Managing potential impacts of reservoir enlargement on threatened Macquaria australasica and Gadopsis bispinosus in southeastern Australia

Abstract

Enlargement of a domestic water supply reservoir on the Cotter River in southeastern Australia (4 to 78 Gl) includes an inundation zone that contains 2 threatened fish species, Macquarie perch Macquaria australasica and two-spined blackfish Gadopsis bispinosus. The enlarged reservoir will be 50 m deeper and impound an additional 4.5 km of river and thus poses a number of potential threats to these fish species. The majority of threats relate to the inundation zone or upstream environments, as downstream environments have been degraded by significant flow alterations from the existing Cotter Dam and 2 upstream dams. Threats include the loss of refuge habitat and associated increased predation, loss of preferred food sources, invasion and expansion of alien fish populations, loss of spawning habitat (or access to it), and the introduction of disease. To minimise or mitigate these threats, a collaborative and comprehensive research and management program is underway involving participation from the water utility and various universities and government agencies. Funding by the water utility of an independent senior fisheries scientist, establishment of a stakeholder steering group, independent peer review processes, and dedicated staff within the design and construction alliance are intended to ensure fish requirements are considered in dam design, construction, and operation. The establishment of an independent, collaborative science-driven process, coupled with the establishment of a long-term monitoring program in an adaptive management framework is a model for other infrastructure projects worldwide, particularly those that threaten riverine fish.

Endangered river fish: factors hindering conservation and restoration

“…As an example, stocking (i.e. conservation aquaculture; Drauch Schreier et al 2012, this Theme Section), translocating, or reintroducing an endangered species alone may not address the issue that caused the lack of natural reproduction (Lintermans 2012, Paragamian 2012, both this Theme Section). Monitoring and resto ration programs often dictate success based on recovery or stability of a species listed by government agencies as endangered or threatened.…”

“…This is often the case with habitats that are inundated after dam construction. In general, efforts to address imperiled species in reservoir habitats have been lacking although there are some cases where coordinated enhancement and monitoring programmes have had some success (Lintermans 2012). Rivers are complex systems that interact with the environment both longitudinally and laterally.…”

A review of on-ground recovery actions for threatened freshwater fish in Australia

“…Five fishways for Macquarie perch were constructed in the past decade. Most recovery actions for Macquarie perch have been conducted in streams; however, work has recently also been conducted in impoundments, including deployment of constructed predator refuges, prevention of disease spread, manipulation of water levels to facilitate access to spawning sites, and control of alien species (Lintermans 2012). Macquarie perch provides two good examples (Goulburn-Broken and Cotter catchments) where catchment-wide activities can deliver significant benefits to a focal threatened species.…”

“…drainage works). Other activities included the purchase of a pastoral property (Edgbaston) to protect critical habitat for two spring-dependant species (red-finned blue-eye and Edgbaston goby Chlamydogobius squamigenus), and activities to protect Macquarie perch by preventing the introduction of a virus (epizootic haematopoietic necrosis virus) to a subcatchment (Lintermans 2012).…”

Who do you move? A stochastic population model to guide translocation strategies for an endangered freshwater fish in south-eastern Australia

“…Macquarie perch has two morphologically distinct and geographically disjunct forms which are likely to be separate taxa (Faulks et al, 2010), with both forms listed as endangered under both national and state legislation and the Murray-Darling (western) taxon undergoing significant declines in the last 50 years (Lintermans, 2007). Major causes of decline include habitat loss and alteration, the impacts of alien species, and coldwater pollution (Koehn et al, 1995;Lintermans, 2012;ACT Government, 2007). During the recent Millennium Drought in Australia (1997Australia ( -2010, several populations were severely impacted or extirpated and the species is now restricted to a handful of populations in its native range, plus three populations outside its natural range as a result of historic translocations (Cadwallader, 1981;Lintermans, 2007Lintermans, , 2013b.…”