d’Orbigny, 1844) distribution and niche characteristics in Brazil. J Exp Mar Biol Ecol 508: 1-12.). The absence of the species in these gaps is likely due to water temperature and transparency, the width of the continental shelf, and/or the presence of predators (Siciliano et al. 2002SICILIANO S, DI BENEDITTO APM & RAMOS RMA. 2002. A toninha, Pontoporia blainvillei (Gervais & d´Orbigny, 1844) (Mammalia, Cetacea, Pontoporiidae), nos estados do Rio de Janeiro e Espírito Santo, costa sudeste do Brasil: Caracterizações dos hábitats e fatores de isolamento das populações. Boletim do Museu Nacional–Nova Série Zoologia 146: 1-15, Cunha et al. 2014CUNHA HA, MEDEIROS BV, BARBOSA LA, CREMER MJ, MARIGO J, LAILSON-BRITO J, AZEVEDO AF & SOLÉ-CAVA AM. 2014. Population structure of the endangered franciscana (Pontoporia blainvillei): reassessing management units. PLoS ONE 9: e8563.).

The franciscana dolphin is mainly threatened by incidental capture in artisanal fishing nets, reducing the number of individuals in populations over time (Rocha-Campo et al. 2010ROCHA-CAMPO CC, DANILEWICZ DS & SALVATORE S. 2010. Plano de Ação Nacional para a Conservação do Pequeno Cetáceo: Toninha – Pontoporia blainvillei – Série Espécies Ameaçadas 10. Brasília: Ministério do Meio Ambiente, 77 p., Siciliano et al. 2019SICILIANO S, TAVARES DC, MOURA JF & DI BENEDITTO APM. 2019. Assessment of the fisheries characteristics in southeastern Brazil: Moving towards a monitoring program to assess Franciscana bycatch in FMA 1b – northern Rio de Janeiro. Report of the International Whaling Commission (SC/67B/SM/05), 24 p.). Interactions between these dolphins and artisanal fisheries are described on the coasts of ES and RJ, southeastern Brazil, and in Paraná state (PR), southern Brazil (Secchi et al. 1997SECCHI ER, ZERBINI AN, BASSOI M, DALLA ROSA L, MOLLER LM & ROCCHA-CAMPOS CC. 1997. Mortality of franciscana, Pontoporia blainvillei, in coastal gillnetting in southern Brazil. Rep Internat Whal Comm 47: 653-658., Di Beneditto et al. 2001DI BENEDITTO APM, RAMOS RMA & LIMA NRW. 2001. Sightings of Pontoporia blainvillei (Gervais&D´Orbigny, 1844) and Sotalia fluviatilis (Gervais, 1853) (Cetacea) in South-eastern Brasil. Braz Arch Biol Technol 44: 291-296., Rosas et al. 2002ROSAS FCW, MONTEIRO-FILHO ELA & OLIVEIRA MR. 2002. Incidental catches of franciscana (Pontoporia blainvillei) on the southern coast of São Paulo state and the coast of Paraná state, Brazil. Lat Am J Aquat Mam 1: 161-167., Di Beneditto 2003DI BENEDITTO APM. 2003. Interactions between gillnet fisheries and small cetaceans in northern Rio de Janeiro, Brazil: 2001 - 2002. Lat Am J Aquat Mam 2: 79-86., Santos et al. 2009SANTOS MCO, OSHIMA JEF & DA SILVA E. 2009. Sightings of franciscanas (Pontoporia blainvillei): The Discovery of a population in the Paranaguá Estuarine Complex, Southern Brazil. Braz J Oceanog 57: 57-63., Siciliano et al. 2019SICILIANO S, TAVARES DC, MOURA JF & DI BENEDITTO APM. 2019. Assessment of the fisheries characteristics in southeastern Brazil: Moving towards a monitoring program to assess Franciscana bycatch in FMA 1b – northern Rio de Janeiro. Report of the International Whaling Commission (SC/67B/SM/05), 24 p., Mayorga et al. 2020MAYORGA LFSP ET AL. 2020. Strandings of cetaceans on the Espírito Santo coast, southeast Brazil, 1975–2015. ZooKeys 948: 129-152.). The conservation status of this species is considered ‘vulnerable’ by the International Union for Conservation of Nature (IUCN) Red List of Threatened Species and ‘critically endangered’ by the national list of Brazilian fauna threatened by extinction with a risk of extinction (Zerbini et al. 2017ZERBINI AN, SECCHI E, CRESPO E, DANILEWICZ D & REEVES R. 2017. Pontoporia blainvillei. The IUCN Red List of Threatened Species: e.T17978A123792204., ICMBio 2018ICMBIO - INSTITUTO CHICO MENDES DE CONSERVAÇÃO DA BIODIVERSIDADE. 2018. Livro Vermelho da Fauna Brasileira Ameaçada de Extinção. Mamíferos, 2nd ed, Brasília: Ministério do Meio Ambiente, 622 p.).

In Brazil, an artisanal fishery was defined by Federal Law 11 959 on June 29, 2009, as an activity practiced autonomously by professional fishers or in the form of a family economy, without any employment relationship (Brasil 2009BRASIL. 2009. Decreto nº. 11.959, 29 de junho de 2009. Provides for the National Policy for the Sustainable Development of Aquaculture and Fisheries, regulates fishing activities, revokes Law No. 7,679, of November 23, 1988, and Decree-Law no. 221, of February 28, 1967, and gives other measures. Diário Oficial da União, Brasília, 30 de junho de 2009, nº. 122, Section 1, p. 1-3.). Due to the daily practice of the activity, fishers maintain regular contact with the marine environment, which enables the development of local ecological knowledge (LEK). In fishing communities, LEK is developed for years and increases in each new generation with cultural data transmitted orally from the elders to the younger generation (Peterson et al. 2008PETERSON D, HANAZAKI N & SIMÕES-LOPES PC. 2008. Natural resource appropriation in cooperative artisanal fishing between fishermen and dolphin (Tursiops truncatus) in Laguna, Brazil. Ocean Coast Manag 51: 469-475.). Ethnoecology studies are important in combining LEK and scientific knowledge, and these studies help in the development of fishing management and conservation actions (Silvano & Begossi 2002SILVANO RAM & BEGOSSI A. 2002. Ethnoichthyology and fish conservation in the Piracicaba river (Brazil). J Ethnobiol 22: 285-306., Zappes et al. 2016ZAPPES CA, GAMA RM, DOMIT C, GATTS CEN & DI BENEDITTO APM. 2016. Artisanal fishing and the franciscana (Pontoporia blainvillei) in Southern Brazil: ethnoecology from the fishing practice. J Mar Biol Assoc UK 96: 1-11., Abreu et al. 2017ABREU JS, DOMIT C & ZAPPES CA. 2017. Is there dialogue between researchers and traditional community members?: The importance of integration between traditional knowledge and scientific knowledge to coastal management. Ocean Coast Manag 141: 10-19.).

Previous studies about artisanal fishers’ LEK related to the franciscana dolphin have been specific to some areas and usually have not proposed any management actions that could contribute to the conservation of the species (Pinheiro & Cremer 2003PINHEIRO L & CREMER M. 2003. Etnoecologia e captura acidental de golfinhos (Cetacea: Pontoporiidae e Delphinidae) na Baía de Babitonga, Santa Catarina. Desenvolvimento e Meio Ambiente 8: 69-75., Rosa et al. 2012ROSA GA, ZAPPES CA & DI BENEDITTO APM. 2012. Etnoecologia de pequenos cetáceos: interações entre a pesca artesanal e golfinhos no norte do estado do Rio de Janeiro, Brasil. Biotemas 25: 293-304., Zappes et al. 2016ZAPPES CA, GAMA RM, DOMIT C, GATTS CEN & DI BENEDITTO APM. 2016. Artisanal fishing and the franciscana (Pontoporia blainvillei) in Southern Brazil: ethnoecology from the fishing practice. J Mar Biol Assoc UK 96: 1-11.). Thus, the aim of the present study is to describe and compare the LEK, including the gaps, held by fishers from small ports in the SWAO, which encompasses the species distribution area to evaluate the species’ interactions with artisanal fishery. Based on LEK descriptions and comparisons, we presented levels of educational actions that are needed within the studied communities.

MATERIALS AND METHODS

Study area

This study was developed with ten artisanal fishing communities that were selected to conduct the LEK comparison, and the communities are distributed in the Southwest Atlantic Ocean (SWAO), along the coast of three Brazilian states: Espírito Santo (ES), Rio de Janeiro (RJ), and Paraná (PR) (Figure 1, Table I). Six of these communities (Conceição da Barra, Regência, Barra do Riacho, Atafona, Peças Island, and Superagui Island) have records of the franciscana dolphin, and four of the communities are located in a record distribution gap (Piúma, Anchieta, Arraial do Cabo, and Cabo Frio). The state of ES has approximately 411 km of coastline, and the coastal municipalities of Conceição da Barra; Regência, a district of the municipality of Linhares; and Barra do Riacho, a district of the municipality of Aracruz are located in the northern region; and the coastal municipalities of Anchieta and Piúma, which is one of the ports with the largest volume of fish, are located in the southern portion of the state (Martins et al. 2009MARTINS AS, DOS SANTOS LB, PIZETTA GT, MONJARDIM C & DOXSEY JR. 2009. Interdisciplinary assessment of the status quo of the marine fishery systems in the state of Espírito Santo, Brazil, using Rapfish. J Appl Ichthyol 25: 269-276.). One of the most representative ports in terms of gillnet fishing effort is located in the north of RJ state in the district of Atafona (Di Beneditto et al. 2001DI BENEDITTO APM, RAMOS RMA & LIMA NRW. 2001. Sightings of Pontoporia blainvillei (Gervais&D´Orbigny, 1844) and Sotalia fluviatilis (Gervais, 1853) (Cetacea) in South-eastern Brasil. Braz Arch Biol Technol 44: 291-296.). The east coast of RJ is characterized by a region of great lakes and by industrial fishing in both Arraial do Cabo and Cabo Frio, with mainly hand lines, longlines and octopus traps being used in Arraial do Cabo (Silva et al. 2014SILVA CV, MOREIRA SC, ZAPPES CA & DI BENEDITTO APM. 2014. Pesca artesanal e cetáceos que ocorrem no litoral leste do Rio de Janeiro: Uma abordagem etnoecológica para verificar a existência de manejo tradicional. Bol Inst Pesca (Online) 40: 521-539.). In the state of PR, more specifically in the Paranaguá Estuarine Complex (PEC), the preferred areas for fishing are mainly on the coasts of Superagui Island and Peças Island (Zappes et al. 2016ZAPPES CA, GAMA RM, DOMIT C, GATTS CEN & DI BENEDITTO APM. 2016. Artisanal fishing and the franciscana (Pontoporia blainvillei) in Southern Brazil: ethnoecology from the fishing practice. J Mar Biol Assoc UK 96: 1-11.). The coasts of Conceição da Barra, Regência, and Barra do Riacho were impacted in 2015 by a dam that released millions of iron mining waste into the Atlantic Ocean. This impact is considered a threat to franciscana dolphin (Pinheiro et al. 2019PINHEIRO FCF, PINHEIRO HT, TEIXEIRA JB, MARTINS AS & CREMER MJ. 2019. Opportunistic Development and Environmental Disaster Threat Franciscana Dolphins in the Southeast of Brazil. Tropical Conserv Scie 12: 1-7.). The communities were selected according to the guidelines of the franciscana dolphin National Action Plan (NAP), which indicates priority areas for its conservation on the Brazilian coast (Rocha-Campo et al. 2010ROCHA-CAMPO CC, DANILEWICZ DS & SALVATORE S. 2010. Plano de Ação Nacional para a Conservação do Pequeno Cetáceo: Toninha – Pontoporia blainvillei – Série Espécies Ameaçadas 10. Brasília: Ministério do Meio Ambiente, 77 p.). Fishers located in the distribution gap of the franciscana dolphin were also interviewed to confirm the absence of the species.

