[2026] PTE Academic Writing - Summarize written text

The world's oceans play a crucial role in climate regulation by absorbing approximately one-quarter of the carbon dioxide emitted by human activities. While this process helps mitigate atmospheric global warming, it leads to a chemical change known as ocean acidification, which significantly lowers the pH level of seawater. This shift in ocean chemistry is occurring at a rate unprecedented in the last 300 million years, posing a direct threat to marine biodiversity.

The primary victims of acidification are calcifying organisms, such as corals, oysters, and sea snails, which rely on calcium carbonate to build their protective shells and skeletons. As acidity increases, these essential structures become more difficult to produce and are even prone to dissolving, which can lead to the collapse of entire reef ecosystems. Because coral reefs provide habitat for twenty-five percent of all marine species, their decline triggers a cascading effect throughout the global food web, ultimately impacting human food security.

Addressing this crisis requires a twofold strategy focusing on the drastic reduction of global carbon emissions and the active restoration of seagrass meadows, which can naturally buffer acidity. While marine environments have shown some resilience in the past, the current speed of acidification may exceed the evolutionary capacity of many species to adapt. Therefore, international cooperation in marine conservation is essential to preserve the oceanic resources that billions of people depend on for their livelihoods.