Winner:
Dr Pim Bongaerts, Postdoctoral Research Fellow, Global Change Institute, University of Queensland
Concept title: Deep Coral Reefs: a lifeline to shallow reefs in the face of climate change
Summary:
The goal of this project is to promote protection of existing deep reef habitats on the GBR and investigate the feasibility of boosting local resilience through the establishment of artificial “deep-water bommies”.
Our global climate is changing drastically and is having major impacts on coral reefs, including the Great Barrier Reef (GBR). However, the GBR is different from many other reef systems in that most of its (documented) reefs are confined to shallow depths (less than 20 m) and, as such, are more susceptible to reef stressors. In other parts of the world, deep reefs have provided a crucial escape during mass bleaching events and tropical storms, as the impacts of these disturbances were restricted to shallow water.
This project proposes to:
(1) prioritise protection of deep reef areas in the GBR to boost overall reef resilience, and
(2) investigate the feasibility of increasing resilience locally by introducing artificial “deep-water bommies” adjacent to shallow-water reefs.
Although most inshore and mid-shelf reefs of the GBR are largely confined to depths of less than 20m, there is a vast abundance of reefs along the length of the continental shelf edge with coral communities extending well beyond 30m.
The greater depths of these coral communities appear to convey greater protection to disturbances, and although this is a concept that has been repeatedly observed in other parts of the world, it remains a relatively foreign concept on the GBR due to the difficulty of accessing deep reefs. The development of new technologies has opened up these reefs for exploration, literally allowing us to put these areas on the map and assess their potential role as refugia to reef disturbances.
Potentially, the resilience of inshore and mid-shelf reef systems on the GBR could be improved by allowing these coral reefs to extend into deeper water. The major limiting factors to such development are the lack of available hard substrate and sedimentation, which could be overcome by introducing artificial structures in deep-water (20-40 m) that could provide a holdfast for corals and allow development of reef communities at greater depths. Such structures or rock piles could be left to be colonised by the adjacent shallower habitat or manually seeded with a range of coral species (ideally incorporating a significant amount of the population’s genetic variation). The location of these artificial “deep-water bommies” in deeper water increases the chances of survival of the colonizing community during disturbances and could provide a source for re-colonisation either through their reproductive output or through manual transplantation of fragments back to their original habitat.