Jens Hegg

Jens Hegg

Jan 11, 2018

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Small fishing boats at low tide near São Luis, Maranhão, Brazil (Image: Jens Hegg)

How it all ended up: A (very) late synopsis of the successful collaboration you funded.

First, let me apologize for the delay in updating you on the results of my visit to Amazonia. I realize that it is more than a bit dastardly to leave you midway through the trip, with the promise of Amazonia and an imminent trip to São Luis, only to go silent and leave you hanging like the lonely half of a forgotten high-five. I am sorry.

In my defense I had my reasons, and the biggest of these was my defense. That sounds awfully circular but it’s true. Let me explain.

After a whirlwind trip to São Luis, then back to Belém, I made it home and immediately was overwhelmed by the work needed to finish my Ph.D. dissertation before funding ran out. So, I’m not just playing with words. My reason for not writing this sooner was my mad dash to defend my Ph.D. (you can watch my defense presentation here if you want)

Part of the magic of crowdfunding is the ability to forge connections between scientists and those of you who care about understanding the world we live in. That relationship should be more than just data collection or reporting of dry, statistical results. I am pretty sure none of you were generous enough to donate because you wanted to know the p-values of a statistical test. I know that I am doing this work because I care about the species, as well as the places, and the people that make their environment special and interesting. I think, more than likely, that is what drives your interest as well.

So, by way of posting our “results”, this lab note will be part explanation of the continuing work you made possible, and part travelogue of my time in Amazonia last year. The pictures I can’t work into the story I’ll post at the bottom.

When I left all of you hanging in my last lab note I had just landed in Belém, at the mouth of the Amazon river. I had met with my collaborator Tommaso Giarrizzo and we had just begun planning the next phases of our project. We left the next day for São Luis, in the state of Maranhão, to meet with a collaborator who could potentially help is in finding sawfish samples. São Luis is not in Amazonia proper, it is on the Atlantic coast south of the outlet of the Amazon river. The large estuary surrounding the city, and the coastal areas stretching on either side, make for large numbers of sawfish encounters. But...that is getting ahead of ourselves. Belém is worth spending some time on.

The city of Belém, Pará at night

Belém...the first time

Belém, with its lush jungle and oppressive humidity, is exactly what you expect of the Amazon. The Ver-o-Peso market holds fruits, fish, crafts and natural remedies both spiritual and medicinal from all over Amazonia. The gorgeous old architecture from the boom days of rubber seems to be constantly at war with the roots, vines and saprophytes. The smell of the Amazon is the smell of decay and decomposition, leavened by that “fresh smell of rain” after each of the several showers (and often downpours) that come like clockwork each day.

Belém seems to be in a constant struggle to hold back the jungle as this old, un-repaired, house attests.

Thousands of old mango trees line the streets and Belém is also known as the city of mangos for these monstrous, gnarled, old mango trees. It rains on schedule, every afternoon. Some days it rains all day, especially in the rainy season when I was there. The rain is never really cold by North American standards but it comes down in buckets when it comes. The towering storm clouds coming over the long horizon are impressive, especially at sunset. The city is a gritty, working class but quickly modernizing testament to hundreds of years of the Amazon’s history. Walking through the central city there are cool old buildings and some really interesting street art to be found.

A graffiti mural near the Umarizal neighborhood in Belém

The local food is backed by millennia of Amazonian food tradition and unlike anything else in Brazil. Dishes like the local specialty tacacá, are ubiquitously filled with cassava and its derivatives (tapioca, tucupí, farinha, maniçoba, etc.), packed with the fish and shrimp of the Amazon river and estuary. It is often spiced with the jambú plant that, even when cooked, leaves your mouth with a slight “fresh from a root canal” Novocain tingle...eaten raw the flower scrambles tastes and tongue sensations in a wave of culinary psychedelia, and sends your salivary glands into overdrive.

