The effect of the Green Revolution was primarily the increase in agricultural production. The Green Revolution involved the adoption of new agricultural technologies, including high-yield variety seeds, chemical fertilizers, and improved irrigation techniques, which significantly boosted crop yields in many parts of the world, particularly in developing countries.
The other options listed (shrinkage of the Aral Sea, increase of fish population in lakes, and decrease in pollution) are not directly associated with the Green Revolution's primary outcomes. In fact, some of these could be seen as negative consequences of increased agricultural practices and water use.