Ecosystem services provided by coastal and marine environments are increasingly recognised as of paramount importance for human wellbeing. To inform marine spatial planning and its implementation, as well as to manage conflicts between marine resource beneficiaries, we developed a comprehensive estimate of the economic value of the ecosystem services of Algoa Bay (AB) from 2000 to 2019. This is to assist in the development of effective policies concerning the management of marine resources. We quantified and assessed the monetary value by integrating 15 ecosystem services (ES) across five ecosystems using a range of economic valuation techniques and four scenarios. The scenarios differentiate between the local and global beneficiaries of the services and a conservative and alternative valuation estimate. These latter two valuation benefits are calculated using different sets of valuation estimates. We identified that onshore ecosystems, and recreation and tourism services, hold the most value. We estimated that the value grew from USD 613.4 million to USD 1695.9 million for local beneficiaries and from USD 1127.7 million to USD 2787.9 million for global beneficiaries between 2000 and 2019. The local values are roughly equivalent to the municipal budget, implying that the value of the ES is at least equal to that of the combined value of public service delivery. This highlights the significant economic contributions of marine and coastal ecosystems to local economies. This valuation provides a framework to make explicit the value that beneficiaries derive from marine ecosystems and provides a novel perspective on the valuation of ES in the coastal and marine ecosystems. This framework can be replicated elsewhere where there is a need to develop the ocean economy in an equitable and sustainable way.