Marine ‘refugia’ in the Keppel Region of the Great Barrier Reef

The concept of marine no-take areas has historically been used as a tool for managing ecosystem function on coral reefs. Reserves have flow-on benefits to the fish stocks on surrounding reefs (Hughes, Bellwood et al. 2006) and promote resilience to chronic traumas such as anchoring and bleaching. While no-take marine reserves have now been firmly established as management tools globally, the choice of most has been typically based on a range of human socio-economic values and biophysical representativeness rather than on the potential resilience of corals (Riegl and Piller 2003). Understandably, given the size of the reef areas under their jurisdiction, few marine managers have had the resources to conduct robust biophysical assessments on which to base these choices. Unfortunately, many established marine reserves are now located in regions deemed vulnerable to temperature-induced coral mortality (Maxmen 2008) and a recent study has highlighted their failure to have a positive effect on ecosystem response to large-scale disturbance (Graham, McClanahan et al. 2008). While the current system of marine reserves has a vital role in protecting fish stocks and enhancing recovery, they may do little to provide reef-wide resilience from the compounding threats posed by increased temperature, ocean acidification, rising sea level, land runoff, changing hydrodynamics and increasing severity of storms and floods. Considering predictions that these threats will escalate and the likelihood of a corresponding decline in the resources available to protect them, it may be necessary to earmark reefs based on the resilience of corals and their potential to provide the seed stock for surrounding reef regeneration when conditions improve: Noah’s arks for reefs. Extending protection of small pockets of highly diverse but ecologically resilient corals by way of improved water quality and protection from extractive activities may improve the capacity of these ‘refugia’ to seed regeneration on a reef-wide scale following climate-induced catastrophic destruction in the future.