The Gulf of Mexico oil spill is having only minimal environmental effects on land, but it may be causing serious problems in the water, some scientists say.

Wind, currents and chemicals being sprayed on the oil are combining to keep most of the oil gushing from the sea floor out in the water. Scientists say they are growing increasingly concerned about two effects: the damage the oil might do to sea life and the possibility that currents might take some oil around Florida and up the East Coast.

Researchers...