Brazil — When we arrive at the first site in the Madeira River
researchers from Amazonas State University (UEA) and Harvard position themselves at the stern and bow of the voadeira
The vessel floats 15 kilometers (9.3 miles) upstream of Humaitá municipality
to start an endeavor to monitor the water quality and mercury contamination of the largest tributary in the Amazon River Basin
river dolphins feed in the water while squirrel monkeys jump from branch to branch in the embaúbas trees and two riverine men fill buckets with water in front of a banana plantation
a ferry passes loaded with cargo and two illegal gold mining dredges go upstream
The UEA researchers collect their water samples in seven small bottles
which will be analyzed in the boat and inland laboratories
and they take notes of a few parameters measured right away with a probe
besides filling their own water in two 1-liter (2-pint) bottles and two 10-L (21-pt) recipients
also collect riverbed sediments and riverbank soils
The Madeira River is key to the Amazon River Basin both environmentally and economically
From its headwaters in the Bolivian Andes mountain range
it stretches more than 3,315 km (2,060 mi) until reaching the Amazon River
among the 20 longest water bodies in the world
The Madeira spans more than 1.42 million km2 (548,265 mi2) across three countries
home to the largest fish diversity in the Amazon Basin — 60% of the species already described in the rainforest live there
Ten percent of the production moved on waterways in Brazil flows through the Madeira
and it hosts two major hydropower plants that account for roughly 7% of Brazil’s energy
While navigating the Madeira in Amazonas state
it became clear to the scientists the social importance of their research
Municipalities with fewer than 60,000 inhabitants each spread over 800 km (497 mi)
with a riverine population extremely dependent on the resources provided by the Madeira and its tributaries
“We are concerned about the pollution of the aquatic ecosystem
so we have two goals here,” said biologist Adriano Nobre
a scientist of the UEA’s Chemistry Applied to Technology (QAT) research group
“The creation of a water quality index for whitewater rivers and understanding the effects on environmental and public health regarding the presence of illegal miners and
the mercury contamination in the water and in the fish that the population consumes.”
That was the second expedition in the UEA and Harvard partnership to investigate water quality and mercury contamination in the Amazon rivers. In September 2023, a group of scientists sailed the Negro River, the second-largest tributary of the grand Amazon to benchmark its waters, and found the river in good shape
The expedition led to the first water quality index (WQI) for the Amazon Basin
With many more communities along its banks than the Negro
the Madeira shows higher levels of fecal coliforms and ammoniacal nitrogen
according to initial results from the expedition
although still way below the maximum limits established by authorities
All points also exceeded the safe levels of total phosphorus
probably resulting from agricultural fertilizers
The river has been an illegal mining hub for many years
Miners use quicksilver mercury to extract gold from the riverbed sediments
which is usually discarded directly into the river
Although this type of mercury is not highly soluble in water and tends to deposit on the riverbed
be released into the atmosphere and enter the food chain through fish
usually done with floating dredges that stir up the riverbed sediments
can accelerate the process of mercury contamination
This poses a serious threat to the health of the river ecosystem and the local communities that depend on it for their livelihoods
While the first data from the Harvard study reveal that total mercury levels in the Madeira River water are still below the limit recommended by Brazil’s Ministry of Health
it is considered elevated when compared with other rivers globally
“The Madeira has the added complexity of gold mining mercury inputs
so we would like to see if there are significant impacts on the levels in the water and if that contamination translates in the fish that people are eating,” said biochemist Evan Routhier
a researcher at Harvard’s Sunderland Lab
a group dedicated to the study of global contaminants
The Harvard scientists found that predatory fish in the Madeira
such as pirarara (Phractocephalus hemioliopterus)
have mercury levels above the safe limit for human consumption
these levels were found to be below the recommended
but still in an amount that demands the attention of public authorities as well as the need for continuous monitoring
On board an 18-meter (60-foot) research boat
Mongabay joined this expedition through the Madeira River in April 2024
navigating more than 1,800 km (1,118 mi) over 12 days between the cities of Manaus and Humaitá
The Sunderland Lab scientists study the mercury cycle in the Negro and the Madeira rivers in the water
soils of the riparian forest and fish most consumed by local populations
The two largest tributaries of the Amazon River have opposite chemical characteristics that can influence the behavior of mercury
such as pH and dissolved organic carbon concentration
there are dams upriver and more deforestation in the basin
which could also cause differences in the amount of mercury that’s coming into the system,” Routhier said
The Madeira expedition will also help the UEA scientists develop the first WQI for whitewater basins
“This index is mainly used for public supply
and it needs to be adjusted to take into account the chemical
physical and biological characteristics of the basin,” Nobre said
In the six days navigating upstream the Madeira
the researchers could observe its complexities: the vast diversity of fauna and flora in the water and in the forest
the pastures of buffaloes and cattle in the mouth of the river region
the traditional floodplain agriculture of the riverine communities
the fishing in the main river watercourse and in the blackwater tributaries
Madeira’s most populous municipality in Amazonas state
Fishing is the source of income for 3,700 of the 60,000 inhabitants
the researchers came across stands full of nursery tambaquis (Colossoma macropomum) and little diversity
“The most missing ones are the scalefish — pacu
They used to be the most traditional species here,” Osvaldo de Araújo
I would catch 500 kilos [1,102 pounds] in my canoe within five days
the fishers spend 12 days in order to bring that much.”
