– The remarkable forces that shape Guyana’s Rupununi Wetlands
Imagine being able to travel back in time to almost 2 billion years ago: long before dinosaurs existed, when the Earth was mostly water, with only microscopic life. Any exposed land would seem strange and otherworldly – rocky landscapes completely bare of plants and animals.
Though most of these ancient landscapes have long disappeared, there is a little-known area along the northern coast of South America where ancient mountains from the Earth’s deep past still stand – a unique geological time machine that remains core to Guyana’s present and future prosperity.
At 1.7 billion years old, the Guiana Shield covers six countries, with Guyana at its centre. It contains the oldest mountains in the Americas, and some of the world’s most unaltered natural landscapes. But because of the Shield’s great age, much of Guyana’s interior soils have been washed and weathered over millennia, leaving them very nutrient-poor. It is in these highlands, however, where most of Guyana’s rivers spring forth, carving canyons into this ancient landscape, and creating the foundation for forests, savannahs, and all the wondrous habitats in between. Here rivers function like arteries, pulsing with the seasons and circulating nutrients across many habitats.
In the geographical heart of Guyana, and the Guiana Shield, sits the Rupununi – a wetland unlike any other, with a bonanza of rainforests, savannahs, bush islands, mountains, oxbow lakes, and large inland flood plains. About 180 million years ago, the Rupununi’s distinctive rolling savannahs sat at the bottom of a giant inland lake fed by rivers flowing off the Guiana Highlands. Smaller remnants of this primeval lake still exist, and spread across the savannahs like an echo through time during the intense Rupununi rainy seasons.
It is on this ancient floodplain where the headwaters of two giant South American rivers reach out across the savannahs and connect, creating a “portal” between worlds and watersheds, and setting the scene for a remarkable but little understood migration of animals through a wetland unlike any other. During periods of high rainfall, the region’s major rivers – the Rupununi, Ireng and Takutu – overflow their banks, creating a slow-moving, shallow sheet of water that acts as a temporary path for fish and other aquatic animals to traverse.
The connection between the Amazon and Essequibo that happens in the Rupununi has allowed for the mixing of species from both eco-regions, creating a unique and extremely rich combination of animals, habitats and ecosystems. This mix includes some of the planet’s largest and most diverse bat and freshwater fish populations, as well as a giant Arapaima species that may be new to science.
Despite the Rupununi’s extremely poor soils, the area’s intense seasonal flooding brings much needed nutrients from its forested areas into its savannahs, driving the landscape’s ability to be productive and sustain the communities that live there.
With the area coming into focus for accelerated development – including international road links, petroleum, agricultural diversification, community development, conservation, and tourism development – integrated planning and management have never been more critical.
The Rupununi is home to the Wapichan, Macusi and Wai-Wai indigenous peoples, who have long depended on the area’s natural production for their livelihoods and well-being. Now covered by a mosaic of land uses – community-owned lands, protected areas, ranches, state leases, mining concessions, expanding urban centres, and the town of Lethem – the Rupununi and its continued productivity is central to achieving national prosperity. Protecting the richness of the Rupununi requires an integrated, landscape-level and nature-based approach. Whether designing roads to allow for water flow, or fostering sustainable economies across the region, there are still many nature-centred approaches available in pursing development in the Rupununi; approaches that can bring needed benefits to Guyanese, while still decreasing how much natural production is lost in the process.
This critical wetland also contributes to the productivity of our coastlands. As it expands and contracts in the centre of Guyana, fine sediments flow in two opposite directions: north to the Essequibo, and south to the Amazon. These sediments spend years travelling down their respective rivers, eventually meeting again on the far distant shores of Guyana’s Atlantic Coast. Here a powerful natural earth engine pulls new land from the ocean, creating extremely young coastal wetland ecosystems with the potential to save our coast from the most severe impacts of the climate crisis.
Look out for “The Mud That Makes Us: The extraordinary earth engine shaping and reshaping Guyana’s coast” as we take our exploration of Guyana to the one-of-a-kind coastal and mangrove forests along our shores.