Tasmanian Wilderness

The Chytrid fungus (Batrachochytrium dendrobatidis) has dramatically affected amphibians across the world. There are four frog species in Tasmania at some risk of extinction from this pathogen (Skerratt et al. 2016). The World Heritage site is assumed to still be largely disease-free, although more data is required to inform and appropriately assess the risk to native species in the TWWHA (DPIPWE, 2021) and the current extent of spread is not known. Some reports indicate that since 2010 there is little spread of the fungus in the site and no decline in frog distribution has been detected since 2010 (IUCN Consultation, 2024). Spreading of Chytrid is known to be associated with human disturbance and the fungus is mainly moved by people (Allan et al., 2009; Pauza et al. 2010). Management plans to stop the fungus from affecting frogs in the site are in place, but with increasing movement of people within the site, including in the most remote parts of the site, the risk is increasing and challenges remain in implementation. Initial chytrid research within the World Heritage site has shown that where chytrid is present the concentration of zoospores is very low suggesting that some characteristics of the site, such as low pH, may be restricting the impact of this disease on frogs in the World Heritage site (IUCN Consultation, 2020).

Psittacine Circoviral Disease is present in wild and captive populations of the Critically Endangered orange-bellied parrot. The disease is highly transmissible and can accumulate in the environment. The disease has been known to result in morbidity and mortality of nestlings and adult birds in captivity and in the wild. There have been no recent outbreaks or significant mortality in the wild population, with the last outbreak resulting in significant mortality occurring in 2014/15 (IUCN Consultation, 2024). The Tasmanian Wilderness World Heritage Area Biosecurity Strategy 2021-2031(DPIPWE 2021) provides a high-level strategy to guide decision making and provide direction on minimising the risks and impacts of invasive diseases on the natural and cultural values of the TWWHA, and highlights the need for monitoring and evaluation to allow for evidence-based adaptive management.

Plant diseases and dieback, especially Phytophthora dieback caused by the root pathogen Phytophthora cinnamomi pose a major threat to the plant communities of the World Heritage area. Phytophthora cinnamomi was previously restricted to hiking trails, but increasing road access due to logging and mining operations in the proximity to the World Heritage site open up more pathways to this fungus and numerous other organisms into wilderness areas (IUCN and ICOMOS, 2015; HVEC, 2007; 2009; SWST, 2008; Hitchcock, 2008; Law, 2009). In 2010 a significant new infestation was detected on the Loddon Plains and trial stream monitoring was conducted on the boundary for Phytophthora species. A Tasmanian Phytophthora cinnamomi management plan is in place to mitigate the risk of further spread and management of the pathogen (State Party of Australia, 2015). In 2018, Phytophthora cinnamomi infections were reported affecting alpine communities on Mt Read at over 1000m altitude. Although outside of the World Heritage site, this is a significant increase in altitudinal limit for this pathogen (potentially linked to climate change), which increases the risk posed in the World Heritage site (IUCN Consultation, 2020).

A volunteer led and government supported campaign to control species threatening coastal geomorphic and ecological processes (marram grass (Ammophila arenaria) and sea spurge (Euphorbia paralius) has achieved major results in managing and eradicating both invasives, such that it now requires only annual removal of sporadic invaders (although due to the highly invasive nature of these species, each could re-establish quickly without an ongoing control effort). The program has undertaken over 8,500 days work to remove 14.4 million sea spurge plants and has achieved approximately a 99 per cent reduction in sea spurge plants and a 98 per cent reduction in marram grass clumps (Wildcare, 2023). Should volunteer control efforts cease, the threat rating from sea spurge and its potential impact on the coastal values of the TWWHA may result in a high threat rating in the future.

Inland weed species such as blackberry (Rubus fruticosus) are mostly a problem in areas of mechanical or natural disturbance such as roadsides and river banks and are highly sporadic in their occurrence (Parks and Wildlife Service, 1999). Exotics reported as spreading include gorse (Ulex europaeus), ragwort (Senecio jacobaea), broom (Cytisus scoparius), Canadian pond weed (Elodea canadensis) and holly (Ilex spp.) (Parks and Wildlife Service, 2004; Hitchcock, 2008). The level of impact of environmental weeds in the World Heritage site has increased as a result of there being more invasives now in the TWWHA than there were prior to the addition of the extension area in 2013, which incorporated some established weed issues into the site (Balmer et al., 2017). The Tasmanian State of the Environment report (TPC, 2024) analysed 38 declared weeds and found 14 are present in the World Heritage area with two having spread to the World Heritage area since 2009 (crack willow and slender thistle).