two large hydroelectric plants began operating in the Madeira River
with abrupt daily variations in the river level that affect the fish’s migratory patterns
and many fishers shifted to illegal activities that degrade the forest and aquatic environments: deforestation
“We used to drink this water from the Madeira,” José Pessoa
The people who live on the riverbank suffer a lot from this because they have no other resource
They must travel far away to buy water in the city.”
The Paraizinho community sits 10 km (6.2 mi) upstream from Humaitá
The daily life of 33 families in this community revolves around the Madeira River
a source for consumption and personal hygiene and irrigation for floodplain plantations
Small-scale farming supports this community, whose production is acquired by government programs. However, fishing has been hindered by the unpredictable water level variations caused by hydroelectric plants
the fishers need to travel to more distant locations if they want to maintain production
“People are abandoning fishing because they can’t afford the expenses to search for fish,” said João Mendonça
a 50-year-old community health agent and president of the Paraizinho farmers association
“Many people have shifted to mineral extractivism
but they have to support their families,” he told Mongabay
the research boat passed a few meters away from a huge mining raft in operation
The dredge was immersed in the river and scraped sediments off the riverbed
The material was sent to mats on the second floor of the vessel
would be retained in a carpet with the use of the quicksilver mercury
“One thing that surprised me was just how much discharge was being dumped just right into the river,” Olivia Pietz
a 24-year-old PhD student in environmental science and engineering at Harvard
The researchers collected samples in sites above and below mining operations
Illegal gold mining ostensibly occurs in the Middle Madeira region
which covers the municipalities of Humaitá
two Federal Police operations in the region destroyed hundreds of mining rafts
Initial data from the Harvard study revealed high levels of mercury in the Madeira, although still below the limit of 0.2 micrograms per liter (µg/L) recommended by Brazil’s Ministry of Health. When comparing its data with 446 rivers around the world, Routhier found that the Madeira falls in the upper third of these global rivers examined in an article published by Nature
“So it’s in the range of what we would consider elevated.”
notes that some elemental mercury used in gold mining may still be in the pure liquid phase
the metal tends to seep into the riverbed and sometimes into the soil of the surrounding areas
“My guess is that some mercury used is still quite patchy in its distribution and hasn’t fully diffused into the surrounding environment
this is good news because you can’t see a widespread impact yet
even though you know that activity is occurring,” said Sunderland
a professor of environmental chemistry and planetary sciences at Harvard
this doesn’t mean the Madeira River is free from a severe problem
that mercury can work its way into the river and mix with the sediments and enter the atmosphere as a gas
and then you’ll have an issue that is more widespread
Mercury dissolved in river water makes it easier to get into the food web as well as the fish,” she said
a traditional species in the diet of the Madeira’s riverine
“This mercury thing has never affected us,” 59-year-old fisher Ancelmo de Menezes told Mongabay
“It has never resulted in health problems for us
president of Manicoré’s fishers association
sees the Madeira as already polluted due to the incessant traffic of ferries
we used to treat the Madeira’s water and drink it
but this water is no longer consumed here in the city,” he told Mongabay
“We have artesian wells with top-quality drinking water to consume.”
Harvard researchers collected 29 fish in Humaitá
the maximum safe limit established by Brazil’s authorities
Ten jaraquis purchased in Manicoré had an amount of mercury within the limits for non-predatory fish
Scientists will investigate the reasons for these results — whether they occur due to mining activity or to fish ecology
The predators biomagnify the mercury and are too high for people to eat regularly
But the other ones look OK for regular consumption
and it would be interesting to craft advice depending on how much people eat,” Sunderland said
“Monitoring helps identify which species can be consumed more frequently than the others without exceeding health-based guidelines for safe mercury exposure
That’s the kind of advice that the government can provide.”
