This article first appeared in the the Coffs Coast Advocate, 1.10.11
Commercial fishing in Australia is a major rural industry, ranking fifth most valuable after beef, wool, wheat and dairy. While the wild fish catch is declining, the shortfall is being made up by a booming aquaculture industry, which, according to DAFF, has grown exponentially, at an average 12 per cent per annum since 1992-93. This mirrors the phenomenal rise of aquaculture globally, from a baseline of less than 1 million tonnes in the early 1950s, to nearly 52 million tonnes by 2006. Aquaculture now accounts for more than half the world’s supply of fish, and more than three-quarters of the world’s fresh fish, with China being the largest producer.
The total value of the aquaculture industry to Australia was approaching $900 million in 2008-9. Fish farming – salmon, tuna, oysters, prawns, abalone, barramundi, and many others – is big business. The industry in NSW is currently worth $54 million per year, with the bulk of that – $40 million – derived from oyster production, including businesses on the Bellinger and Nambucca Rivers. Across the state, aquaculture employs 1500 full and part-time jobs, according to DPI.
Many concerns have been raised about the social and environmental impacts of intensive fish farming, such as the discharge of waste water, the destruction of coastal ecosystems, and the excessive reliance on fish meal as the primary feed. In particular, the practices of sectors of the prawn farming industry in Asia and Latin America have attracted strong criticism, as well as being the focus of protest and resistance from many civil society groups.
In Chilika on the Bay of Bengal, for example, hundreds of square kilometres of coastline have been enclosed by a ‘prawn mafia’, who produce high value tiger prawns for export. The feeding and spawning areas for local fish species have been severely reduced, and waters polluted, threatening the livelihoods of 250,000 artesanal fisherfolk. According to some local fisherman, over ten years the average catch has dwindled by 90% or more. Many of the prawn farms are illegal, and the fisherman (see picture) are threatening to demolish them, even though the repercussions from the ‘prawn mafia’ could be violent.
In NSW, regulators are conscious of the environmental concerns, and so commercial aquaculture operations have to comply with the requirements of the State’s sustainable aquaculture policy, incorporated into SEPP 62. Amongst other things, this planning instrument restricts the sites on which aquaculture can be located, prohibits the location of aquaculture ponds on any permanent water courses, and requires that no farmed stock escape into natural water bodies.
Yet one of the biggest questions regarding the sustainability of aquaculture concerns the amount of fishmeal used to produce the farmed fish. While the commonly quoted figure is a feed conversion ratio of 1.6, i.e., it takes 1.6 kg of fish meal to produce 1 kg of fish, fish meal is dried and pelleted. Making 1.6 kg of dried fish meal actually takes about 8 kg of wet fish. This suggests that in much commercial aquaculture as it currently operates, there is a net loss of 7 kg of fish protein for every 1 kg produced.
The fish commonly used for fish meal are edible species, such as anchovies and herring. Given that global hunger is a major problem which humanity has not solved, the ethics of grinding up mountains of anchovies to produce high value farmed species such as salmon and tuna are questionable, to say the least.
These are the sorts of issues that Steve McGrane, who is studying aquaculture at the National Fishing Education Centre at Trenayr Campus of North Coast TAFE, Grafton, is thinking about. Steve, who is the coordinator of the Coffs Harbour community garden being built at Combine St, wants to produce fish, but he’s not planning to embark on commercial aquaculture. He’s experimenting with solar-powered aquaponics systems in his backyard; and in another column I’ll explain how he’s doing it.