Document ID: chunk:federal_register_of_legislation:F2013L01314:reg:2013:p6
Version: federal_register_of_legislation:F2013L01314
Segment Type: reg
Provision Reference: reg 2013 (pt 6/24)
Character Range: 14263–17056

al., 2013).
The result of this extreme pattern of natal philopatry is that the Australian sea lion is unlikely
to recolonise habitat or expand its range in the short to medium term.

2.5 Current abundance

Estimating the abundance of the Australian sea lion is difficult. Techniques used are based
on estimates of pup production and the use of population models. Using these techniques,
the best estimate for the 2011 population was approximately 14 700 Australian sea lions,
with most (86 per cent) occurring in South Australian waters (Shaughnessy, et al., 2011).

2.6 Population trends

The analysis of population trends for the Australian sea lion requires reliable estimates of
pup numbers over a number of breeding seasons. Unfortunately, reliable data of this type only exist for a number of the larger colonies, with few sources of information available for most
of the smaller colonies. The colonies which have the most robust data sets are Seal Bay,
North and South Page Islands and Dangerous Reef — all of which are in South Australia.

Seal Bay — The most comprehensive time-series data on population trends is from the Seal Bay colony. Data have been collected from this population by a range of people and agencies since 1962, with various collection methods being employed. In an attempt to estimate population trends at this site, a detailed data set was created using only post-1985 data, as earlier population counts were considered unreliable. These data show a decline of approximately 11 per cent over the period 1985 to 2007, with significant variability between breeding seasons (Shaughnessy, et al., 2006). These data also suggest that the decline
is ongoing.

The Page Islands — Estimates of pup numbers at north and south Page Islands have been collected from 1986 to 2007 (Shaughnessy & Goldsworthy, 2007; Shaughnessy, et al., 2011). Like the Seal Bay population, numbers at north and south Page Islands have varied considerably between seasons ranging from 381 to 607. However, unlike the Seal Bay population, no clear trend in pup numbers is evident over the period of analysis and further counts are required to determine the population status at this colony (DEWHA, 2010).

Dangerous Reef — Estimates of pup production from the Dangerous Reef population have been collected from 1975 to 2007. Like the other data sets, the methodologies used to collect the data over time have varied. The most recent analysis of the data suggests the population at Dangerous Reef underwent a period of growth (DEWHA, 2010). The beginning of the period of population growth at Dangerous Reef coincided with the 2001 introduction of restrictions on demersal gillnetting in the Spencer Gulf region, a key foraging ground for this colony.

3 Conservation
Status

The Australian