BP Chief Executive Tony Hayward
© Patrick Semansky / The Associated Press
BP Chief Executive Tony Hayward on Fourchon Beach in Port Fourchon last week.BP

Chief Executive Officer Tony Hayward is refuting claims by scientists that there are large undersea plumes from the Gulf oil spill.

Hayward said Sunday the oil is on the water's surface, and that BP's sampling shows "no evidence" of oil in the water column.

Scientists from several universities have reported plumes of what appears to be oil suspended in clouds that stretch for miles and reach hundreds of feet beneath the Gulf's surface.

Hayward also said the company is narrowing its response to the oil spill to the Louisiana coast and bulking up cleanup forces there for a fight that could last months.

Almost six weeks into the nation's worst spill, no significant oil has hit other Gulf states, but they remain guarded.