Document ID: chunk:federal_register_of_legislation:F2019L00106:body:0:p14
Version: federal_register_of_legislation:F2019L00106
Segment Type: other
Provision Reference: 
Character Range: 37377–40289

m/s. Hatching usually occurs after 10–11 days at water temperatures ranging from 15–17oC (Lintermans 2007). Newly hatched yolk sac larvae shelter amongst pebbles (Cadwallader & Rogan 1977).
Macquarie perch larvae in the Cotter River above Cotter Reservoir in the Australian Capital Territory have been observed during snorkelling surveys schooling in deep sections of river pools which have little to no surface flow along steep rock faces in the upper water column (at depths less than 1 m; Broadhurst et al., 2012). As they grew and became juvenile fish, they developed strong associations with the benthic substrates of boulders, cobbles or large woody debris at the head and tail of pools in relatively shallow water, where some surface flow is present (Broadhurst et al., 2012).
Macquarie perch have been particularly problematic to breed in captivity, requiring flowing water, and typically have relied on the collection of wild breeding stock (Trueman 2007; Farrington et al., 2014). However, there has been some recent success for captive breeding programs of the species by the New South Wales Narrandera Fisheries Centre hatchery, using a new approach employing an artificial stream to coax both males and females into breeding condition (NSW DPI 2010). Until this development, hatchery programs for the species have generally relied on capturing spawning-run fish from the wild (NSW DPI 2010), inducing individuals to spawn through the injection of artificial hormones to collect the eggs and sperm.

    4.4 Behaviour

While anglers regularly capture the species during daylight, it is thought that Macquarie perch search for food more actively at night (Lintermans 2006a, Ebner & Lintermans 2007, Ebner et al., 2009; Thiem et al., 2013). Nevertheless, whilst the species is generally regarded as quite cryptic and docile (Lintermans 2007), during reproduction fish form dense aggregations at the base of pools and within riffles (Cadwallader & Rogan 1977; Tonkin et al., 2010). During such times fish also become quite aggressive, making the species particularly vulnerable to predation and anglers (Tonkin et al., 2009).
In the Cotter Reservoir, Australian Capital Territory, Macquarie perch have been shown to inhabit deeper water depths during the warmer summer months in comparison with other seasons (Thiem et al., 2013). Diel geographical range movements were significantly higher in winter than other seasons, probably due to having to move larger distances to encounter the same quantity of prey items, such as decapods which are in lower abundance during winter (Thiem et al., 2013).
Studies on Macquarie perch in Lake Eildon and Lake Dartmouth in Victoria, found that as water temperatures rose in spring months towards 16°C, fish began migrating to upstream regions of the lake ready to move into inflowing streams once the surface water temperature rose above this level (Cadwallader &