The present invention relates to a composition comprising an aquatic pesticide and a surface-reacted calcium carbonate, wherein the aquatic pesticide comprises rotenone, and the surface-reacted calcium carbonate is a reaction product of natural ground calcium carbonate or precipitated calcium carbonate with carbon dioxide and one or more H30+ ion donors, wherein the carbon dioxide is formed in situ by the H3O+ ion donor treatment and/or is supplied from an external source.
