Abstract. Freshwater environments and their fishes are particularly vulnerable to climate change because the persistence and quality of aquatic habitat depend heavily on climatic and hydrologic regimes. In Australia, projections indicate that the rate and magnitude of climate change will vary across the continent. We review the likely effects of these changes on Australian freshwater fishes across geographic regions encompassing a diversity of habitats and climatic variability. Commonalities in the predicted implications of climate change on fish included habitat loss and fragmentation, surpassing of physiological tolerances and spread of alien species. Existing anthropogenic stressors in more developed regions are likely to compound these impacts because of the already reduced resilience of fish assemblages. Many Australian freshwater fish species are adapted to variable or unpredictable flow conditions and, in some cases, this evolutionary history may confer resistance or resilience to the impacts of climate change. However, the rate and magnitude of projected change will outpace the adaptive capacities of many species. Climate change therefore seriously threatens the persistence of many of Australia's freshwater fish species, especially of those with limited ranges or specific habitat requirements, or of those that are already occurring close to physiological tolerance limits. Human responses to climate change should be proactive and focus on maintaining population resilience through the protection of habitat, mitigation of current anthropogenic stressors, adequate planning and provisioning of environmental flows and the consideration of more interventionist options such as managed translocations.

1. Hypoxic conditions occur frequently during hot, dry summers in the small lentic waterbodies (billabongs) that occur on the floodplains of the Murray-Darling River system of Australia. Behavioural responses to progressive hypoxia were examined for the native and introduced floodplain fish of the Ovens River, an unregulated tributary of the Murray River in south-east Australia. 2. Given the high frequency of hypoxic episodes in billabongs on the Ovens River floodplain, it was hypothesised that all species would exhibit behaviours that would confer a degree of hypoxia-tolerance. Specifically, it was hypothesised that as hypoxia progressed, gill ventilation rates (GVRs) would increase and aquatic surface respiration (ASR) would become increasingly frequent. Fish were subjected to rapid, progressive hypoxia from normoxia to anoxia in open tanks. 3. All tested species exhibited behaviours consistent with their use of potentially hypoxic habitats. As hypoxia progressed, GVRs increased and all species, with the exception of oriental weatherloach, began to switch increasingly to ASR with 90% of individuals using ASR at various oxygen concentrations below 1.0 mg O 2 L )1 . Australian smelt, redfin perch and flat-headed galaxias were the first three species to rise to ASR, with 10% of individuals using ASR by 2.55, 2.29 and 2.21 mg O 2 L )1 respectively. Goldfish and common carp were the last two species to rise to ASR, with 10% of individuals using ASR by 0.84 and 0.75 mg O 2 L )1 respectively. In contrast to other species, oriental weatherloach largely ceased gill ventilation and used air-gulping as their primary means of respiration during severe hypoxia and anoxia. 4. Australian smelt, redfin perch and flat-headed galaxias were unable to maintain ASR under severe hypoxia, and began exhibiting erratic movements, termed terminal avoidance behaviour, and loss of equilibrium. All other species continued to use ASR through severe hypoxia and into anoxia. Following a rise to ASR, GVRs either remained steady or decreased slightly indicating partial or significant relief from hypoxic stress for these hypoxia-tolerant species. 5. Behavioural responses to progressive hypoxia amongst the fish species of the Ovens River floodplain indicate a generally high level of tolerance to periodic hypoxia. However, species-specific variation in hypoxia-tolerance may have implications for community structure of billabong fish communities following hypoxic events.

The contributions of nursery habitats to recruitment of non-native common carp (Cyprinus carpio) were estimated via analysis of water and otolith 87Sr/86Sr and otolith trace element concentrations (Mg:Ca, Mn:Ca, Sr:Ca, Ba:Ca) over 3 years in the Lachlan River, Australia. Water samples and otoliths of postlarval carp were analyzed to characterize 87Sr/86Sr and multi-elemental signatures of nursery habitats. Considerable temporal variation occurred in both water 87Sr/86Sr and otolith multi-elemental signatures, which limited our ability to directly match water and otolith 87Sr/86Sr in nurseries of the lower catchment. However, spatial variation in multi-elemental signatures was sufficient to allow accurate classification of nurseries within years. Assignment analysis of young-of-year fish suggested that several wetland and floodplain systems made significant contributions to young-of-year recruitment in the lower catchment. These contributions were strongly influenced by river flows and water management. Nurseries contributed fewer recruits to the main channel as distance from the nursery increased. Fish from the upper catchment originated from local sources, and there was no evidence of mixing of recruits between the upper and lower catchments. We conclude that identification of recruitment “hotspots” via otolith chemical analysis can assist in developing strategies to control invasive fishes in large river networks.

