Brazilian mangroves at risk

Recent statements from the Brazilian federal government indicate that impacting economic activities, particularly commercial shrimp farming, are being encouraged in mangrove areas in the near future. Alterations of the National Action Plan and legal instruments that partially protected mangrove ecosystems have created an even weaker legal framework than previously existed. Such changes are leading Brazil far from the global call to conserve mangroves and from the Aichi targets and United Nations Sustainable Development Goals. Unfortunately, the loss of mangrove ecosystems and their ecosystem services will negatively impact living standards for Brazilians in coastal areas.


Introduction
Mangroves ( Figure 1) represent highly productive ecosystems, once relatively common along tropical and subtropical oceanic coastlines, especially around estuaries, and currently present over an area about 181,000 km² globally (Donato et al. 2011, Giri et al. 2011). Only about 2% of mangrove stands occur along temperate coastlines (Morrisey et al. 2010). Historically, several impacts have affected mangrove extents, such as: pollution, logging, and conversion to non-sustainable aquaculture and agriculture (Friess et al. 2019). Consequently, the global mangrove area, which is already smaller than previously estimated, continues to decline (Giri et al. 2011), making mangrove ecosystems top priorities for implementing conservation actions (Friess et al. 2019).
Mangrove ecosystems are characterized by transitional gradients of physiological and ecological characteristics, strongly influenced by salinity, nutrient concentrations, soil type, tidal amplitudes, and freshwater inputs, all of which create hostile conditions for most plant species (Walsh 1974, Cintrón & Schaeffer-Novelli 1983, Araujo & Pereira 2009, Silva et al. 2016. The vegetation is characterized by a homogeneous phytophysiognomy with low species diversity, but remarkable specializations in morphology and physiology ( Figure 1) (Walsh 1974, Cintrón & Schaeffer-Novelli 1983, Araujo & Pereira 2009, Silva et al. 2016.
Brazilian mangrove plant associations are dominated by specialized species. These include some species of the genera Acrostichum L.

Range of Brazilian Mangroves
In Brazil, mangrove areas occur along an extensive coastline, from the Oiapoque River mouth in the north, to Laguna, in Santa Catarina state, in the south (Saenger et al. 1983, Novelli et al. 2000, Maia et al 2006. Their Brazilian range represents 7% of the total global mangrove land cover (Giri et al. 2011). Considering only the Brazilian north coast, the country has the largest continuous formation of this ecosystem type in the world (Souza-Filho 2005).

Ecosystem Services
Many animal phyla and species use mangrove forests, such as molluscs, arthropods, fishes, reptiles, birds, and mammals (Giesen et al. 2006). For example, sixty-seven primate taxa, most of them exhibiting rare behaviors shelter or feed in tropical and subtropical mangroves (Supriatna & Wahono 2000, Santos et al. 2019, Presotto et al. 2020. The high productivity rates of mangrove ecosystems are crucial for the benthic and pelagic components of neritic food webs (Robertson et al. 1992), providing direct and indirect resources (Tomlinson 1986, Luther & Greenberg 2009 for transient fishes and crustaceans as nursery and foraging habitats (El-Regal & Ibrahim 2014, Hutchison et al. 2014, Sheaves 2017, Litvin et al. 2018). In particular, mangrove ecosystems are critical for sustaining economically valuable crustaceans (e.g., pink shrimps and swimming crabs), finfishes (e.g., snooks, mullets, sardines, some catfish species, snappers, several sciaenids, and some groupers), and their fisheries (Robertson & Duke 1990, Sheridan 1992, Rogers & Mumby 2019, Sheaves et al. 2020). In addition, mangrove forests provide several other ecosystem services, delivered to human society across local, regional and global extents (Barbier et al. 2011). These include such critically important services as erosion control, water purification, coastal protection from storms, raw materials and food, maintenance of fisheries, carbon sequestration and cultural services associated with tourism, recreation, education, and research ( Figure 2).  Water purification: Rybicki (1997), Lee & Dunton (1999), Gacia et al. (1999), Cornelisen & Thomas (2006, Romero et al. (2006), and Koch et al. (2006). Coastal protection: Fonseca & Cahalan (1992), Koch (1996), Prager & Halley (1999), Hemminga & Duarte (2000), Spalding et al. (2003), and Koch et al. (2009). Erosion: Hemminga & Nieuwenhuize (1990). Maintenance of fisheries: For example, Brazil has some conservation units in which mangrove forests play a major role in creating jobs and income, generating millions of reais per year through tourism, handcrafts, crab extraction, and traditional/commercial fishing. The Parque Nacional dos Lençóis Maranhenses (PNLM) and Delta do Rio Parnaíba (DRP) are both examples of areas that are benefited economically by ecosystem services provided from mangrove ecosystems. The PNLM received 151,786 tourists from all over the world in 2019 (ICMBIO 2020) to visit mainly sand dunes with freshwater lagoons, but also mangrove areas. In the DRP, crab extraction and commercial fishing are the main local economic activities, being the major location of crab harvest in Brazil (Legat et al. 2006, Fogaça et al. 2018).

