“Our eyes grow accustomed” : artisanal fishermen with casting nets and Lahille’s bottlenose dolphin in the landscapes of the Tramandaí River inlet

Enquanto unidade que dialoga com a ideia geográfica de espaço ou território, a paisagem é um conceito multifacetado que nos auxilia no entendimento das interações entre distintos grupos animais e das expressões culturais humanas. Estudos das relações entre pessoas e natureza atuam como instrumentos de compreensão das afetividades e percepções que envolvem complexas teias de relações, o que nos possibilita encontrar nexos relacionais entre humanos e não humanos para pensarmos numa unidade dinâmica a partir de ambos. No Sul do Brasil, ocorre uma peculiar interação entre humanos e não humanos: a pesca cooperativa. Prática ritualizada e tradicional que consagra a Barra de Tramandaí como uma das duas localidades mundiais onde sistematicamente esse fenômeno acontece. Os botos Tursiops gephyreus e pescadores artesanais de tarrafa cooperam na pesca. O boto sinaliza o momento apropriado para os pescadores jogarem suas tarrafas na água, o que otimiza a atividade de pesca e a energia despendida por ambos. A área de estudo localiza-se na “Barra”, um estuário no Litoral Norte do Rio Grande do Sul. O artigo propõe um diálogo entre disciplinas distintas: reunindo os campos biológico e antropológico, através da inquirição de como se dá a cooperação entre cetáceo e ser humano, analisando como os pescadores praticam as paisagens em que estão inseridos. A coleta de dados aliou a observação participante junto aos pescadores a um questionário livre semiestruturado. Através de análise qualitativa dos resultados, podemos inferir que as manifestações bioculturais presentes nas vivências dos pescadores se dão em como eles observam, sentem e leem a paisagem. São experiências portadoras de significados, em que leituras individuais de cada pescador sobre o contexto praticado ressoam transformando-se num conhecimento coletivo e compartilhado, pois entre os pescadores é visto como um domínio de códigos, quanto à interação com os botos e o relato das mesmas dificuldades de manutenção desse fenômeno interespécies.A landscape is a unit that dialogues with the geographical idea of space, either of a territory or region, and is a multifaceted concept that assists in the understanding of interactions between different animal groups and expressions of human culture. Studies on the relationships between people and nature act as instruments to comprehend the affections and perceptions that envelop complex networks, which allows us to find relational nexus between humans and non-humans, such that we are able to reflect on a dynamic unit considering both. A peculiar interaction between humans and non-humans takes place along the coast of the state of Rio Grande do Sul, in southern Brazil: cooperative fishing. A traditional and ritualized practice, the Tramandaí River inlet is one of only two places in the world where this occurs. Lahille's bottlenose dolphin, Tursiops gephyreus, and artisanal fishermen with casting nets cooperate in the mullet (Mugil liza) fisheries. Dolphins signal the appropriate moment for fishers to throw their nets in the water, optimizing the fishing activity and the energy spent by both groups. The study area is the Tramandaí River inlet, an estuarine environment in the northern coast of the state of Rio Grande do Sul. This study aimed to link biological and anthropological fields in the pursuit to understand biocultural manifestations of these interactions, from the familiarity with the artisanal fishermen community, who are part of the cooperative fishing. We aimed to understand how the fishers recognize the landscape they compose and the way they cooperatively coexist with these cetaceans. In addition to participant observation, a semi-structured and open questionnaire was applied. Results were analyzed taking on a qualitative approach. The landscape is perceived by these workers through (and based on) their meaningful experiences, which reverberate in their individual views about the space where they act and the affection they have over their practice and relationship with the dolphins

Pescadores e botos : histórias de uma conexão em rede

"Todo mundo deveria saber o que acontece aqui, sobre os botos e da pesca com eles. Saber como eles ajudam o pescador...”. Com o objetivo de contribuir para a conservação da pesca cooperativa na Barra do Rio Tramandaí a partir de um instrumento didático, realizamos uma investigação qualitativa, que recorreu a abordagens do campo da antropologia visual (fotografia) e de relatos orais de métodos biográficos (histórias de vida/depoimentos). A interação entre essas estratégias permitiu a construção de uma exposição fotográfica itinerante, construída com curadoria dos próprios sujeitos que a significam. Enquanto a imagem parece capaz de valorizar os pescadores e sua prática cultural de forma estética, as narrações baseadas em histórias ampliam oportunidades de expressão e protagonismo destes pescadores artesanais.This study aims at contributing to the conservation of the human–dolphin cooperative fishery in the Imbé/Tramandaí estuary, south Brazil. We used an educational, sensitizing tool to carry out a qualitative survey, based on both the visual anthropology approach (photography) and oral accounts of life stories/testimonials (biographical method). The combination of these approaches lead us to produce an itinerant photography exhibition exploring human–dolphin cooperative fishery, under curatorship of fishermen themselves. While photography enhances fishermen and their cultural practice aesthetically, biographical testimonials expands their way of expressing themselves and our and our ability to help preserve human-dolphin interactions

