ENVIRONMENT: Aquaculture in the spotlight
By John Newbery | September 22, 2021
AQUACULTURE has been for twenty years a kind of pin-up industry for a whole series of interest groups desperate to save the world’s fish stocks while meeting the need to provide safe seafood for human consumption. In Australia, we have strict regulations in place to protect both the environment and competing resource users, regulations in some cases so demanding that the pioneers of fish farms went bankrupt with the costs of compliance before they had to. the chance to make a profit. The money is spent for the first two years in a new business. Industry insiders used to joke that only the second owners of an aquaculture business make money.
Tasmanian Atlantic salmon and, to a lesser extent, sea trout have been massive commercial successes and salmon have become the most consumed fish in Australia. But there are some significant issues with large-scale marine cage culture. One is siltation. As the Scots learned about 20 years ago, if you set up farms in poorly flushed waterways such as lochs, you get a build-up of toxic substances under the cages, with the risk of bad fish health or mass death. If the fish are not healthy, they are susceptible to attack from parasites such as sea lice.
Second, if you place your farms too close to where people live, noise and environmental impact will create bad relationships. Witness Richard Flanagan’s recent book “Toxic: The Rotting Underbelly of the Tasmanian Salmon Industry” and the ABC’s exhibit at 4 Corners Macquarie Harbor a few years ago.
Third, the natural environment is not part of a farmer’s infrastructure and nature should not bear the risk of the business. Thus, shooting at seals and seabirds, even with bean bags or blanks, is just as unacceptable as polluting a stream. And, in the case of salmon, having to catch more wild fish for food than the fish you are raising certainly cannot be sustainable in the long run.
But from a recreational fishing perspective, there are a lot of advantages if the fish culture is done well. Mitigate fishing pressure on the main commercially targeted species and allow stocks to rebuild. Develop rearing techniques to provide large numbers of juveniles for restocking in open and closed streams, both sweet and salty. Leverage R&D efforts to add species such as mangrove trevally, cobia and mahi mahi to the already mastered species of snapper, mulloway, barra and freshwater. And, beyond recreational fishing, when species that feed on non-fish foods from meat meal, legumes and other plant sources are cultivated in large numbers, bait fish and fish are cultivated in large numbers. wild food chains are less threatened. Farmed tilapia, carp, catfish, and our silver perch can help feed the world.