A groundbreaking study sheds light on the alarming role of Brazil’s Pantanal soda lakes in contributing to climate change. These shallow, highly alkaline bodies of water harbor a complex microbial world that directly impacts greenhouse gas emissions. As the Pantanal faces increasing environmental challenges, such as unprecedented wildfires and severe droughts, understanding the intricate relationship between the lakes and climate change becomes crucial for developing effective mitigation strategies.
The hidden biodiversity of soda lakes
Besides its major flooding and dry periods, the Pantanal has special ecosystems called soda lakes due to their high pH and high level of microbial diversity. The study explores the significant impact of these microorganisms on biogeochemical cycles and emissions of greenhouse gases from these lakes.
According to the researchers, there are three main types of soda lakes based on their water chemistry and microbial composition: (i) eutrophic turbid (ET); (ii) oligotrophic turbid (OT); and (iii) clear vegetated oligotrophic (CVO). The ET lakes are the main emitters of methane and have a characteristic pattern of high carbon dioxide as well as nitrous oxide emission, most likely due to the presence of cyanobacterial blooms among others leading to algae growth and organic matter decomposition.
This knowledge will help in predicting future responses of these ecosystems to climate-change phenomena like drought and wildfire, which can perturb both the microbial communities and the lakes’ biogeochemistry.
C17 – Pantanal’s Seasonal movements and the burst of Cyanobacteria
The largest tropical wetland on the planet, the Pantanal is experiencing radical transformations in association with climate change. Between 2000 and 2022, the area of water on this expansion fundamentally decreased, evidenced by satellite imagery revealing an increase in cyanobacteria turning the water green.
The changes are associated with increased temperature, changed patterns of rainfall and previously unseen number of fires in the region. The researchers noticed that a number of the soda lakes they sampled in 2017 had become nearly completely desiccated, underlining just how quickly these ecosystems can be changing.
Cyanobacteria, often called blue-green algae, play an important role in the biogeochemical cycling of nutrients and the emission of greenhouse gases from those lakes. The ability of the algae to photosynthesize in severe weather conditions by absorbing CO2 during dry season, and growing throughout the rainy seasons makes them pivotal when discussing the climate profile of these soda lakes.
Soda Lakes Emissions: To Make a Long Story Short
One of the highest values historically on record, but these measurements are still well within the range of what has been observed in previous high read years around the turn of 20th century far — it seems that researchers will need to dig deeper if they are to truly grasp pitch for how much each functioning soda lake contributes to climate change over all among Pantanal.
This is the same team that published research just days ago on some of these lakes, and are wrapping up studies of how they function geochemically in their formation as they continue changing fast. At the top of her list is an understanding of why some lakes are carrying higher loads of cyanobacteria, which can alter water quality and amplify greenhouse gas emissions.
With the combination of an uncertain future for the Pantanal fueled by increasing impacts from climate change, this research further underscores the imperative for robust monitoring and mitigation measures to safeguard these biomes as they face modern-day challenges. These findings provide invaluable insight into the cascading effects of soda lakes on Pantanal- levels outcomes, as well as the integral role these microbially-influenced processes play in Gaian functioning.
