(a) Purpose of regulations. The regulations in this section implement Section 101(a)(5) of the Marine Mammal Protection Act of 1972, as amended, 16 U.S.C. 1371(a)(5), which provides a mechanism for allowing, upon request, during periods of not more than five consecutive years each, the incidental, but not intentional, taking of small numbers of marine mammals by U.S. citizens who engage in a specified activity (other than commercial fishing) within a specified geographical region.