Pajaro River - Ecology

Ecology

In 2006, the Pajaro River was designated as America's most endangered river by the American Rivers organization, due to levees constructed by the Army Corps of Engineers along its lower 22 miles (35 km) and severe runoff into the river from agricultural fields.

San Felipe Lake, which is the central feature of the “Bolsa de San Felipe”, is designated as a “California Important Bird Area” by the National Audubon Society. The Bolsa is a crossroads for birds migrating between San Francisco Bay to the north, Monterey Bay to the west and the Central Valley to the east. The Bolsa is also identified by the National Audubon Society as a “bird vagrant trap”, a site where bird species far outside of their normal range appear.

The Pajaro River serves as a migration pathway for adult Steelhead trout (Oncorhynchus mykiss) migrating to spawning and nursery habitat in the upper watershed creeks (Uvas, Llagas and Corralitos), although the Pajaro River mainstem provides poor spawning and rearing habitat due to low summer flows and high sedimentation loads. Coho salmon (Oncorhyncus kisutch) have not been present in the river since at least the late 1960s.

Historically it is interesting as one of two Northern California coastal rivers mentioned in 1829 by Russian explorer K. T. Khlebnikov as hosting sturgeon, presumably White sturgeon (Acipenser transmontanus), along with the Russian River.