While the 2023 record-breaking drought led to widespread social-ecological impacts across Amazonia, local impacts of such extreme events are rarely described in detail. Here we leverage a large interdisciplinary data collection related to social and ecological impacts in the Central Amazon. Compound hazards (reduced river water levels, lack of rainfall, high water/air temperatures, river erosion and fire smoke) led to major impacts, including an unprecedented mortality of 209 river dolphins and blooms of the potentially ichthyotoxic Euglena sanguinea phytoplankton. Fish kills in lakes and changes in caiman relative abundance along floodplain channels were observed, as well as lower-than-usual production of flowers and fruits in floodplain trees. Impaired river transportation was the main socio-economic impact, affecting important value chains such as the arapaima fisheries and manioc flour production, as well as access to healthcare, drinking water and urban markets. Our results also show the contrasting impacts between rural and urban populations, with the latter presenting a higher resilience throughout the event. Continuous records of impacts like those presented here are fundamental to guide future disaster management policies in Amazonia. This is particularly important to help vulnerable remote people and ecosystems during extreme hydro-climatic events, which are likely to increase in the near future.
A new study published in Scientific Reports documents the unprecedented social-ecological impacts of the 2023 extreme drought in the Central Amazon. The research, led by Ayan Fleischmann and colleagues from the Mamirauá Institute for Sustainable Development in Brazil, presents comprehensive in-situ data on meteorological, hydrological, ecological, and socio-economic impacts in the heavily affected Mid-Solimões region.
The study revealed that compound hazards led to catastrophic ecological consequences, including the unprecedented mortality of 209 river dolphins (approximately 12% of the local population) in Lake Tefé, attributed to hyperthermia as water temperatures reached 40.9°C. Researchers also documented the first recorded bloom of the potentially ichthyotoxic Euglena sanguinea phytoplankton in Amazonia, along with significant fish kills affecting economically important species like Hypophthalmus edentatus.
Ecological monitoring showed major changes in floodplain forest phenology, with flower production shifting earlier and being lower than usual, leading to reduced fruit production in early 2024. Caiman relative abundance increased fivefold during the drought, while water bird abundance significantly declined afterward.
Socio-economic impacts were severe and multifaceted. Impaired river navigability affected transportation of people and goods, limiting access to healthcare, education, and urban markets. Health centers in remote areas remained without medical professionals, and indigenous villages lost access to basic healthcare services. Food prices increased by 8% on average, with specific items like manioc flour rising by 20% and some vegetables showing fivefold price increases.
Drinking water access became critical as rainwater harvesting systems failed and groundwater wells dried up. Only 2% of households had sufficient water storage capacity to withstand the drought period. The crisis was exacerbated by inadequate infrastructure, including insufficiently deep wells and limited rainwater storage facilities.
The research highlights how the extreme drought disrupted the predictable annual flood pulse that governs Amazonian social-ecological systems, affecting key production chains including arapaima fisheries and manioc flour production. Urban and rural populations experienced different impacts, with urban residents more affected by price increases and rural communities facing comprehensive livelihood disruptions.
The authors emphasize the urgent need for long-term monitoring and adaptation strategies co-developed with local communities, including improved water storage infrastructure, adapted health and education systems, and policies that link ecosystem monitoring with human well-being to address future climate extremes in the Amazon region.
Sources:
Scientific Reports
https://www.nature.com/articles/s41598-025-25125-x .
Provided by the IKCEST Disaster Risk Reduction Knowledge Service System
Comment list ( 0 )