The chemical composition of common carp Cyprinus carpio asteriscus (vaterite) and lapillus (aragonite) otoliths from the same individual and reflecting the same growth period was measured to (1) determine whether there are differences in the uptake of trace metals (Mg:Ca, Mn:Ca, Sr:Ca and Ba:Ca ) and Sr isotope ratios ((87)Sr:(86)Sr) in co-precipitating lapilli and asterisci and (2) compare the ability of multi-element and isotopic signatures from lapilli, asterisci and both otolith types combined to discriminate C. carpio populations over a large spatial scale within a river basin. Depth profile analyses at the otolith edge using laser-ablation inductively coupled plasma mass spectrometry showed that asterisci were enriched in Mg and Mn and depleted in Sr and Ba relative to lapilli, whilst (87)Sr:(86)Sr values were nearly identical in both otolith types. Significant spatial differences among capture locations were found when all trace element and Sr isotope ratio data were aggregated into a multi-element and isotopic signature, regardless of which otolith type was used or if they were used in combination. Discriminatory power was enhanced, however, when data for both otolith types were combined, suggesting that analysis of multiple otolith types may be useful for studies attempting to delineate C. carpio populations at finer spatial or temporal scales.

Imperial Oil has a strong history and culture of continuous improvement (CI). Historically the benefits seen from CI were less in the upstream business than in the downstream and other areas with resulting skepticism on the method validity for the resources business. In recent years, Imperial Oil has tested a more aggressive application of CI methods in upstream operations with positive results. The technical methods for CI are broadly known. The approach taken at Imperial Oil Resources (IOR) was to develop the management techniques for CI initiatives. A project philosophy was used and processes were established for initiating, staffing, tracking and closing each initiative. Dedicated CI personnel were added and trained. Expectations were set for the delivery of results. Hindsight reviews have been established to verify the success of each effort. The toolset used was expanded beyond the published Lean and Six Sigma methodologies. Methods were added, such as those used for improving the profitability of a target business segment and for assessing reliability issues that have been proven in other business functions. An examination of the challenges encountered by CI specialists indicated the need for additional training in leading and influencing others. Project teams have also been assembled with experts external to Imperial Oil's upstream business using company staff from other business lines. Skills have been developed in engaging suppliers, contractors and regulatory agencies in IOR's projects. Positive results have been realized in a broad array of areas. Maintenance improvements, general operating cost reductions, energy efficiencies, environmental impact and volume improvements have been achieved in existing conventional and unconventional operations at surface facilities, plants, well servicing and support functions. In the second year of operation, the CI program at IOR implemented projects that will provide over 30 million dollars per year in ongoing financial benefits. In addition significant benefits were realized from the application of these methods to reduce operating costs in a planned oil sands mining project. Active projects are expanding efforts into other areas such as drilling. Introduction Continuous Improvement (CI) programs have had widely divergent levels of business success. At one end of the spectrum, companies like GE have advertised the strategic impact of Six Sigma programs 1 while other companies have struggled to see any return from significant investments of management effort, money and personnel. Imperial Oil is one of Canada's largest corporations and one of the country's largest producers of crude oil and natural gas. The company's upstream assets include multiple conventional oil and gas properties: Cold Lake - the world's largest thermal in-situ heavy oil operation, a 25% interest in Syncrude - an integrated mining, extraction and upgrading facility, as well as many projects in the exploration and development phase. The downstream assets include four refineries, 1900 service stations, petro-chemical facilities and specialty product operations. Imperial Oil's largest shareholder is ExxonMobil.