Algal growth and the phosphorus cycle

Larger algae and microscopic phytoplankton foul the waters of the Peel-Harvey estuarine system, upsetting the fishery and polluting the beaches. These aquatic plants grow in response to phosphorus runoff from drainage, trapping phosphorus in the estuary and using it in their growth. When they die this phosphorus remains in the system to be recycled for further plant growth. Algal pollution in the estuary can be lessened by reducing the amount of phosphorus entering the system, increasing phosphorus losses to the ocean, or in some way blocking the trapping and recycling processes

A whole of systems approach to improved understanding of the environmental, economic and social values of a frontier marine oil and gas field: establishment, success factors and lessons learnt

The Great Australian Bight is one of Australia's most valuable marine ecosystems supporting globally significant populations of marine mammals, seabirds, and diverse and highly endemic benthic assemblages, as well as important fishing, aquaculture and ecotourism industries. The region is also considered a significant frontier for potential offshore petroleum resources and is actively being explored for oil and gas. The Great Australian Bight Research Program (GABRP) was an innovative, multi-year, $20 million, inter-disciplinary research collaboration involving BP Developments Australia (BP), CSIRO, the South Australian Research and Development Institute (SARDI), the University of Adelaide and Flinders University, that was developed in response to exploration activities in the region. The Program was the first large-scale, integrated study of the Great Australian Bight that involved more than 100 of Australia's leading scientists to generate a whole-of-system understanding of the region's environmental, economic and social values. We outline the processes to establish this strategic research collaboration, identify the key areas for success, and critically the lessons learned in order to guide future initiatives in regions open to exploration and development. As a result of the GABRP, there is now a legacy of data, information and models to inform future sustainable development in the Great Australian Bight; leading to the region now being one of the better understood deep water Australian marine systems.David C.Smith, Gavin A.Begg, Rod Lukatelich, Tim Anson, Ben Baghurst, Jane Ham, Steven Lapidge, Rob Lewis, Phillipa Ormandy, Rochelle Smith, Tim War

Fish predation regimes modify benthic diatom community structures: experimental evidence from an in situ mesocosm study

Publisher versionDiatoms are important primary producers in shallow water environments. Few studies have assessed the importance of biological interactions in structuring these communities. In the present study, benthic diatom community structure in relation to manipulated food webs was assessed using in situ mesocosms, whereby predator-free environments and environments comprising two different fish species were assessed. Zooplankton abundance, settled algal biomass and the diatom community were monitored over a 12‐day period across each of the three trophic scenarios. Differences among treatments over time were observed in zooplankton abundances, particularly copepods. Similarly, the benthic diatom community structure changed significantly over time across the three trophic treatments. However, no differences in total algal biomass were found among treatments. This was likely the result of non‐diatom phytoplankton contributions. We propose that the benthic diatom community structure within the mesocosms was influenced by trophic cascades and potentially through direct consumption by the fish. The study highlights that not only are organisms at the base of the food web affected by predators at the top of the food web, but that predator identity is potentially an important consideration for predator–prey interaction outcomes with consequences for multiple trophic levels