Te Wāhipounamu – South West New Zealand

The World Heritage area is a major domestic and international destination and is a focal point for New Zealand’s burgeoning tourism industry. Visitor arrivals to New Zealand have been expected to grow at 4.6% a year, reaching 5.1 million visitors in 2024 — from 3.7 million in 2017; the total international spend is expected to reach $14.8 billion in 2024, up 40% from 2017 (MBIE, 2024). Major pressure points include Doubtful and Milford Sounds; Great Walks – Milford, Kepler and Routeburn Tracks; helicopter flights and landings at the Fox, Franz and the Tasman Glaciers; and the Hooker Valley at the base of Mt Cook. The establishment of large private accommodation complexes (Ultimate Hikes 2024) along the Routeburn Track has been an intensification arising from a decision to increase the numbers of walkers permitted on commercial tours. According to the NZ government, there were 2.96 million overseas visitor arrivals recorded in 2023, a post-pandemic increase of 1.52 million from the previous year; between December 2023 and February 2024, the number of New Zealanders visiting protected natural areas each month remained near 50% (DOC, 2024a). The high numbers of visitors have increased management challenges at some locations, with problems such as disposal of human waste management at popular sites; increased aircraft demand – particularly related to recreational use and glacier landings; traffic congestion; damage to the natural environment; and management of heavily-used campsites (Adventure Magazine, 2024; Angus & Associates, 2023). Three iconic sites are facing particularly high challenges: Milford Sound / Piopiotahi , Aoraki / Mt Cook, Franz Josef Glacier / Kā Roimata o Hine Hukatere (IUCN consultation, 2025). Visitor experience planning and statutory planning and policy reviews are currently underway at these places. These are reviewing the visitor experience and visitor pressures and impacts at these sites. Trials of limiting parking, booking systems and Park and Ride are all under active consideration. New visitor experience plans will be in place for the 26/27 summer season. These will protect the values of these sites and ensure a world class visitor experience is maintained. Additional infrastructure investment is occurring with new funding from the International Visitor Levy.

A particular concern at some locations is the conflict between the value of the area for its seclusion and tranquillity, and the noise generated by mechanised access, most notably aircraft and jetboats. Approved helicopter and plane landing sites are listed in the national-park management plans and conservation management strategies. There are also flight path protocols to minimise noise in the vicinity of the Milford Track, Westland Tai Poutini National Park, and in the Hooker Valley below Aoraki/Mount Cook. However, other than standard Civil Aviation regulations, which allow planes in ‘uninhabited areas’ to fly as low as 500 feet (152 m) above the ground, there is little control (IUCN Consultation, 2020). The rapid increase in tourism numbers has exacerbated tension between user groups. An example was the dispute over the number of helicopter landings on the Ngapunatoru ice plateau inside the World Heritage site (FMC, 2016; NZAC, 2016; Wilderness Magazine, 2016) and the resulting decision of the New Zealand Ombudsman (Ombudsman, 2018). This conflict as well as the impacts of noise on visitor experience and potentially on wildlife at some locations is acknowledged by the area manager and management plans have proposed means of dealing with the issue (DOC, 2018).

New Zealand has been geographically separated from other land masses for 80 million years, so its flora and fauna evolved independently and are at risk from invasive species, many of which are listed by the Department of Conservation (DOC, 2024b). The site's vegetation suffers from introduced browsing animals such as possums, chamois, deer and Himalayan tahr. The site's native birds suffer from introduced predators including rodents and mustelids. Impacts include loss of vegetation, localised extinctions, reductions in the range of key species, and a significant decline in the abundance of some indigenous biota, particularly native avifauna. The existing policies seek to prevent further incursions, and to control the range and impacts of non-native invasive species. The means of control include poisoning (particularly aerial drops of 1080 poison), baiting, trapping, culling and recreational hunting; research into enhanced methods of control is carried out through government partnerships with educational institutions (DOC, 2024c and 2024e). Use of pesticides throughout the country, including within the World Heritage site, is notified to the public through an interactive map (DOC, 2024d). Many aspects of the program are detailed on this website, including outcomes, highlights, parliamentary supervision and monitoring. The use of 1080 bait attracts criticism and controversy (SAFE, 2019; Chand et al, 2023) but is strongly supported by the country's major nature-conservation group (Forest and Bird, 2020a) and has been backed by parliamentary inquiries and reports (PCE 2011 and 2013a). The Himalayan tahr is another introduced species with impacts on native vegetation within the World Heritage area (Cruz et al, 2014). In autumn 2019 the population of tahr on public conservation lands was estimated to be about 35,000 (despite the target level of 10,000) and parts of the Westland Tai Poutini National Park were described as ‘a tahr game park’ (Wilderness Mag, 2018). A control plan has been in place since 1993 and sets limits and intervention densities to trigger the culling of tahr. The objectives and outcomes of tahr control operations are provided by DOC (2024f). DOC needs to maintain efforts to achieve the goals of the 1993 plan as recreational and commercial hunting have proven insufficient to control numbers adequately. The website of the Department of Conservation identifies many of NZ’s species as threatened (DOC 2024ad) – many of them occur within the World Heritage area. The government takes the threat of invasive animals very seriously and in 2016 announced the 'ambitious' goal of making New Zealand free of predators by 2050 (DOC, 2024g), with a significant program occurring in 120,000 ha of National Park and adjacent land in the South Westland District (Predator Free South Westland) (PF2050, 2021).

