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Recovery of the endangered trout cod Maccullochella macquariensis: What have we achieved in more than 25 years?

Marine and Freshwater Research (Impact Factor: 1.98). 09/2013; 64:822–837. DOI: 10.1071/MF12262

ABSTRACT Recovery of threatened species is often necessarily a long-term process. The present paper details the progress towards the recovery of trout cod, Maccullochella macquariensis, an iconic, long-lived fish species first listed as threatened in the 1980s. The objectives, actions and progress over three successive national recovery plans (spanning 18 years) are assessed, documenting changes to population distribution and abundance and updating ecological knowledge. Increased knowledge (especially breeding biology and hatchery techniques, movements, habitats and genetics) has greatly influenced recovery actions and the use of a population model was developed to assist with management options and stocking regimes. Key recovery actions include stocking of hatchery-produced fish to establish new populations, regulations on angling (including closures), education (particularly identification from the closely related Murray cod, M. peelii) and habitat rehabilitation (especially re-instatement of structural woody habitats). In particular, the establishment of new populations using hatchery stocking has been a successful action. The importance of a coordinated long-term approach is emphasised and, although there is uncertainty in ongoing resourcing of the recovery program, much has been achieved and there is cautious optimism for the future of this species

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    ABSTRACT: Trout Cod Maccullochella macquariensis is an endangered freshwater fish species previously distributed throughout much of the southern Murray-Darling Basin. Severe reductions in the historical distribution of the species have occurred and by the 1980s the Trout Cod was restricted to only one, viable, naturally occurring population located in the Murray River fromYarrawonga Weir downstream to Tocumwal. The distribution of this population has since been reported to have extended further downstream and includes the Murray River from Yarrawonga to around Barmah. This paper reports confirmed Trout Cod captures from the Murray River at Gunbower Island that represent a significant extension in the downstream distribution of trout cod in the Murray River..
    Victorian Naturalist 08/2012; 129(4):152-155.
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    ABSTRACT: Murray cod Maccullochella peelii peelii support popular recreational fisheries in Australia. Catch and release of Murray cod is common due to regulations and a developing trend of voluntary angler release of harvestable fish, but no previous studies have investigated discard mortality of released fish. We estimated discard mortality by measuring post-angling survival of angler-caught wild Murray cod. Angled fish were monitored for five days after hooking, and overall survival rates of 98% were observed. We explored implications of catch and release as a fishing mortality source by comparing our results to roving creel survey estimates of harvest from six fisheries. We applied the maximum likelihood mortality estimate and upper 95% confidence interval to creel survey estimates of the number of Murray cod that were released in the fishery to estimate the total deaths resulting from catch and release mortality. Estimated ratios of deaths from discard mortality to harvest indicated that high numbers of released fish could contribute as much or more to fishing mortality as harvest in some systems. Future Murray cod research should aim to estimate annual exploitation rates to determine the population-level impacts of fishing mortality, and thus, allow effects of hooking and harvest mortality to be considered in future regulation decisions.
    Fisheries Research. 01/2010;

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Jul 17, 2014