A project undertaken at Griffith University, and supervised by Natalie Jones
The goal of this project is to identify the dormant animals that form the foundation of floodplain food webs in Australia. Freshwater zooplankton are microcrustaceans that play an important ecological role. They eat algae and are food for juvenile fish and other animals. Beyond that, they have a remarkable life history adaptation that allows them to transform into an environmentally resistant dormant state. They are not the only organisms that can do this; in fact, many organisms use dormancy as a survival strategy. Bears hibernate in winter, for example, and plants often produce seeds in summer that lie dormant in soil over the cold months before sprouting in spring. In these examples, the organisms use dormancy to avoid a season where conditions are hard.
Figure 1.
Other organisms, like freshwater zooplankton, can remain inactive for decades, centuries, or even thousands of years. This enables them to escape in time and simply wait for the return of favourable conditions. For freshwater zooplankton, good conditions are characterised by the return of water to the floodplain where they live.
Figure 2.
Flooding events are becoming increasingly unpredictable across the globe and in Australia in particular. This is why it is more important than ever to understand how dormancy, a strategy that evolves in unpredictable environments, influences the resilience of these vulnerable ecosystems. To address this, we are collecting sediment from the Narran Lakes floodplain region in northern New South Wales. This wetland complex contains river channels and lakes across a large floodplain. We are sequencing DNA from the sediment and conducting hatching experiments to explore the diversity of these communities to understand how they respond to flooding events.
Figure 3.