Concerning aquaculture, the changing climate causes stress factors for fish that influence their health and growth. Such stress can be mitigated through the application of nutritional interventions, which often include targeted dietary modifications for enhancing the resilience and long-term health condition of fish. Fish tolerance to various stressors is scored higher with functional feed additives, viz. nutraceuticals also improve fish feed conversion efficiency. These interventions allow fish to better handle the adverse impacts of climate change, ultimately enhancing welfare. Species-specific strategies are essential for adaptation and mitigation, which include environmentally sound feeds and precision nutrition. In this review, we consider the physiological effects of the impact of changing the climate on fish and its potential to be countered by particular nutrients and bioactive compounds. These ingredients might improve the immune system, metabolic regulation or stress resilience of fish when participating in their feed.