ORCID Profile
0000-0003-3691-9644
Current Organisations
Dalhousie University
,
International Union for Conservation of Nature
,
James Cook University
,
TrackdAT
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Publications
Shark conservation and fisheries management across the globe
Publisher: CRC Press
Date: 15-09-2022
Near‐term embryos in a P ristis pristis (E lasmobranchii: P ristidae) from B razil
Publisher: Wiley
Date: 06-04-2016
DOI: 10.1111/JFB.12946
Abstract: This paper describes the record of a gravid Pristis pristis from the north coast of Maranhão State (Brazil) in May of 2009 by an artisanal vessel. Size, mass and rostrum length of the adult female were estimated at 5000 mm, 750000 g and 1536 mm, respectively. Total length (LT ) of miscarried embryos ranged from 755 to 800 mm and total mass from 890 to 1120 g. Although this is a single record, it indicates that P. pristis births may be taking place during May or coming months and there may be population differences between Central and South America.
Fine-scale movements of juvenile blacktip reef sharks Carcharhinus melanopterus in a shallow nearshore nursery
Publisher: Inter-Research Science Center
Date: 30-07-2019
DOI: 10.3354/MEPS13010
Daggernose Shark: An Elusive Species from Northern South America
Publisher: Wiley
Date: 03-2019
DOI: 10.1002/FSH.10205
Making the most of aquatic animal tracking: a review of complementary methods to bolster acoustic telemetry
Publisher: Springer Science and Business Media LLC
Date: 16-11-2022
Trophic ecology of sympatric juvenile stingrays within a nursery area
Publisher: CSIRO Publishing
Date: 23-02-2022
DOI: 10.1071/MF21292
Abstract: Nursery areas are crucial for many elasmobranch species, providing advantages such as increased access to prey and reduced predation risk. This study investigated the trophic interactions of two juvenile stingray species within a coastal communal nursery using stable isotope analysis. Muscle, plasma and red blood cells s les were taken from the mangrove whipray Urogymnus granulatus and the cowtail stingray Pastinachus ater, and δ15N, δ13C and δ34S measured. Urogymnus granulatus had higher mean δ13C, δ15N and δ34S than P. ater. General linear models showed no significant trends between δ13C, δ15N or δ34S and body size or sex. Low isotopic niche overlap, combined with previous data on movement patterns, provided evidence of niche partitioning between stingrays that likely reflect differences in feeding grounds and prey selection. Despite the differences in feeding grounds and prey selection, previous studies showed that U. granulatus and P. ater share sand and reef flat areas for most of the day (~20 h). δ13C and δ34S values suggested that mangrove-derived carbon had little importance to stingrays’ diets in the study area. Results presented in this study bring new insights to the feeding ecology of two sympatric stingray species and their trophic interactions within a communal nursery area.
Sawfish (Pristidae) records along the Eastern Amazon coast
Publisher: Inter-Research Science Center
Date: 05-09-2017
DOI: 10.3354/ESR00852
Improved microplastic processing from complex biological samples using a customized vacuum filtration apparatus
Publisher: Wiley
Date: 19-08-2022
DOI: 10.1002/LOM3.10504
Abstract: Plastics represent the largest component of marine debris globally. In this context, it is essential to quantify the current extent of plastic pollution, including microplastics (MP plastics 5 mm), within marine abiotic and biotic compartments. Despite significant effort, MP studies still face methodological impediments to establish accurate and standardized protocols to separate, process and analyze MPs in environmental s les. Furthermore, underestimation and overestimation of MP contamination, either through loss of MPs or introduction of extraneous MPs during handling and processing, is concerning, particularly when assessing risk profiles for marine ecosystems. Presented here is a custom‐made stainless steel vacuum filtration apparatus designed to perform size‐tiered separation and facilitate retrieval of MPs from a variety of environmental s le matrices. Incorporating this apparatus into a standard MP workflow achieved efficient graduated separation of commonly found MP fragments and fibers, validated by spike‐recovery tests. As a case study, the gastrointestinal tracts of three juvenile Australian sharpnose sharks, Rhizoprionodon taylori , were processed using the filtration apparatus, and 46 anthropogenic items ranging from 0.021 to 8.87 mm were retrieved. This study demonstrates the effective use of the size‐tiered stainless steel vacuum filtration apparatus and an improved efficiency in downstream microphotography and spectroscopic analyses of MPs from a complex s le matrix. Finally, it contributes to the MP research field by delivering more reliable estimates of MP contamination in marine ecosystems.
