| 摘要 |
A predator defence system to deter an animal such as an otter, mink or beaver, from fish stock in the form of waterproof sonic and/or visible light transmitter E, the signal(s) produces a disturbance that will deter the animal from hunting and catching the fish stock. The waterproof sonic or light transmitter made be located under or floating (Fig 2) on the water A. Preferably the visible light and/or sonic signal(s) are automatically activated by a passive infrared detector that may be positioned above or below water that turns on the signal(s) when the body heat of an otter, mink or beaver is detected above or in the water. A grid of waterproof sonic or light transmitters can be placed under and/or floating on the water to protect a larger expanse of water. |