The next step of the Harvard study is to analyze the other elements of the mercury cycle
the organic form of this metal that bioaccumulates in fish and can cause health problems for humans
“Understanding the mercury cycle is really important for the region
especially the propensity for methylation and exposure for communities,” Routhier said
fishers were waiting for a school of matrinxãs swimming down the Aripuanã River
while illegal miners were dredging the bottom of the Madeira searching for gold beside an island right in front of the city
president of Novo Aripuanã’s fishers association
said he believes the mining activity contributed to the decline of fish stocks
adding to the impact of hydroelectric plants
Water safety is a priority issue for Novo Aripuanã
the municipality with the second-highest number of diarrhea hospitalizations in Amazonas state – 1,045 per 100,000 inhabitants
Only 13.7% of the city sewage is treated before being disposed of in the Aripuanã River
Silvana Cabral travels from the Madeira Sustainable Development Reserve to Novo Aripuanã to sell her produce from floodplain agriculture: banana
This sustainable management conservation unit has 96% of its area composed of forest from which residents extract Brazil nuts
the Madeira is used for people’s basic needs
the riverine residents buy water in the city
“The Madeira’s water is used for everything,” said Cabral
who is president of the Santa Maria do Uruá community association
about 100 mining rafts gather to extract gold
“The water still has the same color and the same taste
which causes various types of diseases.” She said she believes the water monitoring initiated by UEA and Harvard is important to bring “an improvement to our people.”
The water quality index is usually composed of nine physicochemical and microbiological parameters
“Inserting this variable would be an important strategy to establish acceptable limits within the WQI,” biologist Nobre told Mongabay
the UEA research group needs at least one more expedition during the drought season
But the data from the first campaign already give clues about the condition of this water body
Madeira is healthy — it has been able to handle the multiple human pressures that surround it
As soon as the laboratory boat passes through the municipality of Nova Olinda do Norte
we embark on the voadeira for the campaign’s last sampling sites
The night begins to fall when we reach the final point
surrounded by an aquatic horizon where the Madeira discharges 34.4 million L (9 million gallons) per second into the Amazon River
UEA researcher Christopher Hildemberg states that the journey through these white waters has brought to light the effects of human actions on the Amazon Basin’s largest tributary
“I still hope that the impacts that have already been caused can be mitigated in some way
Banner image: Harvard researchers Evan Routhier collects water from the Madeira River near illegal mining rafts between the municipalities of Humaitá
Kevin Damasio and Bruno Kelly joined the Medeira River expedition with the support of Mongabay and Ambiental Media
Study to benchmark water quality finds key Amazon tributary in good shape
Liu, M., Zhang, Q., Maavara, T., Liu, S., Wang, X., & Raymond, P. A. (2021). Author correction: Rivers as the largest source of mercury to coastal oceans worldwide. Nature Geoscience, 14(12), 956-956. doi:10.1038/s41561-021-00839-5
The “fortress conservation” model is under pressure in East Africa
as protected areas become battlegrounds over history
and global efforts to halt biodiversity loss
Mongabay’s Special Issue goes beyond the region’s world-renowned safaris to examine how rural communities and governments are reckoning with conservation’s colonial origins
and trying to forge a path forward […]
While millions live with regular blackouts and limited energy
plants are being built to satisfy the global demand for digital storage and processing – piling pressure on an already fragile system
Deodato Alves da Silva longs for enough electricity to keep his tucumã and cupuaçu fruits fresh
These highly nutritious Amazonian superfoods are rich in antioxidants and vitamins
and serve as a main source of income for farmers in Silva’s area
the lack of electricity to refrigerate the fruit makes it hard to sell their produce
Silva’s fruit-growing operation is located in the village of Boa Frente, in Novo Aripuanã municipality, one of Brazil’s most energy-poor regions
where there is only one diesel-powered electricity generator working for a few hours a day
The 17 families in the community pay for the diesel
everyone agrees to use the generator only between 6pm and 10pm
This is also the only time they can communicate with the outside world – the region has no mobile phone connection
“Power is supplied for just four hours a night
The motor is switched off and only switched back on the following night,” says Silva
a rural health worker and fruit-grower who has lived in the area since he was born
“I would have a much higher income if we had power to preserve the cupuaçu pulp
but the lack of power prevents conservation.”
