Metadata for "Reductions in Coastal Acidification and Eutrophication Increases Coral Reef Daytime Net Ecosystem Production" by McClain et al. (2026)

Abstract: Wastewater discharge threatens coral reefs and their environmental and economic services. Wastewater injected at the Lahaina Wastewater Reclamation Facility in West Maui, Hawaiʻi reaches the Kahekili Beach Park coral reef ecosystem as nutrient-rich, acidified submarine groundwater discharge (SGD), which has led to macroalgal proliferation and coral loss. When the governor of Hawaiʻi enacted travel restrictions during the COVID-19 Pandemic, visitation to Maui decreased ~98% and wastewater injection (effluent volume and total nitrogen loading) decreased >50%. Here, we show that average pH increased and average nitrate concentrations ([NO3-]) decreased in both SGD (DpH=+0.32; Dn[NO3-] =-104.12 umol L-1) and reef water (DpH=+0.12; D[NO3-] =-0.33 umol L-1), and daytime net ecosystem production increased, indicating improved water quality and reef health during the Pandemic. This work provides evidence that reduced wastewater injection can reduce eutrophication and acidification in coastal waters and promote reef recovery within a relatively short (