The primary driver behind changes in ocean circulation patterns is climate change, particularly through the alteration of temperature and salinity gradients. The increase in global temperatures affects the thermohaline circulation, which is crucial for nutrient distribution and marine ecosystem health. Melting polar ice and increased freshwater inputs can disrupt these patterns, leading to changes in fish migration, weather patterns, and overall ocean circulation. Understanding these changes is vital for managing marine ecosystems and developing effective strategies to mitigate adverse ecological impacts.