Marine heatwaves (MHWs) can cause devastating impacts to marine life. Despite the serious consequences of MHWs, our understanding of their drivers is largely based on isolated case studies rather than any systematic unifying assessment. Here we provide the first global assessment under a consistent framework by combining a confidence assessment of the historical refereed literature from 1950 to February 2016, together with the analysis of MHWs determined from daily satellite sea surface temperatures from 1982–2016, to identify the important local processes, large-scale climate modes and teleconnections that are associated with MHWs regionally. Clear patterns emerge, including coherent relationships between enhanced or suppressed MHW occurrences with the dominant climate modes across most regions of the globe – an important exception being western boundary current regions where reports of MHW events are few and ocean-climate relationships are complex. These results provide a global baseline for future MHW process and prediction studies.

Patterns of climate-forced range shift in the marine environment are informed by investigating the population dynamics of an ecologically important sea urchin (Centrostephanus rodgersii -Diadematidae) across its newly extended range in Tasmania (southeastern Australia). A growth model of C. rodgersii is developed allowing estimation of a sea urchin age profile and, in combination with abundance data, we correlate the sea urchin population dynamic with respect to environmental signals across the range extension region. Growth patterns did not vary across the extension region; however, there was a strong pattern of decreasing sea urchin age with increasing distance from the historic range. The sequential poleward discovery of the sea urchin, a pattern of declining age and a general poleward reduction in abundance along the eastern Tasmanian coastline are consistent with a model of range extension driven by recent change in patterns of larval dispersal. We explore this hypothesis by correlating C. rodgersii population characteristics with respect to the East Australian Current (EAC), i.e. the chief vector for poleward larval dispersal, and reveal patterns of declining sea urchin age and abundance with increasing distance from this oceanic feature. Furthermore, C. rodgersii is generally limited to sites where average winter temperatures are warmer than the cold threshold for its larval development. Potential dispersal and physiological mechanisms defining the range extension appear to be strongly coupled to the EAC which has undergone recent poleward advance and resulted in coastal warming in eastern Tasmania. Predicted climate change conditions for this region will favour continued population expansion of C. rodgersii not only via atmospheric-forced ocean warming, but also via ongoing intensification of the EAC driving continued poleward supply of larvae and heat.

Smith, A. D. M., Fulton, E. J., Hobday, A. J., Smith, D. C., and Shoulder, P. 2007. Scientific tools to support the practical implementation of ecosystem-based fisheries management. – ICES Journal of Marine Science, 64: 633–639. Ecosystem-based fisheries management (EBFM) has emerged during the past 5 y as an alternative approach to single-species fishery management. To date, policy development has generally outstripped application and implementation. The EBFM approach has been broadly adopted at a policy level within Australia through a variety of instruments including fisheries legislation, environmental legislation, and a national policy on integrated oceans management. The speed of policy adoption has necessitated equally rapid development of scientific and management tools to support practical implementation. We discuss some of the scientific tools that have been developed to meet this need. These tools include extension of the management strategy evaluation (MSE) approach to evaluate broader ecosystem-based fishery management strategies (using the Atlantis modelling framework), development of new approaches to ecological risk assessment (ERA) for evaluating the ecological impacts of fishing, and development of a harvest strategy framework (HSF) and policy that forms the basis for a broader EBFM strategy. The practical application of these tools (MSE, ERA, and HSF) is illustrated for the southern and eastern fisheries of Australia.

