Is It A Whale Or A Shark?

By R. J. Archer

The Bay of La Paz is located on the eastern side of the Baja Peninsula about 100 miles north of Los Cabos and about 1,000 miles south of San Diego. As part of the Sea of Cortez (Gulf of California), the Bay is home to an incredible array of marine life including the giant whale shark (tiburon ballena in Spanish).

Because whale sharks feed very close to the surface, La Paz and other select areas around the world have developed a tourism industry around their local populations. In La Paz, many small charter boats are available to take you out to snorkel within a few feet of these “gentle giants” – an experience that’s every bit as incredible as it sounds!

Is it a whale or a shark? The whale shark is definitely a shark and it’s also the largest fish in the ocean, with adults reaching lengths of 60 feet and weighing as much as 60,000 pounds! The whale sharks that visit the Bay of La Paz are juveniles and may be up to 20 feet in length. Whale sharks live on plankton and, despite their size, pose absolutely no threat to humans.

In a behavior not yet fully understood, juvenile sharks return year after year to feed in the Bay of La Paz but once they become adults they leave and never come back. We know this because of the efforts of Whale Shark Mexico, a non-profit organization dedicated to the study and protection of the local whale shark population. This organization is headed by Dr. Deni Ramirez, a marine biologist who has made the study of the whale shark her life’s work.

Each year, Dr. Ramirez and her associates catalog the local whale shark population by photographing each individual and measuring its length. Each whale shark exhibits a unique pattern of spots which serves as its “fingerprint” and the shark’s age and annual growth can be estimated from its length. A complete history of the population is stored in a database, making it possible to know when an individual first appeared in the Bay and how many years that individual returned.

Sadly, these cataloging efforts show that up to 67% of the juvenile sharks in the Bay of La Paz have been hit by boats! To help reduce these unnecessary injuries, Whale Shark Mexico has been instrumental in the creation of a government certification program for tour operators that teaches boat captains how to protect the very animals that provide them with their livelihood. Swimming with a whale shark is a fabulous experience but it is now a regulated activity to protect both the animals and the snorkelers. Before booking your trip, make sure the service provider is authorized by SEMARNAT.

If you’re going to be in La Paz and would like to take part in one of their cataloging trips – and personally contribute to their valuable research – contact the group directly at You can also contribute to the research by “adopting” a specific shark. See the site for more information.