Total mercury and methylmercury in river dolphins (Cetacea: Iniidae: Inia spp.) in the Madeira River Basin, Western Amazon

Challenges and priorities for river cetacean conservation

“…Mercury concentrations were also correlated with high concentrations of selenium, which seems to be produced by the animal (Xiong et al 2019), implying a protective function as has been observed in coastal dolphins (Turnbull & Cowan 1998, Kehrig et al 2016. The use of mercury in smallscale mining to amalgamate gold affects several river basins, including the Ayeyarwady (Smith & Hobbs 2002), Mahakam (Kreb & Budiono 2005), and Amazon-Orinoco (including the Arauca, Tapajós, and Iténez rivers) (Lailson-Brito et al 2008, Roach et al 2013, Mosquera-Guerra et al 2019, Barbosa et al 2021. Preliminary studies have shown that Amazon river dolphins and tucuxis had high mercury concentrations in all analysed tissue samples (Mosquera-Guerra et al 2019).…”

Atomic Spectrometry Update: review of advances in elemental speciation

“…The knock-on effect of this interference was that the organo-I species could not be quan-tied by the difference between the total I and the two measured species. Speciated standard reference materials yielded LOD for 127 I of approximately 24 ng L À1 for iodate and iodide, and for 129 I of approximately 1.8 ng L À1 for iodate and 2.6 ng L À1 for iodide. The method was used to investigate radioiodine contamination in groundwater samples from six wells at the Hanford Site, in Washington State, USA.…”

“…The investigation of I-containing species in ground water and other environmental samples has been the focus of a study using IC-ICP-MS. A rapid technique (<15 min duration) for the simultaneous I speciation (iodide/iodate) and isotopic ratio ( 129 I/ 127 I) measurements by IC-ICP-MS, used O 2 as the reaction cell gas. 109 This eliminated >99% of 129 Xe present in the Ar supply by a charge-exchange reaction and allowed for high precision analysis of 129 I. The downside to the use of O 2 was that Mo, which eluted as a peak from the column, reacted with the O 2 to form a molybdate polyatomic at m/z 127 and 129 due to 95 Mo 16 O 2 and 97 Mo 16 O 2 , respectively.…”

Easy food in the jungle: evaluating presence and relationships of Amazon River dolphin (Inia geoffrensis) at a provisioning site in the Amazon, Brazil

“…The Amazon River dolphin or boto (Inia geoffrensis de Blainville, 1817) is classified as "Endangered" on the IUCN Red List of Threatened Species (da Silva et al, 2018). This is due to anthropogenic stressors and factors such as accidental capture in fishing nets or slaughter as a retaliation for conflicts with fishermen (Alves et al, 2012;Iriarte and Marmontel, 2013a), which includes using their carcasses as bait (Iriarte and Marmontel, 2013b;Brum et al, 2015), the loss and degradation of their habitats (Hollatz et al, 2011;Gomez-Salazar et al, 2012), the increase in disorderly tourist activities that negatively impact these animals (Alves et al, 2011;Romagnoli et al, 2011;Vidal et al, 2017a, b;, and the aquatic pollution by persistent organic pollutants, mercury and other metals, hydrocarbon and oil spills, and plastic debris as additional stressors affecting the individual/population health and critical habitats of botos in the Amazon (Rosas and Lehti, 1996;Torres et al, 2009;Mosquera-Guerra et al, 2019;Barbosa et al, 2021).…”