Congo Lakes (Mai Ndombe and Tumba)
Kartavya Desk Staff
Source: DD News
Subject: Environment
Context: A recent scientific study has found that lakes (Mai Ndombe and Tumba) in the Congo Basin are releasing ancient carbon stored for thousands of years in surrounding peatlands, raising fresh climate concerns.
About Congo Lakes (Mai Ndombe and Tumba):
What they are?
• Lakes Mai Ndombe and Tumba are large, shallow blackwater lakes characterized by their dark, tea-like color. This unique appearance is caused by high concentrations of dissolved organic matter and humic acids leached from the surrounding dense swamp forests and peatlands.
Location:
• Country: Democratic Republic of Congo (DRC).
• Region: Situated within the Cuvette Centrale (Central Basin), a vast depression in the heart of the Congo Basin.
• Wetland Status: They form part of the Tumba-Ngiri-Maindombe area, the world’s largest Wetland of International Importance recognized by the Ramsar Convention.
Formation:
• These lakes are primarily floodplain and wetland-origin lakes, formed through riverine processes associated with the Congo River system.
• Continuous waterlogging led to the accumulation of organic plant material over thousands of years, forming deep peat deposits around the lakes.
• Peat formation occurs when dead vegetation accumulates faster than decomposition under oxygen-poor conditions.
Key Features:
• Shallow Depth: Both lakes are extremely shallow, with average depths of only 3 to 5 meters.
• Blackwater Ecosystem: The high acidity (pH 4.0–5.5) and low oxygen levels in the surrounding flooded forests create a unique habitat for endemic fish species.
• Size Fluctuation: The lakes are highly dynamic, with Lake Mai Ndombe doubling or tripling in size during the rainy season.
• Carbon Reservoir: The surrounding peatlands cover only 0.3% of Earth’s land surface but hold one-third of all tropical peatland carbon (approx. 30 billion metric tons).
Reason for carbon emission:
• Research shows up to 40% of CO₂ emissions from these lakes originate from ancient peat carbon (over 3,000 years old).
• Carbon likely moves from peatlands into lake water and escapes into the atmosphere.
• Key contributing factors include: Drying of peatlands, which reactivates decomposition processes. Climate change, increasing drought and temperature stress. Land-use change, such as deforestation and conversion to cropland.
• Drying of peatlands, which reactivates decomposition processes.
• Climate change, increasing drought and temperature stress.
• Land-use change, such as deforestation and conversion to cropland.