Document ID: chunk:federal_register_of_legislation:F2015L01389:body:0:p69
Version: federal_register_of_legislation:F2015L01389
Segment Type: other
Provision Reference: 
Character Range: 196105–198990

status of native species. Unrestricted visitor access would place additional stress on the park and interfere with its protection and preservation. The introduction of new invasive species by visitors to the park and the increase in the distribution and abundance of existing invasive species are key threats to natural ecosystems in the park.

Feral animals
North Keeling Island is one of the few seabird colonies in the Indian Ocean as yet unaffected by vertebrate pests, such as cats and rats. The vulnerability of seabird colonies to introduced animals is well documented. The protection of the island against the accidental introduction of exotic animals or diseases is paramount.
Weeds
Six exotic or naturalised plant species occur on North Keeling Island: Indian copperleaf (Acalypha lanceolata), limeberry (Triphasia trifolia), wild gooseberry (Physalis minima), pigweed (Portulaca oleracea), pawpaw (Carica papaya), and coral berry (Rivina humilis). None of these plants is considered to be a severe environmental problem, or to have the potential to become one in the foreseeable future (Claussen and Slip 2002). However, the distribution and abundance of some introduced plants, particularly coral berry, appears to have increased during the life of the last management plan. A survey program (the Island Wide Survey) that includes a weed mapping component was initiated in late 2009 (and repeated in 2012) and will be used as a baseline for guiding future weed management programs.
Yellow crazy ants
A survey of the terrestrial invertebrate fauna of selected islands of the Cocos (Keeling) Islands was undertaken during June 2005. Numbers of the yellow crazy ant (Anoplolepis gracilipes) were high in some patches of pisonia forest on North Keeling Island, reaching abundances seen in supercolonies on Christmas Island. This is an important conservation concern, since on other oceanic islands yellow crazy ants are associated with large populations of scale insects, particularly Pulvinaria urbicola, that are also implicated in canopy dieback of pisonia (Hill et al. 2003; Smith et al. 2004; Kay et al. 2003; Handler et al. 2007). Furthermore, yellow crazy ants are known to affect abundance, behaviours, and reproductive success of birds on Christmas Island and in the Seychelles (Feare 1999; Davis et al. in press).
If outbreaks of scale insects occur in the pisonia forest of the park, similar to the scale experienced on Christmas Island, this could degrade nesting sites for seabirds, including the red-footed booby.
Surveys to examine the occurrence of scale insects on the island undertaken by La Trobe University and park staff in May 2011 did not detect the presence of Pulvinaria urbicola scale insects on pisonia, however a mealybug was found on a coconut palm.  This mealybug was also found on coconut palms on all islands surveyed on the southern atoll.  The