Threats to Microbes Responsible for Producing One-Third of Earth’s Oxygen Loom as Scientists Warn of Ecosystem Collapse
Microorganisms that play a crucial role in sustaining life on our planet are facing new and significant challenges.
Particularly affected are cyanobacteria known as Prochlorococcus, considered the most widespread and influential microbes in the global ocean.
These tiny bacteria are responsible for approximately a third of the oxygen we breathe and form vital elements of marine food chains.
However, recent research indicates that rising ocean temperatures are significantly impacting their survival, potentially leading to catastrophic ecological consequences.
Scientists from Washington University, including oceanographer François Ribalet, conducted an extensive study involving the analysis of over 800 billion Prochlorococcus cells collected during 90 expeditions over 13 years.
Their data reveal that the optimal temperature range for these microorganisms is between 19°C and 28°C.
Yet, climate forecasts suggest that within the next 75 years, much of the tropical and subtropical ocean regions will exceed this temperature range, resulting in decreased cell division rates and thus a decline in global oxygen production.
Warmer waters above 30°C hinder cell division almost entirely, threatening the stability of marine ecosystems.
Given the bacteria’s narrow genetic makeup and low complexity—adapted to nutrient-poor tropical waters—the risk of losing critical stress-response genes increases, potentially reducing their resilience to rapid temperature rises.
Meanwhile, other cyanobacteria like Synechococcus, which thrive in high-temperature regions, may start to dominate but require higher nutrient levels.
Overall, such ecological shifts could dramatically influence biogeochemical cycles and the balance of ocean ecosystems.
This situation underscores the urgency of understanding microbial adaptation mechanisms and emphasizes the importance of addressing climate change to preserve the planet’s vital functions.