Ash and chemicals from some of BC’s largest wildfires are winding up in the Fraser River, which could eventually lead to low oxygen levels and harm marine life, say UBC researchers. In a peer-reviewed study, published in the journal Science of The Total Environment, scientists linked increases in the concentrations of compounds like arsenic and lead, and nutrients such as nitrogen and phosphorus, to wildfires that had burned near the 1,375 kilometre long river. These are all compounds that are found naturally in the water. However, researchers tracked a significant increase in compounds as wildfires were happening near the river. The researchers studied fires within 500 metres, 1,000 metres and 1,500 metres. Fires burning close to major waterways had immediate influence on water quality, said Emily Brown, a research scientist at UBC’s institute for the oceans and fisheries. The more distant wildfires had delayed influence on water quality.