Batoid nurseries: Definition, use and importance
Publisher: Inter-Research Science Center
Date: 14-05-2018
DOI: 10.3354/MEPS12545
New record of Carcharhinus leucas (Valenciennes, 1839) in an equatorial river system
Publisher: Springer Science and Business Media LLC
Date: 06-10-2016
Acidentes causados pela arraia fluvial Potamotrygon motoro em comunidades lacustres em Território do bioma Oriental da Amazônia
Publisher: Universidade do Contestado - UnC
Date: 20-10-2021
Abstract: Os ferimentos causados por arraias de água doce são comuns entre os pescadores. A raia Potamotrygon motoro apresenta um ferrão com uma ponta afiada e pontas serrilhadas espalhadas bilateralmente, os ferrões possuem toxinas que promovem a vasoconstrição, causando dor imediata e isquemia. Esses acidentes são extensos e podem manter as vítimas impossibilitadas de trabalhar por semanas a meses. Considerando o impacto das injúrias na subsistência de comunidades ribeirinhas de pescadores, este estudo teve como objetivo analisar relatos de envenenamento pela arraia Potamotrygon motoro em dois municípios localizados no bioma Amazônia Oriental (sítio Ramsar da Baixada Maranhense) no município de Penalva e Viana. A metodologia consistiu em análises descritivas e transversais, a partir da aplicação de 40 questionários semiestruturados em pescadores artesanais a fim de obter dados clínicos e epidemiológicos relacionados aos acidentes causados por P. motoro em pescadores artesanais. Quarenta pescadores feridos por arraias de água doce foram entrevistados. Dor e edema foram os sintomas comuns a todos os pescadores, seguidos de necrose cutânea (70%). As vítimas costumam adotar auto tratamentos inusitados, baseados em conhecimentos tradicionais e culturais, como o uso de urina, ervas, fumaça de saco de estopa e fezes humanas. O número de lesões em cada pescador variou de 2 a 4 vezes (50%) a até 10 vezes (12,5%). Os resultados mostram que as lesões por P. motoro são frequentes em Penalva e Viana, reforçando a necessidade dos órgãos públicos de saúde estabelecerem ações educativas preventivas e proporcionarem melhor qualificação dos profissionais de saúde para realizar o tratamento adequado das lesões. Palavras-chave: Animais venenosos. Raias. Saúde ocupacional. Saúde ambiental.
Analysis of the supply chain and conservation status of sharks (Elasmobranchii: Superorder Selachimorpha) based on fisher knowledge
Publisher: Public Library of Science (PLoS)
Date: 13-03-2018
DNA-based identification reveals illegal trade of threatened shark species in a global elasmobranch conservation hotspot
Publisher: Springer Science and Business Media LLC
Date: 20-02-2018
DOI: 10.1038/S41598-018-21683-5
Abstract: Here, we report trading of endangered shark species in a world hotspot for elasmobranch conservation in Brazil. Data on shark fisheries are scarce in Brazil, although the northern and northeastern regions have the highest indices of shark bycatch. Harvest is made primarily with processed carcasses lacking head and fins, which h ers reliable species identification and law enforcement on illegal catches. We used partial sequences of two mitochondrial genes (COI and/or NADH2) to identify 17 shark species from 427 s les being harvested and marketed on the northern coast of Brazil. Nine species (53%) are listed under some extinction threat category according to Brazilian law and international authorities (IUCN – International Union for Conservation of Nature CITES – Convention on International Trade of Endangered Species of Wild Fauna and Flora). The number increases to 13 (76%) if we also consider the Near Threatened category. Hammerhead sharks are under threat worldwide, and composed 18.7% of s les, with Sphyrna mokarran being the fourth most common species among s les. As illegal trade of threatened shark species is a worldwide conservation problem, molecular identification of processed meat or specimens lacking diagnostic body parts is a highly effective tool for species identification and law enforcement.
Ten simple rules for supporting historically underrepresented students in science
Publisher: Public Library of Science (PLoS)
Date: 16-09-2021
Molecular identification of ray species traded along the Brazilian Amazon coast
Publisher: Elsevier BV
Date: 03-2020
Non-native mud sleeper Butis koilomatodon (Bleecker, 1849) (Perciformes: Eleotridae) in Eastern Amazon Coastal region: an additional occurrence for the Brazilian coast and urgency for ecological asses
Publisher: Regional Euro-Asian Biological Invasions Centre Oy (REABIC)
Date: 2017
Sexual dimorphism of sharks from the amazonian equatorial coast
Publisher: Editorial Pontificia Universidad Javeriana
Date: 03-09-2015
DOI: 10.11144/JAVERIANA.SC20-3.SDOS
Abstract: Sexual dimorphism is a widespread feature in several groups of vertebrates. Chondrichthyans differ sexually due to the presence of the clasper, a structure for internal fertilization, and other sexual differences in secondary characteristics. Nevertheless, studies assessing these variations are fairly rare. The main goal of this study is to identify differences in sexual dimorphism in three species of sharks from the Carcharhinidae family ( em Rhizoprionodon porosus /em , em Carcharhinus porosus /em and em Isogomphodon oxyrhynchus /em ) using morphometric tools. A total of 213 specimens were captured in the Amazonian Equatorial Coast and analyzed using 65 morphometric characters. Discriminant analysis and The Student's t-test were used to demonstrate the morphological differences among sexes. Sexual dimorphism was reported at different levels for the three species. This study suggests that the most likely explanation for the presence of these variations is related to their reproductive characteristics and mating behavior.
