Why must a pelican aim for a fish in a slightly different place than where the fish appears as it flies above the sky?

A pelican must aim for a fish slightly ahead of its actual position due to the time it takes for its beak to reach the water after it dives. Additionally, the refraction of light in water can distort the perceived location of the fish, making it appear at a different point than where it is. By adjusting its aim accordingly, the pelican increases its chances of successfully catching the fish.