Ecological changes over 90 years at Low Isles on the Great Barrier Reef

Abstract Coral reefs are under increasing stress from local and global factors. Long-term perspectives are becoming increasingly important for understanding ecosystem responses. Here, we provide insights from a 91-year study of the Low Isles on the northern Great Barrier Reef (GBR) that begins with the pioneering Great Barrier Reef Expedition (1928-29). We show that intertidal communities have experienced major phase-shifts since 1928, with few signs of a return to the initial state. Coral communities demolished by cyclones 50 years ago and exposed to multiple stressors have yet to recover. Richness and diversity of these communities systematically declined for corals and other invertebrates. Specifically, massive corals have replaced branching corals, and soft corals have become much more numerous. The long-term perspective of this study illustrates the importance of considering multiple factors in reef decline, and potential recovery, of coral reefs, and the importance of tracking changes in community structure as well as coral abundance over long periods.

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Temporal dynamics in coral bioindicators for water quality on coastal coral reefs of the Great Barrier Reef

Marine and Freshwater Research ◽

10.1071/mf08016 ◽

2008 ◽

Vol 59 (8) ◽

pp. 703 ◽

Cited By ~ 39

Author(s):

Timothy F. Cooper ◽

Peter V. Ridd ◽

Karin E. Ulstrup ◽

Craig Humphrey ◽

Matthew Slivkoff ◽

...

Keyword(s):

Water Quality ◽

Coral Reefs ◽

Great Barrier Reef ◽

Temporal Dynamics ◽

High Specificity ◽

Barrier Reef ◽

Pocillopora Damicornis ◽

Skeletal Density ◽

Massive Porites

There is a need to identify effective coral bioindicators that provide quantifiable links between changes in water quality and the condition of coastal coral reefs. Temporal variation in a range of coral bioindicators including symbiont density, concentration of chlorophyll a, skeletal density and colony brightness of Pocillopora damicornis, as well as colony brightness and density of macro-bioeroders of massive Porites spp. was examined for 2 years on a coastal coral reef of the Great Barrier Reef. The specificity to changes in water quality varied among bioindicators. For example, a 2.5-fold variation in symbiont density of P. damicornis was related strongly to mean 14-day sea surface temperature and seasonal changes in water quality, suggesting medium specificity to changes in water quality. In contrast, the density of macro-bioeroders in Porites did not vary seasonally but there were consistently more macro-bioeroders at the coastal than mid-shelf reference locations, suggesting high specificity of spatial differences in water quality. In situ measurements of benthic irradiance and turbidity allowed the quantification of potential stress thresholds for coastal corals. Our data suggest long-term turbidity >3 NTU leads to sublethal stress, whereas long-term turbidity >5 NTU corresponds to severe stress effects on corals at shallow depths.

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Long-term dynamics of coral reefs in the inshore Southern Great Barrier Reef

10.14264/uql.2015.992 ◽

2015 ◽

Author(s):

Mauro Lepore

Keyword(s):

Coral Reefs ◽

Great Barrier Reef ◽

Barrier Reef

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Submerged banks in the Great Barrier Reef, Australia, greatly increase available coral reef habitat

ICES Journal of Marine Science ◽

10.1093/icesjms/fss165 ◽

2012 ◽

Vol 70 (2) ◽

pp. 284-293 ◽

Cited By ~ 63

Author(s):

Peter T. Harris ◽

Thomas C.L. Bridge ◽

Robin J. Beaman ◽

Jody M. Webster ◽

Scott L. Nichol ◽

...

Keyword(s):

Coral Reef ◽

Coral Reefs ◽

Great Barrier Reef ◽

Global Ocean ◽

Suitable Habitat ◽

Barrier Reef ◽

Reef Habitat ◽

Deep Reef ◽

Coral Communities ◽

Coral Reef Habitat

Abstract Harris, P. T., Bridge, T. C. L., Beaman, R. J., Webster, J. M., Nichol, S. L., and Brooke, B. P. 2013. Submerged banks in the Great Barrier Reef, Australia, greatly increase available coral reef habitat. – ICES Journal of Marine Science, 70: 284–293. Anthropogenic global ocean warming is predicted to cause bleaching of many near-sea-surface (NSS) coral reefs, placing increased importance on deeper reef habitats to maintain coral reef biodiversity and ecosystem function. However, the location and spatial extent of many deep reef habitats is poorly known. The question arises: how common are deep reef habitats in comparison with NSS reefs? We used a dataset from the Great Barrier Reef (GBR) to show that only about 39% of available seabed on submerged banks is capped by NSS coral reefs (16 110 km2); the other 61% of bank area (25 600 km2) is submerged at a mean depth of around 27 m and represents potential deep reef habitat that is spatially distributed along the GBR continental shelf in the same latitudinal distribution as NSS reefs. Out of 25 600 km2 of submerged bank area, predictive habitat modelling indicates that more than half (around 14 000 km2) is suitable habitat for coral communities.

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Internal macrobioerosion on five species of Acropora following the 1998 bleaching event: Implications for the long-term impact of bleaching on the Great Barrier Reef

Pacific Conservation Biology ◽

10.1071/pc130409 ◽

2013 ◽

Vol 19 (4) ◽

pp. 409 ◽

Cited By ~ 4

Author(s):

Pat Hutchings ◽

Mireille Peyrot-Clausade ◽

Anke Stuken

Keyword(s):

Coral Reefs ◽

Great Barrier Reef ◽

Internal Erosion ◽

Bleaching Event ◽

Barrier Reef ◽

Storm Damage ◽

Public Attention ◽

Long Term Impact ◽

Increased Susceptibility

While bleaching events have received wide public attention, little attention has been given to the follow on effects on coral reefs. Bleached colonies of five species of Acropora of known age were sampled to study rates and agents of internal bioerosion at two sites on the southern Great Barrier Reef. The dominant erosion agents were worms and sponges and up to 23% of branches were eroded after 37 months. Significant differences were exhibited between species and between sites in terms of the animals responsible for internal erosion. The significance of bleaching and subsequent death of coral colonies is discussed with regard to their increased susceptibility storm damage and the loss of associated fish and invertebrates dependent on these habitat forming corals.

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