Figure 1.
Location of the Hermit Hill spring complex within the Australian Great Artesian Basin (GAB).
The complex is comprised of seven previously identified spring groups (Bopeechee - BO, Dead Boy - DB, Hermit Hills - HS, Old Finniss - OF, Old Woman - OW, Sulphuric - SS and West Finniss - WF). Our five study springs are located in four of these springs groups: BO004 (Bopeechee), DB005 (Dead Boy), SS012 and SS024 (Sulphuric) and WF026 (West Finniss). The large flood channel, which demarcates the separate drainage basins (NE drainage – HS/OF/OW; SW drainage – BO/SS/DB and West Finniss) within the Hermit Hill complex is shown on the map in grey.
Figure 2.
Artesian springs of the West Finniss spring group.
Aerial photo depicting springs typical of the groups that comprise the Hermit Hill spring complex. The West Finniss group is comprised of both active (flowing ground water) and inactive (dry) springs that lie at ground level and do not form prominent raised mounds. The natural patchiness and inhospitable nature of the surrounding arid habitat of the artesian springs ecosystem is also clearly shown. Photo credit: Drew Tyre.
Table 1.
Temporal sample sizes, genetic diversity estimates and inbreeding coefficients.
Figure 3.
Survey data of the aquatic invertebrates endemic to our study springs.
The hydrobiid snail fauna are identified to species (Fonscochlea sp) and genus (Trochidrobia), the endemic crustaceans are identified by type (amphipods and isopods). The data indicates whether or not the species were detected as being either present or absent in the springs.
Table 2.
Mean genetic diversity and inbreeding coefficients (FIS) between pre and post flood snail populations.
Table 3.
Exact tests of microsatellite allele frequencies. P values across 5 loci.
Table 4.
Pairwise estimates of population subdivision among years within springs.
Figure 4.
Results of the temporal assignment tests.
Temporal assignment of individuals to K = 2 inferred clusters from the STRUCTURE analysis across all historical and contemporary snail samples within each of the five study springs. Grey indicates pre flood years (1988–1990) and white post flood years (1995, 2002–2006).
Figure 5.
Comparison of temporal effective population size estimates within each of the five study springs.
Values were estimated using four different statistical methods implemented in four different programs (see methods). White bars indicate values of Ne for pre flood (1988–1990) snail populations and grey bars indicate values of Ne for post flood (1995, 2002–2006) snail populations. Standard errors are indicated on each estimate.