Figure 1
Location of the fishing communities along the Southwest Atlantic Ocean (SWAO), with gaps and Pontoporia blainvillei occurrence areas. Image: Sérgio Carvalho Moreira.
Table I
Study areas and representation of interviewed artisanal fishermen.

Procedures

We conducted 330 ethnographic interviews between 2012 and 2018 with artisanal fishers living within the study area (Table I). Considering that the number of interviews in studies that use traditional knowledge usually varies from 30 to 60 (Mason 2010MASON M. 2010. Sample size and saturation in PhD studies using qualitative interviews. Forum Qualitative Sozial for schung/Forum Qual Soc Res 11: 8.), this study presents an appropriate sample size to obtain data related to LEK. However, in qualitative studies involving cultural data, when the sample size is very large, new data does not necessarily present new information related to the research objectives but only repeat the information (Mason 2010MASON M. 2010. Sample size and saturation in PhD studies using qualitative interviews. Forum Qualitative Sozial for schung/Forum Qual Soc Res 11: 8., Zappes et al. 2013aZAPPES CA, ALVES LCPS, SILVA CV, AZEVEDO AF, DI BENEDITTO APM & ANDRIOLO A. 2013a. Accidents between artisanal fisheries and cetaceans on the Brazilian coast and Central Amazon: Proposals for integrated management. Ocean Coast Manag 85: 46-57.). Therefore, studies must consider the real meanings of the reports of cultural and traditional knowledge that cannot be reduced only to quantitative variables (Mason 2010MASON M. 2010. Sample size and saturation in PhD studies using qualitative interviews. Forum Qualitative Sozial for schung/Forum Qual Soc Res 11: 8., Alves et al. 2019ALVES LD, DI BENEDITTO APM & ZAPPES CA. 2019. Ethnooceanography of tides in the artisanal fishery in Southeastern Brazil: Use of traditional knowledge on the elaboration of the strategies for artisanal fishery. Appl Geogr 110: 102044.). Thus, our sample size is sufficient for this type of study.

The first stage of the field work was an exploratory investigation through participant observation to comprehend the daily fishing activities in each community (Malinowski 2014MALINOWSKI B. 2014. Argonauts of the Western Pacific, 1nd ed, Helion, 279 p.). This followed a pre-established but flexible standard, allowing the interviewer to make adaptations during the process (Kendall 2008KENDALL L. 2008. The conduct of qualitative interview: Research questions, methodological issues, and researching online. In: Coiro J, Knobel M, Lankshear C & Leu DJ (Eds), Handbook of research on new literacies. New York: Lawrence Erlbaum Associates, p. 133-149.); however, after the period of the exploratory investigation the questions were defined and the same questionnaire was used in all the communities. The present study was submitted to the Plataforma Brasil (Brazilian database for registering research involving humans) and to the Sistema de Gestão Nacional do Patrimônio Genético e do Conhecimento Tradicional Associado (SISGEN) and approved by the Ethics Committee (CAAE 07863218.7.0000.5542). Previous consent was requested from the interviewees’ legal representatives, according to the Brazilian law that adresses this type of data collection (Federal Law 13123 from May 20, 2015). Each fisher was informed about the aims of the study, and asked if he or she agreed to participate (Librett & Perrone 2010LIBRETT M & PERRONE D. 2010. Apples and oranges: ethnography and the IRB. Qual Res 10: 729-747.), with an assurance of their anonymity. The vessel name of each fisher was recorded to avoid interviewing workers from the same boat.

The interviews were performed through dialogues, favoring interaction and establishing trust between interviewer and interviewee (Schensul et al. 1999SCHENSUL SL, SCHENSUL JJ & LECOMPTE MD. 1999. Essential Ethnographic Methods: Observations, Interviews, & Questionnaires. In: Schensul JJ & Lecompte MD (Eds), Ethnographer’s Toolkit, 2nd ed, Walnut Creek: Altamira Press, p. 69-89., Opdenakker 2006OPDENAKKER R. 2006. Advantages and disadvantages of four interview techniques in qualitative research. Forum Qual Soc Res 7(4): 11.). All fishers were interviewed individually to avoid interference from others. Following Sanches (2004)SANCHES RA. 2004. Caiçaras e a Estação ecológica de Juréia-Itatins. Histórico de ocupação no contexto político, econômico, social e ambiental do Vale do Ribeira. In: Marques OAV & Duleba W (Eds), Estação Ecológica Juréia-Itatins: Ambiente Físico, Flora e Fauna. Ribeirão Preto: Holos Editora, p. 349-359., the first interviewee was selected made with the help of a local guide. From that point on, we used the snowball method (Bailey 1982BAILEY KD. 1982. Methods of Social Research, 2nd ed, Nova York: The Free Press and Macmillan Publishers, 439 p.), as well as random meetings with fishers in the studied communities.

The questionnaire was divided into categories: (1) fisher’s profile (age and fishing practice time), (2) identification of franciscana dolphin by him/her, (3) occurrence of incidental capture of franciscana dolphin, (4) carcass destination, and (5) causes and solutions to incidental captures. A standard semistructured questionnaire was used during the interviews and was composed of open and closed questions (n = 56 and n = 12 respectively) (Schensul et al. 1999SCHENSUL SL, SCHENSUL JJ & LECOMPTE MD. 1999. Essential Ethnographic Methods: Observations, Interviews, & Questionnaires. In: Schensul JJ & Lecompte MD (Eds), Ethnographer’s Toolkit, 2nd ed, Walnut Creek: Altamira Press, p. 69-89.). The same questionnaire was used with different interviewees at different periods of time (technique of repeated synchronous information) (Melo 2004MELO LG. 2004. Antropologia cultural, objetivo e método. In: Melo LG (Ed), Antropologia Cultural: Iniciação, teoria e temas. 11nd ed, Petrópolis: Editora Vozes, p. 33-78.). The criteria used to select the subjects were (1) being an artisanal fisher, (2) having fishing activity as the main source of income and (3) participating in artisanal fishery in one of the studied communities. At the end of each interview, we showed the fisher an illustrative board containing photographs of small cetacean species that occur within the study area, among which there was a picture of a franciscana dolphin. Visual stimulation helped with analyzing the data collected from the interviews (Miranda et al. 2007MIRANDA TM, AMOROZO MCM, GOVONE JS & MIRANDA DM. 2007. The Influence of Visual Stimuli in Ethnobotanical Data Collection Using the Listing Task Method. Field Methods 19: 76-86.) because the use of the image made it easier for the fisher to indicate which the animals occurred in the region.

Data analysis

Reports were organized into categories related to the questions (Ryan & Bernard 2000RYAN G & BERNARD HR. 2000. Data management and analysis methods. In: Denzin NK & Lincoln YS (Eds), Handbook of Qualitative Research. Sage Publications, Thousand Oaks, p. 769-802.). This allowed us to group data by subjects (categories of the questionnaire described previously) for the classification of the reports and the interpretation of the interviews. We used the triangulation method to compare the reports, aiming to cross and filter collected data based on the methods that were used (participant observations, interviews, and illustrative boards) (Heale & Forbes 2013HEALE R & FORBES D. 2013. Understanding triangulation in research. Evidence-based nursing 16: 98.). Thus, it was possible to obtain maximum veracity from the reports and to establish connections through oral information.

Boolean or Classical Logic (Cockett & Manes 2009COCKETT R & MANES E. 2009. Boolean and classical restriction categories. Math Struct Comput Sci 19: 357-416.) was used to identify the fishers who could recognize the franciscana dolphin accordingly to the taxonomic entity “P. blainvillei”, comparing the reports with the literature on body size, coloration and distribution patterns as well as identification on the illustrative board. As the last two features are linguistic variables, Boolean or Classical Logic helps with their transformation into numeric values with 0 (zero) for ‘incorrect answer’ and 1 (one) for ‘correct answer’ (Table II). The fishers who correctly indicated three or more of the species’ features, including visual recognition on the illustrative board, were classified as those who recognize the franciscana dolphin.

