Fishing Worsens Collapse of Forage Fish

Written by on April 27, 2015 in Fish, Marine Life

A new study reveals that fishing likely played a role in population collapses of some forage fish, like anchovies, herring, and sardines.

Sardines and kelp in the Channel Islands National Marine Sanctuary. Photo credit: Robert Schwemmer, NOAA.

Sardines and kelp in the Channel Islands National Marine Sanctuary. Photo credit: Robert Schwemmer, NOAA.

Scientists have long known that many forage fish populations experience wide fluctuations in abundance, occasionally resulting in complete collapse. (Collapse, in this case, means the stock had fallen to a quarter or less of its long term average.) What they didn’t know, however, is if these fluctuations and collapses were natural or related to fishing. It turns out that fishing plays a role.

“We’ve identified the fingerprint of fishing on population fluctuations, finding that fishing makes the troughs of population cycles deeper,” lead author Tim Essington, a University of Washington professor of aquatic and fishery sciences, explained in a news release. “This is particularly important given the vital role these species play in food webs.”

Forage fish are targeted by some of the largest fisheries in the world, but they are also an important food source of many larger marine animals, ranging from tuna and salmon, to seabirds and whales.

To prevent complete collapse, researchers recommend the use of risk-based management tools that would track a fishery’s numbers and halt fishing when they dipped too low.

Using simulations of this management strategy, researchers determined that by suspending fishing when a population falls below half of its long-term average, 64 percent of collapses could be prevented. What’s even more impressive is that this strategy would only reduce the average catch by two percent in the long term.

“The good news is we find that simple strategies can avoid the worst of the ecological impacts, with little costs to fisheries,” Essington said. “Widespread application of these types of strategies would sustain the benefits people get from forage fish while allowing for sustainable fishing.”

To learn more:

Copyright © 2015 by Marine Science Today, a publication of Marine Science Today LLC.

About the Author

About the Author: Emily Tripp is the Publisher and Editor of She holds marine science and biology degrees from the University of Miami's Rosenstiel School of Marine and Atmospheric Science and a Master of Advanced Studies degree in Marine Biodiversity and Conservation from Scripps Institution of Oceanography. When she's not writing about marine science, she's probably running around outside or playing with her dog. .


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