The California Current — part of the large, swirling North Pacific gyre — flows slowly southward along the west coast of North America, stretching nearly 2,000 miles from southern British Columbia to the tip of Baja California in Mexico. To a casual observer standing on the shore, the vast current betrays no discernible signs, yet life abounds just over the horizon. Stan Ulanski takes us into the water on a journey through this magnificent, unique marine ecosystem, illuminating the scientific and biological marvels and the astonishing array of flora and fauna streaming along our Pacific coast. The waters of the California Current yield a complex broth of planktonic organisms that form the base of an elaborate food web that many naturalists have compared to the species-rich Serengeti ecosystem of Africa. Every year, turtles, seals, fish, and seabirds travel great distances to feast in the current’s distinct biological oases and feeding sites. Apex predators, such as the California gray whale, humpback whale, salmon shark, and bluefin tuna, undertake extensive north-south migrations within the current to find enough to eat. The California Current energizes us to celebrate and protect a marine ecosystem integral to the myriad fisheries, coastal communities, and cultures of the Pacific coast.