In the International Year of Caves and Karst, Brazilian caves are at high risk (Commentary)

Brazil is internationally known for its astonishing biodiversity. Nevertheless, there is another natural heritage for which Brazil should also be recognized: its caves. As a continental-sized country, with a rich geological history, Brazil harbors an estimated 310,000 caves – some of them among the most spectacular in the world. Like for biodiversity, cave protection in Brazil was always challenging, considering most of the country’s economy depend on sectors with known and persistent environmental conflicts, like agribusiness and mining. Presidential Decree 99556 of 1990 stated that all natural caves in Brazil should be treated as a national cultural heritage, and, as such, should be preserved and conserved. But in 2008, after pressures from the Brazilian mining sector, the new Decree 6640 was published stating caves should be then classified as having maximum, high, medium or low relevance, but only those classified as having maximum relevance would be fully protected from the very beginning.

Although Decree 6640 was more technical than its predecessor, establishing, for example, a legal definition for a cave, it also made explicit that only caves classified as having maximum relevance would be fully protected. Via an environmental licensing process, other caves could suffer irreversible negative impacts, including total destruction. Decree 6640 established a compensation system: two similar caves should be protected for each high relevance cave destroyed. For caves of medium relevance, financial compensation could be made, giving priority for research and conservation in maximum and high relevance caves. Decree 6640 also boosted cave inventories in Brazil: 70% of the cave-restricted species officially registered in the country were described from 2009 onwards. Accordingly, the number of maximum relevance caves increased too.

However, in January 2019, in a unilateral process, without proper public disclosure and discussion, and with no participation of the civil society, Brazil’s Ministry of Mines and Energy (MME) proposed new wording in Decree 6640 which, if accepted, would open space for maximum relevance caves to be impacted or even destroyed. Additionally, it would allow state and municipal licensing agencies to relax the criteria for the classification of cave relevance. The MME sent this proposal directly to the Office of the Presidency, which forwarded it to the Federal Attorney’s Office, where it had a favorable opinion for the amendment. The proposal was under consideration by the Ministry of the Environment. However, more recently, in September 2020, MME published its Mining Plan 2020-2023, and among the various goals cited by this plan was a clear intention to change the legislation for the protection of caves in the country. According to the plan, there is a need to “improve” the legislation, but there is no clear indication of what such an improvement is about.

The list of recent decisions potentially affecting caves in Brazil continues: The President of the Chamber of Deputies, Arthur Lira, a close ally of president Bolsonaro, declared his intention to schedule projects on environmental licensing for voting in the coming days. This is a controversial project, aimed to relax the requirements for the environmental licensing in Brazil, a long-term demand from some sectors like agribusiness, mining and real estate companies. And Lira did it. The project, voted on May 12^th, was reported by deputy Neri Geller, who is vice president of the Frente Parlamentar da Agricultura (Agricultural Parliamentary Front – FPA, who played a decisive role in the implosion of the Forest Code in 2012), and approved by 300 of the 513 federal deputies. Despite warnings from several sectors including environmental NGOs, part of the agribusiness, and even some players in the oil and gas sector, the approved bill restricts, weakens or, in some cases, even extinguishes important instruments for the assessment, prevention and control of socio-environmental impacts of construction and economic activities in Brazil. The approved bill now needs to be sanctioned by the Federal Senate. MME’s proposal and the political moves in the Deputy Chamber joins a long, alarming and impacting list of similar initiatives to dismantle the Brazilian environmental legislation put in place by Jair Bolsonaro’s government.

Potential loss of biodiversity, geological resources, and ecosystem services

In 2019, the mining sector accounted for some 4% of Brazil’s GDP: approximately 10,000 legal mines produce nearly 2 billion tons/year; 87% of them are micro or small companies (less than or equal to 100,000 tons per year), but 154 mines reach over 1 million tons year each. All legal mines in Brazil must undergo environmental licensing. Pointing out the precise number of maximum relevance caves in Brazil is not straightforward since such classification can be made by federal and state agencies and there is not a unified data source. However, based on a sample of 1400 caves subject to environmental licensing, 182 had been classified as of maximum relevance and another 412 were designated as testimony caves. Such values provide a glimpse on the number of caves that could be potentially impacted by the proposed policy changes.

Around 22,000 of the estimated 310,000 caves in Brazil are currently catalogued into official cave databases. If implemented, MME’s initiative to modify the current legislation will put a priceless natural asset at risk, threatening the most exceptional caves in the country, thousands of species, and the environmental services they provide. Consequences for species and their habitats will be severe. Underground ecosystems are among the last frontiers of modern exploration. The very specialized cave fauna is poorly documented and subterranean habitats are fruitful sources of exceptional scientific discoveries and insights on eco-evolutionary processes and adaptations. Caves are also hotspots for extreme endemism and frequently contain species known from a single site. There are currently at least 250 troglomorphic species, who are adapted to constant darkness, described for Brazil. Nevertheless, estimates points to another 800 to 1000 species waiting for formal description, in addition to the dozens of new species discovered each year in the country.

In the most recent evaluation of the conservation status of the Brazilian cave-dwelling fauna, 72 out of a sample of 145 species occurred in a single cave each. Considering bats, 72 out of the 182 species known in Brazil were recorded using caves, and four of the seven nationally endangered bat species are cave-dependent. Not by chance, the loss of subterranean habitats contributes most to threaten them. Brazil also harbors geological formations found nowhere else in the world. For instance, rare iron ore caves located mainly in Carajás, Amazonia, at the same site as the largest iron ore mine in the world, are highly endangered due to active mining. Similarly, large Brazilian karstic systems – including some of the most touristic caves in the country – are threatened by agribusiness.

