They would do if they occurred near a coral reef.
Wast and oil spills
coral reef bleaching storms oil spills human intervention over fishing erosion rising sea levels rising sea temperatures
oil spills, coral bleaching, everyday pollution and river run off
The changes occuring to the reef are to do with the Mass Coral Bleaching due to rising sea temperatures in 1998, 2002 and 2006. Pollution and declining water quality are other reasons plus the Crown of Thorns starfish which eats coral. Other things are shipping accidents, oil spills and tropical cyclones.
oil
Stop pollution, littering, overfishing, oil and other chemical spills, boats damaging coral, GLOBAL WARMING or 'climate change'.
The simple answer is oil can kill coral. But, not all spills kill coral. There are many factors at play. Not all coral reefs are the same, and not all oil spills are the same. Please see the related link, which contains additional links. You can find more information by doing a google search.
The only negative impact that humans have on oil spills is if we refuse to clean it up properly.
cargo
It affects the menstruation cycle of young male seahorses.
Usually it happens when an oil carrying boat hits a reef of in some cases an iceberg and tears or rips the hull open, when this happens the oil spills into the ocean.
Dwight Holing has written: 'Coral reefs' -- subject(s): Coral reefs and islands, Corals, Coral reef animals, Juvenile literature, Coral reef biology 'Coastal alert' -- subject(s): Citizen participation, Decision making, Energy development, Environmental aspects, Environmental aspects of Offshore oil well drilling, Offshore oil well drilling