More than 1.3 million Brazilians still live, like Silva, with little or no electricity. Even though it has one of the world’s cleanest power grids
the country has a vulnerability: its reliance on hydroelectric power
which causes fluctuations in power generation and blackouts in times of severe drought
46 new datacentres are either under construction or being planned across the country
By using cooling systems with excessive water use
these companies consume more than small citiesVinícius OliveiraThe rush to build datacentres is part of the growing digitalisation of the Brazilian economy as large multinationals seek more data storage and processing for cloud platforms
and critical private and government services
Brazil has become a hub to meet growing demand in Latin America for streaming
as expanding regional server capacity is critical to minimising delays in transferring data
“If all the data was stored solely in the US
communication would be inefficient and delayed,” says João Xavier
director of institutional relations at ABDC
Rodrigo Pastl Pontes, monitoring manager at Brazil’s National Confederation of Industry
says the need to expand the number of datacentres is closely related to “Industry 4.0” – the integration of technologies to make manufacturing more intelligent
View image in fullscreenAn impression of Scala Data Centers’ planned 700-hectare AI City in Rio Grande do Sul
‘This is our response to the demand for artificial intelligence,’ the firm said
Illustration: Scala Data Centers“Industry 4.0 offers flexibility that meets customer requirements in real time
allowing the company to reorganise constantly,” says Pontes
“Secure datacentres are essential for this.”
One study put Brazil’s Industry 4.0 market at $1.77bn (£1.40bn) in 2022 and expects it to reach $5.6bn by 2028
With an eye on local and global markets, as well as its largely renewable power grid, Amazon and Microsoft have announced new investments in Brazilian datacentres
Amazon plans to invest 10.1bn reais (£1.35bn) in expanding its datacentres and infrastructure over the next 10 years
The company claims to have established solar and windfarm projects with the capacity to match its energy consumption in Brazil – enough to supply 100,000 homes
With datacentres in São Paulo and Rio de Janeiro
the company has signed a deal with the energy company AES Brasil to be supplied for 15 years from a Rio Grande do Norte windfarm
Campaigners and experts say the problem is that implementing new energy projects
could harm local communities just as the country needs to adapt its power grid to the climate crisis
Vinícius Oliveira, a specialist at the Energy and Environment Institute
says: “The impact of datacentres depends on where they are installed and on the type of energy the Brazilian power grid will need to meet the load demanded
“We may have environmental impacts in soil
with land becoming more expensive and families being displaced.” Oliveira also anticipates greater demand for water
as datacentres generally require vast amounts to cool servers
View image in fullscreenOsório windfarm in Rio Grande do Sul
Demand for power is rising so fast that small nuclear reactors are now being considered
Photograph: Alamy“By using cooling systems with excessive water use
these companies consume more than small cities,” he says
stressing that better infrastructure for distribution and power generation will also be required
“This level of investment may affect energy rates,” he adds
Free newsletterGet a different world view with a roundup of the best news
Experts fear that datacentres’ high water consumption will raise pressure on the power grid, as hydroelectric plants supply about half of all power. Lower water levels in reservoirs raise the chances of blackouts and increase demand for pricier and more polluting thermal power plants, fired by oil, gas and coal
show how a lack of rainfall can threaten the national power supply
According to Raul Lycurgo, president of the state-owned company Eletronuclear
“Nuclear is the only [power source] that does not generate greenhouse gases,” he says
But the idea faces opposition due to high capital costs and concerns about how to manage radioactive waste
“Countries with no alternatives can afford to use a more expensive energy,” says Ricardo Lima
“We have much cheaper alternatives than nuclear – we have solar
View image in fullscreenElaine Santos
‘People lose food and medication,’ she says
‘The shortages create tension’Even in São Paulo
residents face increasingly frequent blackouts
a researcher in energy poverty at the University of São Paulo
“People lose food and their medication; the bakery closes,” she says of the power cuts
as everyone knows they will have to cope with their losses alone in neighbourhoods where people live in extremely vulnerable conditions.”