Legal Statute Concerns
As with the global trend, Brazilian mangrove forests have been threatened for years, particularly by deforestation to build ponds for crustacean farming (Ferreira & Lacerda 2016a). However, an astonishing set of recent events has further threatened these ecosystems, derived from an orchestrated sequence of Brazilian political decisions. Since the 2012 alterations in the Brazilian Forest Code (Código Florestal law 12.651/2012), mangrove ecosystems have not been fully protected (Ferreira & Lacerda 2016b). Then, amidst the 2019 oil contamination crisis in coastal ecosystems (Escobar 2019) and government inability to protect the affected areas (Brum et al. 2020), the National Action Plan for Mangroves (Plano de Ação Nacional para a Conservação das Espécies Ameaçadas e de Importância Socioeconômica do Ecossistema Manguezal; PAN Manguezal) was altered. The PAN Manguezal, which identifies priority actions for ecosystem protection, was modified in 2019 to exclude the eradication of shrimp farming and the recovery of mangrove as goals. Later, in September 2020, the number of NGOs, universities and indigenous peoples represented in the National Environment Council (Conselho Nacional do Meio Ambiente; CONAMA) was reduced. The Bolsonaro government subsequently revoked CONAMA resolution 303/2002, which established regulations to protect Brazilian mangrove ecosystems. These two recent changes have created a pathway for increasingly unregulated economic activities and impacts on mangrove ecosystems, leaving them without any protective regulations.
The PAN Manguezal and CONAMA changes imperil mangrove ecosystem services (see mangrove ecosystem services in Barbier et al. 2011) and, as a consequence, economic activities (e.g. tourism and commercial fisheries), that represent the main income and budget in several municipalities along the Brazilian coast. The Bolsonaro's government legal changes ignore global perspectives that consider mangroves as vitally important ecosystems for conservation (Friess et al. 2019). In addition, the new statutes are in opposition to the Aichi targets, which Brazil agreed to follow as part of the Convention on Biological Diversity, and the United Nations Sustainable Development Goals (SDGs). The SDGs are a set of goals aimed at reaching a sustainable planet that started to emerge during the 2012 United Nations Conference on Sustainable Development (Rio + 20), which occurred in Rio de Janeiro and brought together global leaders (Sachs 2015). In particular, the statutes violate four SDGs: SDG 2 (End hunger, achieve food security, improve nutrition, and promote sustainable agriculture); SDG 13 (Take urgent action to combat climate change and reduce its impacts); SDG 14 (Conserve and ensure the sustainable use and development of the oceans, seas, freshwater bodies and marine resources); and SDG 15 (Protect, restore and promote the sustainable use of terrestrial ecosystems, sustainably manage forests, combat desertification, halt degradation, and halt biodiversity loss). See Table 1 for a summary of the status of these statutes. The Brazilian government must reinstitute legal protections for mangrove ecosystems to abide by these global objectives. Otherwise, mangrove forests will be increasingly subjected to impacts that will threaten their biodiversity and the living standards of millions of Brazilian citizens living in coastal areas, whose lives depend on activities directly related to mangrove conservation.