Resilient rivers and connected marine systems: a review of mutual sustainability opportunities

Non-technical summary Rivers are crucial to the water cycle, linking the landscape to the sea. Human activities, including effluent discharge, water use and fisheries, have transformed the resilience of many rivers around the globe. Sustainable development goal (SDG) 14 prioritizes addressing many of the same issues in marine ecosystems. This review illustrates how rivers contribute directly and indirectly to SDG 14 outcomes, and also provides ways to potentially address them through a river to sea view on policy, management and research. Technical summary The United Nations initiated the SDGs to produce ‘a shared blueprint for peace and prosperity for people and the planet, now and into the future’. Established in 2015, progress of SDGs directed at the aquatic environment is slow despite an encroaching 2030 deadline. The modification of flow regimes combined with other anthropogenic pressures underpin ecological impacts across aquatic ecosystems. Current SDG 14 targets (life below water) do not incorporate the interrelationships of rivers and marine systems systematically, nor do they provide recommendations on how to improve existing management and policy in a comprehensive manner. Therefore, this review aims to illustrate the linkages between rivers and marine ecosystems concerning the SDG 14 targets and to illustrate land to sea-based strategies to reach sustainability goals. We provide an applied case study to show how opportunities can be explored. We review three major areas where mutual opportunities are present: (1) rivers contribute to marine and estuary ecosystem resilience (targets 14.1, 14.2, 14.3, 14.5); (2) resilient rivers are part of the global fisheries sustainability concerns (targets 14.4, 14.6, 14.7, 14.B) and (3) enhancing marine policy and research from a river and environmental flows perspective (targets 14.A, 14.C). Social media summary Restoring resilience to rivers and their environmental flows helps fulfil SDG 14.