Santos believes the tech companies must look at the local effects caused by their growing share of the country’s power supply
“If they are going to build datacentres where people don’t even have access to power
the companies need to provide compensation,” she argues
Connecting decision makers to a dynamic network of information
Bloomberg quickly and accurately delivers business and financial information
2023 at 1:55 PM EDTBookmarkSaveLock This article is for subscribers only.Brazilian President Luiz Inacio Lula da Silva’s ambitious pledge to end illegal deforestation of the Amazon rainforest by 2030 is going regional
The eight South American nations that make up the Amazon rainforest have agreed to adopt the pledge in August, Peruvian Environment Minister Albina Ruiz said in a news conference on Thursday
The burning of the Amazon rainforest is intentional and people are seriously afraid
indigenous communities are telling Caritas in the build-up to the Synod on the Amazon
As new photos from Caritas show fires devastating the Brazilian rainforest near to Novo Aripuanã
indigenous communities are expressing dismay at the apparent impunity with which illegal deforestation is being allowed to rip through their traditional lands
This year more than 100,000 fires were registered in Brazil by the end of August
“We feel abandoned by the government,” a leader of the Tururukare community told us (we will not use his name)
A way of life worth defending: fishing in Tururukare
Indigenous and other communities supported by Caritas are in no doubt that the fires are ignited by unscrupulous farmers to appropriate land that should be protected by law as national forest and indigenous territory
Brazil’s National Institute of Space Research (INPE) has stated that most fires in the Amazon are caused by human action
INPE’s satellite data shows an 85% increase in fires across Brazil in comparison with last year
due to the massive expansion of cattle ranches
deforestation and expulsion of communities from their lands,” warns José Batista Afonso
a human rights lawyer who works for Caritas partner CPT
“We are in the middle of a big conflict,” says Batista
“On the one side are those who fight to protect the forest and its peoples
those who want to destroy it.” CPT has recorded over 900 murders of rural workers and land rights defenders in 50 years in Pará alone
The new photos from Caritas show constant fires along roads surrounded by intense human activity near Apuí
next to the indigenous territories of Tenharim and Jiahuí
The crisis underlines the urgency of the Synod on the Amazon
Pope Francis has called for the fires to be brought under control as soon as possible
The Synod (“Amazonia: new paths for the Church and for an integral ecology”) will highlight the extreme seriousness with which Pope Francis views the impact that environmental destruction is having on local communities
the Amazon is already emitting signs of death …” warned Evaristo Pascoal
who attended an “Act in Defence of the Amazon” held in Brazil’s House of Representatives on 5 September
“In the Amazon there is the model of those who live and have always lived in the Amazon: its traditional peoples
and then there is the model of those who come to destroy
to strip and burn the forest and contaminate water.”
A letter was presented to the Brazilian government by members of the Church in the Amazon and Caritas partner REPAM (the Pan-Amazon Church Network)
decrying the “predatory system” that is destroying the forest and the lives of its people
REPAM
who have facilitated the consultation of 87,000 people in preparation for the Synod
climate change and the increase in human activity (deforestation
fires and changes in land use) are driving the Amazon towards the point of no return
We call on all humanity to be aware of the serious threat posed by this situation.”
Fires constantly burn close to trails opened through the forest for illegallogging between Novo Aripuanã and Apuí
The bishops of Latin America and the Caribbean (CELAM) have added their voice
It is a crisis “of planetary proportions” they warn
Caritas partners across the Amazon are helping communities defend their rights and territory against brutal intimidation. Caritas Brazil’s network has 29 members in the Amazon
working to strengthen and support the country’s traditional peoples: indigenous groups
and quilombolas (descendants of Afro-Brazilian slaves)
as well as urban populations living in economically vulnerable conditions
Caritas also works on climate change and disaster risk management
supporting migrants and refugees and the rights of children
Caritas Internationalis and local Caritas from the nine Amazon countries will actively participate in next month’s Synod
with many campaigning initiatives planned to follow up its recommendations
“What happens in Amazonia affects the whole world
So we should really take care of our common home.”
