And with 40 percent of the world’s fish species living in fresh, inland waters, the browning trend is worth examining. For 871 lakes in the U.S. and Canada across a gradient of browning, the researchers assessed water hue relative to resident fish populations. They focused on eight ecologically and commercially important species, looking at fish abundance, growth, and survival rates, as well as individual traits like eye diameter, mouth size, and mouth position. For most fish species, abundance was negatively correlated with browning, but with two notable exceptions. “Because they’re predators, feeding on smaller fish, plankton, and invertebrates, changing their populations can have cascading effects.”Given that lake browning stunts the growth of some fish species, affects population abundance, and shifts fish community compositions, it warrants further research.