Glenn-Marie Lange led the policy and economics work of the World Bank’s environment and natural resources global practice department and was program manager for the global partnership for wealth accounting and the valuation of ecosystem services before retiring in 2021. Lange and her colleague Narriman Jiddawi used their shared Pew fellowship to develop “national income accounts” for marine ecosystems in Zanzibar, a large East African coastal island belonging to Tanzania. National income accounts track the income of entire countries and are the most widely used source of information about national economies. Historically, national accounts have not included the enormous and irreplaceable value of the goods and services provided by marine ecosystems. As a result, countries tend to undervalue the contributions of marine ecosystems to sustainable economic welfare and, consequently, underinvest in marine conservation.
Lange and Jiddawi provided economic indicators and policy analyses to support the establishment of policies critical to marine conservation. They also developed a series of seminars and public workshops that describe their methodology, data, results, and policy analysis. This effort built support for marine conservation among decision-makers in government, nongovernmental organizations, and the public by sensitizing them to the true economic value of marine ecosystems and the economic benefits of marine conservation.