Caritas works to defend the traditional peoples of the Amazon
Photo by Photo by Marcella Haddad / Caritas
GET INVOLVED
20 fishers received a tip that matrinxãs were swimming down the Aripuanã River toward the Madeira
It was their opportunity to interrupt a week of unproductive fishing in Novo Aripuanã
they divided themselves among three wooden canoes and went to the river
It was just a matter of waiting for the shoal
with no sign of the matrinxãs (Brycon melanopterus)
A fisher observed everything from a tip of land at that meeting of white and black waters in the Middle Madeira
while just ahead several pink river dolphins (Inia geoffrensis) and tucuxis (Sotalia fluviatilis) emerged to breathe while fish hunting
because the river is very dry,” Raimundo Dias told Mongabay
the Madeira Basin was transitioning from the wet to the ebb season
fish group into schools and migrate from lakes
tributaries and igarapés (small streams) to feed on fruits
seeds and terrestrial invertebrates that fall into igapós (flooded forests) and in the Madeira flood plains
abrupt and frequent changes in river levels have disoriented migratory patterns
Scientists and fishers attribute these irregular pulses to the Madeira hydropower plants
two large facilities installed in the neighboring state of Rondônia
the flood-and-dry has already happened about four times
It’s very difficult for the fish,” Dias said
Born and raised in Novo Aripuanã, Dias is 50 years old and has always survived on fishing, but making a living from this activity has been increasingly difficult due to the reduction in captures in the Madeira, the most diverse in the Amazon, with 1,406 species of fish catalogued
This hydroelectric plant ruined us,” the fisher said
went into operation in March 2012 and has Brazil’s fifth-highest power capacity
installed 115 kilometers (71.4 miles) upstream
has been operating since September 2013 and is the fourth largest in the country
the most affected species by the plants are the most consumed locally: pacu (Mylossoma)
matrinxã (Brycon) and jaraqui (Semaprochilodus insignis
High-value fish species sold to large cities
such as the migratory catfishes dourada (Brachyplatystoma rousseauxii) and piramutaba (B
This scarcity has an impact not only on trade but on the diet of the Novo Aripuanã citizens
the main protein source for the Amazonian riverine population
has become pricier in markets and restaurants
“We used to sell a handful of matrinxãs for 5 reais [$0.89]
a municipality on the border with Rondônia
fishing productivity is strongly influenced by seasonality
enter Madeira through the mouth and swim upstream to the whitewater river
58-year-old fisher José Pessoa says this migration was impaired because the river lost its currents after the dams
“The fish requires rapids to make the piracema,” he said
the fish we get around here is when the water level gets a little higher
travels to another one and goes up [the Madeira],” said Pessoa
because there’s no water for them to travel.”
fishing has become “almost nonexistent,” according to João Mendonça
president of the local farmers’ association
The community is sustaining itself thanks to floodplain agriculture
whose production is acquired by governmental food programs
“The period that’s supposed to be drying is flooding,” Mendonça told Mongabay
They don’t do their piracema at the right time
people come to buy chicken [in the city] because it is difficult to catch the fish in the community
The dams adopt the run-of-river model, which retains less water in its reservoir but still affects the hydrology of the Madeira
After analyzing discharge data from three hydrological stations
scientists found that the “dam operations significantly increased day-to-day and sub-daily flow variability.”
Scientists measured this by monitoring sudden changes in river flow — or “reversal” events
the sudden shifts from a period of rising to a period of falling levels
This event almost doubled (94%) at the Porto Velho station
5 km (3.1 mi) downstream of the Santo Antônio Dam
who attribute the numbers to fluctuations in energy demand
“The daily hydropeaking events are very frequent due to the hydroelectric plant because it controls the amount of water it retains and releases,” biologist Carolina Doria told Mongabay
She is co-author and coordinator of the Ichthyology and Fisheries Laboratory
“This abrupt variation on the same day has a very big impact on the fish.”
The fish knows that it needs to get out of the flood plains
flooded forests and lakes and swim to the main river when the water level begins to rise daily and gradually
Humaitá locals were used to well-defined periods for fishing
“The fish we expected the most in the flood were the jaraqui and the matrinxã
The fish dynamics is closely linked to the availability of water in the basin
coordinator at the Laboratory of Ichthyology and Fisheries Planning of the Madeira River Valley
“These species did not cease to occur there due to an environmental preference
but because they no longer have access,” Anjos told Mongabay
“The fragmentation of habitats has led to the decline of fish populations.” He said this loss of connectivity is linked to a set of factors: hydroelectric dams
president of the fishers’ association in Humaitá
observed that the riverine people of the Madeira can no longer plan according to the environment’s natural dynamics
“If the river is drying on the new moon we can have a good production because the fish leave the lakes to reproduce,” Moraes told Mongabay
but it’s flooding.” He also noticed changes in the behavior of the fish that live in the tributaries and lakes of the Madeira Basin
a biologist from Amazonas State University (UEA)
“Anthropic [human made] alterations directly affect water quality,” Nobre told Mongabay
“The changes in the hydrological regime made by hydroelectric dams
have influence over the maintenance of aquatic life.”
