Global warming has become a crucial issue that has a significant impact on marine ecosystems. Rising sea surface temperatures, resulting from increased greenhouse gas emissions, create a dark side in the delicate balance of marine life. One of the main impacts of global warming is ocean acidification. When carbon dioxide (CO2) dissolves in seawater, it forms carbonic acid which reduces the pH of the water. This process threatens calciferous organisms, such as corals, mollusks, and some types of plankton, which rely heavily on calcium carbonate to build their shells. The destruction of coral reefs, which are important habitats for many fish species, can reduce biodiversity and affect marine food chains. In addition to acidification, rising temperatures also cause species migration. Many fish and marine mammals are moving towards cooler areas. These changes can disrupt local ecosystems and affect the fishing industry. For example, species commonly found in tropical waters may not be able to adapt quickly to changes in various environmental factors. Along with that, global warming also causes an increase in the frequency and intensity of extreme weather events, such as storms and floods. This event not only destroys coastal habitats but also increases pollution due to land and chemical runoff from land into the sea. This impact worsens water quality and the health of marine ecosystems. Wider impacts are also seen in marine mammal populations such as whales and dolphins. They rely heavily on a balanced food chain and are affected by changes in temperature and prey availability. In the long term, these changes may lead to a decline in their population. Marine life affected by global warming also contributes to socio-economic problems. Communities who depend on fishing for their livelihoods are also feeling the impact. A lack of fish can harm the fishing industry and threaten food security for coastal communities. Conservation initiatives and protection of marine ecosystems need to be carried out to minimize the impact of global warming. Efforts such as reducing carbon emissions, protecting fish spawning grounds, and managing conservation areas can help create a more stable environment for marine ecosystems. Overall, global warming has a broad and serious impact on marine ecosystems. Considering the potential damage it causes, it is important for all parties to participate in maintaining the balance of marine life for the sake of the sustainability of the ecosystem and life on earth.