Table II
Criteria used for the identification of fishers who recognized franciscana dolphin to the species level (Pontoporia blainvillei) (Gervais & D’Orbigny, 1844).
Group of Variables Functions of Pertinence/Proposition Linguistic Terms Literature
Distribution pattern Correct Northern coast of Espírito Santo ‘the beach here in the north’ Siciliano et al. 2002, Freitas Netto & Barbosa 2003FREITAS NETTO R & DI BENEDITTO APM. 2008. Interactions between fisheries and cetaceans in Espírito Santo State coast, southestern Brazil. Rev Bras Zoo 10: 55-63., Secchi et al. 2003bSECCHI ER, DANILEWICZ D & OTT PH. 2003a. Applying the phylogeographic concept to identify franciscana stocks: implications to meet management objectives. J Cetacean Res Manag 5: 61-68., Freitas Netto & Di Beneditto 2008FREITAS NETTO R & BARBOSA LA. 2003. Cetaceans and fishery interactions along the Espírito Santo State, Southeastern Brazil during 1994-2001. Lat Am J Aquat Mam 2: 57-60., Culik 2011CULIK BM. 2011. Odontocetes: The toothed whales. UNEP/CMS/ASCOBANS Secretariat, Bonn, n. 24, Germany: CMS Technical, 311 p., Cunha et al. 2014CUNHA HA, MEDEIROS BV, BARBOSA LA, CREMER MJ, MARIGO J, LAILSON-BRITO J, AZEVEDO AF & SOLÉ-CAVA AM. 2014. Population structure of the endangered franciscana (Pontoporia blainvillei): reassessing management units. PLoS ONE 9: e8563., Amaral et al. 2018AMARAL KB ET AL. 2018. Reassessment of the franciscana Pontoporia blainvillei (Gervais & d’Orbigny, 1844) distribution and niche characteristics in Brazil. J Exp Mar Biol Ecol 508: 1-12.
Rio Doce River mouth ‘exactly in front of the river mouth’
Regência coast ‘only close to Regência’
Barra do Riacho Coast ‘in front of Barra do Riacho’
Northern coast of Rio de Janeiro ‘in the north of Rio de Janeiro, close to the border with Espírito Santo’ Di Beneditto & Ramos 2001DI BENEDITTO APM & RAMOS R. 2001. Biology and conservation of the franciscana (Pontoporia blainvillei) in the north of Rio de Janeiro State, Brazil. J Cetac Res Manag 3: 185-192., Siciliano et al. 2002SICILIANO S, DI BENEDITTO APM & RAMOS RMA. 2002. A toninha, Pontoporia blainvillei (Gervais & d´Orbigny, 1844) (Mammalia, Cetacea, Pontoporiidae), nos estados do Rio de Janeiro e Espírito Santo, costa sudeste do Brasil: Caracterizações dos hábitats e fatores de isolamento das populações. Boletim do Museu Nacional–Nova Série Zoologia 146: 1-15, Di Beneditto 2003DI BENEDITTO APM. 2003. Interactions between gillnet fisheries and small cetaceans in northern Rio de Janeiro, Brazil: 2001 - 2002. Lat Am J Aquat Mam 2: 79-86., Secchi et al. 2003bSECCHI ER, OTT PH & DANILEWICZ D. 2003b. Effects of fishing by-catch and conservation status of the franciscana, Pontoporia blainvillei. In: Gales N, Hindell M & Kirkwood K (Eds), Marine Mammals: Fisheries. Tourism and Management Issues CSIRO Publishing, Australia: Collinwoop, p. 174-191., Culik 2011CULIK BM. 2011. Odontocetes: The toothed whales. UNEP/CMS/ASCOBANS Secretariat, Bonn, n. 24, Germany: CMS Technical, 311 p., Cunha et al. 2014CUNHA HA, MEDEIROS BV, BARBOSA LA, CREMER MJ, MARIGO J, LAILSON-BRITO J, AZEVEDO AF & SOLÉ-CAVA AM. 2014. Population structure of the endangered franciscana (Pontoporia blainvillei): reassessing management units. PLoS ONE 9: e8563., Lavandier et al. 2015LAVANDIER R, ARÊAS J, QUINETE N, MOURA JF, TANIGUCHI S, MONTONE R, SICILIANO S & MOREIRA I. 2015. PCB and PBDE levels in a highly threatened dolphin species from the Southeastern Brazilian coast. Environ Pollut 208: 442-449., Amaral et al. 2018AMARAL KB ET AL. 2018. Reassessment of the franciscana Pontoporia blainvillei (Gervais & d’Orbigny, 1844) distribution and niche characteristics in Brazil. J Exp Mar Biol Ecol 508: 1-12.
Atafona coast ‘in front of Atafona’
Cabo de São Thomé ‘close to Cabo de São Thomé, in the São Thomé Lighthouse’
Palmas Island ‘in the surroundings of Palmas’ Rosas & Monteiro-Filho 2002ROSAS FCW & MONTEIRO-FILHO ELA. 2002. Reproductive parameters of Pontoporia blainvillei (Cetacea, Pontoporiidae), on the coast of São Paulo and Paraná States, Brazil. Mammalia 66: 231-245., Secchi & Wang 2002SECCHI ER & WANG JY. 2002. Assessment of the conservation status of a franciscana (Pontoporia blainvillei) stock in the Franciscana Management Area III following the IUCN Red List Process. Lat Am J Aquat Mam 1: 183-190., Secchi et al. 2003b, Culik 2011CULIK BM. 2011. Odontocetes: The toothed whales. UNEP/CMS/ASCOBANS Secretariat, Bonn, n. 24, Germany: CMS Technical, 311 p., Cunha et al. 2014CUNHA HA, MEDEIROS BV, BARBOSA LA, CREMER MJ, MARIGO J, LAILSON-BRITO J, AZEVEDO AF & SOLÉ-CAVA AM. 2014. Population structure of the endangered franciscana (Pontoporia blainvillei): reassessing management units. PLoS ONE 9: e8563., Amaral et al. 2018AMARAL KB ET AL. 2018. Reassessment of the franciscana Pontoporia blainvillei (Gervais & d’Orbigny, 1844) distribution and niche characteristics in Brazil. J Exp Mar Biol Ecol 508: 1-12.
Barra da Baía ‘more often at Barra’
Inner area of the bay and CEP* ‘in the middle of the canal, near Paranaguá, also between Mel Island and Peças Island’
Superagui coast ‘in the coast of the beach and further out, close to Superagui’
Lajinha and Coroa beaches ‘at Lajinha Beach, where the tower collapsed’
Ponta do Areão beach ‘at Ponta do Areião and further out’
Pontal do Paraná boast ‘in the middle of the canal, along the coast, until Mel Island’
Table II Continuation.
Group of Variables Functions of Pertinence/Proposition Linguistic Terms Literature
Distribution pattern Incorrect Southern coast of Bahia ‘it appears in southern Bahia, in Abrolhos’ Secchi et al. 2003b, Cunha et al. 2014CUNHA HA, MEDEIROS BV, BARBOSA LA, CREMER MJ, MARIGO J, LAILSON-BRITO J, AZEVEDO AF & SOLÉ-CAVA AM. 2014. Population structure of the endangered franciscana (Pontoporia blainvillei): reassessing management units. PLoS ONE 9: e8563., Amaral et al. 2018AMARAL KB ET AL. 2018. Reassessment of the franciscana Pontoporia blainvillei (Gervais & d’Orbigny, 1844) distribution and niche characteristics in Brazil. J Exp Mar Biol Ecol 508: 1-12.
Mesoregion coast, southern coast and along the Espírito Santo coast ‘in front of Vitória,’ ‘it appears in front of Piúma and Anchieta,’ ‘it is along the entire Espírito Santo coast’ Secchi et al. 2003b, Cunha et al. 2014CUNHA HA, MEDEIROS BV, BARBOSA LA, CREMER MJ, MARIGO J, LAILSON-BRITO J, AZEVEDO AF & SOLÉ-CAVA AM. 2014. Population structure of the endangered franciscana (Pontoporia blainvillei): reassessing management units. PLoS ONE 9: e8563., Amaral et al. 2018AMARAL KB ET AL. 2018. Reassessment of the franciscana Pontoporia blainvillei (Gervais & d’Orbigny, 1844) distribution and niche characteristics in Brazil. J Exp Mar Biol Ecol 508: 1-12.
Eastern coast of Rio de Janeiro, Cabo Frio coast, Arraial do Cabo coast ‘near Papagaios Island, between Arraial do Cabo and Cabo Frio,’ ‘in Arraial do Cabo, close to the stone’ Secchi et al. 2003b, Cunha et al. 2014CUNHA HA, MEDEIROS BV, BARBOSA LA, CREMER MJ, MARIGO J, LAILSON-BRITO J, AZEVEDO AF & SOLÉ-CAVA AM. 2014. Population structure of the endangered franciscana (Pontoporia blainvillei): reassessing management units. PLoS ONE 9: e8563., Amaral et al. 2018AMARAL KB ET AL. 2018. Reassessment of the franciscana Pontoporia blainvillei (Gervais & d’Orbigny, 1844) distribution and niche characteristics in Brazil. J Exp Mar Biol Ecol 508: 1-12.

To compare artisanal fishers’ LEK about the franciscana dolphin, the studied communities were grouped in five regions: northern ES (Conceição da Barra, Regência, and Barra do Riacho), with 90 interviews; southern ES (Anchieta and Piúma), with 60 interviews; northern RJ (Atafona), with 30 interviews; the central coast of RJ (central RJ) (Cabo Frio and Arraial do Cabo), with 60 interviews; and PR (Superagui Island and Peças Island), with 90 interviews. From a percentage frequency analysis, we compared the LEK of the fishers who identified franciscana dolphins in each region (Table III).

Table III
Comparison of LEK by status areas related to franciscana dolphin (Pontoporia blainvillei Gervais & D’Orbigny, 1844).

RESULTS

The interviewed fishers were mostly men ranging from 15 to 78 years old, and fishing practice time varied from 4 to 73 years. Only one woman was interviewed, in Regência, ES. The educational level was low in all studied communities: 64.2% (n = 212) of the interviewees attended only elementary school, went to school for less than 5 years, or had never been in school. The boats were made of wood or aluminum. In terms of fishing gear, they had nets (trawl net, gillnet, cast net, squid net, ‘jerivau/gerival,’ artisanal sieve, and ‘cambal and lanço’ (beach sieve), handlines (longline and ‘zagarejo’), traps (octopus trap), and sticks and hooks (tuna fishery) (Table IV). Fishers cited bony and cartilaginous fish, as well as crustaceans as their main fishing targets.

