Figure 1' Chinook salmon growth: habitats, processes and attributes

1
KS Growth (Nov 15-June 1)
KS Food

• Temperature
• Extreme high temperatures are negative

Insects/flies

• Access egress to migration corridor
• SAV canopy will block

Habitat edge channel
U-shaped channel tule edge
Riparian
Marsh plain

• Channels
• Especially small and numerous (minimum 30 cm deep
  at LLW)

Frequency and magnitude
Feeding offsite
Elevation
Figure 1. Chinook salmon growth habitats,
processes and attributes
2
Migratory birds (winter)
KS Survival
Disease
High temperatures increase disease
Size

• Avian predation
• Bigger fish die
• Water clarity
• Concentration of prey

Shading

• Fish predation
• Bigger fish survive

• Temperature
• Seasonal

• Distance from nest (spring)
• Further is better

• Deep channels
• gt30cm at LLW
• Predation
• SAV

• Higher marsh plain
• Marsh structure
• Channel shape

Flying/diving
Wading

• Channel edge or marsh plain
• 0.5m max

• Channels
• ?1m (3 ft) deep 2m (6 ft) wide

Non-breeding winter birds
Figure 2. Chinook salmon survival habitats,
processes and attributes
3
Mercury Sources
Mercury Methylation Processes
Existing
New

• Redox
• Governs methylation
• Sulfate (SO4) reduction

Atmospheric deposition
Geologic
Salinity
Temperature
Anoxic conditions

• Rhizosphere
• O2 around tule roots

• Reservoir effect
• Wetting/drying

Bioaccumulation

• Available organic matter (OM)
• Tules provide OM
• Higher peat has higher sulfate reduction

Demethylation Processes
??
Figure 3. Mercury sources and methylation
processes.
4

• Splittail Spawning
• Mar 15 May 1 (maybe earlier?)
• 5-10 years (wet years)

• Floodplain
• Wet years with extended inundation duration
  (50-150 days?)

• Low marsh plain
• Longer inundation (50-150 days)

• Channels
• Access egress
• Adults are large

• Food resources
• See salmon

Figure 4a. Splittail spawning habitats,
processes and attributes.
5

• Splittail Rearing
• Mar 15 May 1 (maybe earlier?)

• Low marsh plain
• Longer inundation (50-150 days)

• Floodplain
• Diurnally at high water

• Channels
• Access egress
• Adults are large

• Food resources
• See salmon

Figure 4b. Splittail rearing habitats, processes
and attributes.
6

• Delta Smelt Spawning
• Timing intense 7 day cycle
• Every year

• Temperature (10-20º C)
• Variable
• Very important

• Channels
• Small
• Close to breach
• On tules (hard substrate)
• Intense (7 days)
• Central, western southern Delta

Figure 5. Delta smelt spawning habitats,
processes and attributes.