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

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.

Influences of environmental variables on the weight-length relationship of the shrimp Xiphopenaeus kroyeri: Do variations occur along time?

This study analyzes the influences of environmental variables on the weight-length relationship of the penaeid shrimp Xiphopenaeus kroyeri during nine consecutive years (2005 to 2013) in northern Rio de Janeiro State. The main questions raised are: i) Does species relative growth vary along time? and ii) How are the environmental variables sea surface temperature, salinity, chlorophyll-a and/or organic matter related to the relative growth? For males, the long-term mean of the allometric coefficient stayed <3 (immature: 2.49; mature: 2.

Mercury and stable carbon and nitrogen isotopes in the natal Fur of two Antarctic pinniped species.

Southern elephant seal (SES) and Antarctic fur seal (AFS) are short Southern Ocean food web top predators and are spatial and temporal trend bioindicators of Antarctic Hg bioavailability. Hg, stable isotope composition (δC and δN) and trophic position (TP) regarding sex were determined using lanugo samples from Antarctic pinnipeds pups (SES n = 35 and AFS n = 11). Hg concentrations in over 50% of the SES pups (mean 5.

Total and subcellular Ti distribution and detoxification processes in Pontoporia blainvillei and Steno bredanensis dolphins from Southeastern Brazil.

Titanium (Ti), used in many dailyuse products, such as shampoos and sunscreen filters, in the form of TiO nanoparticles (NPs), may elicit adverse marine biota effects. Marine mammal Ti data is scarce, and subcellular distribution and detoxification information is non-existent. Ti concentrations and metalloprotein detoxification in Pontoporia blainvillei and Steno bredanensis dolphins from Southeastern Brazil were assessed.

Mercury, selenium and stable isotopes in four small cetaceans from the Southeastern Brazilian coast: Influence of feeding strategy.

Dolphins are good bioindicators of the contamination status of marine ecosystems, since their dietary and habitat plasticity in both coastal and offshore ecotypes provide information on the trace elements levels originated from natural and anthropogenic sources. In this context, this study aimed to investigate provides mercury (Hg), selenium (Se) levels, trophic ecology and feeding environments of four small cetaceans (Tursiops truncatus, Steno bredanensis, Sotalia guianensis and Pontoporia blainvillei) inhabiting the central-northern coast of Rio de Janeiro State, southeastern Brazil. For the latter, δN and δC stable isotopes were used as indicators in this regard.

Mercury bioaccumulation and isotopic relation between Trichiurus lepturus (Teleostei) and its preferred prey in coastal waters of southeastern Brazil.

The trophic transfer of total mercury (THg) and its bioaccumulation from prey species to the predator fish Trichiurus lepturus was analysed in coastal waters of southeastern Brazil to evaluate the trace element dynamic in this predator-prey system. The isotopic (δ13C and δ15N) relation between this predator and its prey allowed inferences on prey assimilation and predator feeding habits. The THg increment varied from 4.

Mercury species, selenium, metallothioneins and glutathione in two dolphins from the southeastern Brazilian coast: Mercury detoxification and physiological differences in diving capacity.

In the present study, the concentration of trace elements, total mercury (Hg) and selenium (Se) and mercury forms (MeHg, Hginorg and HgSe) in the vulnerable coastal dolphins Pontoporia blainvillei and Sotalia guianensis were appraised and compared, using metallothioneins (MT) and glutathione (GSH) as biomarkers for trace element exposure. The trace element concentrations varied between muscle and liver tissues, with liver of all dolphin specimens showing higher Hg and Se concentrations than those found in muscle. Hg, MeHg and Hginorg molar concentrations showed a clear increase with Se molar concentrations in the liver of both dolphins, and Se concentrations were higher than those of Hg on a molar basis.

Mercury and selenium biomagnification in a Brazilian coastal food web using nitrogen stable isotope analysis: a case study in an area under the influence of the Paraiba do Sul River plume.

Mercury (Hg), selenium (Se) and nitrogen (δ(15)N) stable isotope were assessed in a tropical food web of Rio de Janeiro's north coast. Isotopic data on muscle suggest a difference related to this parameter along the food web; where top-predators (cetacean and voracious fish) displayed heavier δ(15)N over the entire food web. Both top-predators presented similar δ(15)N values.

Selenium and mercury in widely consumed seafood from South Atlantic Ocean.

The growing ingestion of predatory fish by humans has increased their exposure to toxic chemicals. Mercury (Hg) is an exogenous and harmful trace-element that accumulates in all marine organisms. Selenium (Se) is nutritionally important as a micronutrient, but is potentially harmful at intakes above 1mg per day.

Total mercury, organic mercury and selenium in liver and kidney of a South American coastal dolphin.

Selenium and total and organic mercury were determined in the liver and kidney of franciscana dolphin (Pontoporia blainvillei) incidentally caught in fishing nets along two Brazilian coastal areas (southeast and south). Regional differences in the concentrations of these contaminants were observed in P. blainvillei.

Ecological and biological determinants of trace elements accumulation in liver and kidney of Pontoporia blainvillei.

The present work tested whether ecological and biological variables have an influence on the assimilation of trace elements by the tissues of a cetacean from the Western South Atlantic Ocean. No significant differences were observed in the concentrations for both sexes. As individuals from the two sampling areas belong to distinct genetic and morphological populations, animals of similar body length were older on the southeastern than on the southern coast.