exposure. To compare the relationship between time
and LC50 values to expectations for aquatic contaminants
(Fig. 4), Fig. 4 depicts the inverse of 24-h
P. promelas LC50 values, a potential surrogate for
bioavailable toxin(s) concentrations, versus time
(y ¼ 20.9061x þ 0.8359, R2 ¼ 0.8941).