Freshwater lakes across North America and Europe are becoming noticeably browner, reducing underwater visibility and reshaping fish populations. Research found that several popular sport fish, including trout, bass, perch, and whitefish, tend to decline in darker waters. Meanwhile, walleye and north ern pike often become more abundant because they are better adapted to low-visibility conditions. The shift could change both lake ecosystems and the fishing experience for millions of anglers. ...read more read less