Aquatic Plants and their control

• Aquatic plants that are unwanted and undesirable are termed weeds.
• They adapt to grow and reproduce under aquatic conditions and are more harmful than beneficial for fish culture.
• Cause threat to the productive potential of the water body.

Positive role of aquatic plants

• Serve as a food of herbivorous and detritivorous fish.
• Form base of the food chain.
• As a source of oxygen in water and green manure or compost.
• AS food for human beings and fodder for livestock.
• Reduce the water velocity.
• Forms spawning substrates.

Negative role of aquatic plants

• Absorbs nutrients from pond water.
• Shading effects.
• Some aquatic plants release toxic substances.
• Off flavor. Eg:
• Hamper netting and angling operations.
• Offer shelter for fish parasites and predators.
• Interferes fish movements.
• Promote accumulation of deposits leading to siltation.
• Cause imbalance in dissolved oxygen concentration.