Survival of adult female copepods and survival of eggs to 1-week-old larvae were assessed following exposure times of 0, 15, 30, 45, 60 and 90 min of UV-B radiation (450 μW cm−2). An increase in both adult and larval mortality occurred between the 45 min (12,150 J m−2 unweighted) and 60 min (16 200 J m−2 unweighted) treatment levels of radiation. At 90 min (24 300 J m−2 unweighted), all individuals died.