Exploring 4200 years of mercury variation in the antlers of high-Arctic wild reindeer
Data files
Feb 13, 2025 version files 38.79 KB
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README.md
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Sato-Bajracharya_et_al._2025_metadata.xlsx
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Abstract
Anthropogenic mercury (Hg) emissions and climate change are altering the global cycle of Hg. Levels of Hg in natural archives can help us understand not only the historical trends but also the future changes in different ecosystems, including the Arctic. In this study, we investigated the temporal variation of Hg across 4200 years in 78 antlers of the high-Arctic Svalbard reindeer (Rangifer tarandus platyrhynchus). Antler Hg concentrations were higher during the pre-1650 Anno Domini (AD) period compared to the post-1650 AD period. Thus, antler Hg concentrations did not reflect the increased environmental Hg levels caused by high anthropogenic activities during the past three centuries. Trabecular Hg concentrations tended to be higher during the Medieval Warm Period than during the Little Ice Age, as revealed by a post-hoc analysis conducted to explore the relationship between climatic variation and antler Hg concentrations. The overall mean (±SE) antler Hg concentration was generally low (5.29 ± 0.46 ng/g) compared to the present levels of Hg in various tissues of terrestrial Arctic ungulates. Combined with other paleo-archives, this millennial-scale study of Hg using antlers could provide insights into the temporal patterns and potential drivers of Hg variation in Arctic terrestrial ecosystems.
https://doi.org/10.5061/dryad.z8w9ghxqc
Description of the data and file structure
78 individual antlers of Svalbard reindeer (Rangifer tarandus platyrhynchus) were analyzed for (i) mercury (Hg) concentrations using DMA-80 Hg analyzer and (ii) carbon dated to estimate its age using the R package ‘rcarbon’ and calibration curve with the dataset IntCal20 where ‘present’ (~0 BP) was set to the calendar year 1950 AD. Temporal variation of Hg across 4200 years was analyzed during this dataset. Sample collection permits were obtained from the Governor of Svalbard, RID-ID 10015 and 10128
Files and variables
File: Sato-Bajracharya_et_al._2025_metadata.xlsx
Description: This file contains the metadata of the 78 individual antlers that was analyzed in the study, "Exploring 4200 Years of Mercury Variation in the Antlers of Hg-Arctic Wild Reindeer". Variables in this dataset are described below and also can also be found within the Sato-Bajracharya_et_al._2025_metadata.xlsx file. Cells with no information available are indicated as "N/A".
Contacts:
Conceptualization: Saria Sato-Bajracharya, sariasato15@gmail.com; Mathilde Le Moullec, malm@natur.gl; Tomasz Maciej Ciesielski, tomaszc@unis.no
Sample Acquisition and Carbon Dating: Mathilde Le Moullec, malm@natur.gl
Mercury analysis: Saria Sato-Bajracharya, sariasato15@gmail.com; Tomasz Maciej Ciesielski, tomaszc@unis.no
Statistical analysis: Saria Sato-Bajracharya, sariasato15@gmail.com; Mathilde Le Moullec, malm@natur.gl
Variables:
- Sample ID : Unique sample ID per antler
- Replicate ID : Different replicates within an antler
- Median probability (cal BP): The median calibrated age in cal BP (calibrated years before present)
- Age range in calendar years BP (before 1950, 2 sigma): Carbon dated antler age's confidence interval based on 2 sigma uncertainity, calibrated to ‘before present’ (BP) years using the R package ‘rcarbon’ and calibration curve with the dataset IntCal20 (See Materials and Methods Section 2.2)
- C14 Age : 14C antler age in ‘before present’ (BP) years without calibration
- StDev : Associated Standard deviation to the 14C anter age without calibration
- Final Hg (ng/g) : Final mercury concentration in nanograms per gram after blank correction. "N/A" indicates either the sample was below the quantification limit (LOQ) or that the specific layer of a sample was not obtainable due to difficulty in cutting.
- Layer : Antler tissue type: 'cortical' or 'trabecular'
- Time Period : Category based on Pre- or Post- 1650AD carbon dated median age (calibrated)
- Location : Sample location name on Svalbard archipelago
- Section : Section of the antler subsamples for the analysis of mercury, 4 possible categories 'beam', 'base', 'brow tine', 'unknown' (see Materials and Methods Section 2.3)
- Region : 'E'= East and 'W'= West. Part of Svalbard the sampling locations approximately belonged to
- Sex : Sex/age categories, 'YU' = yearling unknown sex, 'FA' = female adult and 'MA' = male adult (See Materials and Methods Section 2.2)
- Climate : Climatic period in Svalbard an antler belonged to (based on calibrate carbon dated median age, see Discussion). 'LIA' = Little Ice Age,750 BP onwards, 'MWP' = Medieval Warm Period 750-1400 BP, 'pre-MWP' = 1400- 4200 BP. "N/A" are non-applicable samples since they are from the post-1650 AD time period