Andrew G Challingsworth
Graduate Certificate of Aquaculture
B.Sc. Environmental Management/Biology
Diploma of Laboratory Technology/Biotechnology
Aquanet Place 1416-1422 RO
Malvern Rd Glen Iris 3146
www.aquanetplace.com
E-mail: aquanet-place@hotmail.com
Temperate subtropical Aquaculture Victoria Australia
Ectothermic; An animal that can not generate enough heat through metabolism to elevate
its body temperature above the ambient temperature; and whose body temperature is
dependent on heat flow to or from the environment.
Temperate subtropical Aquaculture was conducted at the Aquanet Place Research
Facility in Glen Iris Victoria. Where environmental temperature and pH, where studied in
280 liter half wine barrels which where an economical choice, whilst still holding
aesthetic presentation. The wine barrels can be displayed with fish and plants and would
make a worthwhile water feature to any available space that receives a moderate to good
amount of sunlight if not water logged area and placed in position preferably where it
can flourish.
A study of Animalia Aquaculture subjects, Genus/Species Carassius aurautus
the common comet goldfish the shubunkin and Tanichthys albonubes, White Cloud
Mountain Minnow.
Plantae
species Nymphae Hybrid, The Native water lily, The Banana lily, Elodea densa,
where researched and notes and observations were taken on the successful cultivation of
these organisms in the temperate subtropical climate of Victoria Australia.
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Elodea densa seen flowing at the Aquanet Place Research
Facility.
Temperate subtropical aquaculture can be conducted in any available space;
usually the requirements are for good economic representation, available space that can
be utilized that receives a moderate to good amount of sunlight. Sunlight starts
photosynthesis where autotrophsi , algae is produced and hence the food chain is
established! Phytoplankton; Herbivores zooplankton, rotifers, copepodia and daphnae
pulex. Once nutrients can be absorbed and added to the process of photosynthesis.
Often added nutrients, ’Organic’ seaweed liquid fertilizer works well to establish good
populations of Zooplankton. To aid the establishment of the food chain fertilizer can be
added at the small dosage of approximate rate of 7ml to 280l of water every month and a
half. It may have the tendency to make the waters green although this is the presence of
algae in the water, which will establish the food chain especially useful for production of
aquatic organism for the purpose of the aquaculture process. Although if one is
representing the water for visual display the addition of fertilizer is not required.
The most important aspect of our aquatic system is water quality. Measuring parameters
of temperature, potential hydrogen and dissolved oxygen are considered the most
important components of our system, especially on large scale operations or where the
ponds or pond represents moderate too large volumes of water. Although dissolved
oxygen may be better understood in terms of amount of oxygen required to maintain the
pond at its full equilibrium or its carrying capacity of our system. Increasing stocking
densities until resources diminish may need the replenishment of further resources
regularly. If we maintain a consistent supply of clean water to the system it should not be
observed as an over usage of resources.
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Nymphae hybrid ‘White bride’ grown and seen flowering late December
At the Aquanet Place Research facility.
Biosecurity
As seen in the picture below Azolla filicaloids was used as a floating aquatic plant and
was being studied at the facility as a (WANS) weed of national significance in Australia.
Azolla has exponential growth, increases the temperature of the biomass, reduces light
levels to under water flora and decreases pH levels and should not be kept as an
aquaculture representative as it maintains significant pest problems through out South
Eastern Australia.
Azolla filicaloids Photo Dr Maria Gibson Deakin University.
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The wine barrel positioned in the coolest point of the Aquanet Place research
facility was dominated by infrastructure shading the North West area of the facility. The
wine barrels received only 3-4 hours full sunlight. The temperature recorded on
November 16th 2009 was approximately 18 degrees Celsius.
The wine barrels where positioned in both the warmest environment and the coolest
environment at the research facility. Observations where made on environmental
temperature and Ph. and the amounts of sunlight received.
Exposure to an east to west direction in full sunlight was recorded as the warmest
environment the coolest point in the facility exposure to a North Westerly position that
only received 3-4 hours full sunlight as the sunsets.
