Western Kamchatka is still poorly studied in floristic and fishing aspects and there is no accurate understand-ing on the boundaries of different kelp species distribution in the area. During the 2020 field study in the coastal area located from Cape Ambon to the mouth of Utholok river, including the area proximate to Ptichiy Island, we found 5 kelp species, including Phyllariella ochotensis, Pseudolessonia laminarioides, Laminaria inclinatorhiza, Saccharina latissima, and Alaria esculenta sensu lato. The first 3 species are endemic to the mainland coast of the Sea of Okhotsk. A special search off the coast of southwestern Kamchatka for another Okhotsk endemic species, Laminaria appressirhiza, showed that it was absent. A representative of the Ber-ing Sea kelp flora Hedophyllum bongardianum does not occur on western Kamchatka north of 51°N. The morphometric characteristics of plants belonging to different age groups and morphological features typical for Western Kamchatka’s populations of these species are discussed. Additionally, the molecular phylogeny of L. appressirhiza and H. bongardianum collected from the Sea of Okhotsk are discussed. As shown, the first species belongs to the genus Laminaria. From a commercial point of view, this coastal area was estimated as unpromising for the organization of kelp collection by a traditional manual method.
