This week, researchers at the Gulf of Mexico Oil Spill and Ecosystem Science Conference in New Orleans, Louisiana, are assessing the outcome — and sometimes drawing markedly different conclusions from the scant data. Industry scientists argue that the nearly three million litres of subsea dispersant worked as expected and caused minimal ecological damage. Dispersant, they say, should be a standard option for fighting future sea-floor blowouts. But other researchers say that applying dispersants at depth has not yet been proved to be effective, let alone safe