Fish assemblage associations and thresholds with existing and projected oil and gas development

Abstract

Energy development threatens fish and wildlife resources worldwide. This study used constrained ordinations to show fish assemblage structure associated with oil and gas well densities in the Colorado River Basin, Wyoming, but well densities explained only 6.4% of assemblage structure when compared to other factors. Threshold Indicator Taxonomic ANalysis showed significant negative threshold responses by some species to small levels of development (<0.15 wells km−2), whereas positive thresholds were less distinct. Some native and imperilled species could be disproportionately affected if future oil and gas development proceeds in a manner that will impact aquatic resources. Although existing development has not substantially influenced regional fish assemblage structure, it appears to affect a subset of species. Understanding assemblage‐level responses to development can help land managers determine appropriate development levels, prioritise areas for monitoring associated with future development and identify where land protection measures may be needed to offset potential risks.

Evaluating relationships between native fishes and habitat in streams affected by oil and natural gas development

“…Previous work suggests mountain sucker is sensitive to disturbance (Schultz, ). The study results are broadly consistent with previous modelling work in the Upper Green River Basin that suggested native species and salmonids (native and non‐native) were more sensitive to increasing well density (Dauwalter, ). Mottled sculpin was one of four indicator species identified as having a negative threshold response to well density (Dauwalter, ).…”

“…Mountain sucker, mottled sculpin and Colorado River cutthroat trout are all native to the Green River Drainage and are often found sympatrically in mountain streams. Mottled sculpin and mountain sucker are common within their ranges (Dauwalter, ), while Colorado River cutthroat trout populations have been declining and are of conservation concern at the state and federal levels (Hirsch, Dare & Albeke, ).…”

“…Oil and natural gas development density varies across the study area from stream catchments containing few ONG wells and limited infrastructure to highly developed areas with multiple phases of ONG development including processing facilities and long-term contaminant storage lagoons (Figures 1 and 2 (Gelwicks, Gill, Kern & Keith, 2009;Kern, Keith & Gelwicks, 2006 (Dauwalter, 2013), while Colorado River cutthroat trout populations have been declining and are of conservation concern at the state and federal levels (Hirsch, Dare & Albeke, 2013).…”

“…Modelling studies in the Upper Green River Basin, Wyoming, have related the occurrence of native fish species to different land use variables but found ONG development explained only a small proportion of fish assemblage variation (Dauwalter, ; Dauwalter, Wenger, Gelwicks & Fesenmyer, ). However, at that broad spatial scale, variability in landform and fish and vegetation communities may have obscured potential patterns.…”

“…small proportion of fish assemblage variation (Dauwalter, 2013;Dauwalter, Wenger, Gelwicks & Fesenmyer, 2011). However, at that broad spatial scale, variability in landform and fish and vegetation communities may have obscured potential patterns.…”