Total mercury concentrations in Steller sea lion bone: Variability among locations and elements

Mary Keenan; Nicole Misarti; Lara Horstmann; Stephanie G Crawford; Todd O'Hara; Lorrie D Rea; Julie P Avery

doi:10.1016/j.marpolbul.2024.116471

Total mercury concentrations in Steller sea lion bone: Variability among locations and elements

Mar Pollut Bull. 2024 Jun:203:116471. doi: 10.1016/j.marpolbul.2024.116471. Epub 2024 May 15.

Authors

Mary Keenan¹, Nicole Misarti², Lara Horstmann³, Stephanie G Crawford², Todd O'Hara⁴, Lorrie D Rea², Julie P Avery²

Affiliations

¹ Water and Environmental Research Center, Institute of Northern Engineering, University of Alaska, 1764 Tanana Loop, PO Box 75 5910, Fairbanks, AK 99775, USA; College of Fisheries and Ocean Sciences, University of Alaska, 2150 Koyukuk Drive, PO Box 757220, Fairbanks, AK 99775, USA. Electronic address: mpkeenan54@gmail.com.
² Water and Environmental Research Center, Institute of Northern Engineering, University of Alaska, 1764 Tanana Loop, PO Box 75 5910, Fairbanks, AK 99775, USA.
³ College of Fisheries and Ocean Sciences, University of Alaska, 2150 Koyukuk Drive, PO Box 757220, Fairbanks, AK 99775, USA.
⁴ Veterinary Integrative Biosciences, School of Veterinary Medicine & Biomedical Sciences, Texas A&M University, 402 Raymond Stotzer Pkwy, College Station, TX 77843, USA.

PMID: 38754323
DOI: 10.1016/j.marpolbul.2024.116471

Abstract

Mercury is a global contaminant that bioaccumulates in a tissue-specific manner in long-lived predators such as Steller sea lions (SSL). Bone is a well-preserved material amenable for studying millennial scale trends; however, little is known about the distribution and variability of total mercury concentrations ([THg]) within individual bones and among bone elements in SSL. We assessed SSL bone [THg] variability with respect to physiologic age, bone type, longitudinally within a bone, and among bone elements. Pup bones (mean ± SD; 31.4 ± 13.58 ppb) had greater [THg] than adults (7.9 ± 1.91 ppb). There were greater and more variable [THg] within individual long bones near epiphyses compared to mid-diaphysis. Pup spongy bone in ribs (62.7 ± 44.79 ppb) had greater [THg] than long bones (23.5 ± 8.83 ppb) and phalanges (19.6 ± 10.78 ppb). These differences are likely due to variability in bone composition, growth, and turnover rate. This study informs standardized sampling procedures for [THg] in bone to improve interpretations of mercury variability over time and space.

Keywords: Cortical bone; Direct mercury analysis; Mercury; Steller sea lion; Trabecular bone.

MeSH terms

Animals
Bone and Bones* / chemistry
Environmental Monitoring*
Mercury* / metabolism
Sea Lions* / metabolism
Water Pollutants, Chemical* / analysis
Water Pollutants, Chemical* / metabolism

Substances

Mercury
Water Pollutants, Chemical