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The Californian Current helps create highly diverse and productive upwelling ecosystems in the northeastern Pacific Ocean. Prevailing and local winds along the coast blow the surface of the ocean away from the land. This causes cold water on the bottom of the ocean to upwell, or rise to the surface. This water is rich in nutrients, which support abundant phytoplankton, which in turn supports abundant animal life.
Like all upwelling zones, the area off the coast of California and Oregon is home to huge populations of marine mammals, seabirds, and fish. Some species of invertebrates and fish don't live anywhere else in the world. The temperature and salt levels of the ecoregion vary depending on the season. But the water is always sufficiently cold, clear, and nutrient-rich for extensive kelp forests to grow. These dense stands of fast-growing brown algae support a vast array of species, from abalones to sea otters to blue whales.
Numerous species of salmon spend time in the ecoregion before swimming up rivers to spawn. They share the water with many other fish, including yellowfin tuna, sole, Pacific cod, California skate, shovelnose guitarfish, longfin gunnel, and the endemic garibaldi. Colonies of seals and sea lions live on the shores but feed in the ocean, where they may mingle with sea otters, porpoises, whales, and sharks. Several species of sea turtles paddle about, and creatures such as the starlet sea anemone burrow among stands of giant kelp. The air is filled with the calls of birds such as shearwaters and gulls.
Regional coastal waters have become polluted, especially near major cities, leading to problems of contaminated seafood. A major threat to the region comes from oil shipping accidents. Overfishing also poses a serious threat to the region.
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