The requirement to rebuild US fish stocks: Is it working?

• Analyzed biomass trends for fish stocks in Magnuson–Stevens Act rebuilding programs.
• Of 44 overfished stocks, 19 showed significant increases in rate of biomass recovery.
• None of the 44 showed statistically significant declines in rate of biomass recovery.
• Strong relationship shown between policy implementation and rebounds in stocks.

The Magnuson–Stevens Fishery Conservation and Management Act (MSA) was amended in 1996 to require that overfished stocks be rebuilt in as short a time period as possible, not to exceed 10 years, with limited exceptions. This comment examines the basic but important question of whether the implementation of rebuilding plans under the 1996 amendments has in fact been associated with biomass recovery. Specifically, for each of the 44 stocks examined, this analysis compares the biomass trend before rebuilding plan implementation to the trend after rebuilding plan implementation using a linear trend-break model. The analysis demonstrates a statistically significant positive association between the implementation of rebuilding plans and standardized biomass in 19 of 44 stocks. None of the 44 stocks examined showed a statistically significant negative association. The analysis showed a strong temporal relationship between the implementation of the policy and rebounds in fish stocks.