“beginning October 1, 1990, and thereafter, the United States Fish and Wildlife Service can perform work for the Great Lakes Fishery Commission, authorized by 16 U.S.C. 931–939c, Great Lakes Fisheries [Fishery] Act of 1956, on the sea lamprey program on a reimbursable basis: Provided further, That such reimbursements are to be treated as Intragovernmental funds as defined in the publication titled ‘A Glossary of Terms Used in the Federal Budget Process’.”