The Common Murre (Uria aalge) is the most abundant seabird found nesting along the north and central California coast. There are several mainland murre colonies in the central Pacific region at Point Reyes National Seashore, as well as the large offshore colonies found on the Farallon Islands.
Murres spend much of their lives resting on the water or diving in search of food, which makes them particularly susceptible to entanglement in fishing gear. Oil spills are also a threat to murres, and have been an ongoing detriment to the species over the past several decades. The Pacific Coast saw a dramatic decrease in common murre populations in the mid-1980s as a result of birds getting caught in gill nets, in addition to the occurrence of several oil spills along the central coast. Common Murre breeding colonies are very susceptible to human disturbance from aircraft, boats, and people on foot when birds are flushed off their nests resulting eggs being broken or eaten by predators. With the help of various restoration projects to reduce threats, most murre populations are recovering from the large declines of the 1980s. However, recent climatic conditions have resulted in local changes in abundance. Common Murres, like other seabirds, associated with coastal upwelling ecosystems are susceptible to climatic perturbations such as El Niño events when there is less prey.