This data table contains mortality data from 48-h controlled laboratory toxicity experiments with oyster larvae (Crassostrea gigas, Ostrea edulis) conducted at 18 °C and 24 °C. Larvae were exposed to nominal concentrations of copper (Cu), zinc (Zn), cadmium (Cd), and lead (Pb) in 24-well plates. Larval mortality was quantified as the number of dead and alive individuals per batch and replicate after 48 h.

The laboratory experiments were conducted at Plateforme expérimentale de Bouin IFREMER (Latitude: 46.9642, Longitude: -2.0444) from 2024-02-15T12:00:00Z to 2024-04-15T12:00:00Z. Broodstock of Ostrea edulis originated from the IFREMER La Tremblade station (Charente-Maritime, France), and broodstock of Crassostrea gigas from the IFREMER Argenton station (Brittany, France). The oysters were transferred to IFREMER Bouin, where they were held under controlled conditions in the facility prior to the experiments. Before the start of the experiments, broodstock were maintained at 8 °C from November 2023 until January/February 2024 to reset the reproductive cycle, followed by a gradual temperature increase and feeding (Skeletonema marinoi) to initiate conditioning.