This blog is the second in a new series “Little Giants” exploring the importance of forage fish and the marine ecosystems they inhabit around the world.
Sardines may be small, but they are among the most important fish in the marine ecosystem. Now, a critical plan to recover Pacific sardines is under attack.
How Do Pacific Sardines Contribute to Food Webs and Fisheries?
Sardines are a type of forage fish, which transfer food and energy from plankton to larger animals including marine mammals, seabirds, swordfish, salmon, and tuna. They are also economically important, supporting fisheries both as direct catch and as a food source to other commercially important species.
Sardine populations naturally fluctuate over time in response to changes in ocean currents and the availability of their plankton food sources, cycling between periods of abundance and decline. Because of this, they are considered a boom-and-bust species, even without fishing pressure. However, we now know that fishing amplifies forage fish population collapses, and scientists have long warned that we must significantly reduce fishing pressure during periods of natural decline. Not doing so can intensify the chances of population collapse, drastically slow recovery, and leave less food in the water for other marine wildlife.
Despite these warnings, fishery managers have often failed to enact the necessary measures to prevent depleting sardines to dangerously low levels.
Why Have Pacific Sardine Populations Crashed?
At one point, the West Coast sardine fishery was among the largest in the world. Massive canneries drove the coastal economy in California and supplied a staple food source for soldiers during World War II. In the late 1940s and early 1950s, sardines crashed following a period of high productivity. But the intensive fishing pressure didn’t let up. Even after the collapse, fishing continued for another 20 years until the California legislature finally enacted a full moratorium on sardine fishing in 1974. Because the population was so severely depleted, it didn’t rebound to levels that could support a major commercial fishery until the 1990s, and it never again reached the peak levels seen during the 1930s and ‘40s.
In 2012, U.S. federal fishery scientists again sounded the alarm that the Pacific sardine population was collapsing. And again, commercial fishing continued, with U.S. fisheries removing an estimated 30–40% of the remaining Pacific sardine population each year. In 2015, after the sardine population had already collapsed, federal fishery managers finally closed the directed commercial fishery.
Even after the 2015 collapse and closure of the major commercial fishery, loopholes in the management plan allowed for continued fishing pressure, contributing to further decline. This has left Pacific sardines in a hauntingly similar state to the one seen during the 20-year collapse of the 1950s through 1970s.
Impacts of sardine population collapse extend to other fish and wildlife that depend on them for food. From 2013-2016, over 8,000 young sea lions were abandoned by their mothers in what the government labeled an “unusual mortality event.” Federal scientists concluded this was caused by lack of adequate food, primarily due to the sardine collapse.
How Can Pacific Sardines Recover?
In 2019, seventy years after the infamous stock collapse than ended the Cannery Row era, the northern Pacific sardine population was officially designated as “overfished” under the Magnuson-Stevens Fishery Conservation and Management Act — the United States’ primary law governing sustainable fisheries. That designation triggered a requirement to develop and implement a rebuilding plan within 2 years to restore the population to a healthy level.
The first rebuilding plan developed by the government was not based on the best-available science and failed to prevent overfishing or ensure population recovery. Oceana successfully challenged the plan in court, and in 2025, the fisheries service adopted a new plan that provided stronger, science-based protections for the population.
What Challenges Do Pacific Sardines Face Today?
Today, those hard-won protections are under threat. A 2025 Trump administration executive order directed the fisheries service to expand domestic seafood production. In response, federal fishery managers are pushing to eliminate the rebuilding plan by “revising Pacific sardine stock definitions” and allowing increased pressure on overfished sardine populations, sacrificing long-term sustainability for the sake of short-term profits.
Meanwhile, the Pacific sardine population is still not showing signs of recovery with the 2025 stock assessment showing a 97% decline since 2006. With a “Super El Niño” on the horizon and unprecedented ocean conditions expected, the future for sardines is more uncertain than ever.
Now is the time to let the rebuilding plan work for these small but mighty fish and our Pacific coast ecosystems — not dismantle it before it has a chance to succeed. Doing so will ensure that Pacific sardines have a chance to recover and thrive for years to come.
Help protect Pacific sardines by signing Oceana’s petition today.
Dr. Geoff Shester is Oceana’s Fishery Innovation Director and Senior Scientist based in our Monterey, California office. He holds an interdisciplinary doctorate in Environment and Resources from Stanford University and is currently an Adjunct Professor at Stanford University’s Oceans Department. He began working at Oceana in 2002 where he has been a part of victories to protect seafloor habitats, lead expeditions, and prevent whale entanglements, and has been studying the Pacific sardine fishery for 20 years. In his free time, you can find him riding his gravel bike, cooking, and going to the beach with his family.