Table IV
Characteristics of the artisanal fisheries in the southeastern and southern regions of Brazil according to the reports of the interviewed fishers.
Location * Period of fishery Fishery gear (in order of preference) Boats
CF Day and night Handline (n= 41) Longline (n= 15) Octopus trap (n= 2) Gillnet (n= 1) Stick and hook for Tuna fishery (n=1) Type: wooden boat with marry and deck; wooden boat without marry and deck. Length: 5 – 15 m. Motor: 22 – 366HP.
AC Night Handline (n= 26) Longline (n= 15) Squid net (n= 8) ‘Zagarejo’ (similar to hand line for squid) (n= 4) Trawl net (n= 1) Type: wooden boat with marry and deck; wooden boat without marry and deck, and trawler. Length: 5 – 12.4 m. Motor: 6 – 140HP.
SI Day Gillnet (n= 38) Trawl net (n= 37) Longline (n= 13) ‘Lanço’ (similar to beach siege) (n= 4) ‘Cambal’ (similar to beach siege) (n= 2) Artisanal siege (n=2) ‘Jerivau’ or ‘gerival’ (artifact formed by a stick and gillnets) (n= 1) Type: wooden boat, canoe, and aluminum boat. Length: 3- 18 m Motor: 7 - 60 HP or rowing.
PI Day Gillnet (n= 37) Longline (n= 32) Trawl net (n= 10) ‘Jerivau’ or ‘gerival’ (artifact formed by a stick and gillnets) (n= 4) ‘Cambal’ (similar to small Trawling net) (n= 2) Cast net (n= 2) Type: wooden boat with marry and deck; wooden boat without marry and deck, and canoe. Length: 3 – 11 m Motor: 5 - 180 HP or rowing.
  • *Caption: CB – Conceição da Barra; RG – Regência; BR – Barra do Riacho; AN – Anchieta; PM – Piúma; AT – Atafona; CF – Cabo Frio; AC – Arraial do Cabo; SI –Superagui Island; PI – Peças Island.
  • In northern ES, artisanal fishing occurs mainly close of the Rio Doce river mouth, extending towards the extreme north of the state, up to 30 meters deep. In southern ES, the main fishing areas extend from the Guarapari coast (20°38’S - 40°27’W) to northern RJ in the municipality of Macaé (22º22’S-41º47’W), with depths varying from 18 to 70 meters. In northern RJ, fishing activity occurs mainly in the coastal areas of the Campos Basin, from 6 to 70 meters deep, between the cities of Macaé and São João da Barra (21º38’S-41º03’W). In central RJ, fishing extends from 10 to 200 meters in depth between the Campos Basin and Macaé. In PR, the fishery occurs from the Paranaguá Estuarine Complex to Superagui Island, up to 13 meters in depth. The areas described by the fishers are different, and they act in open areas and/or areas protected from the tides.

    Among those who were able to identify franciscana dolphin to the species level (n = 95; 45.2% of 210 interviews without counting the gaps), 23 (25.5%) fishers are from northern ES; one (1.6%) is from southern ES (Anchieta); 20 (66.6%) are from northern RJ; and 51 (56.6%) are from PR. Percentages were calculated from the number of interviews conducted in each region. Among the 120 fishers that works within the species distribution gap, none could identify the species, except for one fisher [southern ES - Piúma (n = 30) and Anchieta (n = 29); central RJ - Cabo Frio (n = 30) and Arraial do Cabo (n = 30)]. The only fisher who recognized it was from Southern ES and described the species according to sightings while fishing close to the Rio Doce river mouth (northern ES). Thus, these areas were classified as: ‘no identification’ - central RJ; ‘extremely low identification’ – southern ES; ‘partial identification’ – northern ES; and ‘good identification’ – northern RJ and PR (Table III). Regarding ethno-denomination, the species is recognized by the fishers as a porpoise, ‘tuninha,’ dolphin, ‘boto,’ ‘bicuda,’ ‘vermelho,’ ‘boto-cachimbo,’ and ‘boca de panela.’ From these results, the following analyses were based on reports from the 95 fishers who recognized the species.

    Interviewees described positive (n = 15), negative (n = 8), and neutral (n = 2) interactions involving franciscana dolphin. Positive interactions were related to the fact that the dolphin ‘helps to find fish and shrimp,’ ‘makes fish approach the net,’ and ‘makes the fisherman happy when he sees it’ [northern ES (n = 7), northern RJ (n = 2), and PR (n = 6)]. Negative interactions were related to incidental captures and, thus, to the damage caused to the nets, described as: ‘the animal destroys the net’ [northern ES (n = 2); northern RJ (n = 3), and PR (n = 3)]. Neutral interactions did not interfere with the fishing routine, and were described as ‘the porpoise does not approach the boat’ and ‘the porpoise does not attack, staying in the water’ [PR (n = 2)].

    When interviewees were asked about the occurrence of incidental captures of the franciscana dolphin, 87.4% (n = 83) reported these events [northern ES (n = 23), southern ES (n = 1), northern RJ (n = 20), and PR (n = 39)], and gillnet were indicated the only gear type responsible for these captures. According to some of the fishers, the occurrence of incidental capture is rare (n = 33) [northern ES (n = 7), southern ES (n = 1), and PR (n = 25)], and is caused by the fact that the dolphin does not perceive (‘It cannot see’) the net in the water.

    Fishers from northern ES [Regência (n = 7) and Conceição da Barra (n = 1)] reported that harpoon fishing for franciscana dolphin was common, but the practice ended when environmental inspections increased 15 years ago. Incidentally captured dolphins are mostly discarded in the sea [northern ES (n = 11), southern ES (n = 1), northern RJ (n = 16), and PR (n = 35)]. Furthermore, some uncommon uses of the franciscana dolphin’s carcasses were: i) fat and muscle tissue being used as bait for shark fishing with longlines [northern ES (n = 7), northern RJ (n = 7), and PR (n = 2)]; ii) carcasses being delivered to researchers from conservation programs and management and inspection programs [northern ES (n = 8), northern RJ (n = 1), and PR (n = 2)]; and iii) the animals being used as food [northern ES (n = 2), northern RJ (n = 2), and PR (n = 1)]. Twelve fishers reported more than one use for the dolphins, which explains why the number of answers (n = 95) was greater than the number of fishers who described incidental captures of the species (n = 83).

    Most fishers (n = 52) reported that they did not know how to avoid incidental capture, with 29 of them saying that there is no solution, 13 stating that the solution is to stop gillnet fishing, and one indicating that fishing at night could be a solution. The number of responses (n = 95) was greater than the number of reports of the dolphins (n = 83) because two interviewees gave more than one answer.

    DISCUSSION

    The aim of this study was to describe the perception of artisanal fishers from southern and southeastern Brazil toward to the species and to comprehend how they interact with it, combining researchers’ information and local actors. This study reaffirms the importance of fishers’ LEK as a qualitative tool to obtain data about the interaction between artisanal fisheries and the franciscana dolphin, as indicated in Rosa et al. (2012)ROSA GA, ZAPPES CA & DI BENEDITTO APM. 2012. Etnoecologia de pequenos cetáceos: interações entre a pesca artesanal e golfinhos no norte do estado do Rio de Janeiro, Brasil. Biotemas 25: 293-304. and Zappes et al. (2016)ZAPPES CA, GAMA RM, DOMIT C, GATTS CEN & DI BENEDITTO APM. 2016. Artisanal fishing and the franciscana (Pontoporia blainvillei) in Southern Brazil: ethnoecology from the fishing practice. J Mar Biol Assoc UK 96: 1-11.. Understanding and quantifying fishers knowledge about cetaceans can increase conservation actions throughout the distribution areas of species (Zappes et al. 2013bZAPPES CA, GATTS CEN, LODI LF, SIMÕES-LOPES PC, LAPORTA P, ANDRIOLO A & DI BENEDITTO APM. 2014. Comparison of local knowledge about the bottlenose dolphin (Tursiops truncatus Montagu, 1821) in the Southwest Atlantic Ocean: New research needed to develop conservation management strategies. Ocean Coast Manag 98: 120-129.).

    Less than 30% of the interviewees from this study (n = 330) were able to identify franciscana dolphin at the species level. For the 120 fishers from southern ES (Piúma and Anchieta) and central RJ (Arraial do Cabo and Cabo Frio), which are located in a distribution gap of the species, this result was expected (Table III), as the species habitat does not occur withing the fishing areas. The physical and behavioral features of the franciscana dolphin, together with the characteristics of the fishing zones that are present within its distribution area, can hinder observations of the species in its habitat. It is a small dolphin, especially when compared to other small cetaceans in the same area, such as the “boto” or Guiana dolphin (Sotalia guianensis; van Benédén, 1864) (Di Beneditto et al. 2001DI BENEDITTO APM, RAMOS RMA & LIMA NRW. 2001. Sightings of Pontoporia blainvillei (Gervais&D´Orbigny, 1844) and Sotalia fluviatilis (Gervais, 1853) (Cetacea) in South-eastern Brasil. Braz Arch Biol Technol 44: 291-296.); its body coloration allows it to blend in with the turbid water in coastal areas close to river mouths, which is its preferred habitat; and the species swims in small groups, usually with two to four individuals, and does not jump out of the water (Siciliano et al. 2002SICILIANO S, DI BENEDITTO APM & RAMOS RMA. 2002. A toninha, Pontoporia blainvillei (Gervais & d´Orbigny, 1844) (Mammalia, Cetacea, Pontoporiidae), nos estados do Rio de Janeiro e Espírito Santo, costa sudeste do Brasil: Caracterizações dos hábitats e fatores de isolamento das populações. Boletim do Museu Nacional–Nova Série Zoologia 146: 1-15, Zappes et al. 2016ZAPPES CA, GAMA RM, DOMIT C, GATTS CEN & DI BENEDITTO APM. 2016. Artisanal fishing and the franciscana (Pontoporia blainvillei) in Southern Brazil: ethnoecology from the fishing practice. J Mar Biol Assoc UK 96: 1-11.). Additionally, in fishing areas where the coast line is exposed, such as the fishing zone in northern ES, coastal waters are generally more agitated by winds and marine currents. Furthermore, this area is influenced by the river mouths of Rio Doce increasing local water turbidity. Therefore, species morphology, behavior and habitat features may hinder the observation and recognition of this inconspicuous dolphin.

    Fishers from northern RJ and PR provided a ‘good identification’ of the Franciscana dolphin and of environmental conditions that facilitate the visualization of the specimens at the sea. Northern RJ has an exposed coast line and its waters are influenced by the river mouth of Rio Paraíba do Sul, which hinders the observation of the species. However, in this region, there are regular reports about incidental captures of franciscana dolphin with gillnets, which are the main gear type responsible for its bycatch (Di Beneditto et al. 2001DI BENEDITTO APM, RAMOS RMA & LIMA NRW. 2001. Sightings of Pontoporia blainvillei (Gervais&D´Orbigny, 1844) and Sotalia fluviatilis (Gervais, 1853) (Cetacea) in South-eastern Brasil. Braz Arch Biol Technol 44: 291-296., Di Beneditto 2003DI BENEDITTO APM. 2003. Interactions between gillnet fisheries and small cetaceans in northern Rio de Janeiro, Brazil: 2001 - 2002. Lat Am J Aquat Mam 2: 79-86., Siciliano et al. 2019SICILIANO S, TAVARES DC, MOURA JF & DI BENEDITTO APM. 2019. Assessment of the fisheries characteristics in southeastern Brazil: Moving towards a monitoring program to assess Franciscana bycatch in FMA 1b – northern Rio de Janeiro. Report of the International Whaling Commission (SC/67B/SM/05), 24 p.). During capture events, a fisher must manipulate the live specimen or its carcass, which would allow a direct and detailed observation of its features such as body size and coloration. This would lead to a more accurate ability to recognize the species. On the other hand, fishers who use trawl nets, lines, or traps, for example, would have an extremely low probability of incidentally capturing this dolphin during their fishing activity. Therefore, their contact with the animal would only be possible through at sea observations, which are not easy due to the reasons explained above. Fishers from PR who participated in this study work in the Paranaguá Estuarine Complex. This zone is considered a preferred habitat for franciscana dolphin in the state (Rosas et al. 2002ROSAS FCW, MONTEIRO-FILHO ELA & OLIVEIRA MR. 2002. Incidental catches of franciscana (Pontoporia blainvillei) on the southern coast of São Paulo state and the coast of Paraná state, Brazil. Lat Am J Aquat Mam 1: 161-167., Santos et al. 2009SANTOS MCO, OSHIMA JEF & DA SILVA E. 2009. Sightings of franciscanas (Pontoporia blainvillei): The Discovery of a population in the Paranaguá Estuarine Complex, Southern Brazil. Braz J Oceanog 57: 57-63., Zappes et al. 2016ZAPPES CA, GAMA RM, DOMIT C, GATTS CEN & DI BENEDITTO APM. 2016. Artisanal fishing and the franciscana (Pontoporia blainvillei) in Southern Brazil: ethnoecology from the fishing practice. J Mar Biol Assoc UK 96: 1-11.), and it has a sheltered coastal pattern, with coves, estuaries and calm waters. This would favor species observations and recognition by local fishers.

