Definition

• A barometer measures atmospheric pressure.barometer image by Peter Baxter from Fotolia.com
  
  Barometric pressure is measured with a barometer, which tells the weight of the atmosphere per square inch. Areas of high pressure have calm and clear weather, and areas of low pressure have stormy or unstable weather.
  
  

Effects

• A barometer can help predict the location and activity of fish. Pressure fluctuations affect the air bladder in fish, which can alter their feeding patterns and behavior.
  
  

Behavior

• When pressure is rising, fish become slightly more active, but when pressure is high, fish tend to slow down, seek cover or head to deeper waters. The most active fishing occurs when pressure is falling. When pressure is slightly lower, many fish will leave cover for shallow water and become more aggressive.
  
  

Tactics

• Shallow-running lures work well when pressure falls.fishing lure image by Brett Bouwer from Fotolia.com
  
  In high pressure, target cover and deeper water. In rising pressure, try fishing brighter lures near cover, and fish at intermediate depths. When pressure falls, speed up your lures and fish near the surface and in shallow water.
  
  

Tips

• Check the weather before you go fishing. Carry a barometer with you and use it to keep track of pressure changes throughout the day to plan your fishing accordingly.