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ORIGINAL RESEARCH article

Front. Mar. Sci., 11 February 2021
Sec. Marine Conservation and Sustainability
This article is part of the Research Topic Emerging Concerns, Biology and Conservation in Key Marine Environments Undergoing Highly Selective Pressures View all 8 articles

Aquatic Wildmeat Consumption of Guiana Dolphins (Sotalia guianensis) in Lake Maracaibo System, Venezuela

\r\nYurasi Briceo*Yurasi Briceño1*Leonardo SnchezLeonardo Sánchez1Fernando TrujilloFernando Trujillo2Lorenzo von FersenLorenzo von Fersen3Sonsire RamírezSonsireé Ramírez4
  • 1Instituto Venezolano de Investigaciones Científicas, Miranda, Venezuela
  • 2Fundación Omacha, Bogotá, Colombia
  • 3Nuremberg Zoo, Nuremberg, Germany
  • 4Sociedad Conservacionista AQUA, Maracaibo, Venezuela

In many regions of the world, the use of cetaceans as bait or protein source has been reported. In most cases the individuals are from bycatch but also from intentionally killed animals. Cetaceans with coastal habits are more susceptible to negative interactions with small-scale fisheries, as in the case of the Guiana dolphin (Sotalia guianensis) in the Lake Maracaibo system. For decades, the use of Guiana dolphins by local communities has been reported in this region and is culturally supported by recipes for its preparation. Most of these data was outdated and some were anecdotal, so the objective of this work was to collect systematically data through surveys using the snowball method in seven artisanal fishing communities and to try to quantify the capture rate and to inquire about the potential impact of this practice on the population of Guiana dolphin. From 2017 to 2019, 95 semi-structured interviews were applied. An average bycatch of 180 individuals/year was obtained, the highest catch rate in the entire geographic distribution, an alarming situation considering that the surveys were not carried out in all the fishing ports, generating an underestimation. A total of 78% of interviewed recognized at least one bycatch event during their fishing effort. Surveys revealed a higher incidence of entanglement of offspring and juveniles (78%). 77% of the respondents deny the sale and commercialization of the species, while 5% mention some type of trade. The most frequent part exploited was the dorsal muscle, confirmed by fishermen (97%, n = 72) and the rest of the animal is discarded. During this investigation three episodes of directed capture were recorded, affecting a total of 23 individuals, two of them were pregnant females. The interviews also revealed that the majority of fishermen (93%) recognize the capture of this species as illegal. Considering the vulnerability of the Guiana dolphin in the country, the high incidence of capture and consumption and the lack of surveillance and sanctions by government entities, it is imperative to immediate actions to mitigate the negative impact on the population.

Introduction

Direct fisheries interaction has been recognized as the main cause of cetacean mortality throughout the world (Mitchell, 1975; Reeves et al., 2013, 2003; Brownell et al., 2019), even nearly causing the extinction of species such as the “vaquita marina” (Phocoena sinus) (Rojas-Bracho and Taylor, 1999; Rojas-Bracho et al., 2006). Cetacean species with coastal habits are even more vulnerable due to anthropogenic threats as the species distribution overlaps with the presence of humans and their activities (Reeves et al., 2003; Lotze et al., 2006; Hawkins et al., 2017).

Historically, the use of cetaceans around the world is diverse, i.e., as bait in shark fishing (Mintzer et al., 2018), as a protein resource (Read et al., 1988; Ávila et al., 2008) and the use of some of parts for mythical/religious purposes (Alves and Rosa, 2008), among others. Generally, these animals come from bycatch and sometimes from intentional capture, but both situations represent a threat to the population stability of many aquatic mammals (Clapham and Van Waerebeek, 2007; Robards and Reeves, 2011; García et al., 2013). Recently, the Convention on Migratory Species generated a concept for this exploitation, thus defining aquatic wild meat as all products derived from aquatic megafauna, used for food or non-food purposes (CMS, 2017).

The Guiana dolphin (Sotalia guianensis) (Van Bénéden, 1864), distributed from Nicaragua (Carr and Bonde, 2000) to Southern Brazil (Borobia et al., 1991; Da Silva and Best, 1996), is listed by the IUCN as “Near Threatened” (Secchi et al., 2018), a species for which frequent bycatch has been reported, which may be affecting its population stability at the local scale. In fact, in Venezuela it is classified as “Vulnerable” (Barrios-Garrido et al., 2015), as in Brazil (Instituto Chico Mendes de. (Conservação)da Biodiversidade (ICMBio), 2018) and Colombia (Trujillo et al., 2006).

The Lake Maracaibo system in western Venezuela, has important economic value because of the oil industry and the benefit it brings to large fishing communities. It is also the main area of occurrence of S. guianensis in Venezuela (Casinos et al., 1981). These anthropic activities generate several negative impacts on this ecosystem such as overfishing, eutrophication processes and frequent oil spills (MARN, 2000; Ferrer and Morales, 2013; Molina and Yedra, 2019).

The population of S. guianensis in Lake Maracaibo has been suggested as a separate management unit due to its unique genetic and morphological characteristics (Caballero et al., 2010, 2018; Cunha et al., 2010; Briceño et al., 2017). Despite its ecological relevance, its use as bait for shark fisheries and as a protein source for humans has been reported for decades and is culturally supported by recipes for its preparation (Ramírez, 2005; Pirela et al., 2006; Sánchez-Criollo et al., 2007; Sánchez and Briceño, 2017), despite the existence of laws in force that prohibit it. In the past, only bycatch dolphins were exploited, but in recent decades (since 2010), a growing interest in live capture has been registered.

