The chemical pollution in rivers and lakes is no longer a specific problem. More and more studies warn about slow and persistent effects that alter the life cycle of fish and their ecosystems.
In this context, biologists warn that certain agricultural pesticides not only kill but also age. The damage is not immediate, but it accumulates over time.
Thus, continuous exposure to low concentrations emerges as an underestimated risk for biodiversity.
When the damage is not seen, but progresses
For years, environmental analyses focused on acute toxicity episodes. However, this approach leaves out more subtle and lasting impacts.
Research led by the University of Notre Dame reveals that the danger also operates chronically. The damage appears even when levels comply with current standards. Thus, the problem is not only how much pesticide reaches the water but how long it stays there.
A study among lakes in China
To verify this, scientists combined fieldwork and laboratory. They analyzed more than 20,000 skygazer fish in different lakes in China.
Then, they replicated those conditions in controlled environments. There, they exposed the fish to low and persistent doses of chlorpyrifos. The results showed a clear pattern between sustained pollution and accelerated biological deterioration.
Damaged telomeres and premature aging
The central finding relates to telomeres, structures that protect DNA and mark biological age. In exposed fish, these shortened significantly.
As a consequence, their regeneration capacity decreased. Animals of the same chronological age appeared biologically older.
Additionally, lipofuscin in the liver was detected, a signal of accumulation of cellular waste associated with aging.
Chlorpyrifos, a pesticide under scrutiny
Among all the compounds analyzed, chlorpyrifos was the only one consistently associated with the observed deterioration. Its use is still allowed in countries like the United States and China.
This occurs despite being banned in the European Union and the United Kingdom. The regulatory difference exposes global tensions in environmental matters.
The most concerning aspect is that the effects appeared below the limits considered safe for freshwater.
The consequences of pesticide use
The impact is not limited to one species. Premature aging reduces populations, alters trophic chains, and weakens entire ecosystems.
Additionally, cumulative damage hinders the natural recovery of lakes and rivers. Fauna loses resilience to other climatic stressors. Therefore, the intensive use of pesticides poses a long-term ecological challenge.
A warning for environmental management
The study shows that chronic pollution can be as harmful as acute. Without changes in regulations, the deterioration will remain invisible.
Protecting aquatic ecosystems requires revising standards and agricultural practices. Otherwise, the silent aging will continue to advance underwater.
