Orange rivers signal toxic shift in Arctic wilderness
a day ago
- #permafrost-thaw
- #climate-change
- #arctic-ecosystems
- Rivers in Alaska’s Brooks Range are turning orange and hazy due to toxic metals from thawing permafrost.
- Thawing permafrost exposes sulfide-rich rocks, creating sulfuric acid that leaches metals like iron, cadmium, and aluminum into rivers.
- This process resembles acid mine drainage but occurs naturally due to climate change, not mining.
- A study in the Proceedings of the National Academy of Sciences highlights contamination in the Salmon River, with similar changes happening across Arctic watersheds.
- Ecologists and researchers observed dramatic changes in water chemistry and landforms, alarming for ecosystems and Indigenous communities relying on fish.
- Metal levels in rivers exceed EPA toxicity thresholds, harming aquatic life and reducing light for insect larvae, a key food source for fish.
- While current fish tissue metal levels aren’t hazardous to humans, indirect threats like disrupted spawning gravel beds could impact subsistence species.
- The contamination is irreversible without permafrost recovery, with no practical mitigation in remote Arctic regions.
- The study underscores the widespread impact of global warming, even in untouched Arctic rivers, urging preparation for future ecological shifts.