ns - Not significantly different from controls (alpha >0.05). 



* - Statistically significantly different from controls (alpha < 0.05). 



Mean response significantly different from controls and 80% or less than control response. 



** 



Usually, when all of the stations at a site were determined to be significantly toxic, the site mean also 

 was different from the controls. When none of the stations was significantly different from controls, in 



35 



