<human>:  How does climate change affect the world's ocean ecosystems?
<bot>: Climate change is having a major impact on the world's ocean ecosystems. Rising temperatures, changes in rainfall, as well as increased ocean acidification due to increased levels of carbon dioxide are all impacting marine life, resulting in shifting species distributions, changes in ecological processes, and increasing risks to ocean health. Warmer temperatures are leading to the bleaching of coral reefs, while higher acidification levels are believed to be contributing to a decrease in the diversity and abundance of commercial fish and shellfish. Additionally, changes in ocean circulation driven by warming are causing disruptions to migration patterns and slowing the distribution of nutrients – both of which can significantly reduce productivity for fisheries. Overall, climate change is making it harder for ocean ecosystems to remain resilient in the face of environmental change.