A Miami port dredging project may have damaged the city's offshore coral reef

Coral reefs around the world are under threat. Acidifying oceans due to the rise of CO2 associated with global warming; the El Nino weather system, which has led to massive die-off and bleaching of corals in parts of the Pacific Ocean. And closer to home, commerce also threatens coral: a recent port expansion may have caused serious damage to the reef off of Miami, Florida.