Bristol Bay, Alaska
Bristol Bay is the most productive salmon system in North America. Every summer, millions of sockeye salmon return from pelagic forays to the streams where their lives began years earlier. Groups of bright red and green adults aggregate in shallow pools, waiting to pair and spawn in nearby gravel beds. After exerting the last of their mortal energy to safely tuck their eggs beneath the pebbles, they die and their bodies disintegrate into the ecosystem. Research indicates that this pulse of resources into otherwise nutrient-poor forests significantly increases the growth rates of trees such as the white spruce shown here.