Carls and Rice Oil-exposed Theragra chalcogramma embryos 



33 



12 



14 16 18 20 



Days after fertilization 



22 



Figure 2 



Timing of hatcli (% per day) of walleye pollock 

 when eggs were exposed to water-soluhle frac- 

 tions of Cook Inlet crude oil in the 0-21 day 

 treatment. 



1.7 



1 2 3 



Concentration (ppm) 



Figure 3 



Length of yolks (measured along the major body axis) and total larval 

 body lengths of walleye pollock plotted against concentrations of 

 water-soluble fraction of Cook Inlet oil to which eggs were exposed. 

 Vertical bars indicate 95% confidence interval. 



(Fig. 3). Mean body lengths at concentrations > 2.3 ppm 

 were significantly (P<0.05) smaller than controls. 



Abnormalities 



Embryos exposed to WSF developed abnormalities. 

 The earliest detected abnormality was the formation 

 of membranous vesicles about the time of blastopore 

 closure (days 6-9). In the 0-21 day treatment, embryos 

 developed 1-5 vesicles along the ventral surface, usual- 

 ly posterior near the blastopore (Fig. 4). These vesicles 

 were roughly spherical, apparently formed by a single 

 membrane. Interior fluid was indistinguishable from 

 surrounding fluid by observation of living specimens 

 with a microscope. Frequency of occurrence and quan- 

 tity of vesicles were correlated with concentration 

 (r = 0.82 and r=0.67, respectively), and vesicle size 

 tended to increase with concentration (Table 7). The 

 median concentration causing vesicle abnormalities 

 was 2.4 + 0.4 ppm. Vesicle formation was not observed 

 in the 1-21 day or 7-21 day treatments; embryos in 

 the 7-21 day treatment were beyond blastopore closure 

 when exposure began. 



Yolksac abnormalities were observed in exposed eggs 

 shortly before hatch and other abnormalities occurred 

 at and after hatch (Table 8). These abnormalities 

 included body curvatures; deformations of yolk, eye, 

 brain, jaw, intestine, and pericardial sac; absence of 

 lower jaw; fin erosion; yolksac bloating; and light 

 pigmentation. Yolksac bloating caused inverted 

 floating. Correlation of abnormalities with concen- 

 tration was strong (r = 0.9 [logit transformation]). Cor- 

 relation between abnormalities at hatch and vesicle 



