Sir

Your News Feature “Fishing for trouble” (Nature 431, 502–504; 2004) focuses on the potential environmental risks associated with tuna farming in coastal waters off North and Central America. In South Australia, on the other hand, tuna farming is being undertaken in what we believe is an ecologically sustainable manner.

Since 1991, the farming of southern bluefin tuna in South Australia has grown into the largest aquaculture industry (by value) in Australia. Production is currently at about 10,000 tonnes per annum, which is considerably greater than that being produced in Mexico or planned for the United States.

When the industry was first established in Australia, many potential environmental risks were identified. Subsequently, as the industry has developed, researchers have been able to confront some of these early speculative statements with real data and experience. An important part of this process has been the development of a system for identifying and quantifying risks, which has been delivered through projects within the Cooperative Research Centre for Sustainable Aquaculture of Finfish (Aquafin CRC), set up in 2002.

The Aquafin CRC aims to develop knowledge and technologies to underpin the sustainable growth of the finfish aquaculture industry in Australia and has funding of A$72 million (US$53 million) over seven years. This investment comes from the tuna and salmon industries, the Fisheries R&D Corporation, universities, and state and federal research agencies.

In contrast to the fears expressed in your News Feature about spreading disease, we have assessed the health of captive tuna and in all cases the risks ranged from negligible to low under current practices (see http://www.sardi.sa.gov.au/sbt). Other studies have investigated the impact of tuna farms on the composition of sediments and benthic infaunal communities below the sea-cages. These assessments provide just one measure of the environmental performance of the industry, so research programmes within the Aquafin CRC are now aimed at identifying the nature and quantities of farm wastes and understanding regional effects, such as the impact of farming operations on silver gulls and other key species, including sharks and pinnipeds.

Although we acknowledge that your News Feature provides information that will inform the debate about potential risks of tuna farming in North America, we would argue that tuna farming (and indeed any finfish aquaculture) can be practised in a sustainable manner. The real strength in the model adopted by the Aquafin CRC and its partners is that these issues, rather than fuelling public concern and criticism about sustainability, are openly and robustly confronted through research and resolved through the development of appropriate mitigation strategies.