Where does the oxygen we breathe come from? Many might say it comes from trees but the fact is that most of the atmosphere’s oxygen is produced by marine plants. According to the United States National Park Services, ocean plants provide about 70 to 80 percent of the oxygen on Earth, making them extremely important in climate change mitigation. Have you ever seen seagrasses? They have roots, stems, and leaves, and are the only flowering plants that grow entirely underwater. Approximately 72 different seagrass species exist on the planet. In 1999, Posidonia fields in Ibiza and Formentera were declared world heritage sites by UNESCO. There is a reason the seagrass has been named after the Greek God of the Seas. One hectare of Posidonia produces a hundred thousand liters of oxygen per day. This is five times more oxygen than a hectare produces in the Amazon rainforest. It also absorbs three times as much CO2 as the rainforest. This makes the Posidonia of essential importance against climate change. Understanding the importance of seagrass, many organizations have been taking action to restore these underwater meadows. Seagrass Ocean Rescue is a joint effort project between Project Seagrass, WWF and Swansea University, and aims to inspire future projects across the UK and the world. Phytoplankton are microscopic algae, an essential part of the marine food chain, living throughout the ocean’s surface waters. These tiny organisms have been producing at least 50% of Earth’s oxygen for hundreds of millions of years. Macroalgae such as kelp have gas-filled bladders that help them float toward the surface where they receive more sunlight for photosynthesis, absorbing CO2 and releasing oxygen. Many studies have shown the potential of seaweed farming to counter climate change as deforestation decimates rainforests and other crucial carbon sinks. Indonesia is the world’s second biggest seaweed exporter after China. Once processed, this valuable resource can be used in everything from food to cosmetics. Restorative aquaculture can help address some of the biggest challenges facing our seas, such as coastal pollution, habitat degradation, and climate impacts.