50 CFR 217.177 - Letters of Authorization.
(a) A Letter of Authorization, unless suspended or revoked, shall be valid for a period of time not to exceed the period of validity of this subpart.
(b) The Letter of Authorization shall set forth:
(1) Permissible methods of incidental taking;
(2) Means of effecting the least practicable adverse impact on the species, its habitat, and on the availability of the species for subsistence uses (i.e., mitigation); and
(3) Requirements for mitigation, monitoring and reporting.
(c) Issuance and renewal of the Letter of Authorization shall be based on a determination that the total number of marine mammals taken by the activity as a whole will have no more than a negligible impact on the affected species or stock of marine mammal(s).