Towards ‘āina momona: Tracking biological response to changes in sediment and nutrient flow through restoration of an urban estuary in He‘eia, O‘ahu

To live in harmony with their environment, ancient Hawaiians employed a sustainable management system using natural watershed boundaries from the mountain to the sea, called the ahupua‘a. The ahupua‘a system depended on resource management that maximized ecosystem services within flooded agroecosystems, fishponds, and the adjacent coral reefs. The He‘eia National Estuarine Research Reserve (He‘eia NERR), designated in 2017, is a living laboratory that blends traditional and contemporary management practices to restore the biological and cultural integrity of the He‘eia ahupua‘a on the windward coast of O‘ahu, Hawai‘i. For the past 20 years, non-profit organizations such as Kāko‘o ‘Ōiwi and Paepae O He‘eia within the He‘eia NERR have been engaging in restoration activities such as removing invasive plants and macroalgae, opening up new waterways and channels to restore lo‘i kalo (wetland taro agroecosystems), and rebuilding the walls and health of an 800-year-old coastal fishpond. We will present preliminary results of water quality monitoring throughout the varying landscapes within the urban watershed, from pristine mountain stream waters to coral reef ecosystems in a subtropical embayment. Measurements of macronutrient consumption and regeneration coupled with movements of sediment and water flow will be discussed. In addition, we will highlight research projects that are aimed at illustrating the return of ‘āina momona, or the rich abundance of the land, in the context of how to understand, adaptively manage, and promote stewardship at the ahupua‘a scale.