RICE ET AL EFFECTS OF COPPER OX NORTHERN ANCHOVY 

 -Air 



Premixed 

 seawater V' 

 and copper ^ > 



-Clear plastic cover 



Glass 



exposure 

 chamber 

 (500 ml) 



Water bath 



Figure l. — Diagram of the exposure chamber and flow-through 

 bioassay s>-stem used to erpwse northern andio\">' embrj-os and 

 larvae to copper 



of organisms from the chamber. The bottom outlet 

 from each exposure chamber was fitted with a 

 valve that could be closed to allow removal of the 

 chamber from the water bath. This was important 

 because during each observation the exposure 

 chambers were removed and illuminated from the 

 side. In this manner both live and dead organism^ 

 could be examined. Observations were made ever> 

 2-4 h during the copper exposures. During embryo 

 exposures, a gentle stream of bubbles was deliv- 

 ered to the bottom of the exposure chamber: dur- 

 ing larval exposures, no aeration was used. Over- 

 head illumination was provided by the fluorescent 

 lighting in the laboratory and followed the regular 

 ambient photoperiod. The number of embryos or 

 larvae exposed during each test is giN^en in Tables 1 

 and 2. 



Exposures continued until li all animals died, 

 or 2 1 in the case of the embryos, until hatching was 

 complete, or 3) in the case of the larvae, until the 



Table l. — Samples mortality data used to calculate LC50 values for northern anchovy embr>-os exposed to different copp>er 

 concentrations. Chi-square tests used the null h\-pothesis that the relationship berw-een dose and response followed the logit model. 



 Labie copper = 1.3 (SD = 0.1) ;ig Cu/I. 

 ' =95°o confidence Bmrt- 

 2"P«0.01: — P«0.001. 

 'Corrected for control mortaSty. 



Table 2. — Samples mortality data used to calculate LC50 values for northern anchoN-y larvae exposed to 

 different copper concentrations. Chi-square tests used the null hj-pothesis that the relationship between 

 dose and response followed the logit model. 



" labie copper = 1.3 (SD = 0.1) /ig Cu I. 

 ^Single measixemerrt 

 ^=95°-o confidence Umit 

 *'PsO-05:— P«0-001- 

 ^Corrected for control mortaSty. 



677 



