Abstract
Research
into the use of recirculating aquaculture systems (RAS) addresses the question
of how to achieve profitable production while consistently recycling water and
nutrients with minimal fresh water demand and waste production. The RAS
facilities require an adequate supply of fingerlings, and a facility for
fingerling production in conjunction with each RAS can prevent disease transfer
and ensure quality and continuous production. The time, space, and financial
investment can be eliminated by hatching (purchased disease free ova) and
rearing of fingerlings every 2-3 months. The present study evaluated (water
quality assessment, feed utilization, production cycle duration) a simple low
cost recirculating hatchery for salmonids as a safe and continuous source of
fingerlings for further rearing in RAS. The tested recirculating hatchery
enabled low cost efficient production on a small scale (at least 5 production
cycles per year, > 63 000 fingerlings per each cycle), low fresh water
demand (0.05 l.sec-1) with maintaining good rearing conditions, and
environmental and zoohygiene safety. Such simple facilities can support the
sustainability of inland aquaculture and strengthen the effort to deliver
quality products with minimal operational and environmental costs.
See my link for 70 fish farm systems on land, comprising more than 8,000 on land fish farms around the world. There is no need anymore for the excessive environmental damage caused by in-ocean fish farms: http://fishfarmnews.blogspot.ca/2012/01/key-document-34-mostly-on-land-closed.html.
Some more text from the study:
The
positive results obtained in a simple recirculating system call into question
the reported need to use additional technologies for hatcheries such as UV
treatment, ozone application, microsieve filtration, oxygenation, and aeration.
The RHS was fully functional without such treatments, thus is more efficient
with respect to initial investment as well as operating costs. Nevertheless,
potential use of additional technologies in enhance the RHS should be
discussed. Added aeration and oxygenation may increase the capacity of RHS, but
benefits such as increased production and increased biofiltration rate are cancelled
out by increased operating costs. Oxygen level and biofiltration efficacy were
found to be sufficient in the current study. -
See more at:
http://www.thefishsite.com/articles/2001/a-simple-and-effective-recirculating-hatchery-for-salmonids#sthash.sdp4Ved9.dpuf.
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