2.1 INTRODUCTION
For many aquatic species, early life stages are the most vulnerable to environmental stressors, and therefore embryos and larvae are commonly used to determine the sensitivity of organisms to pollutants (Kobayashi 1980, Anderson et al. 1994,Fitzpatrick et al. 2008). Despite being short term (hours to days), these tests are presumed to be ecologically relevant because sublethal impacts on these critical life stages can persist after exposure, causing mortality or imparing reproduction later in life (Conroy et al. 1996, Raimondo & McKenney 2005, Tellis et al. 2014).