An environmental assessment of the Tramandaí River Estuary, Rio Grande do Sul, Brazil

A finalidade deste trabalho foi desenvolver um diagnóstico ambiental dos atores sociais e da fauna de vertebrados do estuário do rio Tramandaí, Rio Grande do Sul, Brasil. Esse diagnóstico foi elaborado a partir de (1) entrevistas com atores sociais e monitoramen-to das atividades antrópicas, (2) inventariamento da ictiofauna, avifauna e mastofauna e (3) monitoramento da população de botos-de-Lahille (Tursiops gephyreus). Os atores sociais identificados incluem, em sua maioria, residentes dos municípios que compõem o estuário (Imbé e Tramandaí) e da região metropolitana de Porto Alegre, capital do Estado. Diferentes formas de uso foram registradas, sendo as atividades de lazer e a pesca amadora e profissio-nal as mais frequentes. Foram registradas sete espécies da fauna brasileira ameaçadas de extinção: duas de peixes (Genidens barbus e Pogonias courbina), três de aves (Sterna hirundinacea, Thalasseus acuflavidus e Thalasseus maximus) e duas de mamíferos (Tursiops gephyreus e Ctenomys flamarioni). No estuário do rio Tramandaí, a ocupação humana desordenada resulta em uma série de impactos ambientais, tais como poluição, in-trodução de espécies invasoras, perda de habitat, ameaça à existência de espécies e de práti-cas culturais. Nesse sentido, propõe-se como prioridades de conservação: a pesca cooperati-va entre botos e pescadores artesanais, a tainha (Mugil liza) e as aves migratórias. O diálogo entre tomadores de decisão, cientistas e atores sociais do estuário do rio Tramandaí é funda-mental para a definição de políticas públicas para a conservação da biodiversidade da região.This study aimed to produce an environmental assessment of stakeholders and vertebrates from the Tramandaí River estuary, Rio Grande do Sul, south Brazil. The assessment was based on (1) semi-structured interviews carried out with local stakeholders and monitoring of anthropogenic activities, (2) fish, bird, and mammal inven-tories, and (3) monitoring of the dolphin (Tursiops gephyreus) population inhabiting the estuary. Local stakeholders included residents in the two cities surrounding the estuary (Imbé and Tramandaí) and in cities of the Metropolitan Region of the state's capital, Porto Alegre. Different human uses of the estuary were recorded, the amateur and professional artisanal fisheries being the most frequent. Seven vertebrate species threatened with extinc-tion were recorded: two fishes (Genidens barbus and Pogonias courbina), three birds (Sterna hirundinacea, Thalasseus acuflavidus, and Thalasseus maximus), and two mam-mals (Tursiops gephyreus and Ctenomys flamarioni). Unregulated land occupation in Tra-mandaí River estuary results in pollution, introduction of invasive species, and loss of habi-tat, thus threatening species and cultural practices. Therefore, we propose the following as priorities for conservation: the cooperative fishing between fishers and dolphins, the mullet (Mugil liza), and migratory birds. We stress the need for dialogue between decision makers, scientists, and local stakeholders to develop effective public policies for the conservation biodiversity in the region

Safeguarding human–wildlife cooperation

Human–wildlife cooperation occurs when humans and free-living wild animals actively coordinate their behavior to achieve a mutually beneficial outcome. These interactions provide important benefits to both the human and wildlife communities involved, have wider impacts on the local ecosystem, and represent a unique intersection of human and animal cultures. The remaining active forms are human–honeyguide and human–dolphin cooperation, but these are at risk of joining several inactive forms (including human–wolf and human–orca cooperation). Human–wildlife cooperation faces a unique set of conservation challenges, as it requires multiple components—a motivated human and wildlife partner, a suitable environment, and compatible interspecies knowledge—which face threats from ecological and cultural changes. To safeguard human–wildlife cooperation, we recommend: (i) establishing ethically sound conservation strategies together with the participating human communities; (ii) conserving opportunities for human and wildlife participation; (iii) protecting suitable environments; (iv) facilitating cultural transmission of traditional knowledge; (v) accessibly archiving Indigenous and scientific knowledge; and (vi) conducting long-term empirical studies to better understand these interactions and identify threats. Tailored safeguarding plans are therefore necessary to protect these diverse and irreplaceable interactions. Broadly, our review highlights that efforts to conserve biological and cultural diversity should carefully consider interactions between human and animal cultures

Ecological niche modeling of three species of Stenella Dolphins in the Caribbean Basin, with application to the seaflower biosphere reserve

