50 CFR 217.78 - Modifications to a Letter of Authorization.
(a) Except as provided in paragraph (b) of this section, no substantive modification (including withdrawal or suspension) to a Letter of Authorization issued pursuant to the provisions of this subpart shall be made by NMFS until after notification and an opportunity for public comment has been provided. A renewal of a Letter of Authorization under § 217.77 without modification is not considered a substantive modification.
(b) If the Assistant Administrator determines that an emergency exists that poses a significant risk to the well-being of the species or stocks of marine mammals specified in § 217.70(b), a Letter of Authorization may be substantively modified without prior notification and an opportunity for public comment. Notification will be published in the Federal Register within 30 days subsequent to the action.