Many records on the use of Guiana dolphins in the Lake Maracaibo system are anecdotal, with information derived from easily accessible locations, and those that have been compiled using some methodology are out of date. These factors limit a larger-scale analysis of the problem, as it is difficult to estimate the capture rate and its possible impact on the population. It is also difficult to gain clear knowledge about the current use of these dolphins and their value to the local people. Without this information, conservation strategies may be ineffective or insufficient.

The objective of this study was to present updated information on the consumption of the Guiana dolphin in some areas of Lake Maracaibo, to try to quantify the capture rate and to inquire about the potential impact of this practice on the population of S. guianensis in Lake Maracaibo.

Materials and Methods

Study Areas

The Lake Maracaibo system is located in western Venezuela (9°48′57″N 71°33′24″W), and is considered to be a set of interconnected bodies of water. This system is composed by Gulf of Venezuela, El Estrecho with a length of 55 km, El Tablazo bay and Lake Maracaibo itself, the only one of its kind with its connection to the Caribbean Sea (Rodríguez, 2001; José, 2000). The physicochemical variables differ in these areas, as salinity decreases from the north (influenced by the salinity of the sea) to the south (influenced by the contribution of large rivers) (José, 2000). This gives rise to different habitats with diverse fish fauna, some strictly marine, marine-estuarine and freshwater species (José, 2000; Rodríguez-Olarte et al., 2011).

The lake Maracaibo system has two areas of great ecological value. In the extreme northeast, the Refuge of Wild Fauna and Fishing Reserve “Ciénaga de Los Olivitos” is a wetland with a great diversity of fauna and flora, and in the southwest is the National Park “Ciénagas de Juan Manuel,” characterized by its swampy soil, where delta, flooded forests and tropical forests are also found (Medina and Barboza, 2006) with a high diversity of endemic fauna. The portion of water that the park encompasses is an important habitat for S. guianensis, because the shallow bays in the zone, with the presence of vegetation, which provide shelter and food for the calves (Briceño and Sánchez, 2017).

Localities Evaluated

A total of seven artisanal fishing communities located in the northern, central western and southern regions of Lake Maracaibo were visited (Table 1).

TABLE 1
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Table 1. Localities evaluated in four regions of the Lake Maracaibo system.

The boats used throughout Lake Maracaibo were similar, and were made out of fiberglass and wood with a size between 4 and 7 m, with one 40 HP outboard motor. Generally, activity takes place near the coast.

Despite the fact that in some of these regions there is intensive fishing and some economic income from tourism, all of these communities are considered low-income and the inhabitants have a low level of formal education. These localities were selected because they are the ones with the largest number of formally registered fishermen, and from which previous data (Sánchez-Criollo et al., 2007; Ramírez, 2005) on the consumption of the Guiana dolphin were obtained (Figure 1).

FIGURE 1
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Figure 1. Zulia state with the location of the fishing communities visited San Carlos, Zapara and Toas islands (northwest), Los Puertos de Altagracia (northeast), Barranquitas (central west), Puerto La Concha, and Ologá (southwest).

Interviews

From 2017 to 2019, 95 semi-structured interviews that represents the 10% percent of the fishermen registered (950) in the seven communities grouped in four (4) fishing ports. Open and closed questions were applied in all fishing communities selected of Lake Maracaibo system. In the northwest (NW) a total of 33 interviews were applied (San Carlos island 15, Toas island 10, and Zapara island 8), in the northeast (NE) 12 (Los Puertos de Altagracia), Central west (CW) 10 (Barranquitas), and the Southwest (SW) region 40 (31 in Puerto La concha and nine in Ologá). The non-probabilistic snowball technique was used (Naderifar et al., 2017), which consists of identifying a subject who can provide the required information and then that subject suggests the next person to interview.

The choice of this technique does not allow to know in advance the final number of participants, but it does guarantee that the data collection is less biased and with higher quality, because allows for establishing a link and building trust between the parties involved (Biernacki and Waldorf, 1981; Zappes et al., 2013).

Closed (Yes or No) and open questions were considered to collect more extensive information and allow the fisherman to express himself freely (Huntington, 2000; Kendall, 2008; Albuquerque et al., 2014). The survey began by asking if they knew of or had seen the “tonina,” as they are called locally. They were asked to describe the animal and indicate if it had any relevant characteristics and then a set of images were showed them to verify the identification of the species.

The interviewed persons met these requirements: fishing as the main economic activity, being a resident of the town and having at least 5 years of fishing experience or more, in order to guarantee data quality.

Additionally, direct observations were made in the field, and expeditions were made in search of stranded individuals with evidence of anthropic interaction. A review of the information available in scientific articles and the gray literature on this subject was performed in order to detect changes in the use of this species.

Results

Along most of Venezuela’s coasts the fishermen’s council is led by a local fisherman. These were located to explain the activity to be carried out and invite them to participate voluntarily. A total of 95 interviews were conducted between 2017 and 2019 in seven fishing communities. The surveyed population corresponded entirely to fishermen between 24 and 70 years of age.

Knowledge of the Species

In response to the kind of animal, 9% of them identified the species as a mammal, 14% did not know and 77% (n = 73/95) simply indicated that it was a “tonina.” Twenty-one fishermen (22%) denied bycatch during their fishing operations, while the rest (78% n = 74) stated that an event of this type had occurred on some occasions. A total of 34% of interviewees (n = 25) indicated that more than one dolphin was captured per month. Obtaining an average of 3–4 individuals per month, and at least 180 dolphins per year, the majority (77%) were juveniles (n = 41) and calves (n = 16) individuals, considering the length of the body (Figure 2).

