Venzuela - Upper Río Cuyuní Expedition

Rapid Assessment of the upper Río Cuyuní, Venezuela
Selby Botanical Gardens joined forces with Conservation International-Venezuela, its local partner the La Salle Foundation of Natural Sciences, and 10 other institutions to conduct an intensive biological inventory of the upper Río Cuyuní basin in Venezuela, on the northern flanks of the Sierra de Lema and Venezuela's Lost World. Twenty-five biologists from nine scientific disciplines worked for 16 days to survey an area threatened by illegal gold mining operations and which may be heavily impacted by a proposed large open pit mine. For more information, visit and go to the Research section. Major financing for the expedition was provided by Gold Reserve de Venezuela - Brisas del Cuyuní. Photos by Bruce Holst unless indicated by an EL (Edward Lohnes) or AL (Leanne Alonso).

Searching for Botanical Gold in Venezuela's Lost World -  Bruce K. Holst

Selby Gardens recently joined forces with Conservation International-Venezuela and 11 partner institutions to conduct an intensive biological and ecological survey of a southern Venezuelan river system threatened by gold and copper mining operations. This river system drains a major portion of the Sierra de Lema, a mountain range that forms the northern flank of the “Lost World.” The Lost World was made famous by Arthur Conan Doyle in the late 1800s and is known for its spectacular table mountains, for Angel Falls , the highest waterfall in the world, and for thousands of beautiful plants found nowhere else on earth. With illegal gold mining rampant in the area and a 2,400 foot deep open-pit gold and copper mine proposed by a Canadian mining company in the final stages of permitting, a team of 25 biologists from many different countries and institutions was assembled to conduct a rapid assessment of the region’s flora and fauna. I was invited to join Angel Fernandez and Reina Gonto of the Venezuelan Institute of Scientific Research and Anabel Rial of CI-Venezuela to conduct the botanical portion of the inventory. Other disciplines represented on the expedition were herpetology, ornithology, mammalogy, entomology, limnology, geology, ichthyology, and the study of aquatic invertebrates (for which I can’t come up with an “ology” name for). The support team included cooks, a paramedic, local guides, security personnel, and coordinator of logistics, and a film team captured our work for a future documentary.

It takes two days from Florida to reach the Sierra de Lema, in my case flying first from Sarasota to Caracas and then by a domestic carrier to Puerto Ordaz situated along the immense Orinoco River . Another day of travel by car took us to the infamous Kilometer 88 gold mining region, which is the last place to purchase supplies before venturing into the heart of the Lost World. Near Km 88, we stayed one more night at the “Brisas del Cuyuní” gold mining camp operated by Gold Reserve, Inc., the company proposing the large open pit mine. Obtaining a permit from the Venezuelan Government to conduct such a large scale project is not a simple matter. Many years of planning, enacting social and medical improvements in the community, and conducting environmental studies are required. To further compliance in the environmental arena of their operations, Brisas del Cuyuní entered into an agreement with Conservation International in 2006 to collaborate on environmental issues, including our recent inventory.

Our main target area was in, and around the junction of the Uey and Cuyuní rivers, the area that will be strongly affected by the proposed pit mine and which is being currently degraded by numerous illegal miners. The Cuyuní is the main river system of this region it in turn flows from eastern Venezuela into the Essequibo River of Guyana. There are no roads in the area, so our transportation was by river using four large dug-out style canoes, and in part by air, via helicopter, to establish a forward camp in the foothills of the Sierra de Lema. An advance team had set up the most luxurious base camp that I have experienced, along the Uey, including a generator for providing light at night and charging laptop computers, large work tables, and an ample roof under which to pitch hammocks. The camp was situated on a high bank, which in this area is critical in avoiding the effects of the wildly fluctuating river levels. With approximately 23 feet of rainfall per year (compared with about 4 feet per year in Florida), the Cuyuní basin is one of the wettest in South America, with the river fluctuating up to 10 feet in a day. Even though we were there in the “dry season,” it rained on average three times a day. The wet season must be a truly aquatic experience.

