Term
| Requirments of fish habitat |
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Definition
–Suitable water quality
–Migration routes
–Spawning grounds
–Feeding sites
–Resting sites
–Shelter from enemies and weather.
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Term
| The characteristics of the habitat plays a large role in determining |
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Definition
•numbers, sizes, and species of fishes that can be sustained.
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Term
| Goals of Stream Habitat Management |
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Definition
•Habitat protection:
–Preventing or reducing human generated changes that adversely affect habitat
•Habitat improvement:
―Restore degraded habitat or enhance existing habitat.
•To Protect
•To Restore
•To Improve
Stream habitat.
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Term
| •Despite human activities the following must be maintained: |
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Definition
–Natural habitats
–Coadapted populations
–Critical refugia
–Natural ecosystem processes.
Caution: It is necessary to have clear objectives for fish and fishing oriented purposes rather than install stream structures without a clear purpose.
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Term
| Stream Habitat Factors:•Riparian Influence: |
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Definition
–Riparian Plants:
•Filter sediment and nutrients
•Provide shade
•Stabilize stream banks
•Provide cover (wooden debris)
•Produce leaf litter energy inputs
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Term
| stream Habitat Factors:•Water quality: |
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Definition
Parameters:
•temperature, pH, turbidity, dissolved oxygen (D.O.), alkalinity, dissolved nutrients, presence or not of anthropogenic toxicans.
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–Maintain regional water quality standards for point source discharges of harmful substances.
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Reduce non-point source pollutants by encouraging less abusive human activities on the land |
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Term
| Stream Habitat Factors:•Energy Sources: |
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Definition
–Autochthonous: rooted aquatic plants, periphyton, fungi, bacteria, invertebrates...
–Allochthonous: leaves, needles, twigs, pollen…
–Streamflow, water quality and vegetation changes the amount of energy from autochthonous and allochthonous sources.
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Term
| Stream Habitat Factors:•Physical habitat structure: |
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Definition
–Channel
–Stream bed materials
–Water depth
–Current velocity
–Stream bank slope
–Cover
oThe requirements for the structure of the physical habitat vary among fish species and life history stages.
oWhen water quality or quantity are not limiting, cover is often positively correlated with fish density or biomass.
oManagement techniques that increase amount of cover in a stream can substantially increase fish abundance.
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Term
| Stream Habitat Factors:•Biotic interactions: |
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Definition
–Predation
–Competition
^Affect fishes habitat selection and survival^
oThe abundance of a given species that can be sustained in a stream may depend on the outcome of competition and predation.
oSpecies introductions can result in changes in the abundance of fishes even if habitat quality does not change.
oStream habitat projects: Analysis and Management
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Term
| –Composition of the dominant fish species and invertebrates depend on the |
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Definition
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