Summer has finally arrived in the northern reaches of Canada and Alaska, liberating hundreds of thousands of northern stream fish from their wintering habitats.
Through the long winter, many have endured cramped, icy quarters with perilously low oxygen levels. Others have recently journeyed incredible distances from large rivers and lakes to small summer habitats upstream.
Northern stream fish come from a long line of hardy adapters. Their ancestors were well equipped to survive multiple ice ages and then go on to colonize some of the coldest newly accessible northern habitats. They thrive in some of the most dynamic conditions on the planet, from short intense summers, with up to 24 hours of sunlight, to long cold winters with limited light and food. MORE
Header image: Headwaters of the Wind River within the largely intact Peel River watershed in northern Canada. Credit: Don Reid/Wildlife Conservation Society Canada, Author provided.