Fish Ecology and Fisheries - Freshwater Ecology: Concepts and Environmental Applications - page 446

2. Physiological ecology of fishes is described successfully by the
energetic requirements of various processes, including osmoregulation,
O 2 requirements, responses to temperature, food quality and quantity,
and behavioral considerations.
3. Stock size, production, recruitment, and mortality are central aspects
of fish populations that are used in their management.
4. A variety of methods are used to capture fishes depending on their
size, the habitat being sampled, and reasons for obtaining data on the
fishes.
5. Many indices are used by managers to assess fish populations and
potential yields, including the relative stock density, which is the
percentage of fish in a specified length or age class relative to the total
number of fish estimated by population sampling.
6. A variety of regulations are used to control overexploitation of fish
populations. These regulations require consideration of human
dimensions but also generally involve a trade-off between high
numbers of fish and fewer large fish.
7. Aquaculture of fishes requires understanding of aquatic ecology of
fishes. Problems commonly encountered with aquaculture include
hypereutrophy of fish culture facilities and diseases.
QUESTIONS FOR THOUGHT
1. Do lakes and streams commonly contain unused niches that can be
exploited by fisheries managers wishing to improve sport fisheries?
2. Why are unregulated fisheries overexploited?
3. How might fisheries management for sport fisheries lower diversity of
native fish populations?
4. Do the indices used by fisheries managers, such as RSD, have any
ecological relevance?
5. Why are herbivorous and detritivorous fishes more often utilized for
food in Asia than in North America?
6. Why should genetic diversity of fish stocks be an important aspect of
aquaculture?