Our study reports the ability of Eurytemora affinis to indicate certain responses in 96 h when exposed to resuspended sediment from a polluted site (PS, Seine estuary, France), less polluted site (LPS, Canche estuary, France) and dissolved trace metals. Mortality from dissolved trace metal was highest (57.5 %) followed by PS (38.59 %) > LPS (24.04 %). The exposure to PS sediment resulted in significantly lower no. of early larval stage (nauplii < 2), sex-ratio (39.24 % of males) and higher ovigerous female (>10). Eurytemora affinis bioaccumulated high concentrations of copper (27.3 mg/kg), nickel (12.8 mg/kg), lead (21.8 mg/kg) and arsenic (13.7 mg/kg) from PS exposure with significantly lower bioaccumulation of metals from LPS. The bioconcentration factor (BCF) was highest from dissolved toxicity (>2000) followed by PS that showed significantly higher BCF for Nickel and Copper, compared to LPS. The responses of E. affinis to different matrices exemplify its role as a sentinel.