Crude oil exposure of early life stages of Atlantic haddock suggests threshold levels for developmental toxicity as low as 0.1?g total polyaromatic hydrocarbon (TPAH)/L

Atlantic haddock (Melanogrammus aeglefinus) embryos bind dispersed crude oil droplets to the eggshell and are consequently highly susceptible to toxicity from spilled oil. We established thresholds for developmental toxicity and identified any potential long-term or latent adverse effects that could impair the growth and survival of individuals. Embryos were exposed to oil for eight days (10, 80 and 300 mu g oil/L, equivalent to 0.1, 0.8 and 3.0 mu g TPAH/L). Acute and delayed mortality were observed at embryonic, larval, and juvenile stages with IC50 = 2.2, 0.39, and 0.27 mu g TPAH/L, respectively. Exposure to 0.1 mu g TPAH/L had no negative effect on growth or survival. However, yolk sac larvae showed significant reduction in the outgrowth (ballooning) of the cardiac ventricle in the absence of other extracardiac morphological defects. Due to this propensity for latent sublethal developmental toxicity, we recommend an effect threshold of 0.1 mu g TPAH/L for risk assessment models.

Automated summary

Atlantic haddock embryos are highly sensitive to toxicity from spilled oil due to their ability to bind dispersed crude oil droplets to the eggshell. Our study established developmental toxicity thresholds and identified potential long-term adverse effects. Embryos exposed to different oil concentrations exhibited acute and delayed mortality at different life stages, with an effect threshold of 0.1 μg TPAH/L recommended for risk assessment models due to latent sublethal developmental toxicity.