The Great Barrier Reef, one of the world's largest coral reef systems, covers 344,000 square kilometers. However, only about seven percent of this area is made up of coral reefs themselves, with the rest consisting of sandy ocean floors, seagrass meadows, and mangrove forests. Scientists working to restore coral reefs focus on tens of thousands of square kilometers rather than the entire protected area. Each year, during mass coral spawning events—typically over two to three nights during the end of Australian spring and summer—tens of millions of coral larvae are released by hundreds of species. These larvae are collected by divers before they spread out into the ocean. In an effort to restore damaged reefs, the Commonwealth Scientific and Industrial Research Organisation (CSIRO), in partnership with Southern Cross University, has developed "larval seedboxes." These transparent acrylic containers, filled with coral larvae, are placed on degraded seabed to allow the larvae to settle naturally. A single box can help restore more than two hectares of reef. Since 2018, researcher Peter Harrison has aimed to restore hundreds of square meters, with the long-term goal of reaching square kilometers. However, after seven years, this goal has not yet been achieved. The success of these reseeding efforts varies significantly depending on the location and type of coral. After one to two years, survival rates range from 13 to 91 percent. A 2025 study found that survival rates were as high as 32 percent at Moore Reef but as low as 13 percent in other areas. Another study on a specific coral species, Acropora digitifera, found that more than 60 percent of seedboxes still contained living coral after one year, with survival rates reaching 83 to 91 percent on sites exposed to strong wave action. The Great Barrier Reef has faced six major coral bleaching events since 2016, with the 2024 event marking the fifth since 2016 and the seventh since 1998. In 2024, 792 out of 1,080 surveyed reefs showed some level of bleaching, with nearly half experiencing high or extreme bleaching. The 2025 bleaching event was the second in a row, affecting 281 reefs across the central part of the reef and the Torres Strait. Despite these efforts, the scale of reseeding is much smaller compared to the vast areas impacted by a single bleaching event. Peter Harrison, who started one of the earliest larval reseeding projects, has cautioned against overly optimistic expectations. He notes that while the technique won't save the reef on its own, it can buy time for coral populations to adapt as global emissions are reduced and the climate stabilizes. The method allows scientists to focus on key areas like popular tourist sites, natural coral nurseries, and reefs that support surrounding ecosystems. It also enables the selection and multiplication of coral colonies that are more resistant to heat stress.