Gray Whale Coastal Ecosystems Research Foundation Photo ID Lesson by Dr. William Megill   Example #4 This one is a bit harder, since the region of overlap between the two photographs is a lot smaller. The trick is to look for the dorsal fin (first dorsal ridge), indicated by the green arrow, and find the same structure in the other photographs (also indicated by green arrows). With grey whales, we use the dorsal fin as a landmark, but in other species, such as blue or fin whales, you might also have to use the blowhole, since the whale is too big to fit in one photograph!   This picture shows the left-hand side of grey whale G008. Note the arrows pointing out the dorsal fin in all of the photographs. Can you identify G008 in the three photographs below? Look carefully for the markings circled in blue.    Next Example Coastal Ecosystems Research Foundation Allison Harbour PO Box 124 Port Hardy, BC, Canada V0N 2P0 tel: (604) 202-9350 or 1-877-223-2373 (toll-free) fax: (815) 327-0183 email: info@cerf.bc.ca All photographs and graphics in this document © CERF 1995-2001. Do not reproduce without prior written consent. Facebook Pinterest Twitter © 1997 – 2019 Journey North. All rights reserved.