    Not all fishers who work in the franciscana dolphin’s distribution area can identify it. For example, the ability of workers from northern ES to recognize the species was ‘partial.’ They fish mainly around the Rio Doce river mouth, where there are records of dolphin sightings (Siciliano et al. 2002SICILIANO S, DI BENEDITTO APM & RAMOS RMA. 2002. A toninha, Pontoporia blainvillei (Gervais & d´Orbigny, 1844) (Mammalia, Cetacea, Pontoporiidae), nos estados do Rio de Janeiro e Espírito Santo, costa sudeste do Brasil: Caracterizações dos hábitats e fatores de isolamento das populações. Boletim do Museu Nacional–Nova Série Zoologia 146: 1-15, 2019, Amaral et al. 2018AMARAL KB ET AL. 2018. Reassessment of the franciscana Pontoporia blainvillei (Gervais & d’Orbigny, 1844) distribution and niche characteristics in Brazil. J Exp Mar Biol Ecol 508: 1-12., Pinheiro et al. 2019PINHEIRO FCF, PINHEIRO HT, TEIXEIRA JB, MARTINS AS & CREMER MJ. 2019. Opportunistic Development and Environmental Disaster Threat Franciscana Dolphins in the Southeast of Brazil. Tropical Conserv Scie 12: 1-7., Rupil et al. 2019RUPIL GM, BARBOSA L, MARCONDES MCC, CARVALHO BM & FARRO APC. 2019. Franciscana dolphin (Pontoporia blainvillei) diet from Northern Espírito Santo State coast, Brazil. Biotemas 32: 87-96., Mayorga et al. 2020MAYORGA LFSP ET AL. 2020. Strandings of cetaceans on the Espírito Santo coast, southeast Brazil, 1975–2015. ZooKeys 948: 129-152.). However, the region is at the northern limit of the species distribution, where the population probably has a relatively low abundance (Secchi et al. 2003a, Danilewicz et al. 2012DANILEWICZ D, ZERBINI AN, ANDRIOLO A, SECCHI ER, SUCUNZA F, FERREIRA E, DENUNCIO P & FLORES PA. 2012. Abundance and distribution of an isolated population of franciscanas (Pontoporia blainvillei) in southeastern Brazil: red alert for FMA I? International Whaling Commission, Scientific Committee Paper SC/64/SM17., Amaral et al. 2018AMARAL KB ET AL. 2018. Reassessment of the franciscana Pontoporia blainvillei (Gervais & d’Orbigny, 1844) distribution and niche characteristics in Brazil. J Exp Mar Biol Ecol 508: 1-12.). This would decrease the chances of observing the franciscana dolphin, either by a sighting or by incidental capture. Moreover, the preferred fishing gear type in the area may also play a role, as trawl nets are more frequently used and is an activity that demands maximum attention from the fishers (Zappes et al. 2016ZAPPES CA, GAMA RM, DOMIT C, GATTS CEN & DI BENEDITTO APM. 2016. Artisanal fishing and the franciscana (Pontoporia blainvillei) in Southern Brazil: ethnoecology from the fishing practice. J Mar Biol Assoc UK 96: 1-11.). The practice of this fishery can reduce the chances of observing the marine environment and, consequently, locating the franciscana dolphin.

    Positive interactions between artisanal fisheries and the franciscana dolphin were related to the fact that the animal helps identify shoals for the fishers due to its feeding behavior, as described in the literature (Jefferson et al. 2015JEFFERSON TA, WEBBER MA & PITMAN RL. 2015. Marine mammals of the World: a comprehensive guide to their identification, 2nd ed, San Diego: Academic Press, 616 p., Zappes et al. 2016ZAPPES CA, GAMA RM, DOMIT C, GATTS CEN & DI BENEDITTO APM. 2016. Artisanal fishing and the franciscana (Pontoporia blainvillei) in Southern Brazil: ethnoecology from the fishing practice. J Mar Biol Assoc UK 96: 1-11.). This type of interaction involving other small cetacean species has already been reported in Brazilian waters, e.g. for the the common bottlenose dolphin (Tursiops truncatus; Montagu, 1861) (Zappes et al. 2011ZAPPES CA, ANDRIOLO A, SIMÕES-LOPES PC & DI BENEDITTO APM. 2011. ‘Human-dolphin (Tursiops truncatus Montagu, 1821) cooperative fishery’ and its influence on cast net fishing activities in Barra de Imbé/Tramandaí, Southern Brazil. Ocean Coast Manag 54: 427-432., 2014ZERBINI AN, SECCHI E, CRESPO E, DANILEWICZ D & REEVES R. 2017. Pontoporia blainvillei. The IUCN Red List of Threatened Species: e.T17978A123792204.), and the Guiana dolphin (Przbylski & Monteiro-Filho 2001PRZBYLSKI CB & MONTEIRO-FILHO ELA. 2001. Interação entre pescadores e mamíferos marinhos no litoral do Estado do Paraná – Brasil. Biotemas 14: 141-156., Zappes et al. 2010ZAPPES CA, MONTEIRO-FILHO ELA, OLIVEIRA F & ANDRIOLO A. 2010. O comportamento do boto-cinza Sotalia guianensis (van Bénéden, 1864) (Cetacea; Delphinidae) através do olhar dos pescadores artesanais. Revista de Etologia 9: 17-28.).

    Based on the interviewees’ perceptions, negative interactions with the dolphin involve the damage caused to fishing gear due to incidental capture. Gillnets were noted as being the only artifact responsible for incidental capture in the study area, which is in agreement with information in the literature. Studies that analyzed carcasses from this species throughout its distribution have indicated that gillnets are the main cause of incidental captures (Bertozzi & Zerbini 2002BERTOZZI CP & ZERBINI AN. 2002. Incidental mortality of the franciscana, Pontoporia blainvillei, in the artisanal fishery of Praia Grande, São Paulo State, Brazil. Lat Am J Aqu Mam 1: 153-160., Secchi et al. 2002bSECCHI ER, OTT PH & DANILEWICZ D. 2002b. Report of the fourth workshop for the coordinated research and conservation of the franciscana (Pontoporia blainvillei) in the Western South Atlantic. Lat Am J Aquat Mam 1: 11-20., 2003b, Di Beneditto 2003DI BENEDITTO APM. 2003. Interactions between gillnet fisheries and small cetaceans in northern Rio de Janeiro, Brazil: 2001 - 2002. Lat Am J Aquat Mam 2: 79-86., Rupil et al. 2019RUPIL GM, BARBOSA L, MARCONDES MCC, CARVALHO BM & FARRO APC. 2019. Franciscana dolphin (Pontoporia blainvillei) diet from Northern Espírito Santo State coast, Brazil. Biotemas 32: 87-96., Mayorga et al. 2020MAYORGA LFSP ET AL. 2020. Strandings of cetaceans on the Espírito Santo coast, southeast Brazil, 1975–2015. ZooKeys 948: 129-152.).

    According to the fishers, the main cause of incidental capture is the dolphin’s inability to accurately perceive the presence of fishing gear in the water. This scenario is related to the tension of the net material, which makes its fibers imperceptible (Tregenza et al. 1997TREGENZA NJC, BERROW SD & HAMMOND PS. 1997. Attraction of common dolphins (Delphinus delphis) to boat settings gillnets. European Research on Cetaceans 11: 47-49.). As stated by Dawson (1991)DAWSON SM. 1991. Modifying gillnets to reduce entanglement of cetaceans. Mar Mam Sci 7: 274-282., small cetaceans get stuck not because their sonar system fails in detecting the net, but because they can occasionally get confused, as they do not use that system all the time during the day. The main problem is related to the perception of the obstacle, and not its detection, as the animals can perceive it as a penetrable object (Au & Jones 1991AU WWL & JONES L. 1991. Acoustic reflectivity of nets: implications concerning incidental take of dolphins. Mar Mam Sci 7: 258-273., Tregenza et al. 1997TREGENZA NJC, BERROW SD & HAMMOND PS. 1997. Attraction of common dolphins (Delphinus delphis) to boat settings gillnets. European Research on Cetaceans 11: 47-49.). It is also possible that the dolphins cannot distinguish the sonar reflection as belonging to prey or to nets, which would lead to its entanglement during feeding (Au & Jones 1991AU WWL & JONES L. 1991. Acoustic reflectivity of nets: implications concerning incidental take of dolphins. Mar Mam Sci 7: 258-273.).