FIGURE 2
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Figure 2. Answers to the following questions in each locality evaluated and the total: (A) What kind of animal is it? (B) Has a tonina ever been caught in a net during your fishing operations? (C) How often do you think that happens in this locality? (D) What is the most frequent size of the tonina you caught?

The following measurements were considered >1.7 m (adult), > 1 m < 1.7 (juvenile), and < 1 m (calf) (Di Beneditto and Ramos, 2004; Riquelme et al., 2011; Lima et al., 2017) to determine the ontogeny of captured individuals. This question was applied to them with great precision, using different elements of their environment as a reference. Regarding seasonality and its possible relationship with dolphin catches, it was concluded that the events occurred indistinctly in the rainy (since April to November in the north and center regions, in the south is not delimited) or dry season (since December to March in the north and center regions, not delimited in the south) (José, 2000). Of the total respondents, 84% (n = 62) said they did not notice any difference.

Use of Guiana Dolphin

Twenty-two (26%) fishermen from the northern region confirm the use of meat as bait in shark fishing; this is the zone where the elasmobranch group is found, and 74% (n = 62) reported use as a source of protein. All the interviewees denied any use for mythical/religious purposes.

The most frequent part exploited was the dorsal muscle, confirmed by fishermen (97%, n = 72) (Figure 3). Only two respondents mentioned the use of the ribs and liver. The rest of the animal was discarded directly in the lake according to the data collected (96%, n = 91), while some reported not knowing what the fishermen did with the rest of the captured animal.

FIGURE 3
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Figure 3. Two individuals of Sotalia guianensis (A,B) found in northern region in 2019 with signs of anthropogenic interaction. In both cases, the dorsal muscles were removed.

A high percentage claimed to have eaten Guiana dolphins at least once (80%, n = 67) and stated that it tasted good. Regarding meat preparations, in general, in all communities, the dorsal muscle is cut into pieces and salted until it is consumed, the ribs are salted in the same way and its meat is shredded, and the liver is refrigerated until the moment of its consumption. The recipes vary according to the region. In the northwest, they cook it with spices and shred the meat to prepare a dish known as “pastelitos,” which is a dough of wheat flour filled with dolphin meat and then fried. In the central west region, they also make a stew, and the muscle pieces along with a portion of the fat is fried and consumed as “chicharrón.” In the southwest, they prepare the stewed muscle with spices and coconut cream is added.

Conflicts Associated With Exploitation

Only 5% of the fishermen reported on the commercialization of dolphin meat on some occasions, but is not a regular offer; the majority denied it (77%, n = 73), and the rest indicated they did not know anything about it (18%). In the southwest, all bycatch dolphins are consumed by the fisherman and his close family, and there has never been a commercial supply of this meat. A total of 48% (n = 51) indicated a decrease in their fishing in the last 5 years, as a consequence of constant oil spills.

Fishermen from the southwest reported two particular incidents. In July 2019, a fisherman left a net (400 m long) for a day and approximately 34 Guiana dolphins were trapped. The fishermen arriving at the site disentangled and consumed three dolphins as they were still fresh, discarding the others. The second event was in reference to entanglement with crab fishing lines, and in that case the dolphin, despite being alive, was captured and consumed. In the northeast region, they reported that Guiana dolphins frequently bite fish on nets, specifically when there is “curvina” (Cynoscion acoupa), but they did not mention retaliation against dolphins.

In addition, in the course of this investigation, three cases of directed capture were reported. The first took place on the eastern shore of the lake, fishermen from a band dedicated to hunting dolphins were intercepted by members of the Bolivarian National Guard, finding an individual captured of Guiana dolphin on the boat for later sale. The next event reported in 2018 occurred in the south of the lake where a group of fishermen caught five individuals and brought them to a nearby town in the central region of the lake for sale. The last occurred in the northern region where seventeen individuals were deliberately captured, two of them were pregnant females and all the animals were distributed free within the community for their consumption.

Regarding the legal framework, the majority of fishermen (93% n = 88) know that the capture, consumption, and commercialization of this species are illegal.

Discussion

Knowledge of the Species

All the fishermen in the interviewed communities are fully aware of the Guiana dolphin, despite the fact that many of them cannot place it within its taxonomic group. This may be associated with the low level of formal education and their inability to associate this species with marine dolphins because they are present in a lake, an ecosystem that they consider to be freshwater and which is an estuary.

The fishing activity along the entire coast is generally carried out within the first 15 km, and the Guiana dolphin inhabits precisely that coastal strip, intensifying bycatch.

Use of Guiana Dolphin

More than two decades ago, the exploitation of this species was reported in the northern region (Coty, 1995; Bolaños and Bermúdez, 1996; Pirela et al., 2002; Ramírez, 2005). Ramírez (2005) also documented the beginning of the commercialization of dolphin meat in the northwest, and the hunting of a group of twenty Guiana dolphins (Ramírez, 2005). Previous bycatch estimations for the northwest region indicated 3.42 dolphins/month (Ramírez et al., 2013), and current results show an increase in the same area (northwest) to 4 dolphins/month. The Lake Maracaibo system, as in many communities in the world that consume the meat of dolphins, the dorsal muscle is the most valued portion regardless of whether it is used as bait or as a protein source (Alfaro-Shigueto et al., 2010; Barbosa-Filho et al., 2018). The rest of the body is usually discarded offshore, as in most countries it is a crime to capture these marine mammals (Mangel et al., 2010; Manzan and Lopes, 2015).

