The unexposed control larvae at ambient salinity (32 psu) had the highest survival
rate, 4.2%, whereas, copper-exposed larvae showed a small decrease in survival rate
to 3.5% (p ¼ 0:54). Salinity of 25 psu affected the survival rate negatively by 48% to
2.2% (p ¼ 0; 007) and salinity reduced to 20 psu by 73% to 1.1 % (p ¼ 0:0001).
Synergistic effects were shown for the combination of copper and salinity reduced to
25 psu, where survival rate decreased to 1.2% compared to control (p ¼ 0:0001) (Fig.
1). The larval development observation did not display any significant differences
between treatments as the variation within each treatment was high (Fig. 2). Nevertheless,
a larger proportion of larvae were still free swimming after three days of
exposure irrespective of treatment compared to control, an increase ranging between
35–65%