Dolphins of the genus Stenella occur in pelagic waters of both tropical and warmtemperate oceans. Three species, the Atlantic spotted dolphin (Stenella frontalis), the pantropical spotted dolphin (S. attenuata), and the spinner dolphin (S. longirostris) are abundant worldwide, but in the Caribbean Basin they have been poorly studied and information on their distribution patterns is scarce. Specifically, in Colombia’s remote Seaflower Biosphere Reserve (SFBR) S. attenuata has been reported occasionally, but S. frontalis and S. longirostris have never been recorded before. To address this information gap, an ecological niche modeling approach was used to determine the potential distribution patterns of these three dolphin species in the region. Records of these species for the Caribbean Basin were compiled, including both published and unpublished data. Environmental information, including bathymetry, bathymetric slope, distance to shore, sea surface temperature, sea surface salinity, and chlorophylla concentration was gathered from public databases (MARSPEC and Bio-ORACLE) in raster format. The maximum entropy algorithm (Maxent) for modeling species’ geographic distributions with presence-only data was used. After filtering the data, 210 records of S. attenuata, 204 of S. frontalis, and 80 of S. longirostris were used to run models. The best configuration for each model was chosen based on the 1AICc criterion. For all three species, the final ecological niche models returned AUC test values higher than 0.8, indicating satisfactory model performance. The resulting potential distribution maps suggested that areas closest to continental shorelines of the Caribbean Basin and surrounding islands had the highest environmental suitability for all species (>70%). All models reported high environmental suitability for S. attenuata and S. longirostris in the SFBR, mainly in the southernmost part surrounding San Andrés and Providence Archipelago. Assessment of niche overlap from the predictions of species distributions using the similarity statistic and pairwise map overlap indicated that S. frontalis and S. longirostris had niches slightly more similar in comparison to S. attenuata. As this was a first effort to fill a gap in our understanding of the distribution of species in the genus Stenella in the Caribbean Basin, further studies are necessary using both niche modeling and biological/ecological approaches

Ecological niche modeling of three species of Stenella Dolphins in the Caribbean Basin, with application to the seaflower biosphere reserve

Dolphins of the genus Stenella occur in pelagic waters of both tropical and warmtemperate oceans. Three species, the Atlantic spotted dolphin (Stenella frontalis), the pantropical spotted dolphin (S. attenuata), and the spinner dolphin (S. longirostris) are abundant worldwide, but in the Caribbean Basin they have been poorly studied and information on their distribution patterns is scarce. Specifically, in Colombia’s remote Seaflower Biosphere Reserve (SFBR) S. attenuata has been reported occasionally, but S. frontalis and S. longirostris have never been recorded before. To address this information gap, an ecological niche modeling approach was used to determine the potential distribution patterns of these three dolphin species in the region. Records of these species for the Caribbean Basin were compiled, including both published and unpublished data. Environmental information, including bathymetry, bathymetric slope, distance to shore, sea surface temperature, sea surface salinity, and chlorophylla concentration was gathered from public databases (MARSPEC and Bio-ORACLE) in raster format. The maximum entropy algorithm (Maxent) for modeling species’ geographic distributions with presence-only data was used. After filtering the data, 210 records of S. attenuata, 204 of S. frontalis, and 80 of S. longirostris were used to run models. The best configuration for each model was chosen based on the 1AICc criterion. For all three species, the final ecological niche models returned AUC test values higher than 0.8, indicating satisfactory model performance. The resulting potential distribution maps suggested that areas closest to continental shorelines of the Caribbean Basin and surrounding islands had the highest environmental suitability for all species (>70%). All models reported high environmental suitability for S. attenuata and S. longirostris in the SFBR, mainly in the southernmost part surrounding San Andrés and Providence Archipelago. Assessment of niche overlap from the predictions of species distributions using the similarity statistic and pairwise map overlap indicated that S. frontalis and S. longirostris had niches slightly more similar in comparison to S. attenuata. As this was a first effort to fill a gap in our understanding of the distribution of species in the genus Stenella in the Caribbean Basin, further studies are necessary using both niche modeling and biological/ecological approaches

Región : diario de la mañana: Año X Número 2902 - 1932 Noviembre 19

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Head adaptation for sound production and feeding strategy in dolphins (Odontoceti: Delphinida)

Head morphology in toothed whales evolved under selective pressures on feeding strategy and sound production. The postnatal development of the skull (n = 207) and mandible (n = 219) of six Delphinida species which differ in feeding strategy but exhibit similar sound emission patterns, including two narrow-band high-frequency species, were investigated through 3D morphometrics. Morphological changes throughout ontogeny were demonstrated based on the main source of variation (i.e., prediction lines) and the common allometric component. Multivariate trajectory analysis with pairwise comparisons between all species was performed to evaluate specific differences on the postnatal development of skulls and mandibles. Changes in the rostrum formation contributed to the variation (skull: 49%; mandible: 90%) of the entire data set and might not only reflect the feeding strategy adopted by each lineage but also represents an adaptation for sound production and reception. As an important structure for directionality of sound emissions, this may increase directionality in raptorial feeders. Phylogenetic generalized least squares analyses indicated that shape of the anterior portion of the skull is strongly dependent on phylogeny and might not only reflect feeding mode, but also morphological adaptations for sound production, particularly in raptorial species. Thus, postnatal development seems to represent a crucial stage for biosonar maturation in some raptorial species such as Pontoporia blainvillei and Sousa plumbea. The ontogeny of their main tool for navigation and hunting might reflect their natural history peculiarities and thus potentially define their main vulnerabilities to anthropogenic changes in the environment