One of the 59 growout tanks at Ocean Wave Seafoods
PAUA IN OZ ��� Rewards
for tenacity and hard work
BY JOHN MOSIG
hybrid ���tiger��� variety. This cross occurs naturally in the wild
under certain conditions, when the breeding trigger of the
two species overlaps. Growers have found that the heterosis
gives an advantage on the farm, as well as producing an
attractive line for marketing purposes.
Water is pumped ashore through the tanks at the rate
of 250 litres per second when the farm is running at full
capacity. A 3m x 3m x 3m box covered by 50mm diamond
netting at the intake keeps puffer ���sh, jelly���sh and seaweed
out of the farm.
A bank of eight sand ���lters ensures that the nursery water
is free of particulate matter. They���re ���ushed daily, but when
the loadings of suspended organics is high, ���ushing is carried
out as often as every two hours.
Port Phillip Bay has a narrow opening to Bass Strait and
tidal exchange is limited. In combination with The Bay���s
shallow overall depth ��� it covers 195,000ha but only averages
13m in depth, this creates a wide temperature range for such
a large body of water. Water temperatures range from 23 to
24 degrees Celsius at the peak of summer, and drop to 10
degrees Celsius in the depth of winter.
Joel inspects the condition of
a sheet of newly settled juveniles
balone farming in Victoria has been through some
tough times. From its pioneering days in the 1980s to
the herpes outbreak of recent times, not to mention
the soaring Australian dollar that has reduced dollar value
returns to growers.
It���s been a steep learning curve. One of the pioneers was
Ocean Wave Seafoods Pty Ltd down at Lara Beach on the
entrance to the Geelong Arm of Victoria���s Port Phillip Bay.
Founded in 1998, their farm is now turning over 35 tonnes
a year from its simple yet effective, ���ow-through system.They
produce their own juveniles and cross black lip abalone with
the more reclusive green lip species, to produce the popular
A
14
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NZ AQUACULTURE
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MARCH/APRIL 2013
SPAWNING AND EARLY DEVELOPMENT
Spawning commences in October. The spawners are
conditioned in the hatchery. They���re held at 17 degrees
Celsius from July, by which time their gonads are fully
conditioned.They���re given a temperature shock of 20 degrees
Celsius, after which the temperature is dropped back to 17
degrees Celsius. At the same time the water is given an ozone
boost to induce ovulation and spawning.
The spawners are induced in the same water, but held
separately in 500 litre tanks. The eggs are fertilised manually.
They���re removed and mixed with the milt from a selected
green-lipped male. Although Joel points out that they
don���t have a breeding program as such, they have a family
combination they���re satis���ed with for the time being.
They spawn approximately ���ve million larvae each season.
