Aquaculture has become one of the main avenues to manage the increasing demand for ocean fish supplies; however, recent trends in the industry have resulted in much debate as to the sustainability of this approach. In particular, it is argued that farming fish is simply an additional drain on already diminishing populations of marine life.
by Emma Volrath
1. 97% of Sardines caught in Australia - the majority deemed unfit for human consumption go to feeding the Southern blue fin tuna ranched in Port Lincoln
2. More research needed on the population of feeder fish such as sardines and anchovies - are they a never ending resource? Will there come a point when they too may be under threat? What is the impact on the other species left in the wild that feed on these smaller fish?
3. The Australian based Clean Seas company has suspended it's Southern Bluefin breeding program due to disappointing results and investments required that are beyond the company.
4. 'Time' - included Clean Seas Tuna company's breeding tank in their "top 50 best inventions 2009"
5. In 2009 Clean Seas Tuna stocks were trading at trading at two Australian Dollars - Today they are trading at 2 Australian Cents
6. To date there has been very limited success with raising many species of ocean fish from egg to market size
7. The Southern Blue Fin tuna industry in Port Lincoln is worth $250 million a year
8. 'Cone Bay Barramundi' has been declared a s a sustainable seafood producer by the ACF the food the barramundi are raised on is less than 5% fish meal
9. Feed manufacturers are putting a great deal of R&D into replacing fish meal with other proteins and oils. The only problem with this is that complex omega oils beneficial to humans are only found in wild caught feeder fish that get it from the marine algae that they feed on
10. Cone Bay Barramundi is raised from fingerlings and is at market weight of around 3kg within two years
11. current production of Cone bay barramundi is at 1000 tonnes per year, but has been granted approval by ECP to raise production to 2000 tonnes after meeting the strict guidlines
12. 95% of Southern Bluefin Tuna fished are caught as juveniles on their migratory route
13. The technique pioneered in Port Lincoln happened in the early 1990s around the same time as the exploitation of wild fish stocks reached its peak
14. On Jan 5th Japanese sushi chain 'Kiyomura' paid $1.76 million for the honour of buying the first Southern Bluefin Tuna offered at the opening of the markets
15. In 1989 the Australian quotas for Southern Bluefin Tuna were slashed from 12000 tonnes to 5000 tonnes just before the practice of capturing the juvenile tuna and 'rearing' them was introduced by the Port Lincoln fishermen
16. From the time of capture to shipping to the Tokyo markets as fresh or snap frozen fish takes 6 - 7 months for the juvenile Southern Bluefin Tuna
17. A few years back Tony Santic sold 337 Tonnes of his allocation for $72 million
18. The Southern Bluefin Tuna is not being raised as a solution to the growing demand for fish - rather it is being exported as a highly desirable commodity to a market that will pay top dollar for it
19. The capture and herding of the juvenile Tuna takes between 4 & 5 days using spotter plans to identify the schools of fish and from there they are guided towards the nets on the boats, will then drag them gently into the floating pontoons where they are kept whilst being fattened up
20. National Aquaculture Council set growth targets to increase from current production of 60,000 tonnes to 100,000 by 2015
21. The Salmonid industry (Atlantic Salmon, Ocean Trout, etc) has predicted stand alone growth of 50,000 by 2015
22. 95% of All farmed Salmonids are produced in Tasmania
23. Tassel Group the largest producer of Atlantic Salmon yesterday announced a 23% increase in net profits of $41.06 million dollars
24. Ocean fish - for example Southern Blue fin tuna need 10-12kg of wild caught feed to covert into 1kg of tuna - Atlantic Salmon converts at a much more efficient rate of 3kg of wild caught feed to 1kg of Salmon
25. Blue fin tuna are "ranched" in Port Lincoln SA - the juvenile fish are being taken from a population that is listed as critically endangered.
26. How many Juveniles are left each year to reach maturity and breed to replace mature breeding fish as they are caught or die naturally
27. Studies have been conducted recently to determine the effects of offshore sea cages compared to near shore caging of juvenile Southern Blue fin tuna, whilst more expensive to cage the tuna offshore the study showed that the fish caged offshore had a much lower rate of parasite infestation, lower mortality and reached market weight in a shorter time frame than those caged near shore
28. The Australian Marine Conservation Society (AMCS) has placed a 'red list' rating on all sea cage raised Southern Blue fin tuna due to concerns around the need for wild caught feed, potential spread of disease, parasites and waste problems
29. In Australia 20 Million tons of "industrial fish" - small schooling fish such as Anchovies, Sardines and Pilchard are needed for the Aqua culture industry each year.
30. Concerns over Atlantic Salmon have been raised around transfer of parasites to other species and also the escape of farmed fish into the wild - although it is thought that they cannot survive in the wild?
31. Whilst it is thought that Atlantic Salmon cannot survive in the wild in Australia what studies have been done to prove this and also if they can survive in the wild what impact will they have on native and migratory species?
32. Southern Blue fin Tuna fetches around $70 per kilo whilst Atlantic Salmon fetches $26 and Cone Bay Barramundi for around $30 kg
33. It has been argued that the "trash fish" in the years before aqua culture would have been ground up and turned into feed pellets for chickens and pigs, so the fact that they are now fed to species such as Southern Blue Fin tuna means that we are simply utilising something that was there already and would otherwise have gone to waste. Chickens and pigs however have never needed to eat wild caught fish as part of their diet
34. Since 1970 Aqua cultures contribution to the supply of global seafood has increased from 3.9% to 47%
35. Aqua culture is the fastest growing food production sector in the world and the fastest growing primary industry in Australia with annual growth at 6%
36. The Environmental Footprint of feeding wild caught fish to highly prized species with poor feed conversion rates such as the Southern Bluefin tuna raised in sea cages is unknown