    The use of pingers and light emitting diodes (LEDs) (a visual cue) in gillnets is another action that can minimize the number of incidental franciscana dolphin captures. The sound-pulse emissions of pingers can make the gear perceptible to animals (Barlow & Cameron 2003BARLOW J & CAMERON GA. 2003. Field Experiments Show That Acoustic Pingers Reduce Marine Mammal Bycatch in The California Drift Gill Net Fishery. Mar Mam Sci 19: 265-283., Brotons et al. 2008BROTONS JM, MUNILLA Z, GRAU AM & RENDELL L. 2008. Do pingers reduce interactions between bottlenose dolphins and nets around the Balearic Islands? Endang Species Res 5: 301-308., Carreta et al. 2008CARRETTA J, BARLOW J & ENRIQUEZ L. 2008. Acoustic pingers eliminate beaked whale bycatch in a gill net fishery. Mar Mam Sci 24: 956-961., Mangel et al. 2013MANGEL JC, ALFARO-SHIGUETO J, WITT MJ, HODGSON DJ & GODLEY BJ. 2013. Using pingers to reduce bycatch of small cetaceans in Peru’s small-scale driftnet fishery. Oryx 47: 595-606.). However, the effect of these pulses on targeted fish species is a controversial subject (Dawson et al. 1998DAWSON SM, READ A & SLOOTEN E. 1998. Pingers, porpoises and power: uncertainties with using pingers to reduce bycatch of small cetaceans. Biol Conserv 84: 141-146., Kastelein et al. 2007KASTELEIN RA, HEUL SVD, VEEN JVD, VERBOOM WC, JENNINGS N, HAAN D & REIJNDERS P. 2007. Effects of commercially-available acoustic alarms, designed to reduce small cetacean bycatch in gillnet fisheries, on the behaviour of North Sea fish species in a large tank. Mar Environ Res 64: 160-180., Culik 2011CULIK BM. 2011. Odontocetes: The toothed whales. UNEP/CMS/ASCOBANS Secretariat, Bonn, n. 24, Germany: CMS Technical, 311 p.). Another technique that uses LEDs installed on gillnets reduces bycatch of the small cetaceans, seabirds and sea turtles, and the catch-per-unit-effort of the target species is not negatively affected by the presence of these LEDs (Mangel et al. 2018MANGEL JC, WANG J, ALFARO-SHIGUETO J, PINGO S, JIMENEZ A, CARVALHO F, SWIMMER Y & GODLEY BJ. 2018. Illuminating gillnets to save seabirds and the potential for multi-taxa bycatch mitigation. R Soc Open Sci 5: 180254., Bielli et al. 2020BIELLI A, ALFARO-SHIGUETO J, DOHERTY PD, GODLEY BJ, ORTIZ C, PASARA A, WANG JH & MANGEL JC. 2020. An illuminating idea to reduce bycatch in the Peruvian small-scale gillnet fishery. Biol Conserv 241: 108277.). In addition, the cost of the pingers and LEDs would require a financial investment that is not feasible for Brazilian artisanal fishers, meaning that the government or research institutions would have to provide subsidies if their use is encouraged. However, it is possible to use recycled plastic and glass bottles to create acoustic reflectors and mechanical alarms. Recycled 500 ml plastic bottles produce an acoustic reflection when exposed to the dolphin click. Recycled 350 ml glass bottles with a suspended metal pendulum bolt produce the “clinking” sound. Therefore, these ‘bottle reflectors’ could facilitate gillnet detection by dolphins to avoid entanglement and represent a low-cost method accessible to the artisanal fishers (IWC 2019IWC - INTERNATIONAL WHALING COMMISSION. 2019. Report of the IWC Workshop on Bycatch Mitigation Opportunities in the Western Indian Ocean and Arabian Sea, Kenya, 56 p.). Studies can evaluate the potential effects of using pingers, LEDs and recycled plastic and glass bottles to compare their effectiveness as measures to reduce bycatch beyond their implementation costs. Defining fishing exclusion zones to conserve the species could be an alternative to minimizing incidental dolphin captures. Nevertheless, this approach would interfere with fishing activities and the economy of communities that depend on fishing. Another possibility is fishing management through changes in gillnet use patterns, as suggested by Zappes et al. (2013b) for the conservation of the southern right whale (Eubalaena australis; Desmoulins, 1822) in southern Brazil. Positioning the nets in deeper waters, going beyond 30 meters, which is the preferred habitat of the franciscana dolphin, could decrease the number of incidental captures. The viability of this change in fishing practice would depend on the autonomy of the vessels, which would need to operate in deeper waters, further from the coastline.

    Fishing management is mostly based on scientific data, with little consideration of the LEK of fishing communities (Andrew et al. 2007ANDREW NL, BÉNÉ C, HALL SJ, ALLISON EH, HECK S & RATNER BD. 2007. Diagnosis and management of small-scale fisheries in developing countries. Fish Fish 8: 227-240.). This unidirectional approach leads to inefficient actions, as fishers are excluded from decision-making processes in their own territory. Thus, local knowledge and institutions that represent these workers must be part of these processes to ensure a social identity is attached to the actions developed based on the comanagement of fishing activity and associated resources, which would include incidentally captured organisms (Pomeroy et al. 2007POMEROY R ET AL. 2007. Fish Wars: Conflict and Collaboration in Fisheries Management in Southeast Asia. Mar Police 31: 645-656., Ota & Just 2008OTA Y & JUST R. 2008. Fleet sizes, fishing effort and the “hidden” factors behind statistics: An anthropological study of small-scale fisheries in UK. Mar Policy 32: 301-308.).

    The carcasses of incidentally captured dolphins are usually discarded at sea. Fishers avoid keeping them on board, as injuring or capturing cetaceans is prohibited in Brazil (Brasil 1987BRASIL. 1987. Lei Federal nº 7.643, de 18 de dezembro de 1987. It prohibits cetacean fishing in Brazilian jurisdictional waters, and makes other provisions. Diário Oficial da União, Brasília, 21 de dezembro de 1987, nº. 122, Section 1, p. 22079., Federal Law 7643 from December 18, 1987). Using the fat and muscle tissue obtained from the carcasses as bait for shark fishing and food is not a common practice, as demonstrated through the interviews, and there is probably no intention to capture dolphins for this purpose. Although this practice has been described in Brazil since the 1990s, it involves limited and specific occurrences (Lodi & Capistrano 1990LODI L & CAPISTRANO L. 1990. Capturas acidentais de pequenos cetáceos no litoral norte do Estado do Rio de Janeiro. Biotemas 3: 47-65., Zappes et al. 2009ZAPPES CA, ANDRIOLO A, SILVA FO & MONTEIRO-FILHO ELA. 2009. Potential conflicts between fishermen and Sotalia guianensis (van Bénéden, 1864) (Cetacea, Delphinidae). Sitientibus Série Ciências Biológicas 9: 208-214., 2014). According to fishers, occasionally, incidentally captured dolphin carcasses are transferred to researchers who work on conservation projects, as well as for management and inspection agencies. This scenario could be a result of actions to coordinate fishers and scientists; however although this is efficient, this coordination is rare on the Brazilian coast (Zappes et al. 2009ZAPPES CA, ANDRIOLO A, SILVA FO & MONTEIRO-FILHO ELA. 2009. Potential conflicts between fishermen and Sotalia guianensis (van Bénéden, 1864) (Cetacea, Delphinidae). Sitientibus Série Ciências Biológicas 9: 208-214., 2016).

    The status of need for educational activities related to the impact of fisheries on P. blainvillei was defined based on the local knowledge in the study areas (Table V). The ranking used the criteria established in Table V to identify areas where educational activities are needed. Additionally, Table VI presents proposals for conserving the species together with traditional fishing communities.

    Table V
    Comparison of artisanal fisher’s LEK about the franciscana dolphin (Pontoporia blainvillei) and status of the need for educational and conservation actions in the study area.
    Table VI
    Proposed actions aimed at the conservation of the franciscana dolphin.
    Proposal Stakeholders involved Why? How?
    Strengthen partnerships between fishers, researchers, and environmental managers Researchers working in the socioenvironmental area, environmental agencies, artisanal fishers, and nongovernmental organizations To establish trust among stakeholders to facilitate the development and implementation of comanagement aimed at the conservation of the franciscana dolphin, working together with fishing communities Conducting meetings aimed at comanaging the dialogue between stakeholders, combining the knowledge of fishermen with the technical knowledge of researchers in relation to the biology and ecology of target and nontarget fishing species; developing legislation proposals based on the knowledge of fishermen and environmental agencies
    Increase radio communication between stakeholders Members of fishery communities, employees of fishing institutions, civil servants of the environmental office of city hall and environmental management bodies, researchers from universities, and nongovernmental organizations To request an order to obtain real-time information related to artisanal fishery activity and bycatch of franciscana dolphins to estimate the impact of fisheries on this dolphin, and this would enable immediate assistance to fishers in cases of adverse situations Registering information on fishery activities (fishery gear used, environmental conditions, target species, number, and identification of vessels at sea) and incidental capture of franciscana dolphin (characteristics of the entangled animal and the artifact that caused the capture)
    Provide instructions on the correct disposal of materials derived from fishing Artisanal fishers, employees of fishing institutions, civil servants of the environment office, researchers from universities, and nongovernmental organizations To minimize the irregular disposal of tailings derived from fisheries into the environment, thus minimizing the negative effects of ghost nets on franciscana dolphin and other animals that are not the target of fisheries (for example, other cetaceans, goliath grouper, and turtles) Conducting monthly meetings in areas used by fishers, such as fisher’s institutions, community associations and fish markets, to determine the proper disposal of waste derived from fisheries, with special attention to the language used, which should be accessible to the interested parties

    CONCLUSIONS

    Artisanal fishers LEK about franciscana dolphin within its distribution area in southern and southeastern Brazil is influenced by the probability of observing or having contact with the species in fishing zones. In this sense, LEK is influenced by the presence of the species in the zones (distribution areas vs gaps), type of fishing gear (gillnets vs other artifacts), and habitat features (sheltered sea vs open sea). These conditions facilitate or hinder the observation/contact (and the correct recognition) with of the species, whose physical/behavioral characteristics already limit its observation in the wild.

    When fishers had favorable conditions for recognizing the species, they could identify its features and provide information about its interactions with the fishing activity. Thus, we confirmed LEK as a tool for data generation about P. blainvillei populations when its habitat overlaps with areas of fishing activity in the Southwest Atlantic Ocean (SWAO).

    Incidental captures while fishing was the main cause of franciscana dolphin mortality within its distribution area. It is therefore important to understand traditional knowledge to facilitate the approach of researchers with communities so that they can assist in the comanagement of fishery practices, focused on the conservation of the species. It is believed that environmental education about this animal in the studied communities could minimize the effects of these captures on the species populations or, at a minimum, allow a regular assessment of its mortality. This study contributes to the goals of the Brazilian government aiming to conserve of the franciscana dolphin.

    ACKNOWLEDGMENTS

    We acknowledge the fishers and presidents of the Colonies of Conceição da Barra (Z-1); Barra do Riacho (Z-7); Anchieta (Z-4); Piúma (Z-9); Atafona (Z-2); Peças’ Island (Z-2), Superagui’s Island (Z-2) and Association of Fishers of Regência (Asper). S.C. Araujo, thanks the Coordenação de Aperfeiçoamento de Pessoal de Nível Superior - Brazil (CAPES) - Financing Code 001 for the granting of a Master’s scholarship. C.A. Zappes thanks the Conselho Nacional de Desenvolvimento Científico e Tecnológico / CNPq (304.179/2022-1) and the Yaqu Pacha - Society for the Protection of Aquatic Mammals Species of Latin America. A.P.M. Di Beneditto thanks FAPERJ (Fundação de Amparo à Pesquisa do Estado do Rio de Janeiro, Brazil) (E-26 / 200.797 / 2021) and CNPq (grants n. 302.598/2021-9). To the Fundação O Boticário de Proteção da Natureza (0894-20111).

