Figure 1.
Fieldwork undertaken at Lady Elliot Island, Great Barrier Reef (24°07′S :152°43′E).
(a) A Quickbird satelite image of Lady Elliot Island, showing sample sites for the carbonate production census (red dots, numbering relates to sites detailed in Table 2), reef flat and reef slope ground referencing points (black and green dots) (b) The location of Lady Elliot Island along the Queensland coastline, at the southern end of the Great Barrier Reef, (c) a digital elevation model of Lady Elliot island and the surrounding reef platform.
Figure 2.
Conceptual model of the carbonate budget for Lady Elliot Island.
Table 1.
Average estimates of reef community cover for a range of different assemblages from the underwater video dataset (n = 50) and the reef flat photographs (n = 218).
Figure 3.
Calculated calcification (equation 2) vs. the corresponding measured net calcification for the reef flat hydrochemical samples at Lady Elliot Island.
Dashed lines indicate error bars calculated from the standard error of the 30 samples with the analytical error associated with measurement of aragonite saturation state [25].
Figure 4.
Digital maps of carbonate production at Lady Elliot Island, for the total community and the benthic cover of key benthic carbonate producers.
(a) Net community carbonate production, Gnet (Eqn. 2), (a) branching hard coral, (b) hard coral (non-branching), (c) crustose corralling algae, and (d) Halimeda. Note: Digital versions of these maps can be downloaded in raster format from the author's data archive at www.sarahhamylton/maps.
Figure 5.
Validation of the maps depicting key benthic carbonate producers for 218 ground reference survey points.
Symbology indicates dominant carbonate producer for each survey point. Inset: Validation of net community calcification models using census based estimates from in-situ surveys (Perry et al., 2012).
Table 2.
Census-based estimates of reef community carbonate production for validation transects around the reef platform at Lady Elliot Island (for transect locations, see Figure 1A).
Figure 6.
Simulated reductions in reef flat aragonite saturation state and island accretion rates for Lady Elliot Island, 2000–2100.
Figure 7.
A digital elevation model of Lady Elliot Island generated from a dGPS survey.
The north-south aligned shingle ridges are evident.