Unborn dolphin calves in Brazil were found to carry toxic metals passed from their mothers, raising new concerns about how ocean pollution affects marine life even before birth.
Eric Ralls reports for Earth.com.
In short:
- Scientists analyzing stranded Guiana and franciscana dolphins in southeastern Brazil found copper, zinc, mercury, arsenic, cadmium, and vanadium in fetal tissue, confirming toxic metals can cross the placenta.
- The critically endangered franciscana dolphins showed high fetal metal concentrations, with fetal livers carrying five times more copper and zinc than the mothers’, indicating active transport of some metals in utero.
- Dolphin calves accumulate more toxins as they age, and the study suggests integrating fetal toxicology into broader marine and public health monitoring systems.
Key quote:
“The detection of metals in fetuses is not just a conservation red flag, but a potential indicator of broader ecosystem disruption.”
— Guilherme dos Santos Lima, doctoral researcher at São Paulo State University
Why this matters:
Marine pollution is moving silently through the food web and into the bodies of unborn animals. Dolphins, long considered sentinels of ocean health, show us how toxic metals like mercury, cadmium, and vanadium are circulating invisibly in coastal ecosystems. When these substances are found in fetuses, it points to long-term, persistent exposure and the potential for developmental harm. That has implications far beyond dolphins: Human communities that rely on the same seafood may face similar risks, especially during pregnancy. Studies in humans have already linked prenatal exposure to these metals with lower birth weight, impaired neurodevelopment, and compromised immune systems. What’s circulating in the oceans today could be affecting health outcomes for generations to come.
Related: Ship scrubbers meant to clean fuel are causing ocean pollution
