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

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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.

Steak, wine, and waterfalls: Salta to Iguazu

Salta, a colonial city in Argentina’s northwest, was home for the next few days. San Pedro had been a tiring experience, with a noisy dorm, and excursions starting hours before dawn and going on into the night. Trying to keep some control over our budget, empanadas had been our primary source of (delicious) food. In Salta we crashed,  lazed, indulged in the biggest, most delicious steak of our lives in a buzzing neighbourhood restaurant, enjoyed cheap good wine and freshly cooked meals in the hostel kitchen and leafy patio garden, and plotted our logistics for the upcoming Brazilian leg of our trip which coincided with the high season over Easter. We failed to see or do a single touristy thing in the city, beyond the steak, but soaked up the bustling evening atmosphere when half the city seemed to be enjoying their daily promenade on our walks to and from the supermarket.

Suitably rejuvenated after a few days, it was time to move on. Another night bus awaited us, this time for a 16 hour journey to Posadas, which we boarded in the early afternoon. We settled in to our seats at the front of the top deck, and watched the suburbs give way to lush tropical farms and countryside. In the glow of the late evening sun parrots flashed green and red in front of us. As night fell, dinner was served, with cold meats, cheeses, and bread making a change from the Peruvian chicken and rice bus staple. But then….we were served a second course! It might even have been chicken and rice. Then we were offered some wine. As if on a night-time safari we sipped our Argentinian white, and watched as nightjars rose up from the road in front of us, a snake slithered across our path, and a furry bottom disappeared into the undergrowth. Once in Posadas the next morning we switched onto another bus for a further 5 hours to Iguazu. We were pretty tired on arrival in the heat and humidity at our Iguazu hostel, but went for a wander to the tri-border viewpoint over the Iguazu river, looking across to Brazil and Paraguay.

The next morning we were up early, to be at the Iguazu park entrance when it opened at 8am. It was a beautiful day, and in the cool and quiet of the morning we virtually had the lower circuit of walkways among tropical trees to ourselves. Argentina (9)

We saw toucans and vultures, rainbows, got our first soaking from the spray of the falls, and had a late breakfast picnic of bread, honey and kiwi fruit sitting here:

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Then to the upper circuit, taking in more waterfall rainbows, before joining the throngs that had caught us up for the train to the Devil’s throat walkway.

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Another picnic pit-stop for lunch, and then we headed out along the 1km trail over the river, spying turtles and catfish, and the rising plume of spray from the falls at the end. Standing above the immense cauldron of water falling beneath you was spectacular, and we got soaked to the skin time and again.

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The next day we made a day trip to the Brazilian side, this time under a cooler, moodier, cloudy sky. We looked back at where we’d been the previous day, and got up close to the Devil’s throat falls from beneath them this time, with another drenching. We spotted flocks of swifts swirling in the rain and spray, before flying straight through the walls of water to their nests behind them. Then it was back to the hostel, to get ready to head to Brazil, for real this time, the next day. Argentina (22)Argentina (26)Argentina (27)

San Pedro de Atacama to Salta

Despite being in the middle of the driest region on earth, we set off to explore some lakes before bidding San Pedro de Atacama farewell and heading onwards to Argentina. First, we explored the salt lakes that are vital habitat for flamingos. The lake was slowly evaporating, leaving behind encrusted salt, in the midst of a vast salt plain. Chile (69)

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Then it was onwards to the Altiplanic lakes at 4500m, vivid blue water reflecting the fiercely clear sky, ringed with tough green grass and small herds of vicunas.

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The next day we packed up and set our sights on Argentina, boarding a bus to take us up and out of the desert, over the Andes, and down the other side to Salta, a colonial city in the northwest of the country. We drove up high enough to pop our bags of crisps, past volcanic peaks, including one marking the border with Bolivia, a tantalising glimpse of a destination for next time. We passed lakes ringed with bright white salt, strange rock forms emerging from the desert, spotted vicunas, and somewhere up in the mountains we crossed the border into Argentina.

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Then the descent, by which time we were on the verge of dozing off, but our eyes pinged open when we realised we were in the middle of a brilliant white salt plain stretching into the distance.

Chile (93)Sometime later we entered a dense bank of cloud, and then started making our way down a series of hairpins. As we emerged from beneath the cloud giant cactuses dotted the canyon-like hillside, which gave way to a valley of pink, red, and purple striped hillsides. We had entered the UNESCO World Heritage valley of Quebrada de Humahuaca. As night fell rain started pouring, a welcome relief from the dryness of the desert. We drove onwards for a couple more hours, this time through urban and agricultural lowlands, streetlights and car lights illuminating the raindrops on the windows, and making the earlier succession of natural wonders seem impossible.

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