Throughout the lake there are different fishing strategies with nets, but two forms of them are recurrent. The first occurs perpendicular to the coast, in which the nets, which can vary in length from 200 to 600 m, are cast and left for half an hour to an hour, then lifted to extract the fish. This procedure is reported several times during the fishing day. The second strategy is to leave the net permanently and check it at intervals of 4–8 h to remove the prey. This technique is responsible for the largest amount of bycatch of Guiana dolphins in the Lake Maracaibo system.

Juvenile individuals are more susceptible to bycatch events, possibly due to lack of experience in reacting and avoiding fishing nets, since naturally the behavior described for the Guiana dolphin has been evasion in the face of disturbances (Santos and Rosso, 2007). This is an unfavorable situation, particularly in the south of the lake, where its bays are considered breeding areas for the species (Briceño et al., 2017).

The consumption of S. guianensis is not exclusive to Venezuela. In Brazil, the use of the meat has been reported for the same purpose (Ferreira, 2006; Zappes et al., 2009; Meirelles et al., 2010). In each region evaluated (northeast, northwest, central west, southwest) they are experienced in removing and preparing the dorsal muscles, and it is possible to appreciate its culinary cultural value, due to the existence of recipes that have been passed on through oral tradition.

Currently, some recipes previously reported (Ramírez, 2005) in the northern region are no longer prepared, but in contrast, the meat of this dolphin seems to be acquiring a new culinary value. On the beach of San Carlos Island, tourists were offered “tonina pastries” for the first time as an exotic and exclusive dish.

Conflicts Associated With Exploitation

Certain situations could be responsible for the increase in bycatch and consumption of Guiana dolphin meat. One is the fear of fishermen to move away from the coast due to piracy. Second, the constant oil spills that affect the biota and their work tools (boat, engine, nets) limit the mobility of fishermen, and concentrate their work to the first 5 km of coastline. Furthermore, dolphins are unfortunately a good option because they are easy prey that provide a lot of protein. However, fishing for many of them is still profitable, which suggests that the consumption of Guiana dolphin meat could also be associated with a change in perception, from opportunistic use to the consideration of a new protein source.

Denial of intentional capture of Guiana dolphin is a response conditioned by the fear of being penalized, a situation reported in other locations where this topic has been investigated (Zappes et al., 2013; Barbosa-Filho et al., 2018). However, the data obtained on the three directed hunting events in different regions of the Maracaibo lake system contradicts the version of the fishermen and allows us to affirm the existence of this practice. Currently, it is undeniable that the lack of surveillance has led to the growth of this activity.

These results reflect the highest capture rate of S. guianensis (180 dolphins/year) currently reported in its range of distribution (East Atlantic Coast), an alarming situation considering that the surveys were not carried out in all the fishing ports, generating an underestimation of the number of Guiana dolphins captured incidentally or intentionally in the Lake Maracaibo system.

Conclusion

The lack of appreciation and knowledge about the ecological importance of a species, together with changes in the perception of a population about a group of fauna in particular, can condition its future.

Since 2018, an educational program was started in the southern region of Lake Maracaibo in order to increase knowledge about Guiana dolphin in the school and general population. Recently, some school books and consultation guides in non-technical language were designed to distribute among the fishing community and the local population, material available for the first time and accompanied by workshops. These activities must be replicated in other locations where the incidence of capture and hunting is high.

Furthermore, an information campaign should be generated in the fishing communities about the validity of the Venezuelan laws that prohibit the capture of this species.

Previous investigations have revealed high levels of mercury in S. guianensis tissue in Maracaibo lake, for this reason and considering the frequency of its meat consumption in different towns along the lake shore, a public health alert campaign should be created, information that could counteract the interest for the use of the species.

In accordance with what is stated in the national action plan for the conservation of aquatic mammals in Venezuela, the application of these interviews should continue in the other communities not reached during this study, in order to quantify the mortality caused by this illegal practice and bycatch.

Government entities should increase the enforcement of the law and the surveillance and control effort, and abide by the new recommendations to reduce mortality due to negative interactions with fishing, which would include restricting fishing with nets in areas recognized as vulnerable and breeding grounds for the species, particularly in the south of the lake. In the rest of the lake a short term investigation should be carried out to determine these areas to apply these same regulations. Establish limits on the length of fishing trains, and prohibit that these can be left in areas without the presence of fishermen so that they can realize the timely release of entangled dolphins.

At an international level, the particular case of S. guianensis in Lake Maracaibo has been evaluated and discussed in the last 3 years in the scientific committee of small cetaceans of the International Whaling Commission (IWC) due to the high mortality rate reported. As a result of this, it has been suggested to carry out investigations of abundance, population estimates and population trends, as well as estimation of mortality and identify the area with the highest concentration of the species in order to carry out conservation actions.

In this scenario of a potential decrease in fishing due to anthropogenic impacts, and the possible emergence of a market for Guiana dolphin meat, the threat that looms over this population, considered already vulnerable, merits immediate action to mitigate any negative effects. The short- and medium-term future of S. guianensis in the Lake Maracaibo system will depend on the participation of different actors, civil society and government entities.

Data Availability Statement

The raw data supporting the conclusions of this article will be made available by the authors, without undue reservation.

