Since 2001, Whale Shark Mexico has been dedicated to studying and protecting whale sharks in the Gulf of California. What began with a few curious encounters has grown into one of the most extensive long-term research projects on this species in Mexico.
Our team works in La Paz Bay, Concepción Bay, Mag Bay, the Revillagigedo Archipelago, and beyond. Through collaborations with universities and conservation groups, we share knowledge and strengthen efforts to protect these migratory giants. Today, our catalog includes more than 1,135 individually identified whale sharks – each one with its own story.
How We Study Whale Sharks Photo identification:
Every whale shark has a unique pattern of spots and lines, like a fingerprint. By photographing the left side of each animal, just behind the gills, we can recognize individuals and track them across years and locations. This method allows us to:
- Estimate population size and movements.
- Understand site fidelity (the tendency of sharks to return to the same feeding grounds).
- Document health, injuries, and long-term survival.
What We’ve Found in La Paz
La Paz Bay has proven to be a critical habitat: a place where young whale sharks grow and return year after year. So far, we’ve identified 549 individuals here, and about 60% of the sharks we encounter each season are “old friends.” Many even have names given by our team and community, making science more personal and relatable.
Satellite Tagging
To truly understand whale shark migrations, we need to follow them beyond the bays where they gather. For this, our team places satellite tags on both juvenile and adult whale sharks in the Gulf of California. These tags transmit information about where the sharks travel and how deep they dive.
Our findings have revealed striking differences between juveniles and adults:
- Juveniles tend to remain in the Gulf of California, showing strong site fidelity. Many return to the same feeding grounds year after year.
- Adults, on the other hand—especially pregnant females—leave the aggregation sites soon after tagging and spend most of their time in the open ocean. Some have traveled hundreds of kilometers offshore, diving to impressive depths of more than 1,200 meters.
One of our most remarkable discoveries is that the Gulf of California is not only a feeding ground, but also potentially a breeding area. The consistent presence of pregnant females in deep waters, along with the sighting of a free-swimming newborn whale shark near Espíritu Santo Island in 2015, supports this exciting theory.
Our next step is to expand satellite tagging efforts to the Revillagigedo Archipelago, another key site for these gentle giants.
Monitoring Injuries
Every season, our team carefully documents and analyzes the injuries observed on whale sharks. These wounds—often caused by boat strikes, fishing gear, or other human activities—tell an important story about the challenges these gentle giants face in their natural habitat.
By tracking injuries over time, we can:
- Measure the impact of human activities on the population.
- Identify areas where boat traffic or practices need to be managed. Provide scientific evidence that supports better regulations for tourism and conservation.
Some whale sharks return year after year with visible scars, reminding us of both their resilience and their vulnerability. Through this work, we aim to reduce human impacts and ensure that future generations encounter whale sharks in healthy, thriving oceans.
Plankton Sampling
Whale sharks are filter feeders, and their presence in La Paz Bay is closely linked to the abundance of plankton—the tiny organisms that form the base of the ocean’s food web. To better understand this connection, our team collects plankton samples during each research season.
By analyzing these samples, we can:
- Identify the species of plankton present when whale sharks gather.
- Study how plankton abundance changes through the season.
- Understand how ocean conditions and climate influence feeding behavior.
This research helps us answer a key question: why do whale sharks return to certain sites year after year? By studying their food source, we gain valuable insight into the health of the ecosystem and the factors that sustain these gentle giants.
Biopsies
To uncover what cannot be seen on the surface, our team collects small tissue samples (biopsies) from whale sharks. This minimally invasive technique provides a window into their biology and health.
Through biopsy analysis, we can:
- Study the genetic diversity of whale shark populations and how individuals are connected across the ocean.
- Detect the presence of pollutants or heavy metals, which reveal the impact of human activities on marine ecosystems.
- Explore aspects of whale shark reproduction and physiology that remain a mystery for this endangered species.
Each tiny sample adds to a much bigger picture: understanding how to better protect whale sharks and the ecosystems they depend on.
PUBLICATIONS
*enlaces de artículos e infografías*