Amazon turtles imperilled by dams, mercury pollution and illegal trade

For as long as people have lived in the Amazon, turtles have likely been on the menu. But what was once low-impact subsistence hunting escalated dramatically after the arrival of Europeans. From the 1700s onward, demand for turtle eggs and meat skyrocketed. And the eggs weren’t just for eating: estimates suggest that more than 200 million eggs were harvested for both consumption and oil, fuelling lamps across Europe for two centuries.

This overexploitation led to such dramatic population declines that the Brazilian government eventually stepped in, launching the ambitious Amazon Turtle Program in 1979 — an on-going initiative that has so far protected 70 million turtle hatchlings across the Brazilian Amazon, with the intent of conserving vulnerable species.

But while that program continues to work toward a sustainable future for turtle populations —and for the people who still see chelonians as an important source of protein — three more recent threats loom over Amazonian turtle species: the illegal wildlife trade, widespread hydropower dam construction, and mercury contamination.

Read the full article on Mongabay

The Giant Amazon River Turtle (Podocnemis expansa) is the largest species of neotropical freshwater turtle, and is found throughout the Amazon basin. Overexploited for centuries, the species is making a comeback thanks to conservation initiatives. Photo courtesy of Camila FerraraThe Giant Amazon River Turtle (Podocnemis expansa) is the largest species of neotropical freshwater turtle, and is found throughout the Amazon basin. Overexploited for centuries, the species is making a comeback thanks to conservation initiatives. Photo courtesy of Camila Ferrara

Amazonian catfish’s 5,000-mile migration endangered by dams

singular Amazonian catfish is capable of an amazing feat: hidden from human eyes, the species travels vast distances over its lifetime, making a round trip covering more than 8,000 kilometers (nearly 5,000 miles), to return to its natal breeding grounds, a new study confirms.

But even as this record-setting feat — the longest freshwater migration in the world — is scientifically confirmed, the species is threatened by hundreds of planned Amazonian dams.

Brachyplatystoma rousseauxii is a commercially valuable catfish species and an apex predator, growing to 3 meters (more than 9 feet) long. Understanding the migratory patterns of the fish, whose range spans six Amazonian countries, “is paramount for designing adequate conservation and management strategies, especially in view of the current and proposed hydroelectric development throughout the Amazon basin,” the researchers write in the Journal of Applied Ecology.

Observations in the 1990s concerning the size distribution of catfish caught along the length of the Amazon River first led researchers to suggest that long-distance homing migration might be taking place, explained study lead author Fabrice Duponchelle of France’s Institute of Research for Development. Subsequent genetic analyses were consistent with that hypothesis, but still didn’t offer definitive proof.

Intrigued by the possibility that catfish might be homing over such vast distances, Duponchelle employed an innovative technique in the new study to get conclusive evidence: chemical analysis of the otolith, a type of ear bone.

As otoliths grow, their chemical composition changes to reflect the background levels of particular chemical elements found in the environment. Like tree rings, the layers of bone relate to their age: the center, innermost layer of otolith is the oldest, and reflects life as a hatchling; the outer edge is the most recent, and reflects the last stage of the fish’s life.

Read the full article, originally published on Mongabay, here

The giant Amazonian catfish is a valuable commercial species, an apex predator, and the world's long distance freshwater fish migration record holder. Photo courtesy of the USGS Columbia Environmental Research CenterThe giant Amazonian catfish is a valuable commercial species, an apex predator, and the world’s long distance freshwater fish migration record holder. Photo courtesy of the USGS Columbia Environmental Research Center.

Dams threaten future of Amazonian biodiversity major new study warns

Amazonia’s surge in hydropower development threatens numerous species with extinction, and puts unique habitats at risk, warns a recent study.

River dolphins, giant otters, turtles, fish, birds and monkeys will all have their habitats altered by hydroelectric dams, with some species likely to be completely wiped out, says an international team of biologists that looked at all impacts associated with 191 existing Amazon dams, as well as the 246 dams being planned or under construction.

What’s more, the researchers identified a network of negative interactions between dam construction, mining, climate change, human migration, and biodiversity and ecosystem services which illustrates how impacts can cascade in multiple, devastating ways.

In environmental terms, the most obvious and direct impact of dams reported by the study are on water flow and connectivity. Nutrients that flow downstream from the Andes are interrupted by dams; flood pulses that form a vital part of many species’ lifecycles are modified by the reservoirs and flow patterns that dams create and control; habitat complexity is lost; and species such as river dolphins become isolated in the stretches of river between hydropower developments, which leaves smaller sub-populations vulnerable to decline.

