Swimming with purpose

Every year, over 100 juvenile whale sharks visit the waters around Mexico’s La Paz. As seen in many whale shark hotspots around the world, a rapidly growing whale shark tourism sector quickly resulted in numerous problems for the animals. Widespread campaigning and a collaborative conservation approach, however, managed to turn the face of the city’s whale shark tourism programme around. 

Words and photographs by Nicole Holman
Additional photograph by Shelton Du Preez

Three nautical miles off the coast of La Paz, I sat perched on the edge of a research panga, accompanied by Alberto Garcia Baciero, the project coordinator at Tiburón Ballena México or Whale Shark Mexico. Overhead, a drone whizzed, serving as our watchful eye while we searched for the presence of an elusive whale shark beneath the surface. After a quick glimpse of its dorsal fin, we relied on the drone’s aerial perspective to track its movements. “I’m over its head,” yelled our spotter, prompting the captain to skillfully manoeuvre the boat ahead of the trajectory it was carving through the water. With my camera in hand and Alberto poised with his measuring tools, we prepared to plunge into the water. As the drone closed in, signalling the shark’s approach, we slipped into the water. Following Alberto’s lead, I took a deep breath and dove beneath the surface. The nutrient-rich waters concealed what lay beneath, but after a few metres, I was met by an astonishing sight – a large female whale shark emerging into view, its head the size of a small car. From a distance, the ten-metre length of these sharks creates a slow-motion illusion. But as the gentle giant approached underwater, its real speed became apparent. Alberto, swimming frantically to keep up, dove deeper to capture a photo ID of the whale shark and measure its dorsal fin.

Day after day, year after year, this is what Alberto and the team of scientists at Whale Shark Mexico do. Their valuable findings contribute to a foundation of data fuelling a unique and innovative approach to collaborative conservation efforts alongside the Mexican government, tourism operators and local community. For the past ten years, they have championed the protection of the extraordinary whale shark population in the Sea of Cortez, a unique habitat where these majestic creatures frequent both as juveniles and adults. Thanks to the distinct oceanic conditions of the region, the migratory behaviour of juvenile and adult whale sharks paints an annual pattern. Juveniles prefer shallower coastal areas where they feast on abundant plankton, while adults embark on extensive migrations through the open ocean, guided by ocean currents as they seek warmer waters and diverse places to feed. Nestled in the Bay of La Paz and bordered by the terracotta shores of eastern Baja California Sur, the Mogote Peninsula boasts nutrient-rich waters. During winter months, northern winds stimulate upwelling, bringing plankton to the surface and providing a bountiful feeding ground for approximately 100 juvenile whale sharks between October and April. 

In the vibrant ecosystem of the Sea of Cortez, whale sharks play a distinctive role that sets them apart from other shark species. They act as vital regulators and ensure a balance within the ecosystem. Whale sharks can consume enormous amounts of zooplankton per hour, effectively recycling essential nutrients like nitrogen and phosphorus back into the ocean. This nutrient recycling process is a catalyst for sustaining other species in the ecosystem, from phytoplankton to fish, forming the foundation of the food chain. 

As we returned to the dock that afternoon, Dr. Dení Ramirez-Macías, the founder and lead scientist of Whale Shark Mexico, was there to catch the lines. We sat down as the sun hung low above the horizon and talked about her journey into whale shark conservation. Dr. Ramirez-Macías embarked on her research journey in 2001, long before whale sharks became a well-known species in the area. She recalled: “When I was 20, I went to La Paz on the Gulf of California to follow my dream to become a marine biologist. That was when I had my first encounter with a whale shark. It was the best experience of my life.” At the time, despite the growing global interest in swimming with these gentle giants, La Paz had no tourism centred around the animals and only local fishermen knew of their presence. Driven by her passion for these incredible creatures, Dr. Ramirez-Macías conducted the world’s first study on the genetics of whale sharks in the region. Her groundbreaking research revealed the fascinating annual migration pattern of the whale sharks, demonstrating that they returned to the area every year. Following her academic pursuits, she established Whale Shark Mexico, a NGO dedicated to the research, conservation, and education of whale sharks with a mission to protect them.

As awareness of their presence began to spread, La Paz witnessed a significant surge in its popularity as a destination to experience these majestic animals. Tourism, which initially comprised only a few operators, rapidly expanded to accommodate more than 140 boats. Dr. Ramirez-Macías said: “In the beginning, there were no regulations on how many boats could be in the area, how fast they were allowed to go, and how the guests could behave with the whale sharks.” As her research endeavours continued, the photo IDs collected from the whale sharks revealed a troubling trend. There was an increasing number of incidents where sharks were being injured from collisions with boats. The lack of regulations and responsible tourism practices were taking a toll on their well-being, highlighting the urgent need for conservation efforts and sustainable tourism initiatives.

Despite being celebrated as an iconic megafauna species around the world, whale sharks face numerous threats from fishing, boat strikes, water quality degradation, coastal development, and climate change. “In the late ’90s, there was a significant decline in whale shark populations worldwide,” shared Alberto. “It was during the 2000s that most countries began taking protective measures, banning fishing practices that targeted these gentle giants. The main concerns we encounter today are boat collisions, which result in scratches, and boat strikes, leaving propeller cuts. These challenges may arise from either tourism or fishing activities.”

Additional photograph by Shelton Du Preez

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This feature appears in ISSUE 32: SENTINELS OF CHANGE of Oceanographic Magazine

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