The ocean economy is worth between $3 trillion and $6 trillion and offers vast opportunities for developing countries to build resilience. But marine resources are under threat from climate change, pollution and overfishing. About 11 million tonnes of plastic flow into the ocean each year. Globally, 34% of fish stocks have fallen to levels that are biologically unsustainable. At stake are the livelihoods of about 3 billion people – living mostly in coastal developing countries – who rely on the ocean for food and income. The Trade and Environment Review 2023 analyses the impacts of human activities and global crises on the ocean economy, which includes traditional sectors such as fishing and shipping, as well as emerging ones like offshore wind energy and marine biotechnology.