To read the full article, orginally published on Mongabay, click here.

River turtles in Colombia. Turtles, dolphins and otters are among the aquatic species threatened by dam construction, but risks extend to birds, bats and terrestrial animals too. Photo by Rhett A. ButlerRiver turtles in Colombia. Turtles, dolphins and otters are among the aquatic species threatened by dam construction, but risks extend to birds, bats and terrestrial animals too. Photo by Rhett A. Butler

 

Keeping Amazon fish connected is key to their conservation

Imagine a fish isolated in an Amazonian lake — part of the vast freshwater ecosystem of the Amazon basin, an ever-changing network of rivers, lakes and floodplains that extends to 1 million square kilometers (386,102 square miles).

Now imagine that isolated fish as water levels rise during the wet season, and floodplains vanish beneath up to 15 meters (49 feet) of water. The fish — once restricted by the lake’s edge — swims freely into the flooded forest and mingles with others of its kind from elsewhere.

For thousands of years, isolated fish populations across the Amazon have likewise played a game of musical chairs: intermixing between flooding water bodies, migrating short and vast distances between lakes and along river channels, and then as the waters receded, forming new lake and river populations.

This connectivity — with the genetic mixing it affords — is vital for healthy fish populations, but is extremely vulnerable to changes in the annual “flood pulse” that inundates forests.

Read the rest of the article on Mongabay.

A South American Leaf Fish (Monocirrhus polyacanthus). More than 2,000 fish species live in the Amazon, the highest fish biodiversity in the world. That diversity has been greatly enriched due to the periodic isolation and intermixing of freshwater species that occurs across the region. Photo © Rhett A. Butler/MongabayA South American Leaf Fish (Monocirrhus polyacanthus). More than 2,000 fish species live in the Amazon, the highest fish biodiversity in the world. That diversity has been greatly enriched due to the periodic isolation and intermixing of freshwater species that occurs across the region. Photo © Rhett A. Butler/Mongabay

Ethics, sustainability, and Amazon hydropower: mission impossible?

Latin America’s largest electrical company operates 45 hydroelectric dams, and is responsible for 34 percent of Brazil’s generating capacity. The company, Eletrobras, makes laudable claims about its corporate values, including a commitment to sustainability, and to “operating through a well-balanced environmental, social and ethical responsibility.”

But with grave concerns raised about the environmental and social impacts of hydroelectric dams in the Amazon, and with Eletrobras itself a key actor in the hugely controversial Belo Monte dam, how sustainable are dam-building companies really being? Are the business decisions they make driven by a genuine commitment to sustainability? And, perhaps more importantly, how can we pragmatically assess the true motivations behind those decisions?

Ethical analysis may hold the answers, according to a recent study published in Sustainability. An international team of researchers suggest it is possible to pinpoint what lies behind a company’s decision-making process through a rigorous ethical analysis.

Read the full article, published in May 2016 on Mongabay, here.

Imperiled Amazon freshwater ecosystems urgently need basin-wide study, management

My latest piece for Mongabay looks at some of the threats facing the Amazon’s freshwater ecosystems, and at how a fragmented protected area network and policy framework – based on terrestrial ecosystems – is failing to protect the connectivity of the freshwater world. As multiple impacts interact with each other the functioning of the whole ecosystem is under threat. You can read the full article here.cropped-p1030605.jpg

Damming the Amazon: new hydropower projects put river dolphins at risk

A little while ago I wrote about the plight of Amazon river dolphins in the face of dam-building across the region. Here’s the opening few lines, but to read the whole piece please follow the link to the original on Mongabay. A National Geographic photographer kindly let us use some of his pictures, so it is worth a look!

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A dam-building boom is underway in the Amazon. More than 400 hydroelectric dams are in operation, being built, or planned for the river’s headwaters and basin. Scientists know that tropical dams disrupt water flow and nutrient deposition, with negative consequences for aquatic animals, especially migratory species. But little detailed knowledge exists as to the impacts of dams on specific species, or as to the best mitigations to prevent harm.

A recent study that tries to fill in that knowledge gap zeroes in on Brazil’s river dolphins. It found that as many as 26 dams could negatively impact dolphin populations and their prey.