The wine barrels was preconditioned with Elodea densa and Azolla filiculoides and left to
age the Azolla was removed and destroyed prior to introduction of eight 3” Carassius
auratus common comet goldfish which were added gradually over a period of two
months. The population of comets is thriving excellently stocking densities have been
accomplished at approximately 8. An Australian native water lily Nymphae hybrid
‘White bride’ was added to the wine barrel. Water changes where conducted every 18-21
days where the volume of water was replenished moderately about approximately one
third of the wine barrel was replenished as a result of this water cycle a stable ph was
maintained at approximately 6.4-6.6 which is ideal for the purpose of breeding temperate
subtropical fishes. A regular cycle of water was conducted which allowed for optimum
growing conditions.
Above the wine barrel positioned in the coolest point of the research
Facility accommodated Nymphae hybrid ‘White bride’.
The ability to with stand environmental temperature the Carassius auratus the common
comet goldfish thrived excellently, after the wine barrels had been fully flushed of water
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for a period of six months to remove any traces of wine acidification. The ability of the
Carassius auratus to survive the temperate subtropical conditions illustrates an
ectothermic environmental adaptation where body temperature corresponds to the
surrounding environment. Throughout fish evolution these fluctuations in environmental
parameters especially environmental temperature have and should hold constant which
seems to illustrate the long periods of species time in the family of fish. Which can
present a handful of endemic native fish that can be maintained in the temperate
subtropical conditions in Victoria, Australia. Which also supports a handful of
Ornamental fish species. In order to understand the principles of Aquaculture we need to
know environmental temperature and the highs and lows recorded throughout the season.
By acquiring this knowledge temperature observations and water quality parameters can
be implemented into seasons, for the purpose of fish species selection and culture and
aquatic plant culture.
Populations of goldfish where established in both warm and cold environments.
Although the only difference was the photoperiod that accommodated for a less than a 12 Celsius degree difference. The photoperiod accommodated was for approximately 8
hours a day in the warmer part of the facility.
Biosecurity
Pest populations of Carassius auratus’ Goldfish’ have been recorded in South Eastern
Australia and as a result of a wide range of conditions which can be tolerated by these
fish it has the potential to build up pest populations as should only be kept as an
aquaculture representatives.
As environmental temperatures in the warmest part of the facility, was only good enough
to sustain aquatic plant growth which must be completely shaded by shade cloth and a
piece of corrugated iron was placed over the wine barrels covering approximately 40% of
the total surface area of the wine barrels to create further shade from the direct and
harmful rays of the sun! ‘Because of the high phototrophic and high temperature levels
observed’. Excellent growth was seen in Ambulla, Nymphae Hybrid and Elodea densa
over the summer months! Late, December, January and February and March at the
facility.
As extreme temperatures where recorded from late December where the temperature
reached approximately 42 degrees Celsius, resulting in the wine barrels being depleted of
oxygen for the requirements of fish. The wine barrels are relatively shallow being 51cm
deep with a radius of approximately 36cm.
There are eight comet goldfish in the front wine barrel (NW) and as size increases so
does oxygen consumption and the rate of water exchange required. The eight fish are
feeding well approximately twice a day a ‘good pinch’ of pellets providing for excellent
results.
In conclusion we can see from this study that we need to know our environmental
temperatures both at the highest point and the lowest point. From here we can divide the
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year up into Aquaculture seasons October, November, December are ideal for breeding
temperate-subtropical fish, January, February, March are ideal seasons for the cultivation
of Aquatic Plants as the temperature is quite hot and can reach the 42 degree Celsius
mark and over and is not good for fish culture. Whilst April May June July August is a
good representation of dormancy in the Aquaculture system and can be allocated the time
period of grow-out where we feed and ad size to our fish. Also knowing the Ph. is of
importance and with frequent water changes we may be able to maintain a Ph. of 6.4-6.6
So the wonders of Aquaculture can now be further explored by the hobbyist and some
exceptional results obtained with fish growth and aquatic plant growth, also the
production of Zooplankton can be achieved to feed our rarer specimens and maintain
optimal somatic growth and gonad development in our rarer species of fish that we may
keep in door or in the home Aquaria.
Wine Barrels placed in the warmest area at the Aquanet Place Research Facility
where excellent for the cultivation of Aquatic Plants over the Summer Months
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An organism that makes its own food, thereby sustaining itself without eating other organisms or their
molecules. Plants, algae, and photosynthetic bacteria are autotrophs.
Reference: Biology Concepts & Connections Autotrophs; Campbell, Mitchell Reece.
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