Planning tools for environmentally sustainable tropical finfish cage culture in Indonesia and northern Australia

• University of New South Wales, Australia
• Research Institute for Coastal Aquaculture, Indonesia
• Marine Harvest, Australia
• Research Institute for Coastal Fisheries, Indonesia
• Hasanuddin University, Indonesia
• Central Research Institute for Aquaculture, Indonesia
• Gondol Research Institute for Mariculture, Indonesia
• Directorate General for Aquaculture, Indonesia
• Balai Budidaya Laut, Lampung, Indonesia

Fish farming using cages is a lucrative industry for otherwise poor coastal communities spread throughout the tropics of Asia. Marine finfish are in demand, particularly in the live fish markets of Hong Kong. Recent advances in farming, or culturing fish, have further enhanced the potential of caged fish farming in tropical waters.

The environmental effects of this activity are not year clear, other than in reported economic losses, which can reach more than 10 per cent of the value of production. There is concern about the environmental impacts of fish farming in cages.

Governmental land and coastal habitat managers do not have the necessary tools to address the key environmental issues. The lack of:
planning tools;
the ability to estimate capacity; and
cost effective impact assessment tools all limit environmental assessments. The risk of disease is another associated issue that is difficult to identify without the appropriate tools and framework to assist in planning.

This project aims to develop and apply planning tools to:
establish sustainable capacity thresholds for tropical finfish cage aquaculture;
establish a database detailing the environmental effects of finfish cages in Indonesian and Australian locations, by data mining and by direct measurement;
adapt/develop an appropriate model to determine carrying capacity of tropical marine coasts for fish cage culture;
develop a coastal aquaculture classification scheme for seacage and land-based aquaculture by combining and integrating the findings from this project and those of ACIAR Project Land capability assessment and classification for sustainable pond-based, aquaculture systems (FIS 2002/076); and
facilitate adoption of project outputs by Indonesian agencies.

Objective 1
Collect and synthesise data on farm locations, cultured species, yield, feeding regimes and food conversionratios from regional fish cage culture operations
Conduct measurements of ecosystem processes in the vicinity of fish cages in Aruwange and Labuange Bays, Barru, South Sulawesi, Pegametan Bay, Bali (Indonesia) and Marine Harvest farm, Bathurst Island (Australia)
Objective 2
Synthesise monitoring data (standing stocks) and process data (fluxes), incorporating information on other inputs into coastal zones used for aquaculture.
Adapt/develop ecological model appropriate to all sites, emphasising environmental assimilative capacity
Develop predictive guidelines for siting and best environmental practice of tropical marine fish cage culture, compatible for both northern Australian and Indonesian environments
Objective 3
Analyse data from joint socio-economic surveys to identify potential stakeholder conflicts arising from competing activities
Refine sea cage and land-based farmer level site selection criteria
Integrate and test mapping models and develop combined coastal aquaculture classification scheme
Apply integrated mapping criteria and protocols to produce sea and land-based aquaculture capability maps for selected areas in South Sulawesi
Objective 4
Plan and disseminate project outcomes via local and national advisory groups
Conduct training workshops in Indonesia
Disseminate research outputs and facilitate adoption throughout the Asia-Pacific region

This was the first time that ACIAR had established two projects to run parallel to address an emerging problem - the unfettered growth of aquaculture in the coastal zone of Indonesia. This project ran in parallel with FIS 2002/076 'Land capability assessment and classification for sustainable pond-based, aquaculture systems'. Combining sustainability assessments for both land- and sea-based aquaculture was intended to address a broad range of aquaculture planning issues across the coastal zone, and to recommend ways of avoiding conflicts in coastal zone usage.
This project produced a computer package entitled CADS_TOOL (Cage Aquaculture Decision Support Tool) that includes several different models for the calculation of carrying capacity. CADS_TOOL includes modules for site classification, site selection, four different modules for calculation of carrying capacity in a range of tropical environments, and an economic calculator. The program is available for download from the project website.
In addition, a workshop entitled 'Modelling carrying capacity for tropical finfish cage culture: towards a consensus view' was convened in conjunction with NACA (Network of Aquaculture Centres in Asia) and attended by participants from seven countries (Australia, China, India, Indonesia, Philippines, Thailand, and Vietnam) Participants adopted CADS_TOOL as the working model for the region.
Fieldwork took place at the two sites in Indonesia and the one site in tropical Australia in both the dry and the wet seasons. Unfortunately the Australian component was compromised when the farm was destroyed by bad weather in January 2006. Nevertheless, the project team found that the environmental footprint of all the studied sea-cage farms was highly localised.
Understanding the circulation of water near farms was found to be critical to understanding the physical dispersal of aquaculture wastes. In the microtidal environments of Indonesia wastes do not disperse far from the cage area, and chemical and biological transformation processes are more important in removing waste products. In macrotidal environments such as Bathurst Island, strong tidal currents remove and distribute waste products over a large area.
Products from the project have been successfully applied for aquaculture planning in both Indonesia and Australia.