Search

Marine pollution by trace elements is a global concern due to potential toxicity to species and ecosystems. Copper is a fundamental trace element for many organisms; however, it becomes toxic at certain concentrations. The green turtle (Chelonia mydas) is a good sentinel species, due to its circumglobal distribution, long life cycle, coastal habits when juvenile, and is subject to environmental pollution. Quantifying and comparing copper levels makes it possible to understand the availability of this trace element in nature. During this research, comparisons were made between the levels of copper found in the liver, kidneys, and muscles of 35 turtles, from the United States (Hawaii and Texas), Brazil, and Japan. Copper was found in all specimens. In the liver, animals from Hawaii (91.08 µg g -1 ), Texas (46.11 µg g -1 ), and Japan (65.18 µg g -1 ) had statistically equal means, while those from Brazil (16. 79 µg g -1 ) had the lowest means. For the kidney, copper means were statistically equal for all Hawaii (3.71 µg g -1 ), Texas (4.83 µg g -1 ), Japan (2.47 µg g -1 ), and Brazil (1.89 µg g -1 ). In muscle, the means between Texas (0.75 µg g -1 ) and Japan (0.75 µg g -1 ) were the same, and the mean for Brazil (0.13 µg g -1 ) was the lowest. Among the organs, the highest levels of copper were found in the liver (28.33 µg g -1 ) followed by the kidney (2.25 µg g -1 ) and with the lowest levels in the muscle (0.33 µg g -1 ). This is the first study of copper levels among marine vertebrates in distant parts of the globe using similar comparative filters between different locations. Similar levels in turtles from such distant locations may indicate that there is a pantropical pattern of copper distribution in the biota, and that these animals are subject to the process of bioavailability of this metal in the environment and metabolic regulation., (© 2024. The Author(s), under exclusive licence to Springer-Verlag GmbH Germany, part of Springer Nature.)

Pollution is one of the biggest threats to marine life and trace elements are among the most toxic pollutants in this environment. Zn is an essential trace element for biota but becomes toxic at high concentrations. Sea turtles are good bioindicators of trace element pollution, due to their longevity and cosmopolitan distribution that allow bioaccumulation for years in their tissues. Determining and comparing Zn concentrations in sea turtles from faraway places is relevant for conservation due to the lack of knowledge of geographically broader distribution patterns of Zn in vertebrates. In this study, comparative analyses of bioaccumulation in the liver, kidney, and muscles of 35 C. mydas from Brazil, Hawaii, the USA (Texas), Japan, and Australia of statistically equal sizes were performed. Zn was found in all specimens, with the highest levels in the liver and kidneys. Specimens from Australia (30.58 µg g -1 ), Hawaii (31.91 µg g -1 ), Japan (29.99 µg g -1 ), and the USA (33.79 µg g -1 ) showed statistically equal means in the liver. Kidney levels were the same in Japan (35.09 µg g -1 ) and the USA (37.29 µg g -1 ) and the same in Australia (23.06 µg g -1 ) and Hawaii (23.31 µg/g). Specimens from Brazil had the lowest means in both organs (12.17 µg g -1 in the liver and 9.39 µg g -1 in the kidney). The pattern of equal Zn values for most specimens in the liver is an important finding, demonstrating that there are pantropical patterns in the distribution of this metal even in regions so far from each other. A possible explanation is due to the essential nature of this metal linked to metabolic regulation, in addition to the bioavailability for biological absorption in marine environments, such as RS in Brazil, with a lower standard bioavailability also found in other organisms. Therefore, factors such as metabolic regulation and bioavailability indicate that there is a pantropical distribution of Zn in marine biota and green turtles can be a useful model as a sentinel species., (© 2023. The Author(s), under exclusive licence to Springer-Verlag GmbH Germany, part of Springer Nature.)