In our latest story, “A Little Fish with Big Impact In Trouble on U.S. West Coast,” science reporter Elizabeth Grossman investigates the devastating 90-percent decline in the Pacific sardine stock. She comes away with a daunting list of culprits, from climate change to aquaculture to burgeoning demand for fish oil and other supplements. And she explains how the plummeting supply of forage fish, such as sardines and anchovies, could be disastrous for marine animals farther up the food chain. The full story is available today at our media partner, Yale Environment 360.
“Sardines, anchovies, herring and other forage fish are enormously important to ocean ecosystems, playing a key role in moving food at the bottom of the food web to the top,” writes Grossman. “Along the Pacific Coast, where they ply the waters of the California Current, from southern British Columbia to Baja California, sardines and anchovies are essential prey for salmon, tuna, whales, dolphins, sea turtles and other species. More than 70 percent of this year’s sea lion pups may not survive because of a lack of sardines that lactating mother seals rely on, NOAA scientists say.”
In July, the Pacific Fishery Management Council will close the sardine fishery because of depleted supplies. The council has been criticized for succumbing to industry pressure and not taking steps sooner to protect the sardine stock. As Grossman reports, the sardine collapse has been driven in part by ravenous demand for supplements like fish oil, and, especially, fishmeal for aquaculture.
While some forage fish are eaten fresh or canned, the vast majority are used for other things. “According to one report, some 90 percent of the world’s forage fish—an estimated 24 million tons—goes to aquaculture, agriculture or fish-oil capsules and other nutritional supplements,” Grossman writes, adding that global fishmeal production in particular has tripled in the past half century.
Scientists, however, blame climate change as well as overfishing. As with all forage fish, the population cycle of sardines expands and contracts naturally. Numbers typically rise as water warms, but part of the problem may be that ocean water is warming beyond the normal limits. “A mass of unusually warm water has been parked in the eastern Pacific off the North American coast,” says Grossman. “The ocean here is now warmer than it’s been since recordkeeping began.”
Grossman notes that these critical fish now face a complex and interrelated network of threats. The sardine fishery is soon to be closed, but it will be years before we will know whether that will be enough to save it.