Arriving at the muddy, makeshift port to begin our journey, we were surprised to find dozens of boats loading and unloading provisions. We learned that normally only one or two boats would be at the port on any single day, but gold-fever was raging in the area, fueled by a new find high up the Cuyuní and by rapidly rising international gold prices. Little seems to be done by the government to curb these illegal operations in what is a virtually lawless area of the country. After arriving at base camp an hour upstream from the port and claiming our sleeping berths, we began work. Boats would depart and arrive at all times of day, well before dawn for the birders and late at night for the mammalogists. The ichthyologists impressed me with their willingness to jump into the murkiest of waters to ply their nets, and would come up with a wide array of fishes (some upon which we would later dine), and would occasionally even net a stingray or an electric eel. The limnologists carefully sampled fish tissues to later be analyzed for mercury contamination, a byproduct of the illegal miners. The kitchen was always open, and the food good and filling. Our paramedic, Sol, earned her keep tending to the numerous minor scrapes and cuts, and she also doctored one of our guides through a sting from a Tityus scorpion, known to be highly venomous. His evacuation by river in the middle of the night was a sobering experience, and the treatment that he received, including an unusual injection of scorpion anti-venom may have saved his life. Only one other evacuation was required, this one by helicopter, when another scientist slipped on some rocks at a secondary camp and dislocated his shoulder.

We established two additional light camps, one at the furthest navigable point on the upper Uey, an hour upstream from Base Camp, and another in a narrow canyon several thousand feet higher in the Sierra de Lema, and only reached by helicopter. It was at the upper Uey camp that I got up close and personal with the quickly changing river levels. The rain was heavier during the several-day period that five of us camped on what seemed to be a sufficiently high bank along the river. Late one night we noticed that our boat, previously tied far down on the rocky shore was clanking about the shrubbery adjacent to our camp. Fortunately, it had not become trapped behind too many branches, so we quickly packed camp and headed downriver at midnight through heavy rain and swollen water, crashing through tree branches now at river level and with every headlamp turned on to help our captain guide his way downstream to base camp. If there was any time that we were going to tip over on the trip, I was sure this was it, but our skilled pilot brought us safely back to the Base Camp.

For 16 days we kept up a frantic work pace. Botanically speaking, we found the area very rich in plant life and collected over 800 samples. In an area like this there is always the chance of finding new species for science, but that often takes years of study to determine. One interesting find was the discovery of several species thought restricted to higher elevations of the table mountains, at up to one thousand feet lower than previously recorded. Distribution information such as this will become increasingly helpful in our knowledge of how plants might be able to adapt to the affects of climate change. We also noted that certain plants were completely absent from areas where mining has occurred, even many years in the past. This was true in particular for the saprophytes, those plants that obtain their nutrients from decaying organic matter rather than through photosynthesis, perhaps not too surprising given the level of soil disturbance from hydraulic mining.

With literally thousands of specimens in hand, it was finally time to break camp. We enjoyed a 6-hour celebratory bus ride back to Puerto Ordaz where we reluctantly parted company. For me, it was back to Caracas to work for six days preparing my specimens and identifying plants in the national herbarium. Our results will be tallied and published later this year, along with our conservation recommendations to the government. It is feasible that the upper Uey river can be added to the adjacent Canaima National Park , or at least to provide a sizeable buffer between the mining area and the park. While in Caracas, I learned that we had received a grant from the Wonken Foundation of Venezuela to support the next two years of work in the Sierra de Lema, including funds for more helicopter time into areas never before visited by biologists. We are, without a doubt, looking forward to that!

Acknowledgments. I wish to thank the staff of Gold Reserve de Venezuela-Brisas del Cuyuní for their excellent logistical support and substantial financial support, to Conservation International-Venezuela and the Fundación La Salle for inviting me to participate and especially to Selby Volunteer Marge Schmiel for additional financial support. Also, thanks to M.C. Aime for mushroom identifications and to E. Sanoja for various tree identifications.


For more information

View a slide show of the expedition (with emphasis on botany).

Learn more about the Lost World area of Venezuela and purchase useful reference books.

Read a 2008 report from the company proposing the open pit mine in the Cuyuní River basin (1.5 mb file).

Participating Institutions: