50 CFR §217.202

1. (a)Under Letters of Authorization issued pursuant to § 216.106 of this chapter and § 217.207, the Port of Anchorage and MARAD, and persons under their authority, may incidentally, but not intentionally, take marine mammals by harassment, within the area described in § 217.200, provided the activity is in compliance with all terms, conditions, and requirements of these regulations and the appropriate Letter of Authorization.
2. (b)The taking of marine mammals under a Letter of Authorization is limited to the incidental take, by Level B harassment only, of the following species under the activities identified in § 217.200(a): Cook Inlet beluga whales (Delphinapterus leucas), harbor seals (Phoca vitulina), harbor porpoises (Phocoena phocoena), and killer whales (Orcinus orca).
3. (c)The taking by injury or death of the species listed in paragraph (b) of this section or the taking by Level B harassment, injury or death of any other marine mammal species is prohibited and may result in the modification, suspension, or revocation of a Letter of Authorization.