The reduction in cave protection, as proposed by the MME and the Deputy Chamber, is not supported by the scientific literature, which, in fact, points to the opposite: the protection of caves must increase globally. Such demand is sustained both by the intrinsic conservation value of its species, and their fascinating evolutionary history, but also because it is increasingly clear that caves and their associated fauna provide important ecosystem services for humans. From the daily removal by cave bats of hundreds of tons of insects considered to be agricultural pests and disease vectors for humans and the livestock, to the role cave bats also play in the pollination and seed dispersal of plants of commercial interest, the processes and interactions in which caves and their associated fauna are involved have direct impacts on the ecological dynamics of other non-cave systems, on the nutrient cycling and matter flow, and even on the fixation processes of atmospheric carbon. Subterranean systems also effectively participate in water supply, water regulation, and waste treatment processes, essential for maintaining water quality. In Brazil, several cities are supplied with water stored in karst aquifers, a service which may be compromised by the weakening of the cave protection system. Karstic areas are also directly involved on soil retention and formation processes. A large number of fungi and bacteria with broad biotechnological potential are hidden in cave ecosystems. In fact, several maximum relevance caves in Brazil have unique structures and processes, some developed by microbial activity, which is still little known in the country.

Precious paleoclimatic archives are recorded in the walls and ceilings of Brazilian caves, providing clues for a better understanding of how the climate changed in the South American continent. Some of Brazil’s maximum relevance caves are also of extreme archaeological importance and help us to understand the history of human species. Luzia, the oldest human fossil found in South America, from around 11,800 years old, was found in a cave in Minas Gerais state. Dozens of maximum relevance caves receive thousands of tourists annually, providing income into the local economy and enabling the public use of this priceless environmental and cultural heritage. Therefore, the value of protecting caves is greatly enhanced when their biological, cultural and socioeconomic values are taken into account.

Brazil’s maximum relevance caves are thus classified precisely because they contain attributes identified as unique, exceptional and irreplaceable. This classification is often made by experienced professionals who understands that such caves are outstanding, unlike any other in the country or in the world. MME’s proposal to redefine and reduce the environmental impact licensing, exposes maximum relevance caves to irreversible negative impacts, does not consider the value Brazilian caves have, and ignores their loss. Such a view is not aligned with the most modern discussions on sustainable development. Furthermore, it violates the Federal Biodiversity Policy and several international treaties to which Brazil is a signatory, such as the Convention on Biological Diversity. It is unimaginable to consider the possibility that such caves could be destroyed, meaning the unprecedented and irreparable loss of Brazil’s most relevant natural and cultural underground components.

Given the importance of the subject and due to the strong negative consequences it may have, we strongly advocate that any proposal to change the classification criteria for the relevance of Brazilian caves should be preceded by a public, careful and qualified scientific debate, but not in an accelerated and unilateral way, like the one conducted by the MME. The Deputy Chamber has the obligation to discuss any pending proposal in a proper way, calling for public discussions. A clear and effective legal framework is necessary, but the expertise and arguments of professionals and of the Brazilian scientific community must be heard and taken into consideration. The proposal being considered by MME and the Deputy Chamber contains conceptual and procedural flaws and, if accepted, it will inevitably bring technical and legal insecurity to the environmental licensing processes in the Brazilian mining sector. In this sense, this proposal cannot be considered as consensual, and must be rejected. The 2021 International Year of Caves and Karst must not be remembered as the year in which Brazil abandoned and condemned its speleological heritage

Banner image caption: Speleothems in Gruta Bonita cave, Peruaçu Caves National Park, in Minas Gerais state, southeastern Brazil. Image courtesy of Rodrigo Lopes Ferreira. 

Citations:

• Abessa, D., Famá, A. & Buruaem, L. The systematic dismantling of Brazilian environmental laws risks losses on all fronts. Nat Ecol Evol 3, 510–511 (2019). https://doi.org/10.1038/s41559-019-0855-9Mammola, S. et al. Scientists’ warning on the conservation of subterranean ecosystems. BioScience 69, 641–650 (2019)Medellín, R. A., Wiederholt. R. & Lopez-Hoffman, L. Conservation relevance of bat caves for biodiversity and ecosystem services. Biological Conservation 211, 45–50. (2017)

  Furey, N., & Racey, P. A. in Bats in the Anthropocene: Conservation of bats in a changing world (eds. Voigt, C.C. & Kingston, T.) Ch. 15 (Springer International Publishing, 2015).

  Luo, J. et al. Bat conservation in China: Should protection of subterranean habitats be a priority? Oryx 47, 526-531. DOI: 10.1017/S0030605311001505

  Ward, B. et al. Reconstruction of Holocene coupling between the South America Monsoon System and local moisture variability from speleothem δ18O and 87Sr/86Sr records. Quaternary Science Reviews 210, 51-63 (2019).

  Feathers, J. et al. How old is Luzia? Luminescence dating and stratigraphic integrity at Lapa Vermelha, Lagoa Santa, Brazil. Geoarchaeology 25, 395-436 (2010).

   

Article published by Willie Shubert

Caves, Commentary, Environmental Policy, Mining, Wildlife

Brazil, Latin America, South America

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