278
13. Nile Perch Population Dynamics in Lake Victoria :
• Haplochromine conservation and Nile perch production may not be mutually exclusive goals. They may be cross-correlated objectives.
• The most productive and well balanced fishery may be the most difficult
to manage. Allowing anyone group to dominate the system is less challenging than keeping them all in balance.
• The ability of fishery managers to rapidly institute management decisions
will greatly affect their ability to meet conservation objectives.
• The socioeconomics of the fishery will affect the manager's ability to
meet objectives.
• A deep and broad understanding of the biology of the fish community is
essential. Our model includes a large number of unknowns that must be
elucidated before the model can be applied to real-world management
scenarios.
13.4. Conclusions
Biological models are limited abstractions of the natural world . Their utility
is in allowing the developers and users to contemplate component relations
and dynamics , to develop management objectives, and to play out various
scenarios that cannot be produced in the field. The Nile perch model of this
chapter is not likely to produce an absolute fishing intensity that would be
of use in the real world .
Developing the Nile perch model has prompted us to consider the practicalities of managing the fishery, and the potential for bottom-up and topdown effects upon the yield. It has also given us hope for the future of the
lake. The classic dichotomy between those who praise the Nile perch fishery, and those who cry for fish conservation in Lake Victoria, is moot and
rhetorical. It seems probable that the productivity of Nile perch greatly depends upon the conservation of their prey. But it appears that these objectives will require considerable action by the stakeholders. The system is
no longer pristine, and , if we are to reach our goals of feeding people, protecting diversity, and boosting the economy, the system requires our best
active, adaptive, co-management efforts.
At best , we have just begun the process of modeling the Lake Victoria
fish community. We believe there are years of work and several modeling
objectives ahead. The interactions between the artisanal and commercial
fishery with fishes other than Nile perch have been excluded from our
analysis, and are briefly touched upon in Schindler et al. (998). We hope
to bring those relations into future versions of the Lake Victoria model.
We've also completely avoided the topics of eutrophication, pollution,
and invasion of water hyacinth (a destructive plant introduced to the lake).
Feedback between the fish community and lake ecosystem is potentially of
huge importance. Each of these, we believe , needs sep arate treatment, but
each requires that we first focus on building a realistic model of the fish
community itself.
13. Nile Perch Population Dynamics in Lake Victoria :
• Haplochromine conservation and Nile perch production may not be mutually exclusive goals. They may be cross-correlated objectives.
• The most productive and well balanced fishery may be the most difficult
to manage. Allowing anyone group to dominate the system is less challenging than keeping them all in balance.
• The ability of fishery managers to rapidly institute management decisions
will greatly affect their ability to meet conservation objectives.
• The socioeconomics of the fishery will affect the manager's ability to
meet objectives.
• A deep and broad understanding of the biology of the fish community is
essential. Our model includes a large number of unknowns that must be
elucidated before the model can be applied to real-world management
scenarios.
13.4. Conclusions
Biological models are limited abstractions of the natural world . Their utility
is in allowing the developers and users to contemplate component relations
and dynamics , to develop management objectives, and to play out various
scenarios that cannot be produced in the field. The Nile perch model of this
chapter is not likely to produce an absolute fishing intensity that would be
of use in the real world .
Developing the Nile perch model has prompted us to consider the practicalities of managing the fishery, and the potential for bottom-up and topdown effects upon the yield. It has also given us hope for the future of the
lake. The classic dichotomy between those who praise the Nile perch fishery, and those who cry for fish conservation in Lake Victoria, is moot and
rhetorical. It seems probable that the productivity of Nile perch greatly depends upon the conservation of their prey. But it appears that these objectives will require considerable action by the stakeholders. The system is
no longer pristine, and , if we are to reach our goals of feeding people, protecting diversity, and boosting the economy, the system requires our best
active, adaptive, co-management efforts.
At best , we have just begun the process of modeling the Lake Victoria
fish community. We believe there are years of work and several modeling
objectives ahead. The interactions between the artisanal and commercial
fishery with fishes other than Nile perch have been excluded from our
analysis, and are briefly touched upon in Schindler et al. (998). We hope
to bring those relations into future versions of the Lake Victoria model.
We've also completely avoided the topics of eutrophication, pollution,
and invasion of water hyacinth (a destructive plant introduced to the lake).
Feedback between the fish community and lake ecosystem is potentially of
huge importance. Each of these, we believe , needs sep arate treatment, but
each requires that we first focus on building a realistic model of the fish
community itself.