Jambú leaves for sale at Ver-o-Peso market in Belém

Outside of Amazonia açaí, the earthy tasting fruit of the açaí palm, is eaten as a sweet. In most of the rest of Brazil açaí (pronounced ah-sy-eE) is used in sweet pudding. Here in the U.S. we’re used to seeing it as a “super-food” that is added in barely tastable amounts to sweet drinks and snacks. In Amazonia açaí is most traditionally a savory, eaten unsweetened, only açaí pulp in water, like a fruit soup. It’s deeply earthy, with no acidity, not quite bland but also not super flavorful. It is almost impossible to describe but is very refreshing and even now gives me cravings. It makes a perfect compliment to a plate of fresh-fried dourada catfish right on the docks at Ver-o-Peso.

A meal of fresh dourada catfish (one of our study species) with a bowl of fresh açaí at Ver-o-Peso market in Belém

It turns out that one of our study species, dourada, the catfish that makes the longest freshwater migration in the world…is also by far the best fried catfish I have ever eaten, hands down! The flesh is extremely firm, tasty but without much "fishy" taste at all, and with little fat. Tommaso’s PhD student Kurt met me at Ver-o-Peso and insisted that there was no fresher fish or açaí than at the market where the fish are unloaded. I’m glad I took him up on it, it was phenomenal!



São Luis

Driving to São Luis from Belém is a study in changing tropical ecosystems. The big, green, leafy jungle begins to fade away slowly as the climate becomes less rainsoaked, giving way to workable land. More than half of the drive to the Atlantic coast is through agricultural land and palm savannah, with large expanses of grassland and farms beneath scattered, large palms. It is remarkable how the changes in local climate are mirrored by the types of palm trees you see as you move further from the rain of the Amazon basin. São Luis itself is built on two lobes of an island that extends into the surrounding estuary. It is absolutely beautiful, with wide white sand beaches on all sides.

A horse cart in the old city of São Luis, Maranhão

The city itself is a study in contrasts. One half of the island holds the old city with its colonial, blue and yellow tiled architecture that is now a UNESCO world heritage site. Winding streets full of shops hug the hill that originally guarded the harbor. The other side of the island is all gleaming luxury. High-rises and brand-new architecture sprout up along gorgeous beaches, with a harbor full of expensive yachts and catamarans. Unfortunately, despite the inviting beaches I was told that swimming wasn’t the greatest idea…sewage treatment hasn’t kept pace with the growth and bacterial counts in the surrounding water are not good.

São Luis also sports a gigantic shopping mall with a GIANT ball-pit taking up the entire central atrium. For scale, note the inflatable crocodile in the background would be almost three stories tall if stood on end!! It is a city of contrasts.

The source of the money for this apparent luxury and growth is easy to see. As you near the city the road is flanked on one side by a busy railroad. Miles of fast moving train cars zip Amazonian ore to the port as fast, or faster, than the traffic. An above-ground oil pipeline hugs the opposite side of the road, exporting oil from the interior to a Petrobras terminal at the river mouth.

The collaborators with three donated sawfish samples at a private museum. Counter-clockwise from top left: Jens Hegg, Tommaso Giarrizzo, Jorge Nunes, Masters Student Leonardo Feitosa.

Close-up of a donated sawfish rostrum from a private museum in São Luis

In São Luis we met Jorge Nunes, a professor at the local university. We immediately agreed that we should head out in search of sawfish, to get an idea of how often these fish were caught and see what fisherman know that we don’t. We didn’t have a source in mind but had heard that if you asked the right questions in the Umbanda shops of the old city there are those who believe that sawfish teeth provide spiritual protection. Umbanda is the Afro-Brazilian religion, related to Voodoo and Candomblé, that is the second most practiced religion in Brazil.

sawfish "catana" and shark jaw displayed in Umbanda shop in São Luis, Maranhão

This resulted in a day spent traversing the streets of the old city of São Luis, ducking into Umbanda shops between periodic rainstorms and asking about “catana” as the toothy rostrum of a sawfish is known in Portuguese…after the samurai “katana” sword. Although the shop owners were all mostly willing to talk, we struck out. Only one shop had a catana displayed and they were not willing to part with a tooth for a sample, nor did they know where they came from.

Most of the shop owners hadn’t heard of sawfish teeth as a good luck charm. The ones who had, suggested that it was probably a regional belief in other parts of the region but wasn’t widely believed in São Luis. Despite this, Jorge had been given a small catana that had, according to the restaurateur, been affixed to the wall of his restaurant to ward off bad omens.

