380 Monitoring Threatened Species and Ecological Communities
Creation of artificial spring habitat
Several attempts have been trialled or are underway to ‘create’ new habitat. In 2014,
a small dam fed by the homestead bore was dried (to remove gambusia), modified,
fenced with barrier fencing, and re-wetted to simulate spring conditions. The pond
was inoculated with wetland plants and six red-finned blue-eye. However, f low
into the dam could not be regulated and it soon became too deep for red-finned
blue-eye to persist. Simultaneously, a small-scale prototype artificial spring,
nicknamed ‘Bubbles’, was created on a soil platform and supplied with water via
the bore. Although ‘Bubbles’ has a surface area barely more than 3 m^2 , it has
sustained a pair of red-finned blue-eye since 2015, which bred in early 2016, and
many offspring persist as of November 2016. A much larger facility that replicates
natural springs is now under construction at Edgbaston, and will be capable of
supporting a much larger population.
Translocation of red-finned blue-eye to gambusia-free springs
Establishing new populations of red-finned blue-eye in gambusia-free springs
(either natural or artificial) remains the preferred option for increasing the number
of populations (captive breeding is concurrently underway and ex situ
translocation has been considered but rejected for now). The first translocation
trials occurred in 1994 (Wager 1994), with the populations persisting until 1998
before either gambusia infestation or spring drying extirpated the translocated
populations (Kerezsy and Fensham 2013).
Translocation attempts re-commenced in 2009. Groups of 20 fish sourced from
two naturally occurring populations (springs NW30 and NW90n) were moved to
springs where no fish of any species occurred, and the chance of the receiving
spring being colonised by gambusia was considered small due to location in the
landscape (Kerezsy and Fensham 2013). In 2009, red-finned blue-eye were
translocated to springs E501, E502, NW72 and E525 and, in 2011, three additional
groups were translocated to springs E524, E518 and E504 (Figs 30.2, 30.3). Further
translocated events to single springs occurred in September (NW80) and
December (E509) of 2012 (Fig. 30.3).
Monitoring to inform adaptive management
Management interventions are evaluated through interpretation of data from a
simple, long-term monitoring campaign (Fig. 30.3). At the core of the monitoring is
a very simple proposition: which fish species are present in each spring at the time
of monitoring? This is determined using direct observation (Wager 1994; Kerezsy
and Fensham 2013), which is possible at Edgbaston because the shallow, clear pools
allow unobstructed inspection of the water column and substrate. Although it is
possible to estimate the number of individuals present, the error inherent in these