Could Acidified Environments Intensify Illicit Drug Effects on the Reproduction of Marine Mussels?

The increasing oceanic uptake is a direct response to the increasing atmospheric burden of CO₂. Oceans are experiencing both physical and biogeochemical changes. This increase in CO₂ hosts in oceans promotes changes in pH and seawater chemistry that can modify the speciation of compounds, largely due to dependent element speciation on physicochemical parameters (salinity, pH, and redox potential). So, ocean acidification can trigger enhanced toxicity of illicit drugs to non-target marine organisms due to the combined effects of crack cocaine and low pH (from 8.3 to 7.0 pH values) on the reproduction of the marine mussel Perna perna. Fertilization rate and embryo–larval development were used as endpoints to assess the effects of crack-cocaine concentrations (6.25, 12.5, 25, 50, and 100 mg L⁻¹) and its association with pH values variation (8.3, 8.0, 7.5, and 7.0). The IC₅₀ was calculated from the results of an embryo–larval assay in different methods of acidification (CO₂ and HCl), which evidenced that HCl treatment was more toxic than CO₂ treatment for the same drug concentrations. Results showed that the gametes of P. perna react to acidification when exposed to crack-cocaine concentration and pH reductions.