"550 experts from 86 countries released a 1600-page assessment on the state of the world's oceans. Human activity, including coastal development and pollution, is severely degrading marine ecosystems. 80% of Caribbean coral reefs have declined since the 1970s, and 90% of global reefs are at risk if warming exceeds 1.5°C. 52 million tonnes of plastic waste enter the ocean annually, impacting over 4,000 species. Only 27% of the seafloor has been mapped as of 2025, highlighting significant knowledge gaps."