Plankton and Fish Size Spectra (led by Jason Everett)

ARC-DP 190102293 (Richardson et al. 2019-2021)

“Future fisheries under climate change: the missing role of zooplankton”

Fish are the main source of protein for 3 billion people, yet fish catches are declining. Current models of future fish biomass under climate change do not consider the complex role that zooplankton play in transferring energy from phytoplankton to fish. This research aims to make an innovative leap by developing the first global ecosystem model with a more realistic representation of zooplankton. By resolving this link between phytoplankton and fish, this project will vastly improve estimates of future global fisheries production and how it is likely to vary regionally. Such knowledge is vital for future food security in Australia and globally, and also to understand the role of zooplankton in carbon export in the ocean.

Fisheries provide US$100 billion annually, support livelihoods of 820 million people, and are culturally important, yet these socio-economic benefits are threatened by climate change. By developing the first global ecosystem model with more realistic zooplankton representation, this project will produce more robust estimates of future fish production under climate change in Australia and globally, and provide a better understanding of carbon cycling. Improved forecasts of fish will help meet key policy goals such as the UN Sustainable Development Goals for zero hunger, climate action and life below water. Better resolving ocean carbon export will inform whether targets to limit global warming to 1.5°C in the Paris Accord are achievable.

ARC-DP150102656 (Suthers et al. 2015-2018, completed)

“The missing link in our oceans: how zooplankton size spectra couple phytoplankton with fisheries”

The links between phytoplankton, zooplankton and fisheries are unknown.  The frequency distribution of zooplankton size provides an innovative approach to estimating ecosystem metabolism, carbon export and zooplankton production for fish. Analysis of an international database of zooplankton size distributions from tropical to polar environments will reveal the vital rates of pelagic ecosystems. The project will develop innovative mathematical models of rates and trophic status. These zooplankton rates will enable us for the first time to understand the link between remotely-sensed phytoplankton and fisheries, and will significantly improve ecosystem models and global assessments.

Zooplankton is the link between the aquatic pastures of the oceans and fisheries. A novel database of the size structure of zooplankton communities combined with phytoplankton estimates from satellites, will reveal critical ecosystem processes on a global scale such as the export of carbon and fisheries production. This will inform environmental assessments and ecosystem sustainability, from water quality problems to fisheries, including the viability of super-trawlers in Australian waters.