    REFERENCES

    • ABREU JS, DOMIT C & ZAPPES CA. 2017. Is there dialogue between researchers and traditional community members?: The importance of integration between traditional knowledge and scientific knowledge to coastal management. Ocean Coast Manag 141: 10-19.
    • ALVES LD, DI BENEDITTO APM & ZAPPES CA. 2019. Ethnooceanography of tides in the artisanal fishery in Southeastern Brazil: Use of traditional knowledge on the elaboration of the strategies for artisanal fishery. Appl Geogr 110: 102044.
    • AMARAL KB ET AL. 2018. Reassessment of the franciscana Pontoporia blainvillei (Gervais & d’Orbigny, 1844) distribution and niche characteristics in Brazil. J Exp Mar Biol Ecol 508: 1-12.
    • ANDREW NL, BÉNÉ C, HALL SJ, ALLISON EH, HECK S & RATNER BD. 2007. Diagnosis and management of small-scale fisheries in developing countries. Fish Fish 8: 227-240.
    • AU WWL & JONES L. 1991. Acoustic reflectivity of nets: implications concerning incidental take of dolphins. Mar Mam Sci 7: 258-273.
    • BAILEY KD. 1982. Methods of Social Research, 2nd ed, Nova York: The Free Press and Macmillan Publishers, 439 p.
    • BARLOW J & CAMERON GA. 2003. Field Experiments Show That Acoustic Pingers Reduce Marine Mammal Bycatch in The California Drift Gill Net Fishery. Mar Mam Sci 19: 265-283.
    • BERTOZZI CP & ZERBINI AN. 2002. Incidental mortality of the franciscana, Pontoporia blainvillei, in the artisanal fishery of Praia Grande, São Paulo State, Brazil. Lat Am J Aqu Mam 1: 153-160.
    • BIELLI A, ALFARO-SHIGUETO J, DOHERTY PD, GODLEY BJ, ORTIZ C, PASARA A, WANG JH & MANGEL JC. 2020. An illuminating idea to reduce bycatch in the Peruvian small-scale gillnet fishery. Biol Conserv 241: 108277.
    • BRASIL. 1987. Lei Federal nº 7.643, de 18 de dezembro de 1987. It prohibits cetacean fishing in Brazilian jurisdictional waters, and makes other provisions. Diário Oficial da União, Brasília, 21 de dezembro de 1987, nº. 122, Section 1, p. 22079.
    • BRASIL. 2009. Decreto nº. 11.959, 29 de junho de 2009. Provides for the National Policy for the Sustainable Development of Aquaculture and Fisheries, regulates fishing activities, revokes Law No. 7,679, of November 23, 1988, and Decree-Law no. 221, of February 28, 1967, and gives other measures. Diário Oficial da União, Brasília, 30 de junho de 2009, nº. 122, Section 1, p. 1-3.
    • BROTONS JM, MUNILLA Z, GRAU AM & RENDELL L. 2008. Do pingers reduce interactions between bottlenose dolphins and nets around the Balearic Islands? Endang Species Res 5: 301-308.
    • CARRETTA J, BARLOW J & ENRIQUEZ L. 2008. Acoustic pingers eliminate beaked whale bycatch in a gill net fishery. Mar Mam Sci 24: 956-961.
    • COCKETT R & MANES E. 2009. Boolean and classical restriction categories. Math Struct Comput Sci 19: 357-416.
    • CRESPO EA, PEDRAZA SN, GRANDI MF, DANS SL & GARAFFO GV. 2010. Abundance and distribution of endangered franciscanas (Pontoporia blainvillei) in Argentine waters and conservation implications. Mar Mam Sci 26: 17-35.
    • CULIK BM. 2011. Odontocetes: The toothed whales. UNEP/CMS/ASCOBANS Secretariat, Bonn, n. 24, Germany: CMS Technical, 311 p.
    • CUNHA HA, MEDEIROS BV, BARBOSA LA, CREMER MJ, MARIGO J, LAILSON-BRITO J, AZEVEDO AF & SOLÉ-CAVA AM. 2014. Population structure of the endangered franciscana (Pontoporia blainvillei): reassessing management units. PLoS ONE 9: e8563.
    • DANILEWICZ D, MORENO IB, OTT PH, TAVARES M, AZEVEDO AF, SECCHI ER & ANDRIOLO A. 2010. Abundance estimate for a threatened population of franciscanas in southern coastal Brazil: uncertainties and management implications. J Mar Biol Assoc UK 90: 1649-1657.
    • DANILEWICZ D, ZERBINI AN, ANDRIOLO A, SECCHI ER, SUCUNZA F, FERREIRA E, DENUNCIO P & FLORES PA. 2012. Abundance and distribution of an isolated population of franciscanas (Pontoporia blainvillei) in southeastern Brazil: red alert for FMA I? International Whaling Commission, Scientific Committee Paper SC/64/SM17.
    • DAWSON SM. 1991. Modifying gillnets to reduce entanglement of cetaceans. Mar Mam Sci 7: 274-282.
    • DAWSON SM, READ A & SLOOTEN E. 1998. Pingers, porpoises and power: uncertainties with using pingers to reduce bycatch of small cetaceans. Biol Conserv 84: 141-146.
    • DI BENEDITTO APM. 2003. Interactions between gillnet fisheries and small cetaceans in northern Rio de Janeiro, Brazil: 2001 - 2002. Lat Am J Aquat Mam 2: 79-86.
    • DI BENEDITTO APM & RAMOS R. 2001. Biology and conservation of the franciscana (Pontoporia blainvillei) in the north of Rio de Janeiro State, Brazil. J Cetac Res Manag 3: 185-192.
    • DI BENEDITTO APM, RAMOS RMA & LIMA NRW. 2001. Sightings of Pontoporia blainvillei (Gervais&D´Orbigny, 1844) and Sotalia fluviatilis (Gervais, 1853) (Cetacea) in South-eastern Brasil. Braz Arch Biol Technol 44: 291-296.
    • FREITAS NETTO R & BARBOSA LA. 2003. Cetaceans and fishery interactions along the Espírito Santo State, Southeastern Brazil during 1994-2001. Lat Am J Aquat Mam 2: 57-60.
    • FREITAS NETTO R & DI BENEDITTO APM. 2008. Interactions between fisheries and cetaceans in Espírito Santo State coast, southestern Brazil. Rev Bras Zoo 10: 55-63.
    • HEALE R & FORBES D. 2013. Understanding triangulation in research. Evidence-based nursing 16: 98.
    • ICMBIO - INSTITUTO CHICO MENDES DE CONSERVAÇÃO DA BIODIVERSIDADE. 2018. Livro Vermelho da Fauna Brasileira Ameaçada de Extinção. Mamíferos, 2nd ed, Brasília: Ministério do Meio Ambiente, 622 p.
    • IWC - INTERNATIONAL WHALING COMMISSION. 2019. Report of the IWC Workshop on Bycatch Mitigation Opportunities in the Western Indian Ocean and Arabian Sea, Kenya, 56 p.
    • JEFFERSON TA, WEBBER MA & PITMAN RL. 2015. Marine mammals of the World: a comprehensive guide to their identification, 2nd ed, San Diego: Academic Press, 616 p.
    • KASTELEIN RA, HEUL SVD, VEEN JVD, VERBOOM WC, JENNINGS N, HAAN D & REIJNDERS P. 2007. Effects of commercially-available acoustic alarms, designed to reduce small cetacean bycatch in gillnet fisheries, on the behaviour of North Sea fish species in a large tank. Mar Environ Res 64: 160-180.
    • KENDALL L. 2008. The conduct of qualitative interview: Research questions, methodological issues, and researching online. In: Coiro J, Knobel M, Lankshear C & Leu DJ (Eds), Handbook of research on new literacies. New York: Lawrence Erlbaum Associates, p. 133-149.
    • LAVANDIER R, ARÊAS J, QUINETE N, MOURA JF, TANIGUCHI S, MONTONE R, SICILIANO S & MOREIRA I. 2015. PCB and PBDE levels in a highly threatened dolphin species from the Southeastern Brazilian coast. Environ Pollut 208: 442-449.
    • LIBRETT M & PERRONE D. 2010. Apples and oranges: ethnography and the IRB. Qual Res 10: 729-747.
    • LODI L & CAPISTRANO L. 1990. Capturas acidentais de pequenos cetáceos no litoral norte do Estado do Rio de Janeiro. Biotemas 3: 47-65.
    • MALINOWSKI B. 2014. Argonauts of the Western Pacific, 1nd ed, Helion, 279 p.
    • MANGEL JC, ALFARO-SHIGUETO J, WITT MJ, HODGSON DJ & GODLEY BJ. 2013. Using pingers to reduce bycatch of small cetaceans in Peru’s small-scale driftnet fishery. Oryx 47: 595-606.
    • MANGEL JC, WANG J, ALFARO-SHIGUETO J, PINGO S, JIMENEZ A, CARVALHO F, SWIMMER Y & GODLEY BJ. 2018. Illuminating gillnets to save seabirds and the potential for multi-taxa bycatch mitigation. R Soc Open Sci 5: 180254.
    • MARTINS AS, DOS SANTOS LB, PIZETTA GT, MONJARDIM C & DOXSEY JR. 2009. Interdisciplinary assessment of the status quo of the marine fishery systems in the state of Espírito Santo, Brazil, using Rapfish. J Appl Ichthyol 25: 269-276.
    • MASON M. 2010. Sample size and saturation in PhD studies using qualitative interviews. Forum Qualitative Sozial for schung/Forum Qual Soc Res 11: 8.
    • MAYORGA LFSP ET AL. 2020. Strandings of cetaceans on the Espírito Santo coast, southeast Brazil, 1975–2015. ZooKeys 948: 129-152.
    • MELO LG. 2004. Antropologia cultural, objetivo e método. In: Melo LG (Ed), Antropologia Cultural: Iniciação, teoria e temas. 11nd ed, Petrópolis: Editora Vozes, p. 33-78.
    • MIRANDA TM, AMOROZO MCM, GOVONE JS & MIRANDA DM. 2007. The Influence of Visual Stimuli in Ethnobotanical Data Collection Using the Listing Task Method. Field Methods 19: 76-86.
    • OPDENAKKER R. 2006. Advantages and disadvantages of four interview techniques in qualitative research. Forum Qual Soc Res 7(4): 11.
