Metals occur naturally in the environment; however, anthropogenic practices have greatly increased metal concentrations in waterways, sediments, and biota. Metals pose health risks to marine organisms and have been associated with oxidative stress, which can lead to protein denaturation, DNA mutations, and cellular apoptosis. Sharks are important species ecologically, recreationally, and commercially. Because they occupy a high trophic level, assessing muscle tissue metal concentrations in sharks may reflect metal transfer in marine food webs. In this study, concentrations of cadmium, copper, lead, nickel, selenium, silver, and zinc were measured in the muscle of Rhizoprionodon terraenovae (Atlantic sharpnose shark) from 12 sites along the coast of the southeastern United States. Activities of antioxidant enzymes (superoxide dismutase, catalase, glutathione peroxidase, and glutathione reductase) also were examined in the muscle tissue of R. terraenovae. A total of 165 samples were analyzed, and differences in trace element bioaccumulation and enzyme activity were observed across sites. R. terraenovae samples collected from South Florida and South Carolina had the highest cumulative trace element concentrations whereas those collected from North Carolina and Alabama had the lowest cumulative concentrations. Trace element concentrations in shark muscle tissue were significantly correlated to antioxidant enzyme activity, particularly with glutathione peroxidase, suggesting that this enzyme may serve as a non-lethal, biomarker of metal exposure in R. terraenovae. This is one of the most extensive studies providing reference levels of trace elements and oxidative stress enzymes in a single elasmobranch species within the U.S.

金属自然存在于环境中；但是，人为做法大大增加了水道，沉积物和生物区系中的金属浓度。金属对海洋生物构成健康风险，并与氧化应激有关，氧化应激可导致蛋白质变性，DNA突变和细胞凋亡。鲨鱼在生态，娱乐和商业上都是重要的物种。由于鲨鱼的营养水平很高，因此评估鲨鱼肌肉组织中的金属浓度可能反映了海洋食物网中金属的转移。在这项研究中，测量了非洲根霉（Rhizooprionodon terraenovae）肌肉中镉，铜，铅，镍，硒，银和锌的浓度。来自美国东南沿海12个地点的大西洋尖嘴鲨。还检查了陆地龟的肌肉组织中抗氧化酶（超氧化物歧化酶，过氧化氢酶，谷胱甘肽过氧化物酶和谷胱甘肽还原酶）的活性。总共分析了165个样品，并且观察到了不同部位的痕量元素生物积累和酶活性的差异。。从南佛罗里达州和南卡罗来纳州收集的样品具有最高的累积痕量元素浓度，而从北卡罗莱纳州和阿拉巴马州收集的样品具有最低的累积浓度。鲨鱼肌肉组织中的微量元素浓度与抗氧化酶活性显着相关，尤其是与谷胱甘肽过氧化物酶相关，这表明该酶可能是在R.terraenovae中金属暴露的非致命生物标志物。这是最广泛的研究之一，提供了美国单一弹性分支物种中微量元素和氧化应激酶的参考水平