"Dispersants" Helping Them Lie About Extent Of Disaster?

Hidden halfway in a story from AP titled
BP Tries Yet Another Tactic to Siphon Oil at Leak

"Meanwhile, BP began spraying undersea dispersants at that leak site and said the chemicals appear to have reduced the amount of surface oil."

Since these chemicals are adding to the toxic damage to gulf waters, it wouldn't be surprising if the only reason to use them is to cover up the massive destruction by keeping the oil from rising to the top.