Which of the following is a limitation of using maximum sustainable yield (MSY) in fisheries management?

Which of the following is a limitation of using maximum sustainable yield (MSY) in fisheries management?

• A. It accounts for environmental variability
• B. It ignores age structure of the population
• C. It fully reflects ecosystem interactions
• D. It remains constant over time

Answer: (B)

MSY is built on a simple view of the stock that treats all individuals the same, regardless of age. In the real world, fish of different ages contribute differently to population growth and to future catches: younger fish may not yet reproduce, older fish often have higher fecundity and longer lifespans, and survival and growth rates change as individuals age. Because MSY doesn’t distinguish these age classes, it can misrepresent how many fish the population can sustainably support over time, especially for species with late maturity or strong age-related differences in reproduction. This gap in the model means the recommended sustainable catch may be too high or too low when age structure and its effects on recruitment are important.

MSY is built on a simple view of the stock that treats all individuals the same, regardless of age. In the real world, fish of different ages contribute differently to population growth and to future catches: younger fish may not yet reproduce, older fish often have higher fecundity and longer lifespans, and survival and growth rates change as individuals age. Because MSY doesn’t distinguish these age classes, it can misrepresent how many fish the population can sustainably support over time, especially for species with late maturity or strong age-related differences in reproduction. This gap in the model means the recommended sustainable catch may be too high or too low when age structure and its effects on recruitment are important.