2.2. Sediment collection
Sediment samples from three wetlands, Mandina,
KC-road and Willalooka, were used as the
source of zooplankton eggs bank. These water bodies
differ in salinity, and represent a salinity gradient.
Willalooka is fresh with a salinity range from 200
to 400 mg dm-3. Mandina and KC road wetlands
are saline with a salinity range from 13 000 to
38 000 mg dm-3) at the time of sampling. Sediment
containing zooplankton eggs was collected
from Willalooka wetlands in January 2010 while
samples from Mandina and KC-Road wetlands were
collected in March 2010. No inundation period was
identifi ed during sampling periods. Samples of sediments
15 cm3 were collected from random locations
throughout the wetlands. Three samples for each wetland
were obtained and then were mixed to get one
composited sample for each wetland. According to
Nielsen et al. (2008), composited samples maximise
the number of zooplankton propagules and minimise
the variability within each wetland. The sediment
was stored in plastic containers prior to transport
to laboratory. The sediment samples were air dried
on plastic trays for one week or until the sediment
samples appeared dry. Air dried sediment was then
gently crushed by hand to avoid damaging the egg
bank and mixed thoroughly before experimental
treatment (Nielsen et al. 2003a).