The Tasmanian Wilderness World Heritage Area (TWWHA) has globally significant natural and cultural values, some of which are dependent on the absence of fire or the presence of particular fire regimes. Planned burning is currently used to reduce the risk of loss of world heritage values from unplanned fires, but large and damaging fires still occur, with lightning as the primary ignition source. Lightning-caused fire was rare in the TWWHA before 2000. There has since been an increase in both the number of fires following lightning storms and the area burnt by these fires. In the absence of a direct measurement of lightning strike incidence, we tested whether changes in rainfall, soil dryness and fuel load were responsible for these changes in fire incidence and extent. There were no relationships between these variables and the incidence of fires associated with lightning, but the variability in the Soil Dryness Index and the mean of 25% of driest values did predict both the number and area of fires. Thus, it appears that an increase in the proportion of lightning strikes that occur in dry conditions has increased ignition efficiency. These changes have important implications for the management of the TWWHA’s values, as higher projected fuel loads and drier climates could result in a further increase in the number of fires associated with lightning.

The regeneration of plants post-fire has widely been shown to be attractive to vertebrate herbivores. However, there are few data relevant to the effect of fire size on herbivore densities. In dry eucalypt forest in one region and hummock sedgeland in another region, we used timed scat counts to test the effect of fire and fire size on Tasmanian macropod densities 6 months after burning.We also tested whether soil characteristics and the nature of ground cover related to the degree of attractiveness of post-burn regeneration. Soil nutrients and higher covers of grasses and herbs in ground layer vegetation were associated with higher macropod densities. In dry eucalypt forest, fire incidence and fire size did not affect macropod density, while in hummock sedgeland, fire had a positive effect on macropod density, but fire size had no effect.

Science is frequently used by opposing sides in environment–development debates. Scientific input from an environmental perspective can be inhibited if those in favour of development control research funding. We test whether such a situation can result in outcomes desired by neither of the protagonists, and seek to identify how negative outcomes can be avoided, using the example of fish farming in Macquarie Harbour, Tasmania. A marked decline in dissolved oxygen (DO) at 19–21m depth in Macquarie Harbour, Tasmania, occurred between 2009 and 2011. DO continues to be low. DO change was associated with changes in the benthic biota, with effects extending from fish farms into the Tasmanian Wilderness World Heritage Area and threatening a Tasmanian endemic fish. The reverse precautionary response of industry and government was to undertake further research because the causes of the changes were not fully understood. We present simple graphs and analyses that suggest that the only substantial predictor of benthic DO reduction is fish production from marine farms, with variability in discharge, catchment rainfall, wind speed, sea surface temperatures and sea level pressure having no effect. Adaptive management of fish farming in Macquarie Harbour seems to require an estuary-wide approach rather than the current attention to the effects of single pens. The broader implications of the case study are that the science related to the environmental impacts of an industry needs to be undertaken by scientists in secure positions funded independently of industry and government.

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