1. POND CARRYING CAPACITY
Concepts of Carrying capacity
Carrying capacity –
Must be careful of overloading

2. POND CARRYING CAPACITY
Concepts of Carrying capacity
Flow index:
Density Index:

3. POND CARRYING CAPACITY
Concepts: Factors
Density
Oxygen
Ammonia
Suspended solids

4. POND CARRYING CAPACITY
Data needed:
1. Physical parameters
Pond dimensions
Water use
Elevation above sea level 
Daily mean water temperature
Water inflow rates

5. POND CARRYING CAPACITY
2. Chemical parameters:
3. Water discharge permit specifications:
ammonia
Solids
phosphate

6. POND CARRYING CAPACITY
4. Feed quality
metabolizeable energy (kcal/kg)
Density Carrying Capacity (spatial requirements)
Wden = V*Di
Wden: Biomass (kg) per unit length (cm)
Di: Density index (kg/cm/m3)

7. POND CARRYING CAPACITY
Species kg/cm/m3
RBT
Steelhead
Chinook salmon
Coho salmon
Atlantic salmon

8. POND CARRYING CAPACITY
Density-based permissible biomass in the rearing unit
Bio = Wden*L
Bio: permissible biomass (kg)
Wden: biomass per unit body length (kg/cm)

9. POND CARRYING CAPACITY
Oxygen carrying capacity
  Single-pass system
W = F*L*I 
W: permissible biomass
F: flow index (see table)
L: length
I: water inflow
F value:

10. POND CARRYING CAPACITY
Multiple-pass system (w/o aeration)
Increases potential of fish health problems:
accumulation of waste products
Reduction in DO available
Dependent on fall ht, water temp, elev., etc.
Simple method - Life support index (from tables 14/15) should be reduced by 25% for first use and 30% for additional ponds

11. POND CARRYING CAPACITY
Multiple-pass system (with aeration)
Pumped air or pure O2
Treat as single-pass (be careful)
Risk of nitrogen supersaturation (acute >110%, chronic 102%)
Water quality

12. POND CARRYING CAPACITY
Circulating water systems
- Similar concepts, but lower water flows
- Generally need supplemental aeration
- May remove dependency of fish on DO

13. POND CARRYING CAPACITY
Ammonia carrying capacity
- Ammonia in unionized form (NH3) is harmful
- End-product of protein metabolism
Single-pass –
Multiple-pass – may exceed limit of 0.03
  - Accumulation with each reuse of water
- Must reduce feeding rate

14. POND CARRYING CAPACITY
Circulating systems
- Accumulation due to increases water retention time  -
- Recirculating systems
  -
  -

15. POND CARRYING CAPACITY
Suspended solids carrying capacity
– no reliable method to calculate
                Depends on:
1. Digestibility of feed (FCR)
2. Feeding techniques
If solids accumulate – fish health problems

16. POND CARRYING CAPACITY
Application of CC:
Stock pond for “take-out”
- number of fish (plus mortality) that are to be removed at a specified time
1. Establish date 2.
3. Calculate temp.-based daily growth rate (table 4) 4. 5.
6. Nat. mortality ( % per day)
7.  

17. PRODUCT DEFINITION Product potential/planning The 5 W’s: Who What
Where
When
Why