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Scientists turned 20 lakes into little laboratories. Fish stocking didn't make a dent in the fish population. Creating better habitat did.
Warren Cornwall, Anthropocene, March 8, 2023
Every year, wildlife agencies around the world pour millions of young fish into lakes, streams and rivers. The work is usually done with the twin goals of propping up fish populations and giving anglers something to catch.
While the actions might seem like a straightforward equation (add more fish, get more fish), an elaborate study suggests that the math doesn’t work that way. Just adding more fish has little long-term effect. It’s the habitat that matters.
“Restoring central ecological processes and habitats—ecosystem-based management—is likely to have stronger long-term effects for rebuilding fish species and populations than narrow, species-focused conservation actions,” said Johannes Radinger, a scientist at Germany’s Leibniz Institute of Freshwater Ecology and Inland Fisheries, who helped lead the research.
The new findings raise questions not just about the benefits of artificially supplementing fish populations, but about the potential pitfalls of any initiative aimed at boosting wildlife numbers by raising and releasing more animals.
Cited Research: Radinger, et. al. “Ecosystem-based management outperforms species-focused stocking for enhancing fish populations.” Science. March 2, 2023.