Browsing by Autor "Natalia Carpintero"

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Concentrations and stable isotopes of mercury in sharks of the Galapagos Marine Reserve: Human health concerns and feeding patterns
(2021) Laurence Maurice; Gaël Le Croizier; Gabriela Morales; Natalia Carpintero; Juan M. Guayasamin; Jeroen E. Sonke; Diego Páez‐Rosas; David Point; Walter Bustos; Valeria Ochoa‐Herrera
The human ingestion of mercury (Hg) from sea food is of big concern worldwide due to adverse health effects, and more specifically if shark consumption constitutes a regular part of the human diet. In this study, the total mercury (THg) concentration in muscle tissue were determined in six sympatric shark species found in a fishing vessel seized in the Galapagos Marine Reserve in 2017. The THg concentrations in shark muscle samples (n = 73) varied from 0.73 mg kg-1 in bigeye thresher sharks (Alopias superciliosus) to 8.29 mg kg-1 in silky sharks (Carcharhinus falciformis). A typical pattern of Hg bioaccumulation was observed for all shark species, with significant correlation between THg concentration and shark size for bigeye thresher sharks, pelagic thresher sharks (Alopias pelagicus) and silky sharks. Regarding human health concerns, the THg mean concentration exceeded the maximum weekly intake fish serving in all the studied species. Mass-Dependent Fractionation (MDF, δ202Hg values) and Mass-Independent Fractionation (MIF, Δ199Hg values) of Hg in whitetip sharks (Carcharhinus longimanus) and silky sharks, ranged from 0.70‰ to 1.08‰, and from 1.97‰ to 2.89‰, respectively. These high values suggest that both species are feeding in the epipelagic zone (i.e. upper 200 m of the water column). While, blue sharks (Prionace glauca), scalloped hammerhead sharks (Shyrna lewini) and thresher sharks were characterized by lower Δ199Hg and δ202Hg values, indicating that these species may focus their foraging behavior on prey of mesopelagic zone (i.e. between 200 and 1000 m depth). In conclusion, the determination of THg concentration provides straight-forward evidence of the human health risks associated with shark consumption, while mercury isotopic compositions constitute a powerful tool to trace the foraging strategies of these marine predators. CAPSULE: A double approach combining Hg concentrations with stable isotopes ratios allowed to assess ontogeny in common shark species in the area of the Galapagos Marine Reserve and the human health risks concern associated to their consumption.
Exploring inter- and transdisciplinary research on land use under climate change in the tropical Andes of Quito: the role of landscape history and local knowledge
(2025) Elisabeth Dietze; Ann-Kathrin Volmer; Alejandra Valdés‐Uribe; Liseth Pérez; Michał Słowiński; Elizabeth Velarde; Jessica Budds; Natalia Carpintero; Andrea Carrión; Lisa Feist
Global challenges resulting from climate change, resource depletion, and land use change require local solutions that acknowledge the configuration and history of its landscapes and the related social-ecological processes. Particularly sensitive to climate change are high-mountain tropical regions. The Andean ecoregion, where Ecuador&#8217;s capital Quito is located, is home to c. 3 million people and host globally-important biodiversity hotspots. These include near-urban cloud forest remnants and unique p&#225;ramo grasslands, characterized by their organic rich soils and water storage capacity of utmost importance for irrigation and drinking water in rural and urban areas.We would like to discuss how we explored the potential to: 1) initiate inter- and transdisciplinary research on land use and landscape dynamics under global and local change, and 2) co-design this research by identifying the most pressing subtopics in the area surrounding Quito. Our research team includes researchers from Ecuadorian, German, and Polish research institutions as well as members of NGOs. Within these group, we had two in-person, a few online meetings and a three-week field visit that included two community-oriented workshops in summer 2024. We exchanged scientific and local perspectives, including those from community and NGO contexts, on &#8220;landscape&#8221; as a potential conceptual framework. Discussions focused on methodologies on &#8220;how to research together&#8221; and the exchange of knowledge on human and natural history, all within the context of a decolonial/political ecology framework.We furthermore explored lakes and sedimentary deposits as archives for historical landscape dynamics, land use change and their transformation over time, as well as current ecosystem functioning using vegetation surveys with state-of-the-art remote sensing and field mapping. As a result, we identified future study areas and pressing topics that our inter- and transdisciplinary research can focus on, i.e., wildfires that intensify under climate change, water quality, soil erosion and volcanic eruption risks. With this initial phase of transdisciplinary research, we recognize high potential to co-create actionable knowledge that addresses the interconnectedness between societal and natural (or more-than-human) systems, and to contribute to tackling ongoing and future land use challenges in the tropical Andes.