Toxic sludge oozing out of the bottom of a shrimp pond of a farm in Indonesia after the harvest. The liquid pictured here contained sulfuric acid resulting from oxidation of pyrite contained in the soil. Such contamination of a pond leads to stunted growth of the shrimp and increased mortality rates; the growth of the plankton is reduced drastically.[62] Liming can be applied to counteract to some extent the acidification of the water in ponds on acid sulfate soil,[63] such as mangrove soils.[64]