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Harvesting natural populations in a randomly fluctuating environment
Science (New York, N.Y.)
|July 29, 1977
Summary
Increased harvesting effort and yield slow animal population recovery and increase yield variability, especially near maximum sustained yield (MSY). These effects are more pronounced under constant quotas than constant effort harvesting strategies.
Area of Science:
- Ecology
- Fisheries Science
- Population Dynamics
Background:
- Harvesting animal populations for sustained yield is a common practice.
- Environmental disturbances can impact population recovery rates.
- Yield variability is a critical factor in fisheries management.
Purpose of the Study:
- To analyze the relationship between harvesting effort, yield, and population recovery.
- To investigate how yield variability changes as maximum sustained yield (MSY) is approached.
- To compare the effects of constant quotas versus constant effort harvesting strategies.
Main Methods:
- Theoretical analysis of population dynamics under harvesting.
- Examination of yield and variance in relation to harvesting effort.
- Comparison of harvesting strategies (constant quota vs. constant effort).
Main Results:
- Increased harvesting effort and yield prolong population recovery times after disturbances.
- The coefficient of variation of yield increases as the maximum sustained yield (MSY) point is approached.
- Overexploitation leads to lower average yields with higher variance, particularly under constant quotas.
Conclusions:
- Harvesting strategies significantly influence population resilience and yield stability.
- Approaching MSY increases yield unpredictability, posing risks to sustainable management.
- Findings are applicable to both ecological sustainability and economic revenue maximization.
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