Science Chat #17 | Science Expeditions on the Marañón

The Marañón River has intrigued many scientists and adventurers to date. It is threatened with the construction of more than 20 hydropower dams, which encouraged multiple scientists to put their knowledge into action. Today we discuss with Luigi, Nathan and Natalie.

Luigi Marmanillo Cateriano got involved in the protection of the Marañón River when he joined a ‘paddle for purpose’ trip on the river 5 years ago. Together with Ben Web, initiator of this trip, he now runs a rafting company on the river (Marañón Experience, see also Marañón Waterkeeper), to enable adventurers as well as scientists to explore this river and spread the story of the headwaters of the Amazone. Luigi shares his experiences in his work where the link between visitors and local communities is of high importance to him.

Dr. Natalie Kramer Anderson is a fluvial geomorphologist and professional whitewater kayaker.  In 2015, she partook in a whitewater expedition down the Marañon that collected baseline data on sediment, water chemistry and invertebrates.  A diverse array of products resulted from the trip including the documentary film, Confluir (English, Spanish) by Henry Worobec, which documents their journey and provides historical and sociopolitical context for the Marañon river.  Other tangible products included reviewed scientific articles, conference papers, printed magazine articles, a childrens’ story in National Geographic Explorer Kids as well as several online articles.  She summarizes their trip and what she learned with regards to making a scientific expedition meaningful beyond simply collecting data and introduces RARR (rapid assessment of rivers at risk), her current project, which has the goal make exploratory baseline data collection by adventurers more accessible by setting up a data repository on (still in development).  She has found that, in the end, it is not the hard data, but the empowerment of existing local efforts and the intangible personal connections made on these expeditions that end up having the largest impact.

A final report of the trip in 2015, including links to talks, presentations, papers and reports can be found here. Natalie was co-author on a paper about the natural wood regime in rivers, which forms the third leg of a tripod of physical processes that supports river science and management, along with the natural flow and sediment regimes. 

Dr. Nathan Lujan is an ichthyologist at the American Museum of Natural History in New York. His research examines freshwater fish diversity in tropical South America and the North American Great Lakes. In over 20 expeditions to Bolivia, Brazil, Colombia, Ecuador, Guyana, Peru, Uganda, and Venezuela, Nathan has discovered over 30 new fish and invertebrate species and has collected samples and data that have revealed for the first time how large portions of the Neotropical ichthyofauna are interrelated, how historical geologic events have affected the evolutionary diversification of fishes, and how feeding specialization affects how fishes interact ecologically.

Nathan has led three expeditions to Peru, including two small biodiversity surveys of the Marañon River in northern Peru and one large biodiversity survey along an Andes-to-Amazon elevational gradient in the Inambari River of southern Peru. He is now planning fieldwork that will expand his Andes-to-Amazon approach to sampling water physicochemistry, and algal, macroinvertebrate, and fish diversity to the much larger Marañon River. Over 20 hydroelectric dams have been proposed for the Marañon, and several dozen other dams have been proposed for elsewhere along the Andean flanks, so it is critical to establish a better understanding of why longitudinal connectivity in Andean rivers are important to their ecological function and ecosystem services. It is also critical to establish a baseline understanding of biodiversity in the Marañon so as to evaluate future environmental impacts. The expedition being planned will combine elements of scientific discovery with adventure in the form of whitewater rafting and kayaking and an anthropological investigation of indigenous peoples’ perspective on the river and its importance to their lives. The entire experience will be documented on film and in photos that will provide the basis for art exhibits in Lima and New York and a feature-length documentary film.

More information on Nathans projects can be found on this website, including a description of the motives, personnel, and products of his 2006 trip to the Marañon and the 2010 trip to Peru when they conducted the longitudinal gradient survey. Links to papers proceedings from those trips, including various papers on the functional morphology, ecology, nutritional physiology, and gut microbiomes of wood-eating catfishes can be found there.

An analysis of the current legal status of two main planned hydropower dams (Veracruz and Chadin 2) can be downloaded below.

Interested in the Marañón? See some more cool interactive pages that give lots of information on science as well as the cultural/spiritual importance of river sites.