Increased visitor impacts leading Certain Current to physical disturbance of the site Climate change Reduced altered recharge of Medium Medium to long altered rainfall aquifer and loss of freshwater. term patterns.
Climate change Direct physical damage to Medium Medium to long increased waterbird breeding habitat. term intensity of storms.
Climate change Increased incidence of coral Certain (for Current (disease increased bleaching and disease. coral outbreak summer temperature. bleaching) 2007 2008 coral bleaching 1997 1998 and 2010). xi There is no evidence that there has been any change to any of the critical components; processes or services since the site was listed.
Climate Habitat template Geomorphic setting Hydrology Water quality Waterbirds Land crabs Fish Coral Terrestrial threatened species Invertebrates (non crab) Terrestrial vegetation Biodiversity Food webs Near natural wetaland types Threatened species Distinct or unique wetland species Special ecological; physical or geomorphic features Ecological connectivity Criterion Criterion Criterion Criterion Criterion Critical services Critical components processes Essential elements Figure 5 Simple conceptual model showing the key relationships between components and processes benefits and services and the reasons for the site being listed as a Wetland of International Importance. 3.2 Essential elements The components and processes of The Dales Ramsar site that are considered important in supporting the critical components; processes; benefits and services of the site (and hence termed essential elements ) are described briefly below and summarised in Table 4.
Threat Invasive Species Recreation Groundwater Extraction Climate Change Stressor Yellow crazy ant (Anoplolepis gracilipes) Increased physical disturbance Potentially reduced discharge Variable rainfall Increased temperature Increased intensity of storms Increased predation on land animals Decreased terrestrial vegetation health Coral bleaching Altered community composition Ecological effects Decreased population crabs Changed wetland type Disruption of critical life stage crab migratory pathways Disruption of critical life stage seabird rookeries Facilitation of invasive weeds Component; process; or service Crab fauna; Waterbirds Services Near natural wetland ecosystem Food webs Crab fauna (red crabs) Services Ecological connectivity Distinct wetland species Waterbirds Services Biodiversity Natural wetland eco system Threatened species Physical habitat Hydrology Services Near natural wetland ecosystem Marine fish and coral Services Physical habitat Biodiversity Figure 27 Stressor model of major threats to ecological character of The Dales Ramsar site (after Gross 2003 and Davis and Brock 2008). 5.1 Invasive species (yellow crazy ants) Yellow crazy ants (Anoplolepis gracilipes) are thought to have been introduced to Christmas Island between 1915 and 1934 (O’Dowd et al. 1999).
There is uncertainty in the predicted change in climate for Christmas Island; but in general it is thought that rainfall could decrease and that the intensity of tropical cyclones could increase (McInnes et al. 2008).
Recent modelling is not clear on if rainfall will change due to greenhouse effects; however McInnes et al. (2008) suggest that rainfall decreases are more likely than increases in the driest seasons of the year; winter and spring; and in the annual average rainfall total; which is likely to change by 10 to 3 percent by 2030 and by 28 to 9 percent by 2070 (McInnes et al. 2008).
Fishes and many calcareous organisms (for example corals) will also be negatively affected by the increasing acidity of the oceans associated with global warming (Hoegh Guldberg et al. 2007 Munday et al. 2008) Figure 29 Coral bleaching at Christmas Island (Image courtesy J P Hobbs; James Cook University). 5.3 Natural system modification groundwater extraction There is little permanent surface water on Christmas Island; and water for consumptive uses is extracted from the unconfined aquifers.

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