Navegando por Assunto "Amazonian"

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Artigo
Mercury biomagnification in the food chain of a piscivorous turtle species (Testudines: Chelidae: Chelus fimbriata) in the Central Amazon, Brazil
(2024-05-03) Cunha, Fábio Andrew G; Forsberg, Bruce R; Vogt, Richard C; Domingos, Fabíola X V; Marshall, Bruce G; Brito, Brendson C; Sousa, Otávio P de; Kasper, Daniele; Santos, Ana Laura P; Ândrade, Marcelo
Due to their natural history and ecological attributes, turtles are excellent organisms for studies of heavy metal contamination. Turtles have a large geographical distribution, occupy different aquatic habitats, and occupy various trophic levels. The present study investigated mercury bioaccumulation in the carnivorous chelonian Chelus fimbriata (Matamata turtle) and Hg biomagnification in relation to its aquatic food chain in the middle Rio Negro, AM-Brazil. Tissue samples of muscle, carapace and claws were collected from 26 C. fimbriata individuals, as well as collections of autotrophic energy sources found in the turtle's aquatic habitat area. The samples were collected in February-March/2014 and analyzed for THg concentrations and carbon (δ13C) and nitrogen (δ15N) stable isotopes. The highest THg levels were found in claws (3780 ng.g-1), carapace (3622 ng.g-1) and muscle (403 ng.g-1), which were found to be significantly different [F(2.73) = 49.02 p < 0.01]. However, THg concentrations in muscle tissue were below the consumption threshold indicated by the WHO and Brazilian Health Ministry. The average δ13C and δ15N values in Matamata samples were -31.7‰ and 11.9‰, respectively. The principal energy source sustaining the food chain of C. fimbriata was found to be terrestrial shrubs, with smaller contributions from emergent aquatic herbaceous plants and algae, while δ15N values showed its trophic position to be two levels above the autotrophic energy sources. There was a positive correlation between THg and turtle size, while a significant relationship was found between THg and δ15N, showing strong biomagnification in the food chain of C. fimbriata: y = 0.21x + 0.46; r2 = 0.45; p < 0.001, for which the slope presented a value of 0.21.
Capítulo de livro
PRODUCTIVE CHAINS OF AMAZONIAN SOCIOBIODIVERSITY AND ECODESIGN OPPORTUNITIES
(Edgard Blücher Ltda, 2021) Coutinho, Marcos Eduardo; Pinto, Laura de Souza Cota Carvalho Silva; Vale, Cristiano Andrey Souza do; Pereira, Andréa Franco; Pereira, Andréa Franco; Gaudio, Chiara Del
The chapter discusses the growing demand for intensive production systems due to the growth of the human population, leading to the modification and loss of natural ecosystems and biodiversity. It traces the historical development of conservation efforts, highlighting the emergence of strategies such as “conservation through smart use” and “conservation through sustainable use” to promote the coexistence of wildlife conservation and socioeconomic development. It emphasizes the importance of incorporating various forms of wildlife use into conservation strategies, including commercial, recreational, scientific, aesthetic, and spiritual purposes. However, there's controversy over which forms of utilization are compatible with conservation, particularly concerning commercial use. Proponents argue that commercial use can aid conservation by increasing land productivity, preserving genetic heritage, creating markets, stabilizing fauna product markets, and promoting rural development. Conversely, opponents raise concerns that commercial interests may prioritize profit over ecological conservation, leading to overexploitation and ecological degradation. Ultimately, the effectiveness of commercial wildlife use as a conservation mechanism remains a hypothesis requiring rigorous field experimentation considering both biological and socioeconomic factors.