Did the oil spill shatter the Gulf's food chain? Will fish have trouble reproducing because of exposure to hydrocarbons? What did those dispersants, which were supposed to break up the oil, do to the ecosystem on the bottom of the Gulf of Mexico? Or did the Earth already heal itself?  Scientists can't say for sure, and it may be years or decades before some of these nagging questions about the Gulf oil disaster's impact will be answered with any sort of authority or clarity, they said in interviews.  The lab geeks know this is frustrating both for journalists and the public, but they beg for our patience as they try to put this enormous puzzle together.  "Scientists have two things that probably aggravate the lay public. One of them is 'I wish I had more data' and the other is 'I wish I had more funding,'" said Christopher Reddy, a senior scientist at the Woods Hole Oceanographic Institution, who has been studying the impact of the spill. "But, in this case, prudence trumps urgency -- or, in your case, the curiosity of your readers."  He added: "We have thousands of samples still in the queue to be analyzed or haven't come out. It may take many years to determine whether some (particular) species was affected. You just have to be prudent at this point. The one year anniversary is a day for mourning and reflection; it's not a day for science."  In this relative data vacuum, politicians, pundits and science-types have spun stories about the impact of the oil spill on the natural environment.  There's the bacteria-ate-the-oil-so-everything's-fine storyline, as offered by the National Oceanic and Atmospheric Administration. That federal agency in November issued a much-disputed report saying the vast majority of the oil in the Gulf had evaporated, dispersed or was eaten by microorganisms.
One year after the chocolaty crude started spewing out of the bottom of the Gulf of Mexico, leading to the largest accidental oil spill in history, scientists say they're still trying to piece