Apart from sea spurge and marram, there is a lack of data on occurrence however, the localised impacts on particular values may be significant.

Bushfires, especially ‘landscape-scale fires’ (i.e. fires that are not stopped by natural fire boundaries such as wet forest or major rivers) and peat fires are a significant threat. While fire is a key component of the natural ecology of the World Heritage site, evidence indicates that fire regimes are shifting (PWS, 2015). Lightning strikes now dominate (over 99% of area burnt) as a source of ignition of major bushfires within the World Heritage site. Concurrently, the occurrence of extremely dry and hot summers promotes the occurrence of large, intense fires that pose a severe threat to the site’s ancient life forms, most of which have limited capacity to regenerate after fire (PWS, 2015; Bowman et al. 2021; Bowman et al. 2022). Increased dryness and fires also pose a significant fire threat to the TWWHA’s extensive organic soils and their unique vegetation communities (Prior et al. 2024).

In response to the 2016 bushfires, the TWWHA Bushfire and Climate Change Research Project was launched. The project concluded that the site's values that are most threatened by an increase in fire frequency are fire-sensitive palaeoendemic species, alpine and rainforest ecosystems and organic soils and landforms (Press, 2016). In the summer of 2018/2019 lightning ignited fires burned 6% of the World Heritage site, of which 12.3% consisted of fire-sensitive vegetation, recognized as part of the Outstanding Universal Value of the site (State Party of Australia, 2019), much of which is unlikely to return to the burned sites in centuries, if at all. There was also a loss of some globally rare peat mounds (State Party of Australia, 2019). Management activities are now informed by a TWWHA Fire Management Plan for the World Heritage site (Tasmania Parks & Wildlife Service, 2022) and an Aboriginal Cultural Burning Policy (Tasmania Parks & Wildlife Service, 2023).

In 2025 dry lightning started several major bushfires in western Tasmania and burned across a diverse array of endemic vegetation — from coastal plains to rainforest and sub-alpine woodlands, mostly in areas adjoining the World Heritage area, but some 9,393 ha inside the TWWHA affected a major section of the popular Overland Track (IUCN Consultation, 2025).

Following a fire, especially one of high intensity, geomorphic process is typically accelerated, with active sheet erosion, debris flows and other mechanisms of degradation to be expected (Shakesby and Doerr, 2006).

Compared with the rest of Tasmania and Australia, the TWWHA is characterised by low diversity and abundance of invasive species. Notwithstanding, invasive alien animal species in many taxonomic groups are a significant and permanent threat to conservation values of the World Heritage site. The current management plan mentions 25 vertebrate and 45 invertebrate invasive alien species; however only some vertebrate and invertebrate species are widespread in the TWWHA: brown trout (Salmo trutta), common starling (Sturna vulgaris), superb lyrebird (Menura novaehollandiae), European rabbit (Oryctolagus cuniculus), feral cat (Felis catus), Krefft’s Glider (Petaurus notatus), European wasp (Vespula germanica), honeybee (Apis mellifera), hedgehog slug (Arion intermedis) and the large earth bumblebee (Bombus terrestris). Fallow deer, which are restricted to parts of the Central Plateau region of the TWWHA, have increased their distribution and abundance (Cunningham et al., 2022) partly due to westward migration and partly due to TWWHA boundary extensions. Superb lyrebirds, introduced in the 1930s continue to spread west and north in the TWWHA, doubling their area of extent between 2010 and 2025 (IUCN Consultation, 2025).

Some of these species compete with native species for nesting sites, others alter native vegetation and a few predate threatened species. Efforts to eradicate invasive populations of animals are hindered by the rugged and remote nature of the TWWHA and the requirement for significant funding. Australian heritage grant funding enabled the aerial cull of fallow deer in 2023, 2024 and 2025 substantially reducing their population (PWS 2025). Early detections of New Zealand Screw Shells and Pacific Oysters on Port Davey enabled their eradication.

