Background
Human development is fragmenting and degrading many coastal habitats. Such changes to coastal habitats can affect the production of recreational and commercial fisheries, in part because many finfish and shellfish species are dependent on estuaries for their development. Therefore, many estuaries and coastal habitats like marshes actually serve as nursery grounds for commercially important fish and other marine organisms.
Scenario
The brown shrimp population in the northern Gulf of Mexico may be dramatically affected by changes in habitat types. The instability of their population would endanger the future of this species as an important commercial species. As a fisheries manager, it is your responsibility to design a management plan for the restoration of the brown shrimp stock. You will need to find ways to help keep this shrimp stock a stable population.
Use the population dynamics model below to determine what changes must be made to the parameters to increase the population size and maintain relative steady.
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Management Steps
- What changes did you make to the model parameters, and how did it affect the population size and dynamics?
- Management options fall into several broad categories, which we have listed below. Which option(s) would achieve the changes you made to the population parameters (r, K)?
- Direct intervention (for example: population culling, transplantation)
- Indirect intervention (for example: improved food supply, reduction of predators or competitors)
- Systemic intervention (for example: habitat restoration)
- What management actions specific to this scenario could be taken? Explain how these management steps would improve the status of the shrimp population.
- What are some possible negative consequences of your proposed actions to the larger ecosystem or human society?