Adverse effects of crack / cocaine in the fertilization of the sea mussel Perna perna in different scenarios of ocean acidification Júlia Alves Luzzi, Lorena da Silva Souza, Camilo Dias Seabra Pereira

Abstract

 In response to the increasing atmospheric load of CO₂ and increasing marine uptake, oceans are undergoing physical and biogeochemical changes: surface and deep water warming, reduced underground oxygen, and a reduction in calcium carbonate saturation and pH levels. Changes in pH and seawater chemistry caused by increased CO₂ may modify the speciation of compounds due to largely dependent on physicochemical parameters (salinity, pH, redox potential). The hypothesis of this work is that oceanic acidification will cause greater toxicity of illicit drugs to non-target marine organisms due to the combined effects of crack-cocaine and low pH (from 8.0 to 6.5) on the reproduction of Perna perna marine mussel. The fertilization rate was conducted to evaluate the effects of crack cocaine concentrations (6.25; 12.5; 25; 50 and 100 mg / L) and their association with the variation of pH values. NOEC and LOEC were calculated from the results of the fertilization rate assay, with 25 mg/L of non-observed effect concentration at pH 7.5 and 6.5 and 50 mg/L of low observed effect concentration. No effects on crack-cocaine concentrations were observed when exposed to pH 8.3; 8.0 and 7.0. Our results show that P. perna gametes react to acidification when exposed to crack and cocaine concentration and pH reductions.