Cordell Bank National Marine Sanctuary
2009 Condition Report

Photo of an strawberry anemone

Summary and Findings

Cordell Bank National Marine Sanctuary is an extremely productive marine area off the west coast of United States in northern California. With its southern-most boundary located 42 miles (68 km) north of San Francisco, the sanctuary is entirely offshore, with the eastern boundary six miles from shore and the western boundary 30 miles (48 km) offshore at the 1000 fathom (1829 m) depth contour. In total, the sanctuary protects an area of 529 square miles (1369 square km). The centerpiece of the sanctuary is Cordell Bank, a four-and-a-half mile (7.2 km) by nine-and-a-half mile (15.2 km) rocky undersea feature located 22 miles (35 km) west of the Point Reyes headlands. The bank sits at the edge of the continental shelf and rises abruptly from the soft sediments of the shelf to within 115 feet (35 m) of the ocean surface (Figure 2). Cordell Bank falls within the California Current ecosystem, one of four major eastern boundary currents in the world. Coastal upwelling, a process associated with eastern boundary currents, initiates an annual productivity cycle at Cordell Bank that supports a rich biological community that includes local species as well as migratory sea turtles, fishes, seabirds and marine mammals that travel up to thousands of miles to feed around the bank. The combination of a healthy benthic community on the bank and its close proximity to offshore, open water species contributes to the unique biological diversity in a relatively confined area around Cordell Bank.

Map of Cordell Bank National Marine Sanctuary
Figure 2. Map of the Cordell Bank National Marine Sanctuary and surrounding area. This image depicts the seafloor features from the continental shelf to the continental slope, including the prominent feature of Cordell Bank. (Image created by Pam van der Leeden)

Activities that put pressure on sanctuary resources are diverse. Fishing activity has been conducted at Cordell Bank since the late 1800s and commercial and recreational fishing are still major activities. Restrictions implemented by the Pacific Fisheries Management Council to help rebuild depleted rockfish stocks limit current fishing activity within the sanctuary. The southeast corner of Cordell Bank National Marine Sanctuary is located approximately six miles from the terminus of the northern shipping lanes that funnel commercial vessels into and out of San Francisco Bay. On average, 2,000 large commercial ships transit through the sanctuary each year. There have been several large oil spills just south of the sanctuary in the last decade. Wildlife viewing trips are becoming increasingly popular in the sanctuary as opportunities to see humpback and blue whales and a diverse assemblage of pelagic seabirds draw enthusiasts from around the greater San Francisco Bay Area. Charter trips leave from the port of Bodega Bay.

Because of the offshore nature of the Cordell Bank sanctuary and the distance from major urban population centers, most water quality parameters suggest relatively good conditions. Benthic habitat quality has been impacted over the years as a result of bottom contact fishing gear on the rocky reef and soft bottom habitats of the sanctuary. Many derelict long lines and gill nets remain entangled on rocky areas of the bank. Spatial fishing gear restrictions that are currently in place in some areas will help protect sanctuary habitats and conditions are expected to improve. Living resource conditions within Cordell Bank National Marine Sanctuary are considered to be diminished, because of depleted populations of rockfish, salmon, leatherback sea turtles and some species of seabirds. It might be expected that conditions for living resources will improve due to fishery closures that are helping to rebuild depleted fish stocks, but uncertainty remains due to global changes that are currently affecting our oceans. To date, no maritime archaeological resources have been identified in the sanctuary.

A new management plan for the Cordell Bank sanctuary was released in 2008, and contains a number of management actions that will address current issues and concerns. The plan stresses an ecosystem-based approach to management, which requires consideration of ecological interrelationships not only within the sanctuary, but within the larger context of the California Current ecosystem. It also makes essential an increased level of cooperation with other management agencies in the region. Specific management actions called for in the plan include: a new regulation prohibiting the introduction/release of non-indigenous species into the sanctuary, actions to reduce discharges and develop spill contingency plans, monitoring of sanctuary waters, habitats, and pelagic and benthic communities, and actions to track human use activities and their impacts.

Cordell Bank National Marine Sanctuary

  • 529 square miles (1369 km2)
  • The main feature is an offshore rocky bank 4.5 miles (7.2 km) wide by 9.5 miles (15.2 km) long
  • First located in 1853 by George Davidson, a hydrographer with the U.S. Coastal Survey
  • Congressionally designated in 1989 as a National Marine Sanctuary
  • Submerged offshore bank that is home to dense and diverse temperate benthic and pelagic flora and fauna
  • Upwelling driven productivity supports a rich biological community that includes a combination of resident and migratory invertebrates, fishes, sea birds, turtles, and marine mammals. The sanctuary is a feeding area for humpback and blue whales.
  • Supports marine fisheries and wildlife viewing opportunities