1. Characteristics of Coldwater Streams
Temperature – cold
Flow Variability – high but floods uncommon, close to groundwater
Substrate – relatively coarse
Canopy Cover / Light / Productivity – usually dark with low productivity
Water Chemistry – highly variable but usually soft-water
Other Fishes – few
Socio-Economic Value – high

4. Effect of Temperature on Growth

5. Summer Temperature Regime

6. Flow Variability Spring Fed Desert Ephemeral
Typical Mountain Perennial

7. Substrate Large Boulders are important “pool forming elements.”
Clean gravel sized substrates needed for spawning.

8. Canopy Cover and Light
Closed canopy, dark, cold, low productivity, energy derived from ALLOCHTHONOUS sources.
Open canopy, light, warmer, high productivity, energy derived from AUTOCHTHONOUS sources.

9. Canopy Cover and Light

10. Water Chemistry: strongly dependent on geology
Alk > 20 mg/L
Alk < 5 mg/L

11. Brook Trout “Hot Spots”
Small, Cold, Stable Flow, Clean Gravel Bed, Open-Canopy, Alkaline

12. Associated Species Brook Trout Mottled Sculpin Longnose Dace
Blacknose Dace
Northern Hognose Sucker
Warpaint Shiner
Fantail Darter

13. Northern Hognose Sucker
Associated Species
Small
Cold
Large
Cold
Cool
Warm
Brook Trout
Mottled Sculpin
Longnose Dace
Blacknose Dace
Northern Hognose Sucker
Fantail Darter
Warpaint Shiner

14. $40,000 Economic Value of Coldwater Fisheries in WV
per mile of trout stream per year
in economic benefit directly from angler expenditures
A2n
$15,000 per mile (national average)

15. Trout Population Dynamics
Population numbers tend to be “recruitment limited” (i.e., the number of adult trout is directly dependent on the success of the recruitment class) (what is this phenomenon called?).
Early spring flow regime has a strong influence on juvenile trout recruitment (high flows in spring result in poor y-o-y classes).

16. Trout Population Dynamics
Population biomass tends to be food limited.
Biomass tends to be highest in high light, highly alkaline streams.

17. Trout Population Dynamics
Trout Production is strongly seasonal. Spring and Early Summer are the times to grow. Animals are just holding on at other times.

18. Trout Population Dynamics
The spatial and temporal dynamics of early age classes are determined by the reproductive process.
Spawning, Larval Development, Juvenile Survivorship
The dynamics of adults is strongly influenced by immigration and emigration.
Larger adults move around in the watershed in response to seasonal changes in habitat quality (temperature and food) and life history requirements (spawning, feeding, refuge).

19. Juvenile and Small Adult Distributions are Stable, but not Large Adults

20. Trout Population Dynamics
Local Survivorship
Immigration
Study Sites

21. Large Adults Good for reproduction groundwater stable temp stable flow
bed-moving flows rare
safe from predators
Large Adults
Good for eating
high light
high productivity
lots of small fishes

22. Trout Population Dynamics
Mainstem
High Light Tribs
Low Light Tribs

23. What it Means
Drainage Networks are the Appropriate Management Units…Not Stream Reaches
Movement Barriers, Areas outside of Normal Reproductive Areas, Areas not considered “coldwater”, Fishing mortality at watershed scale.