NEW YORK -- Joe Martens has flipped between government work and environmental advocacy more than once in his adult life. As the Empire State continues to ponder its most visible energy dispute in decades, that career track has some calling for his scalp. Martens is head of New York's Department of Environmental Conservation, making him the regulator closest to a lingering, years-long tussle over whether to end a moratorium here that prevents hydraulic fracturing, or fracking. He is also the most prominent representative on the issue for Gov. Andrew Cuomo, the Democrat with national aspirations who could have much to lose if the state gets the decision wrong.