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| Titel |
Exploring the hidden shallows: extensive reef development and resilience
within the turbid nearshore Great Barrier Reef |
| VerfasserIn |
Kyle Morgan, Chris Perry, Scott Smithers, Jamie Johnson, James Daniell |
| Konferenz |
EGU General Assembly 2016
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| Medientyp |
Artikel
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| Sprache |
en
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| Digitales Dokument |
PDF |
| Erschienen |
In: GRA - Volume 18 (2016) |
| Datensatznummer |
250128690
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| Publikation (Nr.) |
 EGU/EGU2016-8699.pdf |
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| Zusammenfassung |
| Mean coral cover on Australia’s Great Barrier Reef (GBR) has reportedly declined by over
15% during the last 30 years. Climate change events and outbreaks of coral disease have been
major drivers of degradation, often exacerbating the stresses caused by localised human
activities (e.g. elevated sediment and nutrient inputs). Here, however, in the first assessment
of nearshore reef occurrence and ecology across meaningful spatial scales (15.5
sq km), we show that areas of the GBR shelf have exhibited strong intra-regional
variability in coral resilience to declining water quality. Specifically, within the
highly-turbid “mesophotic” nearshore (<10 m depth) of the central GBR, where
terrigenous seafloor sediments are persistently resuspended by wave processes, coral
cover averages 38% (twice that reported on mid- and outer-shelf reefs). Of the
mapped area, 11% of the seafloor has distinct reef or coral community cover, a density
comparable to that measured across the entire GBR shelf (9%). Identified coral
taxa (21 genera) exhibited clear depth-stratification corresponding closely to light
attenuation and seafloor topography. Reefs have accreted relatively rapidly during
the late-Holocene (1.8-3.0 mm y−1) with rates of vertical reef growth influenced
by intrinsic shifts in coral assemblages associated with reef development. Indeed,
these shallow-water reefs may have similar potential as refugia from large-scale
disturbance as their deep-water (>30 m) “mesophotic” equivalents, and also provide a
basis from which to model future trajectories of reef growth within nearshore areas. |
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