pl23_fizh1734.jpg
![Biological research - tagged stones fizh1734.jpg Biological research - tagged stones](https://s3.amazonaws.com/s3-east-testmedia-noaa.woc.noaa.gov/dam/Photos/legacy/pl23_fizh1734.jpg)
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https://www.noaa.gov/media/digital-library-photo/pl23fizh1734jpgDescription
Biological research - tagged stones. Tagged stones were regularly examined todetermine the number of aquatic insects important as fish food. Records ofinsect abundance before and after the stream watershed has been sprayed withDDT enabled BCF biologists to evaluate the effect of pesticides on fishpopulations.
Credit
NOAA Central Library Historical Fisheries Collection
Display Date
1962 circa
Location
Alaska, Prince of Wales Island
Collection
Historic Fisheries