Browsing by Author "Chiang, Gustavo"

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    Body size data collected non-invasively fromdrone images indicate a morphologically distinct Chilean blue whale (Balaenopteramusculus) taxon
    (2020) Leslie, Matthew S.; Perkins-Taylor, Colin M.; Durban, John W.; Moore, Michael J.; Miller, Carolyn A.; Chanarat, Proud; Bahamonde, Paulina; Chiang, Gustavo; Apprill, Amy
    The blue whale Balaenoptera musculus (Linnaeus, 1758) was the target of intense commercial whaling in the 20th century, and current populations remain drastically below prewhaling abundances. Reducing uncertainty in subspecific taxonomy would enable targeted conservation strategies for the recovery of unique intraspecific diversity. Currently, there are 2 named blue whale subspecies in the temperate to polar Southern Hemisphere: the Antarctic blue whale B. m. intermedia and the pygmy blue whale B. m. brevicauda. These subspecies have distinct morphologies, genetics, and acoustics. In 2019, the Society for Marine Mammalogy's Committee on Taxonomy agreed that evidence supports a third (and presently unnamed) subspecies of Southern Hemisphere blue whale subspecies, the Chilean blue whale. Whaling data indicate that the Chilean blue whale is intermediate in body length between pygmy and Antarctic blue whales. We collected body size data from blue whales in the Gulfo Corcovado, Chile, during the austral summers of 2015 and 2017 using aerial photogrammetry from a remotely controlled drone to test the hypothesis that the Chilean blue whale is morphologically distinct from other Southern Hemisphere blue whale subspecies. We found the Chilean whale to be morphologically intermediate in both overall body length and relative tail length, thereby joining other diverse data in supporting the Chilean blue whale as a unique subspecific taxon. Additional photogrammetry studies of Antarctic, pygmy, and Chilean blue whales will help examine unique morphological variation within this species of conservation concern. To our knowledge, this is the first non-invasive small drone study to test a hypothesis for systematic biology.
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    Environment and COVID-19: Pollutants, impacts, dissemination, management and recommendations for facing future epidemic threats
    (2020) Espejo, Winfred; Celis, Jose E.; Chiang, Gustavo; Bahamonde, Paulina
    Coronavirus disease 2019 (COVID-19) has become a global pandemic. Its relationship with environmental factors is an issue that has attracted the attention of scientists and governments. This article aims to deal with a possible association between COVID-19 and environmental factors and provide some recommendations for adequately controlling future epidemic threats. Environmental management through ecosystem services has a relevant role in exposing and spreading infectious diseases, reduction of pollutants, and control of climatic factors. Pollutants and viruses (such as COVID-19) produce negative immunological responses and share similar mechanisms of action. Therefore, they can have an additive and enhancing role in viral diseases. Significant associations between air pollution and COVID-19 have been reported. Particulate matter (PM2.5, PM10) can obstruct the airway, exacerbating cases of COVID-19. Some climatic factors have been shown to affect SARS-CoV-2 transmission. Yet, it is not well established if climatic factors might have a cause-effect relationship to the spreading of SARS-CoV-2. So far, positive as well as negative indirect environmental impacts have been reported, with negative impacts greater and more persistent. Too little is known about the current pandemic to evaluate whether there is an association between environment and positive COVID-19 cases. We recommend smart technology to collect data remotely, the implementation of "one health" approach between public health physicians and veterinarians, and the use of biodegradable medical supplies in future epidemic threats. (C) 2020 Elsevier B.V. All rights reserved.
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    First Genetic Record of a Strap-Toothed Beaked Whale (Mesoplodon layardii) Stranding in Chile
    (2020) Espanol-Jimenez, Sonia; Abaud, Constanza; Aceituno, Camila; Alvarado-Rybak, Mario; Borroni, Cintya; Chiang, Gustavo; Diaz, Javier; Espejo, Winfred; Luisa Estay, Maria; Garcia-Cegarra, Ana M.; Gonzalez, Carlos; Gutierrez, Belen; Gutierrez, Josefina; Henriquez, Daniel; Hirmas, Andrea; Mejias, Pamela; Merino, Constanza; Molina, Charity; Naretto, Camilo; Olivares, Florencia; Pereira, Patricia; Penaloza, Diego; Pincheira, Betsy; Pinto, Nicolas; Rojas, Omar; Sanchez, Carolina; Toro, Barbara; Toro, Frederick; Undurraga, Raimundo
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    Methylmercury biomagnification in coastal aquatic food webs from western Patagonia and western Antarctic Peninsula
    (2021) Chiang, Gustavo; Kidd, Karen A.; Diaz-Jaramillo, Mauricio; Espejo, Winfred; Bahamonde, Paulina; O'Driscoll, Nelson J.; Munkittrick, Kelly R.
    Mercury (Hg) is a global pollutant of concern because its organic and more toxic form, methylHg (MeHg), bioaccumulates and biomagnifies through aquatic food webs to levels that affect the health of fish and fish consumers, including humans. Although much is known about trophic transfer of MeHg in aquatic food webs at temperate latitudes in the northern hemisphere, it is unclear whether its fate is similar in biota from coastal zones of the southeastern Pacific. To assess this gap, MeHg, total Hg and food web structure (using delta C-13 and delta N-15) were measured in marine macroinvertebrates, fishes, birds, and mammals from Patagonian fjords and the Antarctic Peninsula. Trophic magnification slopes (TMS; log MeHg versus delta N-15) for coastal food webs of Patagonia were high when compared with studies in the northern hemisphere, and significantly higher near freshwater inputs as compared to offshore sites (0.244 vs 0.192). Similarly, in Antarctica, the site closer to glacial inputs had a significantly higher TMS than the one in the Southern Shetland Islands (0.132 vs 0.073). Composition of the food web also had an influence, as the TMS increased when mammals and seabirds were excluded (0.132-0.221) at a coastal site. This study found that both the composition of the food web and the proximity to freshwater outflows are key factors influencing the TMS for MeHg in Patagonian and Antarctic food webs. (C) 2020 Elsevier Ltd. All rights reserved.