    • OTA Y & JUST R. 2008. Fleet sizes, fishing effort and the “hidden” factors behind statistics: An anthropological study of small-scale fisheries in UK. Mar Policy 32: 301-308.
    • PERRIN WF, WÜRSIG B & THEWISSEN JGM. 2008. Encyclopedia of Marine Mammals, 2nd ed, San Diego: Academic Press, 1352 p.
    • PETERSON D, HANAZAKI N & SIMÕES-LOPES PC. 2008. Natural resource appropriation in cooperative artisanal fishing between fishermen and dolphin (Tursiops truncatus) in Laguna, Brazil. Ocean Coast Manag 51: 469-475.
    • PINHEIRO FCF, PINHEIRO HT, TEIXEIRA JB, MARTINS AS & CREMER MJ. 2019. Opportunistic Development and Environmental Disaster Threat Franciscana Dolphins in the Southeast of Brazil. Tropical Conserv Scie 12: 1-7.
    • PINHEIRO L & CREMER M. 2003. Etnoecologia e captura acidental de golfinhos (Cetacea: Pontoporiidae e Delphinidae) na Baía de Babitonga, Santa Catarina. Desenvolvimento e Meio Ambiente 8: 69-75.
    • POMEROY R ET AL. 2007. Fish Wars: Conflict and Collaboration in Fisheries Management in Southeast Asia. Mar Police 31: 645-656.
    • PRADERI R, PINEDO MC & CRESPO EA. 1989. Conservation and management of Pontoporia blainvillei in Uruguay, Brazil and Argentina. In: Perrin WF, Brownell RL, Zhou K & Liu J (Eds), Biology and Conservation of the River Dolphins. Occasional Papers-IUCN-SSC, Hong Kong, p. 52-56.
    • PRZBYLSKI CB & MONTEIRO-FILHO ELA. 2001. Interação entre pescadores e mamíferos marinhos no litoral do Estado do Paraná – Brasil. Biotemas 14: 141-156.
    • ROCHA-CAMPO CC, DANILEWICZ DS & SALVATORE S. 2010. Plano de Ação Nacional para a Conservação do Pequeno Cetáceo: Toninha – Pontoporia blainvillei – Série Espécies Ameaçadas 10. Brasília: Ministério do Meio Ambiente, 77 p.
    • ROSA GA, ZAPPES CA & DI BENEDITTO APM. 2012. Etnoecologia de pequenos cetáceos: interações entre a pesca artesanal e golfinhos no norte do estado do Rio de Janeiro, Brasil. Biotemas 25: 293-304.
    • ROSAS FCW & MONTEIRO-FILHO ELA. 2002. Reproductive parameters of Pontoporia blainvillei (Cetacea, Pontoporiidae), on the coast of São Paulo and Paraná States, Brazil. Mammalia 66: 231-245.
    • ROSAS FCW, MONTEIRO-FILHO ELA & OLIVEIRA MR. 2002. Incidental catches of franciscana (Pontoporia blainvillei) on the southern coast of São Paulo state and the coast of Paraná state, Brazil. Lat Am J Aquat Mam 1: 161-167.
    • RUPIL GM, BARBOSA L, MARCONDES MCC, CARVALHO BM & FARRO APC. 2019. Franciscana dolphin (Pontoporia blainvillei) diet from Northern Espírito Santo State coast, Brazil. Biotemas 32: 87-96.
    • RYAN G & BERNARD HR. 2000. Data management and analysis methods. In: Denzin NK & Lincoln YS (Eds), Handbook of Qualitative Research. Sage Publications, Thousand Oaks, p. 769-802.
    • SANCHES RA. 2004. Caiçaras e a Estação ecológica de Juréia-Itatins. Histórico de ocupação no contexto político, econômico, social e ambiental do Vale do Ribeira. In: Marques OAV & Duleba W (Eds), Estação Ecológica Juréia-Itatins: Ambiente Físico, Flora e Fauna. Ribeirão Preto: Holos Editora, p. 349-359.
    • SANTOS MCO, OSHIMA JEF & DA SILVA E. 2009. Sightings of franciscanas (Pontoporia blainvillei): The Discovery of a population in the Paranaguá Estuarine Complex, Southern Brazil. Braz J Oceanog 57: 57-63.
    • SCHENSUL SL, SCHENSUL JJ & LECOMPTE MD. 1999. Essential Ethnographic Methods: Observations, Interviews, & Questionnaires. In: Schensul JJ & Lecompte MD (Eds), Ethnographer’s Toolkit, 2nd ed, Walnut Creek: Altamira Press, p. 69-89.
    • SECCHI ER, DANILEWICZ D & OTT PH. 2003a. Applying the phylogeographic concept to identify franciscana stocks: implications to meet management objectives. J Cetacean Res Manag 5: 61-68.
    • SECCHI ER, DANILEWICZ D, OTT PH, RAMOS R, LAZARO M, MARIGO J & WANG JY. 2002a. Report of the working group on stock identity. Lat Am J Aquat Mam 1: 47-54.
    • SECCHI ER, OTT PH & DANILEWICZ D. 2002b. Report of the fourth workshop for the coordinated research and conservation of the franciscana (Pontoporia blainvillei) in the Western South Atlantic. Lat Am J Aquat Mam 1: 11-20.
    • SECCHI ER, OTT PH & DANILEWICZ D. 2003b. Effects of fishing by-catch and conservation status of the franciscana, Pontoporia blainvillei. In: Gales N, Hindell M & Kirkwood K (Eds), Marine Mammals: Fisheries. Tourism and Management Issues CSIRO Publishing, Australia: Collinwoop, p. 174-191.
    • SECCHI ER & WANG JY. 2002. Assessment of the conservation status of a franciscana (Pontoporia blainvillei) stock in the Franciscana Management Area III following the IUCN Red List Process. Lat Am J Aquat Mam 1: 183-190.
    • SECCHI ER, ZERBINI AN, BASSOI M, DALLA ROSA L, MOLLER LM & ROCCHA-CAMPOS CC. 1997. Mortality of franciscana, Pontoporia blainvillei, in coastal gillnetting in southern Brazil. Rep Internat Whal Comm 47: 653-658.
    • SICILIANO S. 1994. Review of small cetaceans and fishery interactions in coastal waters of Brazil. Rep Internat Whal Comm 15: 241-250.
    • SICILIANO S, DI BENEDITTO APM & RAMOS RMA. 2002. A toninha, Pontoporia blainvillei (Gervais & d´Orbigny, 1844) (Mammalia, Cetacea, Pontoporiidae), nos estados do Rio de Janeiro e Espírito Santo, costa sudeste do Brasil: Caracterizações dos hábitats e fatores de isolamento das populações. Boletim do Museu Nacional–Nova Série Zoologia 146: 1-15
    • SICILIANO S, TAVARES DC, MOURA JF & DI BENEDITTO APM. 2019. Assessment of the fisheries characteristics in southeastern Brazil: Moving towards a monitoring program to assess Franciscana bycatch in FMA 1b – northern Rio de Janeiro. Report of the International Whaling Commission (SC/67B/SM/05), 24 p.
    • SILVA CV, MOREIRA SC, ZAPPES CA & DI BENEDITTO APM. 2014. Pesca artesanal e cetáceos que ocorrem no litoral leste do Rio de Janeiro: Uma abordagem etnoecológica para verificar a existência de manejo tradicional. Bol Inst Pesca (Online) 40: 521-539.
    • SILVANO RAM & BEGOSSI A. 2002. Ethnoichthyology and fish conservation in the Piracicaba river (Brazil). J Ethnobiol 22: 285-306.
    • TREGENZA NJC, BERROW SD & HAMMOND PS. 1997. Attraction of common dolphins (Delphinus delphis) to boat settings gillnets. European Research on Cetaceans 11: 47-49.
    • TRIMBLE M & PRADERI R. 2006. What is the colour of the franciscana (Pontoporia blainvillei)?: A review and a proposed assessment method. Lat Am J Aquat Mam 5: 55-63.
    • ZAPPES CA, ALVES LCPS, SILVA CV, AZEVEDO AF, DI BENEDITTO APM & ANDRIOLO A. 2013a. Accidents between artisanal fisheries and cetaceans on the Brazilian coast and Central Amazon: Proposals for integrated management. Ocean Coast Manag 85: 46-57.
    • ZAPPES CA, ANDRIOLO A, SILVA FO & MONTEIRO-FILHO ELA. 2009. Potential conflicts between fishermen and Sotalia guianensis (van Bénéden, 1864) (Cetacea, Delphinidae). Sitientibus Série Ciências Biológicas 9: 208-214.
    • ZAPPES CA, ANDRIOLO A, SIMÕES-LOPES PC & DI BENEDITTO APM. 2011. ‘Human-dolphin (Tursiops truncatus Montagu, 1821) cooperative fishery’ and its influence on cast net fishing activities in Barra de Imbé/Tramandaí, Southern Brazil. Ocean Coast Manag 54: 427-432.
    • ZAPPES CA, GAMA RM, DOMIT C, GATTS CEN & DI BENEDITTO APM. 2016. Artisanal fishing and the franciscana (Pontoporia blainvillei) in Southern Brazil: ethnoecology from the fishing practice. J Mar Biol Assoc UK 96: 1-11.
    • ZAPPES CA, GATTS CEN, LODI LF, SIMÕES-LOPES PC, LAPORTA P, ANDRIOLO A & DI BENEDITTO APM. 2014. Comparison of local knowledge about the bottlenose dolphin (Tursiops truncatus Montagu, 1821) in the Southwest Atlantic Ocean: New research needed to develop conservation management strategies. Ocean Coast Manag 98: 120-129.
    • ZAPPES CA, MONTEIRO-FILHO ELA, OLIVEIRA F & ANDRIOLO A. 2010. O comportamento do boto-cinza Sotalia guianensis (van Bénéden, 1864) (Cetacea; Delphinidae) através do olhar dos pescadores artesanais. Revista de Etologia 9: 17-28.
    • ZAPPES CA, SILVA CV, PONTALTI M, DANIELSKI ML & DI BENEDITTO APM. 2013b. The conflict between the southern right whale and coastal fisheries on the southern coast of Brazil. Mar Policy 38: 428-437.
    • ZERBINI AN, SECCHI E, CRESPO E, DANILEWICZ D & REEVES R. 2017. Pontoporia blainvillei. The IUCN Red List of Threatened Species: e.T17978A123792204.

    Publication Dates

    • Publication in this collection
      19 May 2023
    • Date of issue
      2023

    History

    • Received
      14 July 2020
    • Accepted
      5 Dec 2020
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