The outbreak of the lethal Devil Facial Tumour Disease in Tasmanian Devils has resulted in a population decline of over 75% in some parts of Tasmania. Difficulties in access has limited systematic monitoring for disease in the World Heritage site. However, camera monitoring in the TWWHA since 2020 indicates that devils occur widely within the World Heritage site and much of it remains free of the disease (Driessen et al. 2020, 2022, 2024a, 2024b; IUCN Consultation, 2020).

Increased tourism development, recreation and visitor activities and associated infrastructure risks impacting on the OUV of the site, however currently the threat level can be considered low. The use of boats to access remote areas and an increase in the frequency and size of commercial cruise operations, as well as boating and diving activities in the Port Davey, Bathurst Harbour region are known threats to OUV values (Parks and Wildlife Service, 2004; Birdlife Australia et al., 2017). Importantly, these activities and the associated infrastructure may also pose a threat to Aboriginal cultural values in the landscape if not appropriately managed. There are also known biosecurity risks (such as the spread of the introduced invasive freshwater algae Didymo/Rock Snot (Didymosphenia geminata) and impacts on natural values and wild character of the area from an increase in unplanned and therefore unhardened and/or inappropriate walking tracks associated with the increased visitation.

A 2021 Tourism Master Plan for the Tasmanian Wilderness World Heritage Area (DPIPWE 2021) was prepared providing guidance on the constraints and opportunities of increased use of the site.

Community concerns have been reported regarding the potential impacts of increasing development of tourism infrastructure and associated mechanised access on the OUV of the World Heritage site (Birdlife Australia et al, 2017; Wilderness Society, 2019; TNPA 2023). These concerns relate to proposals for infrastructure and increased visitor experiences well within the site, rather than in Visitor Service Zones on the margin of the World Heritage site. Previously concerns were raised about the 2016 rezoning of the World Heritage site to enlarge recreation and visitor service zones (Gogarty et al. 2018a). Situated just outside the site, the new Cradle Mountain Visitor Centre opened in 2020 and has proven to be a useful structure for managing increased tourist numbers and providing better education and interpretation for the area. Further development at the Cradle Mountain Visitor Centre is still in planning with the Tasmanian Office of the Coordinator-General working with an unknown bidder to extend the Gateway Village precinct including erection of a new building at the southern end of the site (OCG, 2025a). Additional tourism infrastructure to cater for increasing visitor numbers at Cradle Mountain have included an upgrade to the viewing platform next to Glacier Rock and the new Dove Lake viewing shelter, which opened in January 2023. Some criticism has focussed on the size and scale of the Dove Lake viewing shelter as being inappropriate for the site, while generally there has been a positive response to the introduction of a bus service transporting tourists from the Visitor Centre to Dove Lake, which has significantly reduced impact on the near surrounds of this high visitation area.

A proposal for cable car access to Dove Lake by the Tasmanian and Australian governments has existed for many years with some federal funding approved in 2018 but then withdrawn in 2023 by a later government. In December 2024 the Tasmanian government announced it still wanted to proceed with the proposal and requested new funding from the federal government (Premier of Tasmania 2024).

The use of helicopters for tourist access to the wilderness has been particularly strongly resisted (Gogarty et al. 2018b) with several proposals not given approval including through extensive legal battles, but with several others still under consideration (ABC News, 2024). The 2016 TWWHA Management Plan made provision for aircraft access on a sliding scale across management zones, with landings in the Wilderness Zone limited to those required for management purposes, and aircraft access prohibited or restricted in key recreational areas to avoid impacting the recreational experience sought by some visitors to those areas.

An Aircraft Access Policy was recommended as a high priority by the 2021 Tourism Master Plan to provide clarity on air access "opportunities" while ensuring the values are not compromised, however it has not yet been released.

The planning, assessment and approval processes for tourism and transport projects inside the World Heritage area is complex involving both the Tasmanian and local government, as well as the State Party. Currently several proposals supported by the Tasmanian government are still awaiting decisions from the federal Environment Minister. The decisions on tourism investment opportunities are undertaken by the Tasmanian government through an expression of interest (EOI) process that is managed by the Tasmanian Office of the Coordinator-General and assessed by an independent panel and if accepted need to undertake a Reserve Activity Assessment managed by the Tasmania Parks and Wildlife Service.

