The Southern Ocean is still a very big white spot on the knowledge map despite its importance for the world’s climate and as an important habitat for many marine organisms. Now, scientists from Australia and the European Union have joined forces to better understand the role of micronekton in the marine food web, holding the first project meeting of the new partnership in Hobart today. The Mesopelagic Southern Ocean Prey and Predators (MESOPP) project focuses on micronekton, which are small fishes, crustacean, squids and jellies that measure between 1 and 20cm.

The Southern Ocean are the water masses that surround Antarctica. Its northern boundary is the Antarctic Convergence and it actually covers the Atlantic, the Indian and the Pacific Ocean. Scientists consider it the most productive marine area in the world and it is the home of numerous animals like Orcas. Picture: Michael Wenger
The Southern Ocean are the water masses that surround Antarctica. Its northern boundary is the Antarctic Convergence and it actually covers the Atlantic, the Indian and the Pacific Ocean. Scientists consider it the most productive marine area in the world and it is the home of numerous animals like Orcas. Picture: Michael Wenger

Head of Southern Ocean Ecosystem Research at the Australian Antarctic Division, Dr Andrew Constable, said while micronekton form the diet of larger fish and predators their exact role in the marine ecosystem is not currently well understood. “The influence of micronekton on Antarctic krill and krill predators is a major gap in our knowledge of Southern Ocean ecosystems,” Dr Constable said. “Filling this gap is central to the Commission for the Conservation of Antarctic and Marine Living Resources (CCAMLR) being able to manage fisheries in the face of climate change.” MESOPP is looking at methods of integrating real world data into marine ecosystem models, including fisheries management models. “On the global scale, many large and exploited fish stocks with significant value for the blue economy feed on micronekton. “This new partnership will develop a system to integrate acoustic observations into food web models to estimate the biomass of micronekton across the Southern Ocean,” he said.

Antarctic silverfish (Pleurogramma antarcticum) are one of the key species in the Antarctic marine ecosystem. A number of penguin species, whales and seals feed on this up to 20 cm big fish. They are found in large schools in the shelf waters around Antarctica. Picture: Philippe Koubbi
Antarctic silverfish (Pleurogramma antarcticum) are one of the key species in the Antarctic marine ecosystem. A number of penguin species, whales and seals feed on this up to 20 cm big fish. They are found in large schools in the shelf waters around Antarctica. Picture: Philippe Koubbi

The MESOPP project will run until mid-2019, and the scientists hope the data collection and interpretation methods can be rolled out worldwide. The project has eight partners, including the Australian Antarctic Division and is led by Dr Patrick Lehodey from the Collecte Localisation Satellite in France. “Monitoring and reporting on micronekton will help to ensure the future sustainability of ecologically important species, as well as the conservation of their predators,” Dr Lehodey said. “Coordinated research between the European Union and Australia will allow shared scientific questions to be answered, particularly around the impacts of climate change on micronekton populations. Understanding this component of the marine ecosystem is central for the understanding of fish population dynamics.” CSIRO Senior Research Scientist, Dr Rudy Kloser, said micronekton are believed to be relatively abundant at depths between 200 and 1000 meters. “Gathering more knowledge about micronekton will enable marine ecosystem researchers to contribute to tackling large scale societal and economic challenges facing mankind over the next 10 years such as environment, food and bio-economy,” Dr Kloser said. 

This schematic drawing shows the complexity of the Antarctic food web. Even though krill is considered the key species, other groups like micronekton also play an important part. However, the degree of importance is yet to be determined by MESOPP. Credit: L. O’Keefe
This schematic drawing shows the complexity of the Antarctic food web. Even though krill is considered the key species, other groups like micronekton also play an important part. However, the degree of importance is yet to be determined by MESOPP. Credit: L. O’Keefe

The project has received $1.5m from the European Union through its Horizon 2020 science and innovation programme. The project is supported by the Collecte Localisation Satellite, CSIRO, Australian Antarctic Division, Antarctic Climate and Ecosystems Cooperative Research Centre, Institute for Marine and Antarctic Studies, British Antarctic Survey, Universite Pierre et Marie Curie, Institute of Marine Research (Norway) and University of St Andrews (UK).

Source: Australian Antarctic Division