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Shifts in species’ ranges are one of the most frequently reported and globally ubiquitous impacts of climate change, with rates of movement being particularly high in the sea. The arrival of multiple range extending species can cause serious issues for natural resource managers; some species threaten ecosystem function while others present social and/or economic opportunities. An early indication of which species are potentially extending their ranges can provide useful guidance for managers regarding future investments in impact assessment, monitoring or potential management intervention. Given that scientific monitoring data on potential range shifting species are often sparse in the marine environment a rapid assessment that utilises and assimilates disparate data sources that vary in quality, quantity and collection methods is needed. Off the east coast of Tasmania surface waters have been warming at almost four times the global average and dozens of species range shifts have already been documented. Building on existing methods used in the early detection of invasive species, we developed a cost-effective and rapid screening assessment tool that uses monitoring data from a variety of sources, particularly from the citizen science program Redmap, to classify levels of confidence in potential range extensions over a three year time period (2009–2012) for a variety of marine species. From our assessment of 47 species, eight were classified with “high” confidence as potentially extending their ranges. The “high” confidence classification of these species suggests they should be a priority when investigating potential ecosystem and socio-economic impacts. [ABSTRACT FROM AUTHOR]

Abstract: World fisheries, already vulnerable, are under increasing pressure from the impacts of climate change. Using the Tasmanian rock lobster industry as a case study, we considered the efficacy of risk perception as a tool to inform how to communicate the science of climate change and suggestions for management in relation to development of adaptation strategies for fisheries. Fishers surveyed in this study operate in a fishery that is expected to undergo large changes as a consequence of climate change. Fishers also reported observations of similar large changes in the marine environment and lobster fishery consistent with climate change; yet most fishers surveyed expressed doubts about whether climate change was a real process. The important point for adaption of the industry to climate change is that fisher perceptions of risk tended to create barriers to acceptance of climate change as an issue. This means that there is a barrier to communication and awareness about climate change and thus a barrier to future action on the issue. Improving acceptance of climate change and thus ability to adapt will require the development of communications that are culturally appropriate and palatable to fishers. We argue that the application of social learning principles in communications about climate change may be one constructive way forward. [Copyright &y& Elsevier]

A combination of passive tracking and conventional tagging was used to provide insight into the movement patterns of the draughtboard shark Cephaloscyllium laticeps, the most common catshark in coastal areas of southern Australia. A series of acoustic receivers deployed throughout south-eastern Tasmania as well as a receiver array along an isolated reef, Crayfish Point Reserve (CPR), passively tracked 25 C. laticeps from January to July 2003. Cephaloscyllium laticeps were present from 4 to 98 days. The majority of the C. laticeps stayed within the CPR where most individuals were active throughout the night. They were found actively moving ( i.e. when a C. laticeps was consecutively detected by two or more non-overlapping receivers, suggesting the individual was moving) and spending periods of minor movements ( i.e. when an individual was consecutively detected by only one receiver, suggesting it was at rest). The length of these minor movements periods, observed both day and night, ranged from 1 h to 5 days. In addition to passive tracking, 1552 conventionally tagged C. laticeps were released in the eastern and south-western coastal areas of Tasmania and within the CPR between January 2000 and April 2007. The CPR showed a higher recapture rate, 38%, than eastern and south-western areas where the recapture rates were 10 and 3%, respectively. Within the CPR, 36% of the sharks were recaptured on multiple occasions. The maximum time at liberty ranged from 1 month to 7 years. The majority of the C. laticeps were recaptured in the vicinity of where they were released (<10 km), although larger longer-term movements of up to 300 km were recorded. The large amount of multiple recaptures within the CPR, in addition to acoustic tagging results, indicated a high degree of site fidelity for C. laticeps. This isolated reef appears to be an important habitat for this species, and therefore, the current protection status of this area is probably beneficial for the conservation of C. laticeps. [ABSTRACT FROM AUTHOR]

