Five-ribbed kelp
- kingdom: Chromista
- phylum: Ochrophyta
- class: Phaeophyceae
- order: Laminariales
- family: Costariaceae
- genus: Costaria
- species: Costaria costata
Campbell River- Nanaimo
- North Vancouver
- Oak Bay
- Sooke
- Ucluelet
British Columbia
Canada
Sitka
Alaska- Del Monte Forest
- Montara
- Monterey
- Moss Beach
- Pacific Grove
California- Bainbridge Island
- Coupeville
- Friday Harbor
- Rocky Point
- Tracyton
Washington
United States