This leads to a loss of aquifer pressure causing lower spring flows. Almost all of the mound springs in western New South Wales are now extinct due to loss of aquifer pressure. The other main threat to the mound springs in the park comes from trampling and grazing from feral species such as goats ("Capra hircus") and rabbits ("Oryctolagus cuniculus") and from rooting by feral pigs ("Sus scrofa"). Feral pigs can be particularly destructive for mound springs as they dig up the ground searching for roots and tubers. Introduced species, both plant and animal, are a threat to the park's biodiversity. A total of 55 introduced plant species have been recorded in the park. The priority weed species for the park are Bathurst burr ("Xanthium spinosum"), Noogoora burr ("Xanthium occidentale") and African boxthorn ("Lycium ferocissimum"). These species can affect the survival of native species through competition and changing the composition of plant communities. Introduced foxes ("Vulpes vulpes") and feral cats ("Felis catus") are a threat to many small vertebrate species in the park that they prey on. These species contributed to the regional extinction of many vertebrate species and remain a key threatening process for many vertebrates in Australia's arid zone. Over much of the arid zone in Australia grazing by domestic stock and feral species such as rabbits and goats has resulted in modification in the structure and composition of plant communities. The park was previously used for grazing which effected the plant communities through increased erosion and reduced recruitment and establishment of species such as lignum ("Muehlenbeckia florulenta"). Rabbits, feral goats and domestic stock from neighbouring pastoral properties continue to pose a threat to the ecosystems in the park. Introduced fish such as European carp ("Cyprinus carpio") threaten the aquatic ecosystems in the park as they compete with and prey on native species. One of the main threats to the integrity of the wetlands in the park comes from possible future regulation of flows of the Paroo River flows. The ecosystems of the wetlands of the Paroo River are adapted to the highly variable flow regime that is characteristic of this river. Changes to this naturally variable flow regime will impact on the ecological characteristics and the extent of these wetland ecosystems. These impacts could include genetic isolation of populations, fragmentation of breeding populations, removal of breeding cues for waterbird and fish species, changed species composition and loss of habitat diversity.