Close-up of the actual teeth of a sawfish (not the rostral teeth on their nose) from a dried sample. They are stubby, smooth, and more for grinding than biting.

We also spent a good part of the day shuttling between various fishing ports, asking off-duty fisherman and various shady characters, some further along the spectrum of intoxication than others, about their experiences with sawfish. We were able to track down the fact that a black market exists for the dried rostrums, with the largest (from the oldest, probably sexually mature fish) selling for multiple hundreds of dollars. For the most part these are apparently sent to Asia, according to the one black market source who was willing to talk. These large specimens are rare, which isn’t surprising given that they are critically endangered…but because sawfish reproduce later in life the loss of large fish is particularly hard on the population.

Very large rostral teeth, sanded and shaped for use as cockfighting spurs, were available for sale. These teeth would have been from a very large sawfish.

Separately, Tommaso had discovered that teeth from what must have been very large sawfish are occasionally sold for cockfighting at Ver-o-Peso market in Belém. These teeth, almost as long as the width of my palm, would have belonged to an extremely large and old animal. The teeth are shaped and sharpened to a razor point, then attached to the legs of the fighting cocks in place of their natural fighting spurs whose keratin is not as hard or as sharp as the replacement.

Our trips through the fish markets and docks in São Luis also spurred a mutual interest in examining the movements of another large fish. Atlantic Tarpon are large, open-ocean predators that appear to be clad in shiny, stainless steel armor plates. In reality, their scales are just like any other fish, it’s just their coloration that appears metallic. But, their scales are much like armor in the only way that counts; thick and extremely large, it would take sharp teeth and a strong bite to get anything tasty by attacking a tarpon.

Palm sized scale from an Atlantic tarpon in the fishing village of Raposa, Maranhão. The fish itself was significantly longer than I was. The body, cut in half and without the head, just fit inside a floor cooler meant for soft-drinks and was packed under ice. My head would have nearly fit inside it's mouth! Notice the growth rings that are visible on the scale. These can be used to find the age of the fish as well as for uncovering chemicals and tracing their movements.

Because their scales are so large and hard, they contain enough calcium that other researchers have analyzed their chemistry in similar ways to the earbones we use in most fish (and the same way we hope to analyze sawfish teeth). Tarpon move between low salinity and high-salinity water as they grow but the timing of this transition isn’t something we understand very well. By combining forces with other researchers in the Gulf of Mexico we are hopeful we can understand when and why they move into saltier water, and whether their movements change as water conditions change further from the equator.


The city of Belém from the tower at Mangal Das Garças

Back to Belém

Meeting Jorge kick started our work, providing an avenue into the world of sawfish, and upping the excitement about other projects including tarpon ecology. Unfortunately, I couldn’t stay in São Luis forever and Tommaso had other work to complete further south in Bahia. So, we all parted ways and I headed back to Belém by plane.

Photo with Tommaso's PhD student Kurt Schmid who hosted my presentation to the aquatic ecology and fisheries lab at the Federal University of Pará in Belém.

In my remaining days in Belém I gave a talk on my research to Tommaso’s graduate students and toured the Federal University of Pará with Kurt. Despite a language barrier it was great to talk with his graduate students. My talk focused on the similarities between the history of salmon on the Pacific coast of the United States, and the current challenges facing Amazonian migratory catfish.

Salmon on the West Coast of north America were decimated by overfishing and the placement of dams that blocked their spawning migrations. Amazonian catfish are at the same place that salmon were in the early half of the 20th century, overfished and facing the first handful of what will likely be many dams that block their upstream migration. How the goverments and local communities of Brazil, and the other countries with Amazonian territory, deal with these challenges will determine whether migratory catfish face a similar fate as salmon populations.