It is critical to ensure that such processes carefully assess the temporal and spatial cumulative impacts on the OUV and allow for a clear mechanism for community stakeholder engagement. Any lack of transparency in the process, and the political nature of which projects are supported puts at risk future degradation of the OUV of the site. The EOI process has resulted in 28 tourism proposals being proposed and assessed; with 3 lease/licences signed, 7 approvals underway, 2 under assessment, 16 not approved, withdrawn or surrendered (CGA, 2025b).

The Tourism Master Plan for the Tasmanian Wilderness World Heritage Area provides guidance on the constraints and opportunities for a range of tourism and related recreation experiences within the site (State Party of Australia, 2019) and was released in May 2021 (DPIPWE, 2021).

Through the adoption in 2016 of the statutory management plan for the World Heritage site, both levels of government committed to the entire World Heritage site being off limits to commercial logging, with the exception of the harvesting of a few plantations e.g. 'old' pine plantations, which will be followed by restoration (Australian Government, 2019).

Approximately one third of Macquarie Harbour is included in the property. Macquarie Harbour supports the only known population of the Maugean skate (Zearaja maugeana), a cartilaginous fish listed as endangered under both the Commonwealth Environment Protection and Biodiversity Conservation Act 1999 and Tasmania’s Threatened Species Protection Act 1995. It is included in the 2023 Finalised Priority Assessment List for threatened species listing reassessment.

The Maugean skate's population is thought to have declined by almost 50% between 2014 and 2021, with the main threat to the species being degraded water quality (in particular low levels of dissolved oxygen) due primarily to marine finfish farming, compounded by hydro-electric damming and the impacts of climate change (DCCEEW 2025). Recent evidence indicates a high risk of extinction for the species in the near future in part due to substantially reduced levels of dissolved oxygen throughout Macquarie Harbour. There is a significant correlation between the reduction in dissolved oxygen levels and increases in salmonid aquaculture due to the bacterial degradation of organic material introduced into the water column from fish-feed and fish-waste (DCCEEW 2023).

Fish farms (Atlantic salmon) in Macquarie Harbour have generated effluent that has entered the waters of the World Heritage site and de-oxygenated benthic waters, impacting on the endangered Maugean skate (Kirkpatrick et al., 2019). There is substantial concern for the survival of the species in the wild under ongoing cumulative anthropogenic impacts on the habitat conditions within Macquarie Harbour, Tasmania – the location of the species’ last known viable population (DCCEEW 2023). The Tasmanian Government reported in the past that "there is evidence of deterioration in the environmental condition in Macquarie Harbour broadly, and also within the TWWHA region’ and identified finfish aquaculture as one of the drivers of environmental decline" (EPA, 2017).

Marine finfish farming practices occur outside the boundary of the Tasmanian Wilderness World Heritage property. Marine finfish farming in Macquarie Harbour continues to be regulated by the Department of Natural Resources and Environment Tasmania and the independent EPA. Tasmania’s regulatory framework since 2012 has adapted to respond to concerns related to water quality in Macquarie Harbour insofar as they can be impacted by fish farming. Management controls have been imposed on marine farming planning management by the EPA since early 2017 which has resulted in a significant reduction in farmed salmonids within Macquarie Harbour from the peak standing biomass in 2014-15 at over 20,000 tonnes to 9,500 tonnes in 2020. Further controls from September 2022 have included a shift from a biomass cap to a limit on Total Permissible Dissolved Nitrogen Output (TPDNO) as the mechanism to cap the amount of nitrogen entering the aquatic environment. In October 2023 statutory Environmental Standards for Tasmania Marine Finfish Farming under the Environmental Management and Pollution Control Act 1994 came into effect setting out the environmental management conditions that will be prescribed through environmental licences issued to marine finfish farmers, including the forthcoming benthic condition index which will provide a better assessment of seabed health around farms. In February 2025 the EPA Director provisionally approved a Dissolved Oxygen Mitigation Plan and Water Quality Monitoring Plan, as required under the environmental licences for the ten fish farming leases in Macquarie Harbour. Another action taken by the Tasmania Government is the banning of recreational gillnetting in Macquarie Harbour from November 2024. This activity was identified as a threat to the species through entanglement. In addition, improved monitoring of water flow releases from the Gordon Dam hydro power station has been progressed to inform the impact to the halocline and oxygenation of the harbour. The suite of controls on marine finfish farming and favourable oceanic recharge events may have contributed to improvements in environmental conditions in Macquarie Harbour. EPA monitoring of dissolved oxygen levels in the harbour indicate an upward trend and are within the range measured by the EPA from 1993 to 2010 at several locations (EPA Tasmania, 2024). Median dissolved oxygen levels across Macquarie Harbour are at their highest levels in more than a decade and higher than 2021 (EPA Tasmania, 2024b). Since January 2023 over 99 percent of seabed video surveys at 35 metre compliance sites, including those within the Tasmanian Wilderness World Heritage area, are compliant with Environmental Licence Conditions (IUCN Consultation, 2025).

