Analyses of ecological time series in the Murray–Darling Basin (1905–2013) indicated periods of decline and recovery according to cycles of drought and flood. Meta-analysis revealed a small, but statistically significant declining trend, consistent with a pattern of historical decline to a hybrid ecosystem followed by slow, recent decline for some components and stability for others.

Colloff et al. in Marine and Freshwater Research (http://dx.doi.org/10.1071/MF14067) analysed 301 biological datasets for the Murray–Darling Basin, concluding that the overwhelming pattern was one of fluctuating stability, irretrievably affected by changes in land use. We provide evidence that their conclusions are inadequately supported, and multiple factors, particularly water resource development, continue to degrade freshwater ecosystems, requiring restoration of flows.

We aimed to compare relative efficiencies of six types of gear where an array of restrictive recreational fishing regulations are in place for freshwater crayfish. Open topped traps and those fitted with fixed entrance rings, to reduce by-catch entry, were most efficient particularly when fished actively with short soak-times. Encouragingly, fixed entrance rings didn’t affect catch efficiency or size-structure.

Marine species undertaking range shifts in response to environmental change must produce viable gametes and their offspring must survive in new areas. Examination of reproductive characteristics suggests that Octopus tetricus can reproduce and the population may be self-sustainable within its new range in south-eastern Australia. The reproductive biology of O. tetricus may thus facilitate the establishment and prevalence of the population in the new environments.

Viral lysis may be a major cause of mortality and, at times, comparable to grazing-induced mortality. We compare the two distinct processes of bacterial mortality in two different trophic conditions using natural populations. Changes in nutrient concentrations can play an important role in the balance between viral lysis and heterotrophic nanoflagellate grazing in the bacterial mortality.

The native seaweed Caulerpa filiformis has reportedly been spreading over rocky reefs throughout NSW. We document the extent of C. filiformis over 5 years and test whether the seaweed is associated with nutrient enrichment and particular habitat types. C. filiformis is predominately found where there is a mixture of rocky reefs and beaches and is not closely associated with human activities or nutrient levels over large areas.

Little is known about the sensitivity of freshwater elasmobranchs to minute electric fields produced by their prey. This study determined that the obligate freshwater stingray, Potamotrygon motoro, is up to 5 orders of magnitude less sensitive to electric fields than its marine relatives. Despite decreased electrosensitivity, P. motoro still successfully locates prey owing to multiple sensory systems working synergistically.

The release of free-swimming larvae (zoeae) by saltmarsh-dwelling crabs after tidal flooding of saltmarsh provides important food sources for estuarine fish, including glassfish. On ebbing tides in a temperate Australian estuary, glassfish fed on zoeae following saltmarsh flooding, but when tides flooded only the adjacent mudflats, ghost shrimp larvae were the main prey. The feeding of glassfish is therefore triggered by tidal action and the ingestion of prey is influenced by which coastal estuarine habitats are flooded by incoming tides

The turtle Chelodina longicollis is a freshwater obligate with strong overland dispersal capacity and adaptations to terrestriality – traits that connect populations and reduce divergence. Genetic results showed two ancient haplogroups partitioned either side of the Great Dividing Range, each with demographically stable subpopulations and signals of isolation by distance. These results demonstrate that that landscape history can overwhelm life-history traits even in a highly vagile species.

Little penguin populations have been seriously declining across South Australia, for reasons still not fully understood. I investigated breeding performance and survival of little penguins on Granite Island for 17 years and found that both adult and sub-adult survivals were extremely low, with sub-adult survival being the most critical variable affecting population growth. Further investigation into factors influencing juvenile mortality is clearly needed, with a particular focus on food availability and parasites, which are known reasons for poor juvenile survival in other colonies.

The variability of populations from an endemic lineage of brown trout out of its reported natural range highlight the difficulty in management of species diversity. The phylogeny of mtDNA sequences demonstrate that the natural origin of brown trout populations of the Duero lineage was outside the Duero Basin, and exclude a recent origin by human translocations. This divergent lineage shows the need for differentiated management for Duero lineage populations inside the Duero Basin.