Assigning shark fin origin using species distribution models needs a reality check
Publisher: The Royal Society
Date: 07-2021
Towed-float GPS telemetry: A tool to assess movement patterns and habitat use of juvenile stingrays
Publisher: CSIRO Publishing
Date: 2019
DOI: 10.1071/MF19048
Abstract: GPS telemetry provides high-accuracy spatial data on animal movement however, it has rarely been used with benthic organisms, such as stingrays, because of their irregular surfacing behaviour or bottom-dwelling habits. This study evaluated the use of towed-float GPS tags to assess movements of juvenile stingrays, with active tracking performed simultaneously for comparison. Four juvenile Urogymnus granulatus in iduals (2 females and 2 males average 32.2-cm disc width) were tracked in April 2016. In iduals travelled 1332.15±269.58m south-east across Pioneer Bay at an average speed of 6.87mmin–1 in 3.7h. Stationary tests demonstrated that the quality of the data obtained by towed-float GPS tags could not be matched by active, acoustic or ARGOS telemetry, reaching, on average, 99% of successful fixes and & -m accuracy. Location error varied significantly based on the number of satellites detected, with error decreasing as the satellite number increased. This study demonstrated the potential of towed-float GPS telemetry for high-resolution assessment of movement patterns and habitat use of juvenile stingrays in shallow coastal water. If well applied, this technique can increase our knowledge of juvenile stingray ecology and their essential habitats.
Tidal–diel patterns of movement, activity and habitat use by juvenile mangrove whiprays using towed-float GPS telemetry
Publisher: CSIRO Publishing
Date: 2021
DOI: 10.1071/MF20078
Abstract: Stingrays are a erse and widespread group of elasmobranchs. Despite their ecological and economical importance, many aspects of stingray ecology remain poorly understood. Few studies have examined fine-scale movements of juvenile stingrays within nursery areas. This study aimed to examine diel movement patterns in juvenile mangrove whiprays (Urogymnus granulatus) by using towed-float GPS telemetry within a reef flat habitat of the Great Barrier Reef. Juvenile mangrove whiprays travelled distances from 394 to 2189m, moving at a rate (mean±s.e.) of 3.97m min–1±2.5 during tracking periods ranging from 1.35 to 9h. Movements of juvenile mangrove whiprays were influenced by tidal height and diel period. In iduals chose more direct paths during outgoing and incoming tides and their activity space was significantly larger during the day than at night-time. In iduals showed preference for mangrove areas during high tides, which was likely to reduce predation risk. Our findings have established the use of the towed-float GPS telemetry as an effective tool to assess short-term movement patterns and habitat use of juvenile stingrays, as well as highlighted how juvenile mangrove whiprays use reef-flat environments.
Advances in understanding the roles and benefits of nursery areas for elasmobranch populations
Publisher: CSIRO Publishing
Date: 2018
DOI: 10.1071/MF18081
Abstract: Nursery areas are critical to the survival of many marine species, and it is widely accepted that elasmobranch species use nursery areas where they improve species fitness. A 2007 review proposed an approach to identify elasmobranch nursery areas to help clarify their location and use. Here we examine progress towards defining elasmobranch nurseries in the intervening ≥10 years. Many studies have used these criteria, and some have tested their effectiveness, but it is apparent that there is still much to learn. Our current understanding of elasmobranch nurseries is biased towards tropical coastal shark species with few studies of temperate, pelagic, deep-water or batoid species. Recent research has used the criteria to more accurately identify nursery areas, determine that some species may not use them and, at times, improve conservation and management. Results are also revealing that some areas considered to be nurseries do not meet the criteria. Although we have learned a great deal about the location and use of elasmobranch nurseries, there are still several questions to be answered and species to be considered. Continued application of nursery criteria and improved knowledge of nursery areas will lead to improved conservation and management systems.
Diurnal activity patterns and habitat use of juvenile Pastinachus ater in a coral reef flat environment
Publisher: Public Library of Science (PLoS)
Date: 27-02-2020
Global trends in aquatic animal tracking with acoustic telemetry
Publisher: Elsevier BV
Date: 2022
DOI: 10.1016/J.TREE.2021.09.001
Abstract: Acoustic telemetry (AT) is a rapidly evolving technique used to track the movements of aquatic animals. As the capacity of AT research expands it is important to optimize its relevance to management while still pursuing key ecological questions. A global review of AT literature revealed region-specific research priorities underscoring the breadth of how AT is applied, but collectively demonstrated a lack of management-driven objectives, particularly relating to fisheries, climate change, and protection of species. In addition to the need for more research with direct pertinence to management, AT research should prioritize ongoing efforts to create collaborative opportunities, establish long-term and ecosystem-based monitoring, and utilize technological advancements to bolster aquatic policy and ecological understanding worldwide.
Related Organisations
Related Funding Activities
No related grants have been discovered for Ana Barbosa Martins.