The University of Tasmania’s Institute of Marine and Antarctic Studies has released a series of reports on its research into the Maugean skate population status (Moreno et al. 2025). The most recent report indicates that there are signs of recovery of the species as the capture of juveniles in 2022, 2023 and 2024 shows some recruitment success. The primary conclusion of the report is that the population appears to be recovering and that more robust sampling is required. A National Recovery Team for the Maugean skate has been jointly established. The Recovery Team includes representation from all stakeholder groups with a significant interest, or relevant technical expertise, in Maugean skate conservation planning. It provides expertise in environmental remediation, and in addressing potential impacts to the community. Using guidance from the Commonwealth Threatened Species Scientific Committee, as outlined in the approved Maugean Skate Conservation Advice, as well as the Tasmanian Government’s Maugean Skate Conservation Action Plan, the Recovery Team developed a Roadmap of Agreed Actions which prioritises key research and conservation management actions for recovery of the species, many of which are currently underway.

In the past extensive erosion on the Central Plateau occurred due to historic land use practices. Ongoing bank erosion on the middle Gordon River can be attributed to flow regulation for electricity generation, while the lower Gordon river is impacted by erosion by boat wave wake, as are several other southwestern estuarine rivers. Coastal erosion is occurring on south-west beaches and estuaries due to extreme climate events, which threaten geodiversity values and dependent natural and cultural values. Studies have been undertaken to assess erosion risk and to devise mitigation options (e.g. Storey and Comfort 2007; Eberhard et al., 2015, Bradbury, 2019). Revegetation of bare ground induced by grazing and burning on the Central Plateau occurred after the removal of stock but has ceased in recent decades (Kirkpatrick and Bridle, 2013), however an increase in extensive extreme bushfires in recent years has increased erosion risk.

Darwin glass (formed by a large meteorite impact) is known to be collected for commercial gain. Other rare minerals are also known to have been collected, while fossils (e.g., thylacine bones) are a potential target. Surveillance is difficult and successful prosecution rare (IUCN Consultation, 2024). Ad hoc observations indicate that unauthorised scientific collecting has occurred in places, e.g. obvious holes defacing outcrop from which core samples have been taken. Casual souveniring is a related albeit relatively minor threat.

Climate change is responsible for a broad range of changes and increasing vulnerability of TWWHA values (DPIPWE, 2021). Tasmania’s complex geography and climate has created biodiversity-rich ecological niches with high levels of endemism, and often relict species (DPIPWE, 2016). Increases in surface and water temperatures may push endemic species to their biophysical limits. Projected increases in temperature and changes to rainfall will likely change terrestrial vegetation structure. Changes in weather patterns and the increase in frequency and intensity of extreme events have dramatically increased the risk of and resulting impacts from landscape scale bushfires such as those which raged through Tasmania in early 2016 and 2018/2019. Fire-sensitive palaeoendemic species (and their associated fauna) - including Huon Pine, Pencil Pine and King Billy Pine, Pherosphaera hookeriana, Diselma archeri and deciduous beech have relictual distributions and are unable to survive fire or disperse and re-establish in the absence of long periods of favourable conditions. Populations of these species which are lost in fires such as those seen in 2016 and 2018/2019 should be considered as permanent losses which are likely irreversible without costly long term climate adaptation interventions. Changes in fire frequency and intensity have also resulted in extensive erosion and peat loss, with a particular concern in the Central Plateau and parts of Southwestern Tasmania, for example in the Davey River area. This process in in turn affects sediment transportation along watercourses. Increasing severity of fire seasons is recognised as the most immediate way climate change will impact natural values within the Tasmanian Wilderness World Heritage Area (TWWHA). Many of the TWWHA ecosystems that contribute to the property’s outstanding natural values are sensitive to fire, including the alpine bogs and meadows, buttongrass plains and ancient rainforests. Dry lightning is lightning that is accompanied by relatively little rainfall. Lightning strikes have been identified as the primary ignition source for some recent large and damaging fires in the TWWHA (Styger et al. 2018). Fires started by lightning strikes in wilderness areas of TWWHA are difficult to identify and suppress due to their remoteness. Overall, the projected increase in variability of rainfall and incidence of drought may result in a further increase in the number of large fires that threaten many of the TWWHA’s natural values (CSIRO et al. 2022).

