Global change threatens marine ecosystems, affecting nutrient shifts and food supply through the marine food web. This proposal examines the impact on marine copepods, focusing on their fatty acid profiles as indicators of food quality under short- and long-term global change scenarios. The project will explore biological responses (fatty acid profiles, physiology, reproduction) to increased temperature and decreased pH through lab and field studies. It will investigate copepods, their food sources, and consumers, integrating food web ecology, stress ecology, and biochemical and molecular profiling for ecosystem functioning and sustainable aquaculture insights.