Tappan Zee Constructors are employing a bubble curtain beneath the surface of the Hudson River during construction of the bridge to protect the aquatic life from harmful sound waves generated by pile driving, according to The Journal News.
Air is pumped into aluminum rings placed around the steel tubes, which will hold up the Tappan Zee Bridge. As pile drivers strike the tubes, underwater noises are dampened by the layer of bubbles generated around the piles.
In addition to protecting fish from harmful sound waves, which can be deadly, the bubbles are said to discourage fish from swimming near the construcion area.
Tappan Zee Constructors was required by the state to reduce the noise underwater, the report says.
Source: The Journal News