Marine heatwaves (MHWs) are prolonged extreme oceanic warm water events. They can have devastating impacts on marine ecosystems -for example, causing mass coral bleaching and substantial declines in kelp forests and seagrass meadows -with implications for the provision of ecological goods and services. Effective adaptation and mitigation efforts by marine managers can benefit from improved MHW predictions, which at present are inadequate. In this Perspective, we explore MHW predictability on shortterm, interannual to decadal, and centennial timescales, focusing on the physical processes that offer prediction. While there may be potential predictability of MHWs days to years in advance, accuracy will vary dramatically depending on the regions and drivers. Skilful MHW prediction has the potential to provide critical information and guidance for marine conservation, fisheries and aquaculture management. However, to develop effective prediction systems, better understanding is needed of the physical drivers, subsurface MHWs, and predictability limits. [H1] IntroductionProlonged extreme ocean warming events -also known as marine heatwaves (MHWs) -can severely impact marine ecosystems and the services they provide 1-6 . Yet despite their significance, dedicated and coordinated research only became prominent following the extreme event off Western Australia in 2011 7,8 . Indeed, it was during this event that the term 'marine heatwave' was first used to characterise an extensive, persistent and extreme ocean temperature event 9 (Box 1), spurring a new wave of research into their physical processes and corresponding impacts. Since 2011, MHWs have been observed and analysed both retrospectively and contemporaneously, and are now recognised to occur over various spatio-temporal scales. For example, given the ocean's heat capacity and dynamical scales, MHW events can persist for weeks to years [10][11][12][13][14][15][16] . They further vary in spatial extent and depth depending on the processes that cause and maintain them, as well as the geometry of the regions in which they occur. For instance, MHWs can be locally confined to individual bays 17 , around small islands or along short sections of coastline, or be broadly distributed over regional seas 10,18 , ocean basins 15,19 , or even spanning multiple oceans 20,21 (for a map of major MHW events, see Fig. 1). As well as the physical drivers, the ecological impacts of MHWs have also been studied in considerable depth. The effects include biodiversity loss and changes in species behaviour or performance 3,7 , loss of genetic diversity and adaptive capacity 22 , economic impacts from changes in fishery catch rates 1,[23][24][25] , and mortality or altered performance of farmed aquaculture species 13 .The impacts of MHWs are particularly evident on coral reefs (promoting widespread bleaching, including pan-tropical events 26 ), kelp forests (driving significant loss of kelp forest habitats off the coast of Western Australia, New Zealand, Mexico and the North Atlantic 7,27-30 ...

Southern bluefin tuna (SBT), Thunnus maccoyii (Castelnau), is a quota-managed species that makes annual winter migrations to the Tasman Sea off south-eastern Australia. During this period it interacts with a year-round tropical tuna longline fishery (Eastern Tuna and Billfish Fishery, ETBF). ETBF managers seek to minimise the bycatch of SBT by commercial ETBF longline fishers with limited or no SBT quota through spatial restrictions. Access to areas where SBT are believed to be present is restricted to fishers holding SBT quota. A temperature-based SBT habitat model was developed to provide managers with an estimate of tuna distribution upon which to base their decisions about placement of management boundaries. Adult SBT temperature preferences were determined using pop-up satellite archival tags. The near real-time predicted location of SBT was determined by matching temperature preferences to satellite sea surface temperature data and vertical temperature data from an oceanographic model. Regular reports detailing the location of temperature-based SBT habitat were produced during the period of the ETBF fishing season when interactions with SBT occur. The SBT habitat model included: (i) predictions based on the current vertical structure of the ocean; (ii) seasonally adjusted temperature preference data for the 60 calendar days centred on the prediction date; and (iii) development of a temperaturebased SBT habitat climatology that allowed visualisation of the expected change in the distribution of the SBT habitat zones throughout the season. At the conclusion of the fishing season an automated method for placing management boundaries was compared with the subjective approach used by managers. Applying this automated procedure to the habitat predictions enabled an investigation of the effects of setting management boundaries using old data and updating management boundaries infrequently. Direct comparison with the management boundaries allowed an evaluation of the efficiency and biases produced by this aspect of the fishery management process. Near real-time fishery management continues to be a realistic prospect that new scientific approaches using novel tools can support and advance. K E Y W O R D S : eastern Australia, habitat preference, satellite archival tags, southern bluefin tuna, spatial management.