Anthropogenic use of high density, toxic elements results in marine pollution which is bio-accumulating throughout marine food webs. While there have been several studies in various locations analyzing such elements in fish, few have investigated patterns in these elements and their isotopes in terms of ocean depth, and none have studied the greatest depth zones. We used a flame atomic absorption spectrophotometer-hydride system and an inductively coupled plasma-mass spectrometer to determine concentrations of the high-density elements arsenic (As), cadmium (Cd), chromium (Cr), cobalt (Co), copper (Cu), lead (Pb), mercury (Hg), nickel (Ni), selenium (Se), plus the light-metal barium (Ba), in fish ranging from bathyal (1000 m in Monterey Bay) to upper hadal zones (6500–7626 m in the Kermadec and Mariana Trenches) in the Pacific Ocean. Five species of fish—including the Mariana Trench snailfish, the world's deepest known fish newly discovered—were analyzed for patterns in total element concentration, depth of occurrence, Se:Hg ratio, plus mercury isotopes in the deepest species. Co and As levels decreased with depth. In the Mariana Trench, Pb, Hg, Cd, and Cu were higher than in all other samples, and higher in those plus Ba than in the Kermadec Trench. The latter samples had far higher Ni and Cr levels than all others. Mercury relative isotope analysis showed no depth trends in the deepest species. Se:Hg showed a large molar excess of Se in bathyal flatfish species. These patterns indicate that exposures to pollutants differ greatly between habitats including trenches of similar depths.
Coal-related elements are toxic and persistent pollutants that have spread globally since the industrial revolution, mainly from point-source emissions. A sediment core was collected from Deep Lake in northeastern Washington State (USA) by the Washington State Department of Ecology, with the aim of assessing recent changes in atmospheric deposition in the US Pacific Northwest. The core was divided into depth intervals and dated by lead-210. A sample from each cross section was digested and analyzed for toxic metals and metalloids using inductively coupled plasma-mass spectrometry. Data show recent increases in the concentrations of arsenic, barium, selenium, and mercury. Comparison with 1993 US Geological Survey ice core data from the Upper Fremont Glacier in Wyoming (USA), Asian coal consumption data, and weather patterns suggests that pollutant inputs to Deep Lake sediments are the result of coal-burning activities in the Asia-Pacific region. Most notably, mercury deposition in Deep Lake has increased from approximately 20 ppb in 1996 to 9470 ppb in 2014 (an~400-fold increase), and since 1993 when the ice core was analyzed. Environ Toxicol Chem 2020;39:335-342. © 2019 SETAC
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.
hi@scite.ai
10624 S. Eastern Ave., Ste. A-614
Henderson, NV 89052, USA
Copyright © 2024 scite LLC. All rights reserved.
Made with 💙 for researchers
Part of the Research Solutions Family.