Ethics Statement

Ethical approval was not provided for this study on human participants because in each fishing community there is a legal figure called the Council of Fishermen, backed by the Venezuelan legal framework and led by a local fisherman. This person was consulted in each of the seven investigated communities and asked to convene a meeting of fishermen to obtain approval to conduct the interviews and ensure that participation was voluntary. In addition, it was requested that all participants be of legal age (18) in accordance with the provisions of Venezuelan law. Written informed consent for participation was not required for this study in accordance with the national legislation and the institutional requirements.

Author Contributions

YB: proposing the article, data collection in the field, analysis, and preparation of the first draft. LS: data collection in the field and analysis and contributing with the first draft. FT: review of data, organization, and review of the manuscript. LF: manuscript review and data presentation. SR: contribution of historical data and collaboration in the revision of the manuscript. All authors contributed to the article and approved the submitted version.

Funding

This work was supported by the Organization for the Conservation of Latin American Aquatic Mammals – YAQU PACHA e.V.

Conflict of Interest

The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest.

Acknowledgments

We want to thank the collaborators in the field, Juan Chacín, Carlos Valencia, Omar Morales, Joselo Morales, and Junior Morales, who contributed to the collection of data and links with the fishermen in the investigated localities.

Supplementary Material

The Supplementary Material for this article can be found online at: https://www.frontiersin.org/articles/10.3389/fmars.2021.625801/full#supplementary-material

References

Albuquerque, P., Cunha, L., Lucena, R., and Alves, R. (2014). Methods and Techniques in Ethnobiology and Ethnoecology. New York, NY: Springer, doi: 10.1007/978-1-4614-8636-7

CrossRef Full Text | Google Scholar

Alfaro-Shigueto, J., Mangel, J., Pajuelo, M., Dutton, P., Seminoff, J. A., and Godley, B. J. (2010). Where small can have a large impact: structure and characterization of small-scale fisheries in Peru. Fish. Res. 106, 8–17. doi: 10.1016/j.fishres.2010.06.004

CrossRef Full Text | Google Scholar

Alves, R., and Rosa, I. (2008). Use of tucuxi dolphin Sotalia fluviatilis for medicinal and magic/religious purposes in north of Brazil. Hum. Ecol. 36, 443–447. doi: 10.1007/s10745-008-9174-5

CrossRef Full Text | Google Scholar

Ávila, I., García, C., and Bastidas, J. (2008). Use of dolphins for bait in the artisanal fisheries of Bahía Solano, Chocó, Colombia. Paper Presented at the SC/60/SM6 Presented to the IWC Scientific Committee, Impington, CA. doi: 10.13140/RG.2.1.1659.0484

CrossRef Full Text | Google Scholar

Barbosa-Filho, M., Barreto, R., Siciliano, S., Seminara, C., and Costa-Neto, E. (2018). Use of cetaceans as bait in southern Bahia, Brazil, by expert fishermen that market shark fins. Ethnobiol. Lett. 9, 12–18. doi: 10.14237/ebl.9.2.2018.953

CrossRef Full Text | Google Scholar

Barrios-Garrido, H., Boher-Bentti, S., De Turris-Morales, K., Espinoza, N., Ferrer- Pérez, A., Herrera-Trujillo, O., et al. (2015). “Tonina costera,” in Libro Rojo de la Fauna Venezolana, 4th Edn, eds J. P. Rodríguez, A. García-Rawlins, and F. Rojas-Suárez (London: Provita Fundacion Empresas Polar), 1–5.

Google Scholar

Biernacki, P., and Waldorf, D. (1981). Snowball sampling. Problems and techniques of chain referral sampling. Sociol. Method Res. 10, 141–163. doi: 10.1177/004912418101000205

CrossRef Full Text | Google Scholar

Bolaños, J., and Bermúdez, V. (1996). “Un caso de malformaciones óseas en delfín estuarino (Sotalia fluviatilis) en el estado Zulia. Resumen,” in Proceedings of the Libro Memorias, 3° Congreso de Ciencias Veterinarias Eduardo Mendoza Goiticoa, Maracay, 101.

Google Scholar

Borobia, M., Siciliano, S., Lodi, L., and Hoek, W. (1991). Distribution of the South American dolphin Sotalia fluviatilis. Can. J. Zool. 69, 1025–1039. doi: 10.1139/z91-148

CrossRef Full Text | Google Scholar

Briceño, Y., and Sánchez, L. (2017). Identificación de Áreas Vulnerables Para Sotalia guianensis en el Sur del lago de Maracaibo. Scientific report to International Center for Tropical Ecology (CIET). Parroquia Macarao: Venezuelan Institute for Scientific Research (IVIC), 25.

Google Scholar

Briceño, Y., Sánchez, L., Herrera, O., Ferrer, A., Bolaños, J., Ramírez, S., et al. (2017). “Tonina costera, Sotalia guianensis (Van Bénedén, 1864),” in Plan de acción para la Conservación de los Mamíferos Acuáticos de Venezuela: Delfines de Agua Dulce, Nutrias y Manatíes 2017-2027, eds A. Ferrer, O. Herrera, F. Trujillo, F. Mosquera-Guerra, G. De La Cruz Melo, D. Lew, et al. (Caracas: IVIC), 92.