The research, led by Dr Claryana Araújo of the Federal University of Goiás, Brazil, focused on two freshwater species: the Amazon River Dolphin, or boto (Inia geoffrensis), which is sometimes famously pink; and the Tucuxi (Sotalia fluviatilis).

The river dolphins of South America are charismatic emblems of rainforest biodiversity, and have captured the public imagination. Swimming in rivers, lagoons, and among submerged tree trunks in flooded forests to chase down prey, they can be found as far inland as the upper reaches of Amazonian tributaries, more than 2,600 kilometers (1,615 miles) from the Atlantic Ocean.

To continue reading, click here.

Forest loss increased annually for 25 years at oldest Amazon mega-dam

Researchers examining changes in forest cover encircling the Amazon’s oldest mega-dam have found that hundreds of square kilometers of forest have been lost each year of the dam’s 25-year history. The study, published in Applied Geography late in 2015, was undertaken by an international team from the US, Brazil, and the Netherlands. They describe the Tucuruí dam, constructed in the 1980s, as “an ideal case for understanding the long-term impact of mega-dams on rainforest loss.”

Great rivers across the Amazon region carry a mind-boggling amount of water: more than 6,500 cubic kilometers — a box 1,559 square miles on each side — flow from the Amazon River into the Atlantic each year, originating from the Andes, the Guiana Shield, and Central Brazil. That flow has extraordinary hydroelectric generating potential, and Amazonian rivers are today caught up in a frenzy to generate power. More than 400 Amazon dams are already in operation, under construction or proposed, with 256 in Brazil, 77 in Peru, 55 in Ecuador, 14 in Bolivia, six in Venezuela, two in Guyana, and one each in Colombia, French Guyana and Suriname.

My latest article for Mongabay, read more here.

Sometimes, rainforest creatures come to you…

My first night of a 4 month field season, I settled down to sleep listening to the buzzes and squawks of the jungle night, mosquito net carefully tucked in all around my mattress. After a while, in the pitch dark, I felt the net trembling, as an animal climbed down the cord that held it up. Then it climbed down the net itself, and then – I’m not sure if it was the first night or later on once this had become routine – it ran across my toes. Welcome to the rainforest, where the creatures come to you.

A few minutes later I heard it knock over all the things I’d unpacked onto my shelves in an attempt to settle in to my new home. It turned out to be an opossum, a large mousey marsupial, which was encouraged on its nightly forays by a long-term resident at the field station who lived in the room next to mine, who left apple cores out for it to find.

Earlier in the evening I’d discovered a very effective (for someone who isn’t good with spiders) energy saving device above the lightswitch. spider lightswitch

It was a good introduction, as various animals were frequently found in the station buildings, from the boa that settled in a couple of metres beyond my desk in the library, to the (absolutely massive) tarantula that appeared in my bedroom (some may wonder why an arachnophobe would live in the jungle), the frogs and geckos that patrolled the bedroom walls, the curly centipedes that would drop from the palm thatched dorm roof, the cockroaches that could be found snacking on soap in the middle of the night, and once a tiny black scoprion in the middle of my bedroom floor.

I became quite attached to one particular creature that I shared a cabin with for a while, although the first time I saw it – a black frog appearing in the toilet bowl when I flushed it – it made me jump. He would appear as the flush was pressed, swim hard against the current to avoid being swept away, and disappear again under the rim afterwards. It took me ages to figure out he wasn’t living just out of sight in the bowl, but up in the cistern. What the toilet offered over the forest I don’t know, but he was always there, swimming away. Until one day I was devastated to see him swim not quite hard enough, and disappear down the pipe. I was happy to see him again a few days later, or if not the same frog, another who shared its taste in cisterns.

My field assistant once encountered a jaguar a few metres away when he made a night-time trip from the dorm building to the bathroom cabin, at CICRA’s satellite station CM1. The two buildings are separated by a short stretch of grass. As he was about to return to the dorm, he spotted huge eye-shine in the beam of his headtorch, and could even make out the markings on the jaguar’s face. The eyes moved down to the ground, and back up again, as if sizing up prey. The following morning dawned grey and rainy, meaning no mist-netting could be done, and I wondered why he was up and wide awake so early. He hadn’t been able to get back to sleep.

CM1 bathrooms are evidently treacherous places, as this photo from good friend and fellow CICRA resident,  Brian Phillips, shows. Might make you re-think how badly you need to go.

snake chain