NEW YORK ( TheStreet) -- Oil tanker stocks spiked Monday as the BP ( BP) oil spill in the Gulf of Mexico expanded in severity and investors anticipated a bounce in crude shipping rates caused by the environmental disaster.That's because the spreading slick -- which, some say, could eclipse the Exxon ( XOM) Valdez accident in scope -- threatens to impede the offloading of oil on the Gulf Coast of the U.S. Tankers may have trouble docking at refineries in Louisiana, Mississippi and Alabama, and although weather has so far cooperated in keeping the slick from reaching the Louisiana Offshore Oil Port, or LOOP, which pumps some 1.2 million barrels a day into the U.S. from the wells of the Gulf, the facility remains susceptible to disruption. If these operations do suffer outages, the U.S. will need to bring more of its crude from overseas, which would entail longer journeys on more trans-ocean ships. That, in turn, would skew the supply-demand balance, driving rates higher. Last week, industry players already appeared to be anticipating just that. Forward freight assessments for Suezmax ships that travel from Nigeria to the U.S. over the Atlantic gained ground on just this kind of speculation, noted Dahlman Rose analyst Omar Nokta in his weekly shipping report to clients on Monday. (Called FFAs, the instruments are used like futures contracts by ship owners and ship charterers to hedge against fluctuations in freight rates.) Still, Nokta wrote, "It is too early to determine the impact of the Gulf of Mexico oil spill on the tanker trade," which has, meanwhile, entered its earnings season, with General Maritime kicking things off last week. In afternoon action, shares of Frontline ( FRO) paced the gainers, jumping 6% to $38.72 on heavy volume.