Studying the Effects of Catastrophic Events on Marine Biogeochemical and Ecological Processes

Extreme events caused by global change are increasingly affecting the ocean’s biogeochemical cycling and ecosystem functioning. However, our current understanding of how biogeochemical disruptions affect trophodynamics is limited because of the inherent challenges of studying food web responses to rapid habitat disturbances. In this project, we seized a unique opportunity to understand how specialists and generalists in a hydrothermal vent area respond and adapt to drastic biogeochemical disruptions. In 2016, the shallow hydrothermal vents at Kueishantao (KST) Island in East China Sea were hit by the two consecutive extreme events, an earthquake and a typhoon, causing a near vent shutdown for two years.

By using multiple geochemical tracers, we aim to conduct the first studies of temporal variability of the vent system, its responses to large geophysical and meteorological perturbations, and the effects on local biogeochemical and ecological processes. We also use stable isotope (d13C, d 15N, d 34S) as well as compound specific isotope ratios of individual amino acids to understand benthic food web shifts after extreme disturbances. The KST catastrophic events are analogous to man-made perturbations on coastal and deep-sea ecosystems, e.g., by industry discharges, mineral mining, or seabed dredging. Hence, quantifying their impact on marine ecosystems might shed light on the management of such anthropogenic perturbations.