Observation

Majority of the candidates responded to this question.

In part (a), majority of the candidates could not list four ways of handling brood stock.

In part (b), majority of the candidates could not state six activities that are carried out in preparing an earthen pond before stocking.

In part (c), some candidates could state correctly how high temperature, high turbidity and low dissolved oxygen affect fish in a pond.

In part (d), majority of the candidates did not understand the difference between partial and total cropping.

The expected answers include:

(a) - Transport fish brood stock in the cool hours of the day
- Transport fish brood stock in suitable containers
- Quarantine the brood stock
- During inducement, calm brood stock with wet towel to prevent agitation
- Use sterilized / new syringe and needle
- Disinfect brood stock after stripping
- Proper feeding of brood stock
- Good water quality maintenance
- Good health maintenance
- Minimize stress

(b) - Completely drain water from pond
- Remove any fish and other organisms
- Remove debris / weed / silt accumulation
- Expose pond bottom to dry
- Check for leakage / cracks and repair
- Lime the pond
- Impound the pond
- Fertilize the pond

(c) (i) - Retards growth of fish
- Fish may stop feeding
- Could cause stress / death of fish
- Reduces rate of reproduction
- Oxygen demand of fish is higher / high respiration

(ii) - Clay particles clog gills of fish
- Increases acidity of the pond water
- Reduces light penetration hence food availability
- Causes low dissolved oxygen in pond
- Plankton turbidity uses dissolved oxygen from the pond leading to slow fish growth / reproduction / death / fish kill / stress

(iii) - causes fish to gasp for air at water surface
- retards growth / reproduction of fish
- causes reduced feeding of fish
- could lead to stress / death of fish

(d)  - Total / complete cropping – the pond is totally drained and appropriate gear used to harvest all fish
-  Partial cropping – the pond may be partially drained and appropriate gear used to harvest some of the fish