Google Scholar

Brownell, R. Jr., Reeves, R., Read, A., Smith, B., Thomas, P., Ralls, K., et al. (2019). Bycatch in gillnet fisheries threatens critically endangered small cetaceans and other aquatic megafauna. Endanger. Spec. Res. 40, 285–296. doi: 10.3354/esr00994

CrossRef Full Text | Google Scholar

Caballero, S., Hollatz, C., Rodríguez, S., Trujillo, F., and Baker, S. (2018). Population structure of riverine and coastal dolphins Sotalia fluviatilis and Sotalia guianensis: patterns of nuclear and mitochondrial diversity and implications for conservation. J. Hered. 109, 757–770. doi: 10.1093/jhered/esy049

PubMed Abstract | CrossRef Full Text | Google Scholar

Caballero, S., Trujillo, F., Vianna, J. A., Barrios-Garrido, H., Montiel, M. G., Beltrán-Pedreros, S., et al. (2010). Mitochondrial DNA diversity, differentiation and phylogeography of the South American riverine and coastal dolphins Sotalia fluviatilis and Sotalia guianensis. Lat. Am. J. Aquat. Mamm. 8, 69–79. doi: 10.5597/lajam00155

CrossRef Full Text | Google Scholar

Carr, T., and Bonde, R. (2000). Tucuxi (Sotalia fluviatilis) occurs in Nicaragua, 800km north of its previously known range. Mar. Mamm. Sci. 16, 447–452. doi: 10.1111/j.1748-7692.2000.tb00936.x

CrossRef Full Text | Google Scholar

Casinos, A., Bisbal, F., and Boher, S. (1981). Sobre tres ejemplares de Sotalia fluviatilis del Lago de Maracaibo, Venezuela (Cetacea: Delfinidae). Publi. Dep. Zool. 7, 93–96.

Google Scholar

Clapham, P., and Van Waerebeek, K. (2007). Bushmeat and bycatch: the sum of the parts. Mol. Ecol. 16, 2607–2609. doi: 10.1111/j.1365-294X.2007.03378.x

PubMed Abstract | CrossRef Full Text | Google Scholar

CMS (2017). Convention on the Conservation of Migratory Species of Wild Animals. Available online at: https://www.cms.int/en/document/aquatic-wild-meat-1 (accessed October 17, 2020).

Google Scholar

Coty, J. (1995). Vertebrados Terrestres de la Ciénaga de La Palmita, Costa Oriental del Lago de Maracaibo, Venezuela. Degree thesis, Facultad Experimental de Ciencias, La Universidad del Zulia, Maracaibo, 71.

Google Scholar

Cunha, H., Da Silva, V., and Solé-Cava, A. M. (2010). “Molecular ecology and systematics of Sotalia dolphins,” in Manuel Ruiz-Garcia and Joseph Shostell Biology, Evolution and Conservation of River Dolphins within South America and Asia, (New York, NY: Nova Science), 261–283.

Google Scholar

Da Silva, V., and Best, R. (1996). Sotalia fluviatilis. Mamm. Spec. 527, 1–7. doi: 10.2307/3504117

CrossRef Full Text | Google Scholar

Di Beneditto, A., and Ramos, R. (2004). Biology of the marine tucuxi dolphin (Sotalia fluviatilis) in south-eastern Brazil. J. Mar. Biol. Assoc. 84, 1245–1250. doi: 10.1017/S0025315404010744h

CrossRef Full Text | Google Scholar

Ferreira, M. (2006). The environmental conflicts and the estuarine dolphin (Sotalia guianensis) conservation from the Costeira da Armação community point of view, in the anhatomirim environmental protection area, south of Brazil. Nat. Conserv. 4, 152–162.

Google Scholar

Ferrer, O., and Morales, I. (2013). Relative yield-per-recruit and management strategies for Cynoscion acoupa (Perciformes: Sciaenidae) in Lake Maracaibo, Venezuela. Rev. Biol. Trop. Rev. Biol. Trop. 61, 173–180. doi: 10.15517/rbt.v61i1.10943

PubMed Abstract | CrossRef Full Text | Google Scholar

García, I., Van Waerebeek, K., Alfaro-Shigueto, J., and Mangel, J. (2013). Entanglements of large cetaceans in Peru: few records but high risk. Pac. Sci. 67, 523–532. doi: 10.2984/67.4.3

CrossRef Full Text | Google Scholar

Hawkins, E., Harcourt, R., Bejder, L., Brooks, L., Grech, A., Christiansen, F., et al. (2017). Best practice framework and principles for monitoring the effect of coastal development on marine mammals. Front. Mar. Sci. 4:59. doi: 10.3389/fmars.2017.00059

CrossRef Full Text | Google Scholar

Huntington, H. (2000). Using traditional ecological knowledge in science: methods and applications. Ecol. Appl. 10, 1270–1274. doi: 10.1890/1051-0761(2000)010[1270:UTEKIS]2.0.CO;2

CrossRef Full Text | Google Scholar

Instituto Chico Mendes de. (Conservação)da Biodiversidade (ICMBio) (2018). Livro Vermelho da Fauna Brasileira Ameaçada de Extinção, Vol. 2. Brasilia: Mamíferos.

Google Scholar

José Alió. (2000). Los recursos vivos del Sistema del Maracaibo. in Rodríguez, G. (ed.) El Sistema de Maracaibo. 2da Ediciín, Caracas, Instituto Venezolano de Investigaciones Científicas, IVIC. 153–173.

Google Scholar

Kendall, L. (2008). “The conduct of qualitative interview: research questions, methodological issues, and researching online,” in Handbook of Research on New Literacies, eds J. Coiro, M. Knobel, C. Lankshea, and D. Leu (New York, NY: Lawrence Erlbaum Associates), 133–149.

