Overfishing has a significant impact on marine ecosystems. Overfishing depletes fish populations, which can disrupt the balance of the ecosystem. It can also cause changes in the food chain, as predators may have to find new sources of food. Additionally, overfishing can lead to the destruction of habitats, as fishing gear can damage coral reefs and other habitats. Finally, overfishing has been linked to changes in climate, as the reduction of fish populations can lead to an increase in carbon dioxide levels in the ocean.