Changes in water availability, evapotranspiration and the prevalence of heat wave conditions will reduce the probability of eucalypts being able to attain giant tree/very tall forest status in future (DPIPWE 2018). The response of wet eucalypt forest to heatwave conditions has been shown to be a dramatic loss of productivity resulting in tip from carbon sink to carbon source (Wardlaw, 2024). Changes in precipitation, temperature and evaporation have been modelled and are expected to increase risk to the biota of the shallow alpine lakes of the Central Plateau (Davies and Driessen, 2025). Change in snow incidence on taller mountains has not yet been demonstrated to have changed, however snow has been decreasing at lower elevations (Kirkpatrick et al. 2017), which impacts specialist snow patch vegetation.

Furthermore, climate change may impact the Highland Sphagnum Bogs and Associated Fens listed as an endangered ecological community nationally. Increasingly areas of the community are being destroyed or damaged by fires, and the impacts of climate change are predicted to be greatest on the Central Plateau where most of the community occurs (IUCN Consultation, 2020). The TWWHA has the vast majority of Australia’s peatland known as Organosols (Minasny et al. 2023), which support globally exceptional ecosystems and the nation’s most significant terrestrial carbon sink (Isbell, 2021). The trend in soil condition is considered to be getting worse (Cotching, 2018; Cotching and Kidd, 2010; Grose, 2015) particularly in relation to progressive drying of sphagnum bog soils which is then in danger from increased fire frequency and magnitude, along with increased occurrence of dry lightning strikes (Earl et al. 2019).

In addition to coastal erosion, climate change is likely to include temperature rise, sea level rise, extreme weather events and flash flooding which are anticipated to affect rates and magnitudes of further change, including fluvial systems, alpine landforms, karst and in the extensive blanket bogs supporting buttongrass ecosystems. Climate change may also allow establishment of some weeds, pests and diseases currently absent from the property.

The cultural values of the TWWHA are vulnerable to coastal erosion, rockfalls and slumping impacting the integrity of the coastline, including coastal First Nations cultural heritage sites such as rock shelters, shell middens, rock markings, hut depressions, quarries and artefact scatters. Further work is required to fully assess the vulnerability of and risks to cultural values in the TWWHA associated with climate change (CSIRO et al. 2022). In addition to coastal erosion, climate change is likely to include temperature rise, sea level rise, extreme weather events and flash flooding which are anticipated to affect rates and magnitudes of further change, including fluvial systems, alpine landforms, karst and in the extensive blanket bogs supporting buttongrass ecosystems. In montane and subalpine areas, a change in fire regimes may reduce the range of fire-sensitive palaeoendemic trees - including Huon Pine, Pencil Pine and King Billy Pine and is likely to cause a significant decline in the populations of alpine fire-sensitive palaeoendemic species, such as Pherosphaera hookeriana, Diselma archeri and deciduous beech (CSIRO et al. 2022).

To respond to the challenge of the impacts of a changing climate, the Australian Government commissioned an updated climate vulnerability assessment of Australia’s World Heritage properties and a climate change toolkit (State Party of Australia, 2023). The current management plan fully recognizes the challenge (DPIPWE, 2016) and a TWWHA Natural Values Climate Change Adaptation Strategy has been developed (DPIPWE, 2021).