Extreme climate events lower resilience of foundation seagrass at edge of biogeographical range

Concurrent extreme climatic events, such as marine heatwaves and floods, can drastically reduce the resilience of foundation seagrass species at their biogeographical range limits. A study on Amphibolis antarctica in Shark Bay revealed that a combination of elevated temperatures (Ningaloo Niña) and turbid floodwaters (Gascoyne floods) led to widespread defoliation due to a negative carbon balance. While leaf biomass showed partial recovery two years later, below-ground biomass—critical for the species' tolerance to disturbances—declined by an order of magnitude. This loss of resilience poses catastrophic risks to Shark Bay's ecosystem, where A. antarctica dominates 85% of seagrass cover (~3700 km²). The research highlights the amplified ecological impacts when multiple stressors coincide, particularly in systems near thermal tolerance limits.

Fraser, M. W., Kendrick, G. A., Statton, J., Hovey, R. K., Zavala‐Perez, A., & Walker, D. I. (2014). Extreme climate events lower resilience of foundation seagrass at edge of biogeographical range. Journal of Ecology, 102(6), 1528–1536. Portico. https://doi.org/10.1111/1365-2745.12300