The fishier side of fish farms

I uncovered some pretty interesting information about fish farming while researching content for my most recent radio show. Much of this was not in circulation when I have previously researched the topic and thought it was worthy of sharing, in addition to my personal perspective, having travelled through Cambodia and Vietnam.


For the salmon-lovers in particular among us, the following may change the way you feel about it (or perhaps not), so for this I do apologise. However, I am a big believer that knowledge is power. So here goes!!


Up to 75 percent of fish species globally are currently being overfished or fished at their biological limits. The most pressing concern of this is the inability of individual fish species to replenish stock numbers through natural reproduction.


Enter fish and shellfish farming…


Otherwise referred to as aquaculture, this has become one of the fastest growing food production sectors in the world, providing almost 40 percent of the world’s current fish supply.


Top five farmed species in Australia

Tuna, pearl oysters, salmon, edible oysters and prawns are the current top five.


What makes a fish a good farmed species?

 • Happy to consume an artificial diet;

• have a good conversion rate (amount of food required in return for weight);

• Ability to live in small spaces;

• Non aggressive and

• Cause minimal environmental impacts if it was to escape into the wild.


Current concerns about fish farming include:

• Competition or predation with local species / fauna;

• Breeding with wild species, if to escape, with unforeseen changes in genetic make-up;

• Introduction of disease into surrounding wild populations;

• Degradation of marine environment, with the release of solids and nutrients inevidentably into the surrounding waterways.


Some fast fishy facts about Tasmanian farmed salmon

• Some 18 tonne of antibiotics were fed to farmed salmon 2006-08, including amoxicillin, which is routinely prescribed to humans;

• Tassal Brand, according to the ABC’s report, was responsible for using up to 16 tonne;

• Antibiotics are deemed necessary by the industry (although attempts are being made to reduce their use), given the high stocking rates of fish (some 50 000 fish per pen) and the potential spread of disease;

• A manufactured colourant is fed to salmon, to enhance their muddy grey flesh.


In Australia, our current demand for seafood, both wild and farmed varieties, is double that of our capacity (Seafood Importers Association of Australia). Therefore, we import a significant proportion of this – some 70 percent of all seafood consumed in Australia (Fisheries Research and Development Corporation, 2011). Our penchant for cheap seafood has seen the increased popularity of fish species such as basa and vannamei prawns, both from Vietnam.


As I discussed in my radio segment, I have travelled throughout Cambodia and Vietnam and it is hard to not notice the poor state of their waterways. This is not surprising, given the role of rivers in particular as lifeblood for food provision, personal hygiene and housing.  I have included a couple of pics from my travels in Cambodia and Vietnam, including the array of seafood available at local markets, the floating re-fueling stations attached to homes along the river, a crocodile farm and floating homes, to provide an insight into the role of rivers among these communities. 


I also commented during my radio show that although I have not necessarily seen the state of the waterways in which basa and vannamei species are farmed in Vietnam, I have consciously avoided imported seafood, since visiting these countries.


I discussed this with one of my sister’s over the weekend, as she too, has travelled throughout Vietnam. While in the north of the country, she actually saw some basa fish farms. She was shocked at the state of these farms, including the poor water quality and the inability of the fish to move, due to the overcrowding in the pens where they were kept. Interestingly, she was travelling with a friend, a restaurateur, who was selling basa at her restaurant at the time, due to its versatility and flavor. This species has since been removed from her menu, having seen the source first hand.


The Age newspaper reported last year that some fish consignments from Vietnam in 2011 and 2012 were found to contain a banned antibiotic in Australia.


Thankfully we have biosecurity controls in place in Australia. However, it is also important to note that it is unreasonable to expect every consignment of any imported food into Australia is monitored, as it simply is not economically viable to do such.


Next time you have a fish craving and are interested in picking a more appealing farmed species, from an environmental and/or health perspective, blue mussels, oysters, canned salmon (from Alaska and Canada, as it is usually wild-caught) and sardines are better alternatives currently.


I will follow up with a wild-caught fish species blog in the coming weeks!