Document ID: chunk:federal_register_of_legislation:F2016L00043:reg:5:p9
Version: federal_register_of_legislation:F2016L00043
Segment Type: reg
Provision Reference: reg 5 (pt 9/15)
Character Range: 41765–44882

inundation or drying down of connected wetlands, and changes to the timing, frequency
  and duration of floods. These changes affect both habitat availability and type (for example, loss of access to mudflats through permanent higher water levels, or a shift from freshwater to salt-tolerant vegetation communities), and the disruption of lifecycles of plants and animals in the food chain for migratory shorebirds.

Reduced recharge of local groundwater that occurs when floodplains are inundated can change the vegetation that occurs at wetland sites, again affecting habitat and food sources.

Water regulation can alter the chemical make-up of wetlands. For example, reduced flushing flows can cause saltwater intrusion or create hyper-saline conditions. Permanent inundation behind locks and weirs can cause freshwater flooding of formerly saline wetlands, as well as pushing salt to the surface through rising groundwater.

8.3                Anthropogenic disturbance

Research suggests that disturbance from human activities has a high energetic cost to shorebirds and may compromise their capacity to build sufficient energy reserves to undertake migration (Goss-Custard et al. 2006; Weston et al. 2012). Disturbance which renders an area unusable is equivalent to habitat loss and can exacerbate population declines. Disturbance is greatest where increasing human populations and development pressures may have an impact on important habitats. Migratory shorebirds are most susceptible to disturbance during daytime roosting and foraging periods. As an example, disturbance of migratory shorebirds in Australia is known to result from aircraft over-flights, industrial operations and construction, artificial lighting, and recreational activities such as fishing, off-road driving on beaches, unleashed dogs and jet-skiing (Weston et al. 2012).

A recent study by Martin et al. (2014) examined the responses to human presence of an abundant shorebird species in an important coastal migration staging area. Long-term census data were used to assess the relationship between bird abundances and human densities and to determine population trends. In addition, changes in individual bird behaviour in relation to human presence were evaluated by direct observation of a shorebird resident species. The results showed that a rapid increase in the recreational use of the study area in summer dramatically reduced

  the number of shorebirds and gulls which occurred, limiting the capacity of the site as a post-breeding stop-over area. In addition, the presence of people at the beach significantly reduced the time that resident species spent consuming prey. The study found negative effects of human presence on bird abundance remained constant over the research period, indicating no habituation to human disturbance in any of the studied species. Moreover, although intense human disturbance occurred mainly in summer, the human presence observed was sufficient to have a negative impact on the long-term trends of a resident shorebird species. The authors suggested that the impacts of disturbance