In April, UEA researchers began to develop the first Water Quality Index (WQI) for a whitewater river in the Amazon, to understand the Madeira’s health. In March, the group launched the first WQI for the Amazon Basin
Researchers from UEA navigated almost 800 km (497 mi) on the Madeira to assess its WQI; results were not released yet
Osvaldo de Araújo cleaned branquinhas in his stand while recalling the time when he fished in Três Casas Lake
“It was so much fish we couldn’t handle it,” Araújo
Araújo used to catch up to half a ton of fish in five days in his canoe
a fisher can take at least 10 days to get 100 kilos (220.4 pounds)
There was a 39% reduction
in the annual average of the fish landings in Humaitá
comparing the periods before (2002-10) and after (2012-16) the dams
“These species are widely used in local cuisine
and also represent a large part of the fishing effort of this population for regional trade,” said biologist Rogério Fonseca
co-author of the article and coordinator of UFAM’s Fauna and Forest Interactions Laboratory
the most productive years took place before the hydroelectric plants came into operation: 2002 (294 tons)
The worst in fish landings happened after the dams: 2014 (158)
we are not reaching 100 tons anymore,” Moraes said
The Humaitá association has around 3,700 fishers
The dams’ impact “represents a loss of approximately $342,000 per annum for fishing activity in Humaitá,” according to the researchers
Another recent study found that five traditional fishing points became unproductive
There are also places with a strong decline in captures
Fishers needed to seek more distant places and started fishing in 25 new sites
hire staff and buy food for the time in the river
“It’s not worth going far away,” Araújo said
the expense of a canoe to go to a lake is 500
If you don’t bring in enough fish to cover the costs
more than 1,500 fishers from Humaitá went to court against the companies that owned the plants
based on studies that attributed to the dams’ impacts on fisheries and fishing
The lawsuits claimed moral and property damages
the judge of Humaitá considered that the disturbances to the fishers began during the construction of the plants in 2007
so he decided that the lawsuits were prescribed because the time limit had already passed
and the cases are now in the Amazonas Court of Justice
many boxes filled with jaraquis arrived at Manicoré’s local market
a municipality 355 km (220.5 mi) downstream of Humaitá
but just now this fish is coming,” said Ancelmo de Menezes
he said he used to capture fish in a higher amount and diversity
“The most abundant fish species became very scarce,” said Antônio Veiga
president of the fishers’ association in Manicoré
the decline was not greater because Manicoré is surrounded by five large tributaries of the Madeira River
who has been head of the association for 25 years
there was no public hearing or consultation regarding the hydropower plants in the region
“We had no knowledge of anything good or bad that it could bring to our municipality
but the impact came down to Amazonas,” he said
The fisherman no longer knows when the water comes
“Generations of fishermen are being forced to change their jobs
The mining and deforestation are at their door
Illegal activities are being pushed to these people
who are seeing themselves without opportunity,” Fonseca said
Novo Aripuanã fishers were still surprised by the absence of matrinxã schools
they haven’t come down,” said Allan de Barros
president of the city’s fishers’ association
This is an example of the uncertainty of fishing activity caused by the Madeira’s imbalance
“We consumed a range of 100-150 tons of fish per year in the municipality
and exported more than 500 tons to Porto Velho and Manaus,” Barros said
we don’t even catch enough to meet the city’s demand
the piramutaba used to climb the Madeira up to three times a year
“we have never seen a school in our river again,” Barros said
He also notes that the catfish species have decreased in size: the filhote (Brachyplatystoma filamentosum) used to reach 80 kg (176.3 pounds) and the dourada
the number of active fishers in the association nearly halved
“The fish are far away and the expense is huge,” Barros said
“The city has no ice factory or diesel and gasoline subsidies
We do not have a cold room to store the fish
so we could sell it cheaper in the off-season
How will the fisherman go that far to catch this fish and sell it for a fair price?”
