Iguaçu National Park

ICMBio seeks to increase visitation to protected areas. The park is the second most visited federal protected area in Brazil, and there is an increasing trend of visitor numbers (from 645,000 in 2002 to 1.9 million in 2018). On national holidays the park received up to 13,000 visitors a day (State Party of Brazil, 2020). During 2024 the park received 1,8 million tourists, becoming this year the most visited after the COVID 19 pandemic (Seven Wonders, 2025). The Iguaçu National Park Public Use Plan (PUP) was developed through a multi-stakeholder consultation to explore gaps and opportunities to unlock the park's potential for sustainable tourism, while ensuring appropriate regulation (ICMBio, 2020). It is a non-binding, non-exhaustive program of action that outlines strategies, guiding principles, and key actions - including over 50 studies, assessments, projects, protocols, and regulations - to be developed and implemented to promote public use, diversify visitation opportunities, enhance the visitor experience, and guide tourism management. The plan is consistent with the park's conservation objectives, zoning and management plan, and ICMBio guidelines for planning and managing public use in protected areas (State Party of Brazil, 2024).

The Itaipu dam (Brazil and Paraguay) on the Parana River and the four Brazilian dams on the Iguaçu River, including the Baixo Iguaçu Hydroelectric Power Plant, have significantly altered the flow of water that feeds the falls, and the flora and fauna of the river, although the details are not known. Potential environmental impact drivers that may affect these attributes are changes in the river’s water flow and quality patterns, as well as the isolation of aquatic species populations upstream and downstream of the dam.

The Baixo Iguaçu Hydroelectric Power Plant (HPP) became operational in December 2018. The State Party did not submit a specific assessment of its impact to the World Heritage Centre as requested (UNESCO, 2023). It is located a few hundred meters from the eastern boundary of the park (State Party of Brazil, 2020). The National Water Agency (ANA) requires a minimum flow of 350 m³/s at the Iguaçu Falls to preserve their scenic beauty, and this condition was met as of June 2024 (State Party of Brazil, 2024). Extensive conditions have been imposed by the ICMBio and the Environmental Institute of Paraná (IAP) for licensing the construction and operation of the HPP. In response, the joint venture responsible for the project has established 32 environmental and social programs (State Party of Brazil, 2024). Monitoring programmes’ results shows that: 1) monitored water and sediment parameters have remained within the expected range for a recently constructed reservoir; 2) ichthyological surveys identified 54 fish species within the area of influence of the HPP, including 22 endemic, 19 native, and 8 exotic species, and no significant changes in water parameters that could compromise the ichthyofauna were observed; 3) Monitoring of semi-aquatic fauna did not find impacts by the construction of the HPP on the populations of surveyed key species Williams’ side-necked turtle (Phrynops williamsi) and Neotropical otter (Lontra longicaudis) (State Party of Brazil, 2024). Additionally, ICMBio carried out the National Action Plan for the Conservation of Aquatic and Semi-Aquatic Fauna of the Lower Iguaçu (PAN Baixo Iguaçu), supporting the conclusion that the damming of the Iguaçu River has not been shown to impact Phrynops williamsi or Lontra longicaudis. Overall, ICMBio believes that the monitoring system in place is adequate (State Party of Brazil, 2024).

However, while ongoing monitoring efforts are welcome, the potential impacts of the HPP and other hydroelectric developments on the Upper Iguaçu River watershed on the OUV of the property require continued attention to inform adaptive management of the HPP.

Reported plans to further develop tourism in the property, specifically the proposal to construct a cable car and further expand other tourism-related infrastructure is of concern (UNESCO, 2023). In 2022, ICMBio awarded a new 30-year concession contract for the provision of visitor services in the Iguaçu National Park. The concession includes the revitalization, modernization, operation and maintenance of the tourism infrastructure, as well as the obligation to cover expenses related to the conservation, protection and management of the park. The investment commitments established in the concession have allowed the launch of a comprehensive infrastructure improvement program, developed in accordance with the strategies outlined in the Public Use Plan (PUP) released in 2020.
The cable car project proposal is listed as a mandatory investment for the concession holder and its preliminary location is at the mouth of the São João River, about 8.5 km downstream from Iguaçu Falls. The project remains subject to a locational study to determine the most suitable site for its execution, considering the environmental and heritage impacts, as well as its technical and financial feasibility (State Party of Brazil, 2024). While ICMBio asserts that the infrastructure development program poses no threat to the property’ OUV, the proposed project and all future development projects need to be subject to Environmental Impact Assessments.