In many locations on the periphery of the World Heritage area, native vegetation is threatened by introduced plant species. These include lupin, broom, non-native grasses, buddleia and a variety of 'wilding conifers'. 'Wilding conifer' is the New Zealand term for introduced conifers that are spreading across the landscape – self-sown and unwanted. They include cedars, pines, firs, cypress, larches and spruces. Wilding conifers have spread in eastern parts of the World Heritage site; they modify natural ecosystems such as tussock grassland so much that the unique New Zealand landscape is lost and native plants and animals are evicted or die (DOC, 2024h). The pressure from invasive weeds is manageable with sustained effort and various control methods. The challenge is sustaining this management effort and ensuring that these invasive plants do not get a foot hold (IUCN consultation, 2025). Efforts to address this problem are shared by community groups and government through a national strategy and an associated control program (DOC, 2024i). Freshwater weeds and marine exotic seaweeds in the waterways of Fiordland are also a problem (DOC, 2024j). Several catchments in the northern section of the World Heritage area have been invaded by herbaceous weeds and woody shrubs that, without intervention, can spread rapidly. Species such as tradescantia take hold of understoreys as a groundcover, preventing seedlings of native species to establish. Annual control of herbaceous and woody weed species is preventing further spread and, in some places, has successfully reduced seed load for future years; however, use of new techniques, such as biological controls, are being trialled on species that are more resistant to chemical and manual control (IUCN Consultation, 2020). New Zealand also has a strong biosecurity regime (DOC, 2024j). The website of the Department of Conservation identifies many of NZ’s species as threatened (DOC, 2024ad) – many of them occur within the World Heritage area, and some are threatened by weed invasion.

Highly visible effects of climate change include measurable reductions in permanent ice fields and glaciers (eg Fox, Franz and Tasman). The Department of Conservation strongly acknowledges the significance of this threat, warning of higher temperatures, more extreme weather events, changing rainfall distribution, threats to particular species and ecosystems, interactions with other threats (such as invasive species), and impacts on human activities and infrastructure within the World Heritage area (DOC, 2024n). Loss of glacier ice represents a significant impact on a major contributor to the site's Outstanding Universal Value; this has been well documented and studied (NIWA, 2018; Purdie et al., 2018; Purdie and Kerr, 2018; NIWA, 2024) and is part of a global phenomenon. Studies indicate that many glaciers at lower altitudes or on the periphery of the area face an ‘extinction horizon’, with accelerated ice-loss underway since the 2000s (NIWA, 2024a). Under current temperature projections, it is predicted that up to 50% of the indigenous alpine species may become endangered or extinct by 2100 because of encroachment by shrubs and trees, fragmentation of habitat, invasion by alien species; and severe weather-related events (McGlone et al., 2011; NIWA, 2024b). Other studies also describe the 'thermal squeeze' impacting alpine environments as well as the aquatic and marine threats (Keegan et al, 2022). Impacts on aquatic environments such as lakes are poorly understood but could be significant (NIWA, 2020a). The sheer size, diversity and basically unmodified nature of the area provide resilience as well as maintaining connections across landscapes that allow plants and animals to move as they adapt to the inevitable disruptions caused by a changing climate. Nevertheless, the ecological impacts of climate change are pervasive and are likely to be significant in the medium to longer term. Focus on how to build greater resilience into the ecosystems and landscapes to ensure that the impacts of climate change can be reduced is necessary e.g. through greater effort on animal and plant pest control across the area (IUCN consultation, 2025).