A duty assignment for an active duty member of the Coast Guard in support of a declaration of a major disaster or emergency by the President under the Robert T. Stafford Disaster Relief and Emergency Assistance Act (42 U.S.C. 5121 et seq.) or in response to a spill of national significance shall be treated, for the purpose of section 701(e) of title 10, as a duty assignment in support of a contingency operation.