The University is about as “wild”, in the most literal sense, as I have ever seen. The entire university is built along the swamps bordering the Rio Guamá, full of all the critters you might expect. Tommaso’s laboratory borders the edge of this swamp at the far edge of campus. Apparently, following the flood cycles of the river or perhaps simply hunger and curiosity, the caiman and anaconda occasionally make a sweep through the labs…taking with them all of the ever-present stray dogs and cats. Kurt also related the story that restaurant in the middle of campus was cleared by a large anaconda that decided to come in the front door one day on his way through campus. Bastion of the frumpy, pipe-smoking, stained-glass and cathedral-ceilinged ivory tower it is not, but the Federal University of Pará (UFPA) is home to some great research into Amazonian ecology both terrestrial and aquatic.

My hosts during my final days in Belém: former host brother during my undergraduate study abroad Daniel Bahia, his wife Paloma Bezerra, and their incredibly cute French bulldog, Lilly.

My final days in Belém were also a chance to reunite with the family I stayed with two decades ago when I studied there as an undergraduate. My old host brother Daniel and his wife Paloma took me in as a guest and made sure I saw the best of what Belém has to offer. These included the incredible Mangal das Garças gardens that include a butterfly enclosure and breeding program for native butterflies, as well as a bird enclosure with numerous native Amazonian bird species.


Future Plans

Now that I have successfully earned my Ph.D., Tommaso, Jorge, and I have kicked the collaboration back into high gear. Jorge and Tommaso have found another researcher who has a large trove of sawfish samples collected in the Lower Amazon region that we can access for analysis. Along with close to a dozen samples we had already collected we have enough samples to begin the work of figuring out how to uncover their chemical secrets.

Theoretically, sawfish teeth are similar to fish earbones (otoliths), growing in sequential bands that trap trace amounts of chemicals that can be used to understand their movements and behavior. But sawfish teeth are also different. They stop growing as some point in life, they also are outside the body and become warn and broken over time, potentially losing important chemical information. We will be one of the first groups to try this technique on sawfish and the method is unproven. We will start with a subset of sawfish teeth, looking carefully to document the structure of the teeth, the presence or absence of growth bands, and finally analyzing them for chemistry to see if we can indeed uncover the information we believe is there.

If this is successful we can then begin to ask the really interesting ecological questions. Questions like: are all sawfish juveniles birthed in freshwater before moving to salt water?; How long do adult sawfish spend in freshwater?; Is the time adults spend in freshwater only for birthing young?; Is the use of freshwater different in sawfish from the Amazon, where the river is so much larger and potentially more productive, than for sawfish in Maranhão on the Atlantic coast?

Three donated sawfish rostra. The top one was donated by a restauranteur and had been affixed to the wall as a protective charm. It was painted orange along with the wall before it was donated.

We will also likely move forward with preliminary research on tarpon movements using their scale chemistry. This is less exploratory since other researchers have proven that the method works. The ecological questions for this work are more wide ranging. Ideally we would like to understand whether differences in life history exist between fish from near the equator (in Brazil) moving up the coast and into the northern Gulf of Mexico where other researchers have ongoing studies.

This trip did not focus on migratory catfish sample collection, mostly because we are still trying to determine what questions to ask. Our first study showed it was possible to study this migration using otolith chemistry, and we found some cool “weird” behaviors that we didn’t expect, some fish were not starting life in the estuary. A subsequent study by another research group confirmed some of these “weird” behaviors. To ask more nuanced questions though we need to target our sampling and try to answer tractable questions.

Again, as in the past, the absolutely gigantic size of the Amazon basin is a problem. To dig deeper into these new migratory behaviors we have uncovered, we need to find a way to sample fish with some control over their location (in our last study we simply took random fish from throughout the entire Amazon). We are still working to find a study design that we are confident can uncover interesting parts of these species ecology in a scientifically robust way.

Of course, all of these things require funding to accomplish. Shipping samples, especially for critically endangered species, requires time and money to apply for the required permits. Samples cost money to prepare and analyze, and none of these high-tech machines come cheap. We are planning to apply for grants both in the United States and Brazil to cover these continuing costs. We are still partnered with Ecologists Without Borders, a nonprofit organization, who can lend logistical support as the projects grow.

