Document ID: chunk:federal_register_of_legislation:F2019L00106:body:0:p51
Version: federal_register_of_legislation:F2019L00106
Segment Type: other
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Character Range: 136097–139142

(Rimmer et al., 2016).
A recent study  characterised the diversity of major histocompatibility complex (MHC) IIB locus in four Australian freshwater perchichthyid fish, including Macquarie perch (Bracamonte et al., 2015). MHC is a key component of the adaptive immune system and is a promising genetic marker of significance in fitness and adaptive potential. It was found that there was a lack of shared alleles between the Murray-Darling Basin and Hawkesbury-Nepean ecotypes (Bracamonte et al., 2015). Although larger samples are needed to confirm these results, they might be indicative of distinct selective environments in these two basins leading to ecologically-driven divergence and/or long divergence times between them (Bracamonte et al., 2015). This may indicate the need to manage the threat of disease differently between these two ecotypes, as these may have adapted independently to prevailing parasite fauna.
Currently megalocytiviruses such as infectious spleen and kidney necrosis virus-like viruses (e.g. DGIV) and Red Sea Bream Iridovirus (mainly affects marine finfish species) are exotic to Australia. Limited reports of their detection relate exclusively to the imported ornamental fish industry and trade (Anderson et al., 1993; Go et al., 2006; Rimmer et al., 2015). Import regulations and surveillance activities of domestic ornamental facilities have been designed to reduce the risk of these agents for Australia's native fish species including Macquarie perch and Murray cod. Nevertheless, historical imports of ornamental fish with minimal regulation has led to the establishment of 22 introduced species with wild breeding populations (Lintermans 2004). These feral populations demonstrate a prospective exposure pathway for subclinically infected imported ornamental fish to aquatic environments, with the potential to hinder recovery efforts.
Another disease to affect Macquarie perch is the parasitic protozoan Chilodonella cyprini, which was first found in Australia on brown trout in the Snobs Creek Fish Hatchery. It was likely spread to native fish, including Macquarie perch, via the stocking of infected trout into Victorian waters (Cadwallader 1996). European carp, goldfish or eastern gambusia have been likely implicated as the source of, and a vector for, the introduced tapeworm Schyzocotyle acheilognathi which has been recorded in native fish species (Dove et al., 1997; Dove & Fletcher 2000). This tapeworm causes widespread mortality in juvenile fish overseas.

6.2.6 Illegal/Incidental capture
With the exception of Lake Dartmouth and the Yarra River (all in Victoria), the taking of Macquarie perch in fishing activities in Australia is prohibited (Vic DEDJTR 2016). In Victoria, there is a closed season for the species between 1 October – 31 December each year, and daily bag/possession limits apply such that recreational fishing take is permitted in Lake Dartmouth and tributaries (1 per day) and the Yarra River and tributaries (2 per day) (DEDJTR 2016). Illegal fishing is recognised as a