The protection given by the Park allowed the increase of wildlife populations attractive to hunters. The Park hosts most of the terrestrial large mammals known to have occurred around 20 years ago, at the time of the first systematic study. The census, conducted every two years since 2010, estimated 93 jaguars in 2022, up from 40 in 2005, highlighting the success of joint conservation efforts (State Party of Brazil, 2024). Recent reports estimate that between 230 and 300 jaguars remain in the Atlantic Forest region, which spans the border region between Argentina, Brazil and Paraguay. A third of them live in the area that includes the Iguaçu National Park and its namesake on the Argentine side. This is largely due to conservation efforts in recent decades (Camargo, 2021). The exception is the white-lipped peccary, which was not recorded in a recent survey. Paca and agouti, medium-sized rodents, are among the most hunted species in the park. Both are important seed dispersers that play a key role in forest regeneration (da Silva et al., 2018; State Party of Brazil, 2020). The park has a program to deter hunters, including joint patrols with neighboring Iguazú National Park, but hunters still venture into the park for cultural, commercial, and subsistence reasons. There is evidence of sport hunting activities in the region (ICMBio, 2018; IUCN, 2015). The monitoring program established between ICMBio and the Baixo Iguaçu HPP has intensified inspection activities and curbed predatory hunting, fishing, and extractivism within the boundaries of the Iguaçu National Park and in the area surrounding the Baixo Iguaçu HPP (State Party of Brazil, 2023).

The Iguazú National Park (Argentina) Management Plan reports an increase in rainfalls and temperatures especially during spring and winter, as well as extraordinary floods. Affectation of sensitive species like the amphibians and changes in the forest composition and physiognomy are expected (APN, 2017). A study conducted in Iguazú National Park shows that climate change, particularly increased rainfall linked to El Niño events, has a severe negative impact on the local yacaré population, a key aquatic predator in the ecosystem (Herrera, 2014). The Argentinian National Meteorological Service (SMN) confirmed that the severe floods during the September-October-November 2023 period were caused by El Niño, with its impacts intensified by climate change. This threat is therefore to be considered recurring in the Iguaçu National Park (Brasil) as well. Currently, there is a need to develop specific adaptation strategies within the Iguaçu and neighbouring Iguazú National Park and to strengthen monitoring efforts to better understand and address the cumulative effects of climate change and upstream dams, which together pose increasing risks to the park’s aquatic ecosystems and biodiversity.

The northern boundary of the property is clearly marked by the limit of the forest and the start of intensive farming. The streams that run from the agricultural zone into the property and down to the river Iguaçu carry heavy sediments. What exactly the sediment carries, in terms of agricultural pollutants (pesticides and nitrates) is a concern. The sediment load of those streams carrying the agricultural run-off is greater than that of the tributary whose entire catchment areas lies in the eastern part of the National Park (IUCN, 2015). While there is limited published information on specific pollutants and their potential impacts on the site’s ecological values, rivers from neighbouring municipalities in both Argentina and Brazil are polluted with untreated or partially treated domestic and industrial wastewater, including sewage and grey water from tourism facilities, which flow into the Iguazú River basin and impact its water quality (APN, 2017). There have also been recent reports from local residents since 2024 about untreated wastewater being discharged directly into the river (Voz de las Cataratas, 2024). The combination of inadequate effluent treatment and the high density of dams highlights the need to better understand cumulative impacts on water quality and to develop transboundary management plans to mitigate harm to the site’s ecological values.

Illegal extraction of palmito (Euterpe edulis) has been maintained over the years, mainly due to cultural reasons since the extraction, consumption and commercialization of palmito is passed from generation to generation (ICMBio, 2018). However, no updated information on the level of this activity was found.

The Park is an island in a sea of ranching and farming right up to the Park’s boundaries, limiting connectivity within the Atlantic Forest Biome in Brazil, primary by low forest cover along Iguaçu river. Large cats from the Park that prey on livestock and peccaries that consume crops outside the Park are eliminated. Connectivity to the Atlantic Forests remaining in Argentina is limited by the area known as the “Argentine Peninsula Bottleneck” (IUCN and UNESCO, 2008). A recent study highlight that the spatial distribution of most terrestrial large mammals within the Park have been negatively affected by edge effects from human-modified landscapes (and tourism and to a lesser extent hunting). For large mammals, that range widely and come into frequent contact with Park limits and beyond, the altered areas overexpose them to human-induced mortality such as road kills, hunting and persecution. In addition, favor biological invasions like the domestic dog across the Park, an example of an edge-induced invasion (da Silva et al., 2018).