California Current: West Coast Waters Show Evidence Of Improved Productivity

A new report provides a snapshot of the health of the California Current ecosystem. With the system shifting from a warmer El Niño to a cooler La Niña-influenced system, the ecosystem may become more productive.

COVID-19 made collecting this evidence and indicator data more difficult, so NOAA researchers teamed up with non-profit, university, state, and commercial partners. Together, they assembled data into a picture of the ecosystem’s current state.

The newest report shows the system transitioned in 2020 from El Niño conditions and a positive Pacific Decadal Oscillation to La Niña conditions and a negative oscillation. These climate conditions are generally associated with higher productivity as reflected by the amount of animal and plant biomass.

Cooler waters supported an abundance of nutritious zooplankton and the continued resurgence of anchovies. This created average to above-average forage conditions for other marine life, including seabirds and sea lions. Surveys found an abundance of northern copepods off Oregon and large krill in plankton nets and sea bird diets in northern and central California. Copepods and krill are the basis of the food web for many important species, including salmon. Generally, good reproduction by seabirds and sea lions also provides evidence of a productive ecosystem.

However, some ecological signs of concern tempered these conditions. These include:

–Low ocean circulation areas

–Low snowpack


–Catastrophic wildfires

–Widespread harmful algal blooms

–Continued presence of pyrosomes and other species associated with unusually warm waters

Researchers also documented the second-largest marine heatwave on record off the west coast of the United States in 2020. This marine heatwave formed more than 1,500 kilometers offshore in June. By mid-September it had grown to more than 9 million square kilometers—almost six times the size of Alaska. Despite these warmer waters offshore, the coastal upwelling of cooler waters from the deep ocean kept the ecosystem productive. The heatwave has reduced significantly in size and remains offshore as of January 2021.

This year’s report refines and expands the habitat compression index —an indicator that tracks coastal upwelling habitat—to three additional regions. The report first introduced this indicator in 2019 to assess the likelihood of ecosystem shifts and shoreward distribution of top marine predators like whales. It reflects how ocean shifts can compress habitats for different species together, leading to conflicts such as whales becoming entangled in fishing lines. Fishermen, researchers, and managers have dedicated significant effort over the past 5 years to reduce the number of entanglements. The habitat compression index may help us better understand and resolve that problem by advising fishermen where they are most likely to encounter whales.

NOAA’s Southwest and Northwest Fisheries Science Centers present this report to the Pacific Fishery Management Council each year. It describes how the ecosystem is changing and the impacts that may bring.

“Through presenting ecosystem trends, our goal is to provide the Council and the public with a snapshot of the health of the California Current ecosystem,” said Toby Garfield, the co-editor of the report. “Understanding these changes is critical to preserving the productivity and sustainability of West Coast fisheries and ecosystems.”

This report is one part of a larger effort to use NOAA’s Integrated Ecosystem Assessment approach to balance the needs of nature and society. This approach engages scientists, stakeholders, and managers to integrate all components of an ecosystem, including human needs and activities, into decision-making processes. For example, this report allows the fishery management council to consider the impacts of fisheries on fishing communities and the ecosystem.

Due to pandemic-imposed safety restrictions in 2020, NOAA canceled or reduced several key ecosystem, oceanographic, and fisheries surveys. With fewer eyes on the water, researchers relied on new sources and partnerships to fill gaps. These included numerous NOAA partnerships with commercial fishing vessels and university-led sampling efforts. For example, Northwest Fisheries Science Center and Oregon State University researchers took all the necessary COVID-19 precautions to ensure researchers’ health and safety to continue surveying the Newport Line. This effort sustained a longstanding hydrographic and plankton data time series.

Similarly, University of California, San Diego staff and scientists staffed the summer California Cooperative Oceanic Fisheries Investigations cruise. A non-profit, Point Blue, collected seabird data in Central California, and citizen science groups collected coast-wide seabird data. Oceanographic data collected via satellites and numerical simulations complemented these on-the-water observations.

Restaurant closures, canceled charter vessels, and outbreaks among industry personnel disrupted commercial and coastal communities and reduced revenues. This spurred a larger emphasis on social-economic data in this year’s report. For example, the 2020 report introduces several new and updated analyses of coastal communities, revenue dynamics, and fishing networks. This may help scientists understand how fishing communities respond to environmental and market changes. NOAA scientists highlighted such work in a recent study examining how the Dungeness crab fishing industry responds to marine heatwave-associated harmful algal bloom closures.

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