Research longline sampling was conducted seasonally from December 2006 to February 2009 to investigate the occurrence and population structure of the broadnose sevengill shark Notorynchus cepedianus in coastal areas of south-east Tasmania. Notorynchus cepedianus showed a consistent temporal trend in seasonal occurrence in Norfolk Bay characterized by high abundances in summer to near absence in winter. This pattern was less pronounced in the Derwent Estuary, where fish were still caught during winter. The absence of smaller total length ( L) classes (<80 cm) from the catches suggests that N. cepedianus are not using these coastal habitats as nursery areas. Of the 457 individuals tagged, 68 (15%) were recaptured. Time at liberty ranged from 6 days to almost 4 years and all but one of the recaptures were caught in its original tagging location, suggesting site fidelity. The large number of N. cepedianus in these coastal systems over summer indicates that these areas are important habitats for this species and that N. cepedianus may have a significant influence on community dynamics through both direct and indirect predator-prey interactions. [ABSTRACT FROM AUTHOR]

The article presents a study which examines the spatial variability in fatty acid profiles of temperate reef species in Tasmania under the classification of tropic structures among marine systems. The study uses the samples of macroalgal plants found on the temperate reefs, the primary producers and consumers of subtidal marine, and the 2-way factor permutational multivariate analysis of variance (PERMANOVA). The study shows that the greatest variation of stable isotope was located at the smaller spatial scales, while the fatty acid profiles have greatest proportion of variance on regional scale. Moreover, the study adds that spatial variance for stable isotopes and fatty acids depends on broader spatial scales and replicate samples.

A key consideration in assessing impacts of climate change is the possibility of synergistic effects with other human-induced stressors. In the ocean realm, climate change and overfishing pose two of the greatest challenges to the structure and functioning of marine ecosystems. In eastern Tasmania, temperate coastal waters are warming at approximately four times the global ocean warming average, representing the fastest rate of warming in the Southern Hemisphere. This has driven range extension of the ecologically important long-spined sea urchin (Centrostephanus rodgersii), which has now commenced catastrophic overgrazing of productive Tasmanian kelp beds leading to loss of biodiversity and important rocky reef ecosystem services. Coincident with the overgrazing is heavy fishing of reef-based predators including the spiny lobster Jasus edwardsii. By conducting experiments inside and outside Marine Protected Areas we show that fishing, by removing large predatory lobsters, has reduced the resilience of kelp beds against the climate-driven threat of the sea urchin and thus increased risk of catastrophic shift to widespread sea urchin barrens. This shows that interactions between multiple human-induced stressors can exacerbate nonlinear responses of ecosystems to climate change and limit the adaptive capacity of these systems. Management actions focused on reducing the risk of catastrophic phase shift in ecosystems are particularly urgent in the face of ongoing warming and unprecedented levels of predator removal from the world's oceans. [ABSTRACT FROM AUTHOR]

The article discusses a study which uses a combined chemical tracer approach to investigate whether the diet of Jasus edwardsii, a lobster, differs between fished areas with low lobster density and reserve areas with higher lobster density in Tasmania. The study discovers that Jasus edwardsii eats a greater proportion of food items from higher trophic levels in fished areas than adjacent reserves. It details that lobster fishing changes the trophic status of prey for predators and proposes that fatty acid analyses is limited in finding out changes in the predators' dietary composition.

Global climate change is leading to redistribution of marine species and altering ecosystem dynamics. Given recent poleward range extension of the barrens-forming sea urchin Centrostephanus rodgersii (Diadematidae) from mainland Australia to Tasmania, there is a need to understand the population dynamics of this ecologically important species in the Tasmanian environment. This paper informs possible population dynamics of C. rodgersii in Tasmania by examining its reproductive ecology in this new environment. Reproductive periodicity (gonad index and propensity to spawn) was assessed bimonthly over 18 months at four sites in eastern Tasmania spanning ∼2° in latitude. At all sites, C. rodgersii displayed a strong seasonal cycle in gonad production with major spawning occurring in winter (∼August) at minimum annual water temperature. Gametes from Tasmanian C. rodgersii were viable as determined by fertilization and early development trials. However, development to the two-arm stage at ∼3 weeks was strongly dependent on water temperature across the 8–20 °C temperature range, with poor development occurring below 12 °C. The range of temperatures tolerated by Tasmanian C. rodgersii larvae was similar to that of larvae from its native New South Wales range, indicating that this species has not undergone an adaptive shift to the cooler Tasmanian environment. There was also no evidence for an adaptive shift in reproductive phenology. Importantly, coastal water temperatures in eastern Tasmania during the peak spawning in August fluctuate about the 12 °C larval development threshold. Recent warming of the eastern Tasmanian coast and further warming predicted by global climate change will result in an environment increasingly favourable for the reproduction and development of C. rodgersii. [ABSTRACT FROM AUTHOR]