The fishers of Novo Aripuanã have not yet gone to court to be recognized as affected by the dams
But Barros said the best compensation would be a continuous transfer of resources
so the city could invest in small-scale fish farming
in order to meet the citizens’ demands and have emergency resources to mitigate extreme events
At the meeting of the Madeira and Aripuanã rivers, Raimundo Dias told Mongabay that the 2023 historic drought also contributed to the unproductive fishing year in the Madeira Basin. As a result, other types of food prices also had risen. With the river drying fast again, he expects another rough season
“If it keeps drying like that until August or September
Kevin Damasio and Bruno Kelly joined the Medeira River expedition with the support of Mongabay and Ambiental Media
Almeida, R. M., Hamilton, S. K., Rosi, E. J., Barros, N., Doria, C. R., Flecker, A. S., … Roland, F. (2020). Hydropeaking operations of two run-of-River mega-dams alter downstream hydrology of the largest Amazon tributary. Frontiers in Environmental Science, 8. doi:10.3389/fenvs.2020.00120
Santos, R. E., Pinto‐Coelho, R. M., Fonseca, R., Simões, N. R., & Zanchi, F. B. (2018). The decline of fisheries on the Madeira river, Brazil: The high cost of the hydroelectric dams in the Amazon basin. Fisheries Management and Ecology, 25(5), 380-391. doi:10.1111/fme.12305
Lourenço, I. H., Doria, C. R., & Anjos, M. R. (2023). Spatial–temporal analysis of the effects of hydropower plants over the artisanal fishing in the middle Madeira region, Southwest Amazon. Fisheries Science, 90(1), 1-14. doi:10.1007/s12562-023-01730-5
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The “fortress conservation” model is under pressure in East Africa, as protected areas become battlegrounds over history, human rights, and global efforts to halt biodiversity loss. Mongabay’s Special Issue goes beyond the region’s world-renowned safaris to examine how rural communities and governments are reckoning with conservation’s colonial origins, and trying to forge a path forward […]
Alarming evidence has revealed that Brazilian city dwellers are regularly dining on endangered animals.
Scientists warn the taste for bushmeat in urban environments poses a particular threat to Amazonian wildlife.
They say that the voracious appetite for jungle-dwelling creatures is two-fold: The high level of poverty makes the animals attractive because they are free, while at the other end of society creatures, such as the yellow-spotted river turtle, are treated as delicacies.
Experts from Lancaster University and Brazil interviewed households in two Brazilian ‘prefrontier’ cities – those that are surrounded by more than 90 per cent of their original forest cover.
They found that virtually all urban households in the cities of Borba and Novo Aripuanã consumed jungle wildlife for food.
Almost all of the 153 households – 99 per cent – eat fish found in the forests at least once a month, while 79 per cent eat bushmeat made up of both mammals and birds.
The study found that bushmeat was eaten at least once a month by 44 per cent of urban households in the Amazonian cities of Borba and Novo Aripuanã.
A total of almost 79 per cent of 153 households surveyed said they have eaten bushmeat in the last 12 months.
Urban households reported consuming 15 species of mammals, 12 species of birds, 62 fish and seven types of reptiles.
Among them are endangered, vulnerable and threatened creatures such as lowland tapir, peacock bass and yellow spotted river turtles.
Nearly half of the households surveyed – 48 per cent - said they eat turtles and tortoises, with 28 per cent feasting on crocodile-like caimans.
Some of the species being eaten are classed as endangered, vulnerable and threatened.
These include the white-lipped peccary – a type of forest pig – which despite being ‘near threatened’,was eaten by 19 per cent of those surveyed.
Some 15 per cent of people living in the Amazonian cities have eaten ‘vulnerable’ lowland tapir and 22 per cent of households have feasted on equally vulnerable yellow-spotted river turtles.
‘The high percentage of families that had recently eaten the yellow-spotted river turtle was probably the most surprising,’ study leader Dr Luke Parry, told MailOnline.
‘I was very surprised to find that such a high proportion of urban households consume bushmeat.’
Rare fish including arapaima, tambaqui, dourada and filhote have also ended up on between 15 and 29 per cent of dinner plates, with the vulnerable peacock bass proving a catch for 59 per cent of households.
It was previously assumed that there is low urban demand for bushmeat, but the study, published in the journal Conservation Letters, claims this is incorrect.
Dr Parry said: ‘The rapid urbanisation of forested wilderness in the Amazon could threaten biodiversity if expanding cities drive demand for wildlife as food.
‘There are around 73 cities such as those we studied, occupying around 1.86 million square km2 of forest.
‘Previously it was thought that city dwellers did not consume much wildlife but we found that was not the case. In fact, nearly every household did.
‘People were hunting, fishing and consuming wildlife for a number of different reasons, for some bushmeat was the most affordable protein source they could access, for others it was a question of preference for eating particular “prestige” species.’
He explained that large turtles can cost £100 each, and that tambaqui fish can fetch a similar amount among Brazil’s growing upper class.
‘Both these species are eaten because they are traditional regional delicacies,’ he said.
He believes that programmes to start a long-term trend away from bushmeat as a means to protein to luxury food, could help the situation, but not solve it completely.
‘We need to find ways of alleviating poverty and supplying poor city-dwellers with affordable alternatives to eating wildlife so that in the long term wildlife ceases to be an economical source of protein for the poor,’ Dr Parry said.
‘Innovative environmental governance could limit wildlife consumption to only harvest-tolerant species.’
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