Speakers: Drs. Leah Bremer, Brytne Okuhata, Angela Richards Donà, and Celia Smith
Abstract:
Groundwater dependent ecosystems (GDEs) are increasingly recognized as a critical component of sustainable groundwater management worldwide. Despite this importance, data linking drivers of hydrologic change to GDEs are scarce. This study focuses on Keauhou, Hawaiʻi Island, where GDEs are culturally and ecologically important, and where there are increasing concerns about the impacts of climate change, urban development, and watershed management on the quality and quantity of submarine groundwater discharge (SGD) that these systems depend on. We use a linked land-sea modeling framework to assess how these drivers influence the quantity and quality of SGD and nearshore GDE waters, and how this may affect the habitat suitability of the native limu pālahalaha (Ulva lactuca) and vulnerability of this coast to the invasive macroalgae, Hypnea musciformis. Results suggest that a dry future climate (under RCP 8.5 mid century), increased groundwater pumping, and degradation of native forest all have the potential to reduce SGD, which translates to decreased growth of limu pālahalaha coupled with increased vulnerability to Hypnea. Results point to the importance of policies and programs to support watershed protection and reduce consumptive water use as achievable steps to protect GDEs and their associated native species.
May 6, 2022 Transcript (download here)
May 6, 2022 Recording (click here)