Google Scholar

Lima, J., Carvalho, A., Azevedo, C., Barbosa, L., and Silveira, L. (2017). Variation of age and total length in Sotalia guianensis (Van Bénéden, 1864) (Cetacea, Delphinidae), on the coast of Espírito Santo state, Brazil. Braz. J. Biol. 77, 437–443. doi: 10.1590/1519-6984.13215

PubMed Abstract | CrossRef Full Text | Google Scholar

Lotze, H., Lenihan, H., Bourque, B., Bradbury, R., Cooke, R., Kay, M., et al. (2006). Depletion, degradation, and recovery potential of estuaries and coastal seas. Science 312, 1806–1809. doi: 10.1126/science.1128035

PubMed Abstract | CrossRef Full Text | Google Scholar

Mangel, J., Alfaro-Shigueto, J., Van Waerebeek, K., Cáceres, C., Bearhop, S., Witt, M. J., et al. (2010). Small cetacean captures in Peruvian artisanal fisheries: high despite protective legislation. Biol. Conserv. 143, 136–143. doi: 10.1016/j.biocon.2009.09.017

CrossRef Full Text | Google Scholar

Manzan, M. F., and Lopes, P. F. M. (2015). Fishers’ knowledge as a source of information about the estuarine dolphin (Sotalia guianensis, van Bénéden, 1864). Environ. Monit. Assess. 187:4096. doi: 10.1007/s10661-014-4096-8

PubMed Abstract | CrossRef Full Text | Google Scholar

MARN (2000). Primer Informe de País Para la Convención Sobre Diversidad Biológica. Venezuela: Ministerio del Ambiente y los Recursos Naturales, 226.

Google Scholar

Medina, E., and Barboza, F. (2006). Lagunas costeras del lago de Maracaibo: distribución, estatus y perspectivas de conservación. Ecotrópicos 19, 128–139.

Google Scholar

Meirelles, A., Ribeiro, A., Silva, C., and Soares-Filho, A. (2010). Records of Guiana dolphin, Sotalia guianensis, in the state of Ceará, northeastern Brazil. Lat. Am. J. Aquat. Mamm. 8, 97–102. doi: 10.5597/lajam00157

CrossRef Full Text | Google Scholar

Mintzer, V., Diniz, K., and Frazer, T. (2018). The use of aquatic mammals for bait in global fisheries. Front. Mar. Sci. 5:191. doi: 10.3389/fmars.2018.00191

CrossRef Full Text | Google Scholar

Mitchell, E. (ed.) (1975). Review of biology and fisheries for smaller cetaceans. J. Fish. Res. Board. Can. 32, 889–983. doi: 10.1139/f75-117

CrossRef Full Text | Google Scholar

Molina, M., and Yedra, D. (2019). Evidencias de sobrepesca y mal manejo del Callinectes sapidus (Rathbun, 1896) en el lago de Maracaibo, Venezuela. J. Mar. Coast. Sci. 11, 81–100. doi: 10.15359/revmar.11-1.6

CrossRef Full Text | Google Scholar

Naderifar, M., Goli, H., and Ghaljaie, F. (2017). Snowball sampling: a purposeful method of sampling in qualitative research. Stride. Dev. Med. Edn. 14, 1–6. doi: 10.5812/sdme.67670

CrossRef Full Text | Google Scholar

Pirela, D., Bolaños Jiménez, J., Hernández, J., Rojas, J., Troncone, F., and Velasco, J. (2002). Estudio Preliminar de las Interacciones Entre la Actividad Pesquera, Cetáceos y Tortugas Marinas en el golfo de Venezuela. Proyecto AC-0806-9, Convenio Corpozulia-ICLAM-MINAMB, con participación de Inapesca, LUZ, Sea Vida. Zulia:ICLAM

Google Scholar

Pirela, D., Urdaneta, A., Escola, F., Chacín, M., and Casler, C. (2006). “Caracterización de la fauna acuática de la cuenca baja del Río Catatumbo, Estado Zulia. Resumen,” in Proceedings of the Memorias I Congreso Internacional de la Cuenca del Lago de Maracaibo, ICLAM-MINAMB, Maracaibo.

Google Scholar

Ramírez, S. (2005). Bases ecológicas para la conservación del delfín estuarino Sotalia fluviatilis en el Golfo de Venezuela. Master’s thesis. Universidad Nacional Experimental de los Llanos Occidentales Ezequiel Zamora, Guanare, 118.

Google Scholar

Ramírez, S., Guerra, N., Montilla, C., and Carroz, E. (2013). “Interacciones entre delfines y los pescadores artesanales del sur del Golfo de Venezuela,” in Proceedings of the Segundo Congreso Venezolano de Ciencia, Tecnología e Innovación, Caracas.

Google Scholar

Read, A. J., Van Waerebeek, K., Reyes, J. C., McKinnon, J. S., and Lehman, L. C. (1988). The exploitation of small cetaceans in coastal Peru. Biol. Conserv. 46, 53–70. doi: 10.1016/0006-3207(88)90108-5

CrossRef Full Text | Google Scholar

Reeves, R., Smith, B., Crespo, E., and Notarbartolo di Sciara, G. (2003). Dolphins, Whales, and Porpoises, 2002-2010: Conservation Action Plan for the World’s Cetaceans. London: IUCN/SSC Cetacean Specialist Group.

Google Scholar

Reeves, R. R., McClellan, K., and Werner, T. B. (2013). Marine mammal bycatch in gillnet and other entangling net fisheries, 1990 to 2011. Endanger. Spec. Res. 20, 71–97. doi: 10.3354/esr00481

CrossRef Full Text | Google Scholar

Riquelme, R., León, T., Hernández, J., and Toyos, G. (2011). Estimación de la edad de la tonina del lago (Sotalia sp.) a través del examen del grupo de capas de crecimiento (GLG’s) de su estructura dentaria. Ciencia 15, 373–387.

