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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]

While governments and natural resource managers grapple with how to respond to climatic changes, many marine-dependent individuals, organisations and user-groups in fast-changing regions of the world are already adjusting their behaviour to accommodate these. However, we have little information on the nature of these autonomous adaptations that are being initiated by resource user-groups. The east coast of Tasmania, Australia, is one of the world's fastest warming marine regions with extensive climate-driven changes in biodiversity already observed. We present and compare examples of autonomous adaptations from marine users of the region to provide insights into factors that may have constrained or facilitated the available range of autonomous adaptation options and discuss potential interactions with governmental planned adaptations. We aim to support effective adaptation by identifying the suite of changes that marine users are making largely without government or management intervention, i.e. autonomous adaptations, to better understand these and their potential interactions with formal adaptation strategies.

Five annual capture-mark-recapture surveys on Jasus edwardsii were used to evaluate the effect of sample size and fishing effort on the precision of estimated survival probability. Datasets of different numbers of individual lobsters (ranging from 200 to 1,000 lobsters) were created by random subsampling from each annual survey. This process of random subsampling was also used to create 12 datasets of different levels of effort based on three levels of the number of traps (15, 30 and 50 traps per day) and four levels of the number of sampling-days (2, 4, 6 and 7 days). The most parsimonious Cormack-Jolly-Seber (CJS) model for estimating survival probability shifted from a constant model towards sex-dependent models with increasing sample size and effort. A sample of 500 lobsters or 50 traps used on four consecutive sampling-days was required for obtaining precise survival estimations for males and females, separately. Reduced sampling effort of 30 traps over four sampling days was sufficient if a survival estimate for both sexes combined was sufficient for management of the fishery.

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., (© 2012 The Authors. Journal of Fish Biology © 2012 The Fisheries Society of the British Isles.)