We also will continue to pursue crowd-funding where it’s appropriate. The experience of directly connecting with the public that Experiment.com provides is as valuable for us as it is for those of you who donate. To keep track of our work feel free to follow me on Twitter (@AFishInSchool), through my profile on ResearchGate (https://www.researchgate.net/profile/Jens_Hegg), or on my personal blog (http://afishinschool.blogspot.com).


Thank You All So Much

Myself overlooking Guajará Bay and the Mangal Das Garças park in Belém.

Again, I can’t thank you enough for providing the funding to make this all possible. Sometimes science feels like an insular, even lonely, endeavor. This experience has been anything but. Beyond your financial contributions it is incredibly powerful to know that ordinary people care about your work. That knowledge certainly gave me a nudge to keep going during late nights of data analysis for my PhD (the first chapter of which was on this Amazonian work).

Thank you.


Sincerely,

Jens Hegg



Additional Photos

If you see nothing else below you have to watch this man shelling Brazil nuts with a machete at Ver-o-Peso market. Wow!


Details from street mural

Rubber paid for some extremely fancy architecture in Belém

Some, like this historic mansion, are being restored into extremely nice homes. Others are not in such great shape.

An afternoon rainstorm approaching from across the city

Dourada catfish, one of our study species, for sale at Ver-o-Peso market in Belém

The strange shovel-nosed head of a dourada catfish. Notice the small eyes...you don't have to see very well if you live in muddy water.

The teeth of a dourada catfish. They are most similar in texture to stiff velcro. They are not for biting but for holding on, the dourada eats things whole.

Peacock bass, probably the most famous Amazonian sport fish, are also great for eating and plentiful at Ver-o-Peso

An unknown (to me) species of armored catfish, possibly tamboatá. There are many, many varieties of these armored catfish in the Amazon. They are apparently tasty and often cooked whole, with the scales, in broth or soup.

a display of traditional dugout and other canoes on the wall of Espaço São José Liberto, a kind of civic center that was created from a notoriously awful prison near the old-city in Belém. The center now has local artisan crafts, a shop that makes fancy jewelry on-site and cultural programming.

Dugout canoe in the foreground with other styles behind

You can still see the axe marks on the inside of this canoe, as well as the patching to fix cracks

Scarlet ibis at the Mangal das Garças park in Belém

Native butterfly in the butterfly enclosure at Mangal das Garças

The butterflies in the enclosure change with the seasons based on when they hatch in the breeding program. The rest of the butterflies (and this one) are mounted.

I'm not sure what kind of bird this is. It was awfully friendly inside the enclosure, one of the few I could get close enough to get a decent picture of.

Another friendly bird from Mangal das Garças


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  • Yuni Atalia
    Yuni Atalia
    A selection of good articles according to the needs of each reader Below is the point to the article: https://design-cibox.de/ https://www.sbvisuelset.com/
    Sep 08, 2024
  • Kevin Roberg-Perez
    Kevin Roberg-PerezBacker
    Stumbled through on a self Google long after your post. A fun read and love the pictures. Armored catfish that is crazy.
    Aug 15, 2021
  • Cindy Wu
    Cindy WuBacker
    It has been exciting to follow your journey. Congrats Dr. Jens Heggs! 👨🏻‍🎓
    Jan 31, 2018
  • Cindy Wu
    Cindy WuBacker

    Dishes like the local specialty tacacá, are ubiquitously filled with cassava and its derivatives (tapioca, tucupí, farinha, maniçoba, etc.), packed with the fish and shrimp of the Amazon river and estuary.

    Yum! 😋
    Jan 31, 2018
  • Neroli Wesley
    Neroli WesleyBacker
    Wonderful to hear how it's going. I did wonder if you'd been eaten whole but I'm so glad that you are alive and well and fighting the good fight. You describe everything beautifully. Write a book? Good luck and stay safe.
    Jan 14, 2018

About This Project

Amazonian catfish make the longest freshwater migration in the world (5,000km). Dams being built could block this migration before we can even understand it completely. Similarly, largetooth sawfish make upriver movements from the Atlantic ocean but we do not know why. We have published one paper using isotopic tracers from fish earbones to reconstruct details of catfish migration and propose to expand our work and to include sawfish, another endangered megafish, in our isotopic migration study.

Blast off!

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