Biologists monitor, tag sturgeon population in Hudson River

Biologists want to make sure the Tappan Zee Bridge construction project doesn't disturb the environment of endangered sturgeon in the Hudson River.
The New York State Thruway Authority has been tagging the fish as a way to monitor the population. Scientists have been tagging both the Atlantic sturgeon and the shortnose sturgeon since spring.
The goal of the tagging process is to determine if dredging or the sound from pile driving on the Hudson River is having any impact on the fish.
The New York State Department of Environmental Conservation is overseeing the research.
Sturgeon became endangered because of over-fishing, and in 1996 the state issued a moratorium.
Officials say there is no accurate measure of how many of the fish live in the Hudson, but the best estimate is tens of thousands.
Biologists say they are about halfway done with a plan to tag 120 sturgeon. They added that there is no evidence yet that work on the bridge is harming the population, which is rebounding.?