Watershed Features Shape Spatial Patterns of Fish Tissue Mercury in a Boreal River Network

• DOI: 10.2139/ssrn.4805447
• Publication Date: 2024-04-24T02:58:45Z
• Authors: David William Fr...; Daniel E. Schindler; Sean R. Brennan; Gordon W. Holtgr...
• Keywords: Mercury

Freshwater mercury (Hg) contamination is a widespread environmental concern but how proximate sources and downstream transport shape Hg spatial patterns in riverine food webs poorly understood. We measured total (THg) slimy sculpin (Cottus cognatus) across the Kuskokwim River, large boreal river western Alaska home to subsistence fishing communities who rely on fish for primary nutrition. used stream network models (SSNMs) quantify watershed instream conditions influencing THg. Spatial covariates local geology slope accounted 55% of observed variation THg evidence sculpins was weak. Empirical semivariograms indicated these most autocorrelation Watershed explained up 70% when SSNMs dependence. Our results provide network-wide predictions tissue based largely publicly available geospatial data open-source software SSNMs.