The effect of waste on the health of rivers and lagoons

Sewage and other forms of human-created waste can harm coral reefs. When it rains in Moorea, rainwater pushes large amounts of waste into the ocean, dramatically increasing the concentration of sewage, sediment, and nutrients in the lagoon (Fong, Gaynus, and Carpenter 2020). These sewage inputs can cause coral disease (Sutherland et al. 2010) and potentially contain harmful chemicals such as endocrine disruptors (Wear and Thurber 2015). Septic waste can also increase nitrogen concentrations in the water (Haßler et al. 2019), which can exacerbate coral death when combined with warm temperatures (Donovan et al. 2020) and lead to increases in harmful macroalgae (Adam et al. 2021). At UC Berkeley Gump Station, researchers are studying how different forms of waste are changing coral reef ecosystems and trying to find ways to improve coral resistance to stress.