FISHERY EQUIPMENT & AERATION

• Most of the countries well stocked fisheries now rely on aeration.
• Aeration protects fisheries against low oxygen summer fish kill.
• Helps prevent ice which, if left, can result in a critical situation.
• Fish will not feed if there is insufficient oxygen and catch rates will plummet in Summer due to this common problem.

Increased aeration can transform a fishery by promoting extended feeding. During hot weather, dissolved oxygen levels may fall dramatically, resulting in fish becoming torpid. A feeding fish may have an oxygen requirement three times the level of a non-feeding fish. Aerators can maintain a more consistent level of dissolved oxygen which will also add long term health benefits for the fish stocks.
  
Paddle-wheel aerators resemble miniature versions of the paddle wheels normally associated with steamers on the River Mississippi. When operational, each partly-submerged wheel turns through a vertical plane, causing the water to become aerated as the blade chop into the water. Water raised by the paddle then falls back into the fishery, increasing the aeration effect. Paddle-wheel aerators can create a wake up to 50 meters behind them.
  
As a rule of thumb, paddle-wheel aerators are 50 per cent more efficient than either air-injection devices or air-diffusion methods. Surface agitators can be controlled with a time switch. As soon as they are switched on they work at 100 per cent efficiency. This is a major benefit as they can be used between dusk and dawn, the period of lowest oxygen concentrations, thereby preventing seasonal
de-oxygenation problems.

AERATION - PART 2