<human>:  What are the effects of overfishing on our ocean environment?
<bot>: The main effect of overfishing is a decrease in the number of fish in the ocean, which can lead to ecological imbalances in the ocean's food web. This can have a domino effect on the health of entire marine ecosystems. As fish populations decline, key predators may starve leading to dramatic decreases in other species and biodiversity. Additionally, overfishing has implications on the larger global climate, as fisheries have historically been a major source of carbon sequestration. Without them, our oceans could become a much greater source of greenhouse gases. Finally, overfishing can also lead to disturbances to ocean habitats such as coral reefs, which provide vital breeding grounds for many species of fish.