Global browning: Why the world’s fresh water is getting murkier
Maggie Xenopoulos straps on a pair of hip-waders, grabs a 1-litre plastic bottle from her truck and wades into Ontario’s Nottawasaga river. “See this brown colour?” she says, scooping up water the colour of weak tea. “That’s dissolved organic carbon. It blocks UV rays. It’s a bit like SPF for aquatic life.”...