Environmental Science
How Dredging Activities Resuspend Heavy Metals in Estuaries
Quick fact
The sediment being dredged in many estuaries is a “dirty sponge” that has soaked up decades of heavy metals like mercury, lead, and cadmium. When a dredge breaks this sediment apart, those metals can be released into the water and become available to tiny organisms at the bottom of the food web—even if the disturbance lasts only hours.
Why this is interesting
Dredging is meant to clean up waterways, but it can actually stir up a toxic cocktail buried in the mud. How can removing sediment make pollution worse?