Google Scholar

Robards, M., and Reeves, R. (2011). The global extent and character of marine mammal consumption by humans: 1970-2009. Biol. Conserv. 144, 2770–2786. doi: 10.1016/j.biocon.2011.07.034

CrossRef Full Text | Google Scholar

Rodríguez, G. (2001). “The maracaibo system, Venezuela,” in Coastal Marine Ecosystems of Latin America. Ecological Studies (Analysis and Synthesis), Vol. 144, eds U. Seeliger and B. Kjerfve (Berlin: Springer), doi: 10.1007/978-3-662-04482-7_4

CrossRef Full Text | Google Scholar

Rodríguez-Olarte, D., Mojica, J., and Taphorn, D. (2011). “Chapter 15, Northern South America: Magdalena and Maracaibo Basins,” in Historical Biogeography of Neotropical Freshwater Fishes, eds J. S. Albert and R. E. Reis (Berkeley, CA: University of California Press), 243–257. doi: 10.1525/california/9780520268685.003.0015

CrossRef Full Text | Google Scholar

Rojas-Bracho, L., Reeves, R., and Jaramillo-Legorreta, A. (2006). Conservation of the vaquita Phocoena sinus. Mammal. Rev. 36, 179–216. doi: 10.1111/j.1365-2907.2006.00088.x

CrossRef Full Text | Google Scholar

Rojas-Bracho, L., and Taylor, B. (1999). Risk factors affecting the vaquita (Phocoena sinus). Mar. Mamm. Sci. 15, 974–989. doi: 10.1111/j.1748-7692.1999.tb00873.x

CrossRef Full Text | Google Scholar

Sánchez, L., and Briceño, Y. (2017). “Anthropogenic interactions increasing mortality of cetaceans in the Maracaibo Lake, Venezuela,” in Proceedings of the 28th International Congress Conservation Biology (ICCB 2017), Cartagena.

Google Scholar

Sánchez-Criollo, L., Briceño-Reina, Y., Bolaños-Jiménez, J., Hernández-Rangel, J., and Bermúdez-Villapol, L. (2007). “Interacciones antrópicas como causas del incremento en la mortalidad y varamientos de cetáceos en el Estado Zulia,” in Proceedings of the Libro Memorias VII Congreso Venezolano de Ecología, Guayana.

Google Scholar

Santos, M., and Rosso, S. (2007). Ecological aspects of marine tucuxi dolphins (Sotalia guianensis) based on group size and composition in the Cananéia estuary, southeastern Brazil. Lat. Am. J. Aquat. Mamm. 6, 71–82. doi: 10.5597/lajam00110

CrossRef Full Text | Google Scholar

Secchi, E., Santos, M., and Reeves, R. (2018). Sotalia guianensis (errata version published in 2019). IUCN Red List Threat. Spec. 2018:e.T181359A144232542.

Google Scholar

Trujillo, F., Diazgranados, M., Garcia, C., and Dussan, S. (2006). “Sotalia guianensis,” in Libro Rojo de los Mamíferos de Colombia, (Bogotá, CO: Conservación Internacional), 273–277.

Google Scholar

Zappes, C., Andriolo, A., Oliveira, F., and Monteiro-Filho, E. (2009). Potential conflicts between fishermen and Sotalia guianensis (van Bénéden, 1864) (Cetacea, Delphinidae) in Brazil. Sitienti. Sér. Ciênc. Biol. Sér. Ciênc. Biol. 9, 208–214.

Google Scholar

Zappes, C., de Sá Alves, L., da Silva, V., de Freitas Azevedo, A., Di Beneditto, A., and Andriolo, A. (2013). Accidents between artisanal fisheries and cetaceans on the Brazilian coast and Central Amazon: proposals for integrated management. Ocean Coast. Manag. 85, 46–57. doi: 10.1016/j.ocecoaman.2013.09.004

CrossRef Full Text | Google Scholar

Keywords: Sotalia guianensis, aquatic wildmeat, consumption, bycatch, Lake Maracaibo

Citation: Briceño Y, Sánchez L, Trujillo F, von Fersen L and Ramírez S (2021) Aquatic Wildmeat Consumption of Guiana Dolphins (Sotalia guianensis) in Lake Maracaibo System, Venezuela. Front. Mar. Sci. 8:625801. doi: 10.3389/fmars.2021.625801

Received: 04 November 2020; Accepted: 06 January 2021;
Published: 11 February 2021.

Edited by:

Salvatore Siciliano, Oswaldo Cruz Foundation (Fiocruz), Brazil

Reviewed by:

Ana Paula Di Beneditto, State University of the North Fluminense Darcy Ribeiro, Brazil
Maíra Laeta, Oswaldo Cruz Foundation (Fiocruz), Brazil
Alexandra Costa, Instituto Bicho D’agua: Conservação Socioambiental, Brazil

Copyright © 2021 Briceño, Sánchez, Trujillo, von Fersen and Ramírez. This is an open-access article distributed under the terms of the Creative Commons Attribution License (CC BY). The use, distribution or reproduction in other forums is permitted, provided the original author(s) and the copyright owner(s) are credited and that the original publication in this journal is cited, in accordance with accepted academic practice. No use, distribution or reproduction is permitted which does not comply with these terms.

*Correspondence: Yurasi Briceño, yurasialejandra@gmail.com

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