E-Mail DURHAM, N.C. - Most of the revenues extracted from use of the world's oceans is concentrated among 100 transnational corporations, which have been identified for the first time by researchers at Duke University and the Stockholm Resilience Centre at Stockholm University. Dubbed the "Ocean 100," these "ocean economy" companies collectively generated $1.1 trillion in revenues in 2018, according to research published Wednesday in the journal Science Advances. If the group were a country, it would have the world's 16th-largest economy, roughly equivalent to the gross domestic product (GDP) of Mexico. "Now that we know who some of the biggest beneficiaries from the ocean economy are, this can help improve transparency relating to sustainability and ocean stewardship," said lead author John Virdin, director of the Ocean and Coastal Policy Program at Duke's Nicholas Institute for Environmental Policy Solutions. "The small number of companies that dominate these industries likely reflects high barriers to entry in the ocean economy. A lot of expertise and capital are needed to operate in the sea, both for the established industries and emerging one such as deep-sea mining and marine biotechnology."