Fig 1.
Map of fish sampling locations.
The map shows the lungfish and mussel sampling locations as well as major impoundments.
Fig 2.
A) Dried and flat scale showing primordium as the black dot. B) Scale after removal of upper squamulae and lower elasmodin surfaces, cleaned area becomes transparent. C) Scale cut to prepare for sampling. D) F14C samples showing the first 11 samples removed in 1mm increments, then 2mm increments to the primordium.
Fig 3.
Radiocarbon results (F14C) from selected fish.
A) Representative F14C from fish smaller than 800mm in length vs. distance from the outer edge of the scale B) Representative F14C from selected fish between 800-1000mm in length vs. distance from the outer edge of the scale. C) Representative F14C from fish >1000mm in length vs. distance from the outer edge of the scale. The radiocarbon bomb pulse is evident in the data from fish >1000mm in length.
Table 1.
Capture/Re-capture fish data in this study.
Fig 4.
F14C reference curve to age Australian lungfish.
Curve generated using the pre-bomb (pre-1950) 14C from old fish, the maximum 14C measured in any of the scales, and the small OTC tagged fish 14C from their outer slice of the scale and small fish collected in 2014.
Fig 5.
OxCal age results from all fish.
A) OxCal probability distributions for lungfish ages from Burnett River overlaid on lungfish calibration curve. B) OxCal probability distributions for lungfish ages from Mary River overlaid on lungfish calibration curve. C) OxCal probability distributions for lungfish ages from Brisbane River overlaid on lungfish calibration curve.
Fig 6.
F14C values for mussel tissue and shell material from 7 locations. The highlighted box shows the range (2012–2015, due to mussels living for several years) in the atmospheric F14C CO2 for comparison.
Fig 7.
Oxytetracycline stained fish scales and F14C.
A) Original fish 745 mm long, on recapture fish 1010 mm long, OTC mark visible on scale. B) Original fish 1036 mm long, on recapture fish 1060mm long, OTC mark not visible on scale.
Fig 8.
Length frequency histogram of Australian lungfish sampled from each river.
Fig 9.
Size at age data for Australian lungfish.
The results from the Burnett River (a), Brisbane River (b) and Mary River (c). The 3 parameter VBGF curves (solid lines) for each river are displayed. For the Burnett River, a previous 2 parameter VBGF mark–recapture curve [13] (dashed line) and a 2 parameter VBGF curve (dotted line) based on the current data are plotted for comparison.
Table 2.
von Bertalanffy growth function parameter estimates for Australian lungfish.
Fig 10.
Age histogram of sub–sampled Australian lungfish.
Results are shown from the Burnett River (a) (n = 28), Mary River (b) (n = 27) and Brisbane River (c) (n = 30). The 5 year bins end in the year labelled on the x axis.
Fig 11.
Histogram of estimated ages for the Australian lungfish populations.
Results are shown from the Burnett River (a), Mary River (b) and Brisbane River (c). The 5 year bins end in the year labelled on the x axis.
Fig 12.
Comparison of the actual age frequency of lungfish with those derived from the ALK.
Results from fish <850 mm in length from the Burnett River derived from radiocarbon aging and that derived using the ALK of the sub–sampled population.