Disruption of the natural carbon cycle and the intensification of the greenhouse effect, driven by escalating atmospheric CO2, are the primary causes of the 'deadly trio' of impacts now profoundly affecting marine ecosystems: ocean warming, ocean acidification, and deoxygenation. Each of these stressors, individually, poses significant threats to marine life and ecosystems. However, their combined and interacting effects create a synergistic feedback loop, amplifying their detrimental consequences. The ocean's immense heat capacity means it has absorbed the vast majority of the excess heat trapped by greenhouse gases, leading to rising ocean temperatures. Simultaneously, the absorption of anthropogenic CO2 is altering the ocean's fundamental chemistry, making it more acidic. And as ocean waters warm, their ability to hold dissolved oxygen decreases, leading to deoxygenation. These interconnected changes are fundamentally altering the environment in which marine organisms have evolved, pushing many species and ecosystems beyond their adaptive limits