Flagship species, especially mammals and birds, are commonly used to increase awareness of conservation issues in marine and terrestrial ecosystems. However, flagship species oriented programs are often ad hoc with initiatives scarce in the freshwater context. Here, we aim to identify potential flagship candidates that would appeal to a broad cross section of society at a continental scale where freshwater ecosystems are under threat from human impacts. We identified 19 species from a list of 299 Australian freshwater fishes on the basis of body size, trophic guild and threatened species status assuming these characteristics of flagship species are transferable from previous work on terrestrial flagship species. We considered the potential of species to be of international appeal but focused mostly on eight relevant interest groups within Australia. This followed the rationale that public engagement with conservation issues in freshwater systems might be more effective if the link between fish species and the decisions people make were better understood, and we acknowledge the diverging interests of stakeholders. This scoping work contributes towards addressing the challenges of connecting societies to the principles of sharing water resources with ecosystems, and represents the first continental-scale assessment of its kind.

The littoral zone of small off-stream water storage containing a translocated population of Galaxias auratus was sampled fortnightly at day and night with fyke nets, electrofishing and snorkelling over 3 months. Variation in population data provided by each method, including relative abundance indices, size structure, and habitat preferences, were examined. Aspects of behaviour and activity patterns were also investigated. Night sampling using all methods consistently yielded larger catches than day sampling. The size structure of catches varied, with electrofishing at night and fyke netting during the day having higher proportions of juveniles, whilst snorkelling at night and electrofishing during the day had higher proportions of adults. Fyke netting at night yielded by far the largest catches ($3-fold more than other methods) and also captured balanced proportions of juveniles and adults. Galaxias auratus had a strong diel activity pattern and were most active at night. The majority of the population migrated into the littoral zone during the night and back into deeper water during the day. A small number of juveniles remained in the littoral zone and some adults sheltered in the dense cover of species-rich littoral vegetation during the day. Shores with shallow depth profiles appeared to be preferred due to higher catches in these areas using all methods. Based on the results of this study, fyke netting at night in littoral habitats is recommended for monitoring populations of G. auratus. Fyke netting is likely to be an effective method for monitoring other lacustrine galaxiid species; however, further work is required to investigate the effects of habitat variables and fish community structure on activity patterns of galaxiids, and hence their catchability with various methods, in more extensive lentic environments.

Golden galaxias Galaxias auratus (31-235 mm fork length, L F ) were collected monthly from littoral habitats in Lakes Crescent and Sorell, Tasmania, Australia, between July 2000 and December 2002. Spawning habitats were identified and monitored in both lakes, and surveyed in Lake Crescent. Trends in gonado-somatic indices and reproductive stages of development indicated that gonad development in both sexes begins in midsummer and peaks in late autumn to early winter. Males mature at smaller sizes (50% at 52 mm L F ) than females (50% at 76 mm L F ), larger individuals are predominately females (95% of fish !138 mm L F ), and overall male to female ratios are female biased (c. 1:2). Spawning occurs late autumn to early spring (water temperatures ¼ 1Á4-9Á7°C) with peaks in spawning activity in winter (mean water temperatures <5°C). Demersal adhesive eggs (c. 1Á5 mm diameter) were found on cobble substrata (c. 20-250 mm diameter) in littoral areas (c. 0Á2-0Á6 m deep) and fecundity of fish 71-181 mm L F ranged from 619 to 14 478 eggs. The rate of change in water level over the 20 days prior to monthly sampling was important in explaining the occurrence of spent fish and this accounted for temporal differences in spawning between the populations. Lake hydrology influences the reproductive cycle of G. auratus by possibly providing a stimulus for spawning and it controls the availability of spawning habitat in Lake Crescent. Seasonal hydrological cycles (i.e. rises during late autumn to winter) and a minimum water level of 802Á20 m Australian Height Datum in Lake Crescent during autumn (above which littoral areas of cobble substratum are inundated) are critical to G. auratus populations.

Hydrological alterations threaten freshwater fishes globally, with infrastructure-related modification of inland waterways (e.g. dams, water diversions) having profound impacts on many species. Adapting existing water-management systems can provide opportunities for undertaking hydrological manipulations to assist management of threatened fishes. The present study conducted two hydrological manipulations in an impounded highland lake system in Tasmania, Australia, under differing hydrological conditions in 2007 and 2009, to assist recovery of an endemic species, Galaxias auratus, following a prolonged drought. Monitoring at egg, larvae, juvenile and adult life stages revealed a positive response by G. auratus in Lake Crescent (recipient of water release), with no adverse impact on the species in Lake Sorell (source of water release). In both years, reproductive constraints imposed by water level-related availability of sediment-free rocky substrata delayed spawning (~1 month) of G. auratus in Lake Crescent. Despite this, spawning and recruitment occurred in 2007 (drought year) and 2009 (drought-breaking year), and the 2007 manipulation resulted in a two-fold increase in the seasonal density of larvae in Lake Crescent and an abundant cohort of YOY fish. Given knowledge of life histories and eco-hydrological relationships, manipulating (or re-instating) hydrologic conditions is a powerful tool for assisting recovery of threatened lacustrine fishes.