由于其自然历史和生态属性,海龟是研究重金属污染的优秀生物。海龟有很大的地理分布,占据不同的水生栖息地,并占据各种营养水平。本研究调查了在RioNegro中部的肉食性鳞翅目flimbriata(Matamata海龟)中汞的生物积累和汞的生物放大作用与其水生食物链的关系,AM-巴西。肌肉组织样本,从26个菌毛个体中收集甲壳和爪子,以及在海龟水生栖息地发现的自养能源的集合。在2014年2月-3月收集样品并分析THg浓度和碳(δ13C)和氮(δ15N)稳定同位素。在爪子中发现最高的THg水平(3780ng。g-1),甲壳(3622ng。g-1)和肌肉(403ng。g-1),发现差异显著[F(2.73)=49.02p<0.01]。然而,肌肉组织中的THg浓度低于WHO和巴西卫生部指示的消耗阈值。Matamata样品的平均δ13C和δ15N值分别为-31.7‰和11.9‰,分别。发现维持C.fumbriata食物链的主要能源是陆生灌木,新兴水生草本植物和藻类的贡献较小,而δ15N值显示其营养位置比自养能源高两个水平。THg与乌龟大小呈正相关,虽然发现THg和δ15N之间存在显著关系,菌毛食物链显示出强的生物放大作用:y=0.21x+0.46;r2=0.45;p<0.001,斜率值为0.21。
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.