WHAT IS WAS LIKE BACK THEN
Baja California’s southern peninsula is a unique convergence of diverse ocean currents and ecosystems. On the Pacific side, the California current brings cooler waters, while the Cape area mixes tropical and cooler waters. The Gulf of California is an entirely different and distinct ecosystem. These varied environments create a fantastic region for studying marine life—bringing aspiring scientists, conservationists and activists here to revel in this hotspot.
I remember when I was an aspiring marine biologist. Back then, you could see hammerheads, silkies, whale sharks, giant manta rays, mobulas, marlin, tuna quite literally everywhere. Jacques Cousteau called the Gulf of California the "aquarium of the world" for this very reason. Unfortunately, in the past 20-30 years, climate change and industrial fishing have taken its toll. What’s left now is far from what it was like when I was first getting started.
Becoming a marine biologist and relocating to La Paz was a dream. Moving away from home to this setting was mind-blowing. The first time I came to La Paz and its neighbor, Espíritu Santo, I thought, "what is this place?!" It was out of this world, and I was amazed. I didn’t ever want to leave. Back then, I was lucky to see these areas still thriving with fish and sharks.
I believe my generation saw the last bit of this climatic era of the Gulf of California, in all of its glory. By the early 2000s, everything had collapsed. And it happened so fast. I think it was a matter of two years where you could see such a drastic change. Snappers, tuna, marlin, groupers—gone. Before that, it was a different place, a marine wonderland that I was fortunate to call home.
(The Gulf of California from above. Photo Credit: Marla Tomorug)
WHALE SHARKS STARTED IT ALL
I guided dive and kayaking tours throughout the Gulf. That’s where I got to learn about marine life—when I was out in the wild. I was a dive guide, a naturalist, who was garnering an up-close-and-personal education on sharks. I was fortunate that a scientist named Eugenie Clark, the "shark lady," took me under her wing in the early '90s. She became my mentor and introduced me to a whole new world—a world I only dreamed of in my younger years.
Eugenie was the first to study whale sharks in the Gulf of California. Under her guidance, I started collecting data on their occurrence and feeding behaviors. This research became my master's thesis. My bachelor's thesis focused on corals and reef ecology in the Revillagigedo Archipelago. So, this transition from reef ecology to sharks was a significant shift for me. I knew little about sharks . but Eugenie's mentorship and influence made it possible for me to ground myself in what I do today.
When I started studying whale sharks with her, we knew so little about them. So, I decided that my master's thesis would be focusing on their distribution and foraging behavior in this region. We identified key aggregation areas for both juveniles and adults, understanding how they fed on plankton blooms. These critical habitats needed protection, and I saw firsthand the unregulated influx of commercial and dive boats disrupting these areas.
It wasn’t until the early 2000s when I drafted the first study on the distribution and abundance of whale sharks in the area, long before the dramatic increase in tourism and the establishment of the official refuge. By 2010, the situation had worsened with 20 to 30 tourism boats in La Paz Bay bombarding and corralling the sharks to shore. Tourists were jumping on sharks to ride them, using flash photography and pointing right at the whale shark's little eye. It was chaotic. The community slowly rallied together to do something about it.
(Dr. James Ketchum leading a shark tagging expedition. Photo Credit: Marla Tomorug)
Years later, the WWF stepped in, recognizing the urgency. They invested in the project and invited me to provide insights based on my research. After what felt like countless months filled with meetings, we successfully established the Whale Shark Refuge in 2017, which includes the outer bay near El Mogote's sand spit in La Paz. This refuge brought strict regulations—limiting the number of boats, ensuring checkpoints, setting in-water guidelines, and managing visitor times. Today, if fewer than six whale sharks are present, the season closes until their numbers increase so there is no overcrowding of boats around individuals.
Fifteen years ago, whale sharks were often thin, unable to feed properly due to constant interruptions. Now, with better management, they thrive. The refuge is surely a success story in the Gulf of California and La Paz. Better late than never, right?
ANOTHER BIG SUCCESS STORY
Then there's the story of Revillagigedo Archipelago. This one has been a major part of my life, dating back to my bachelor's thesis where I studied its corals and reef fishes. This place is unlike anywhere else in the world. To say it's special is an understatement.
In my early twenties, visiting these islands was something else. Back then, the islands were completely open to fishing, and sharks were already becoming scarce. Initially, the islands had no MPA, and when one was established, it was limited to a doughnut shaped reserve of just five nautical miles around each of the four islands. This small reserve did little to deter industrial fishing, which continued unabated, leading to severely depleted marine life by the early 2000s. See a theme here?
In 2008-2009, my colleague, Mauricio Hoyos, and I began studying the sharks around the Revillagigedo Archipelago, tagging various species to understand their movements. By 2014, our data revealed that they moved between San Benedicto, Socorro, Roca Partida, and occasionally the furthest island, Clarion. This connectivity showed the need for a larger MPA ... immediately.
(Tagging sharks with Dr. James Ketchum and his team. Photo Credit: Marla Tomorug)
In 2016, we proposed an expanded MPA to UNESCO, as the archipelago was designated a World Heritage site in 2015. And in partnership with many other organizations, teams and individuals, by the end of 2017, the largest MPA in North America—spanning 148,000 square kilometers—was established. We were thrilled to see our scientific efforts contribute to this massive achievement for Mexico. A few years later, the Marine Conservation Institute evaluated the Revillagigedo MPA for the Blue Park Award, which it received in 2021, recognizing its effectiveness and the importance of science-driven conservation.
WHAT'S AT STAKE TODAY
Today, the situation in the Gulf of California is more concerning than ever. Fish assemblages are struggling, and some species, like groupers and snappers, are nearly depleted, while some sharks are essentially gone, such as a wide variety of hammerheads, particularly the scalloped hammerhead.
Since 2015, my team and I have been working on creating a new MPA in the Gulf of California using data from tagging sharks and other species to build a protection corridor. This “migration corridor” as I like to call it, connects three key hotspots for marine activity: Loreto National Park, Espiritu Santo National Park, and Cabo Pulmo National Park. The goal is to manage and protect these areas from industrial fishing and support local artisanal fisheries.
This is why working with local fishermen has been crucial in building our plans for the MPA. They have unparalleled knowledge of the region, have helped us catch and tag sharks and need this MPA to work for them, just as much as it would work for us. While fishing is many of their primary livelihoods, they are starting to transition to tourism and/or becoming park rangers. This transition is essential as traditional fisheries decline due to the rise of hard-core industrial fishing.
(Fishing base where Dr. James Ketchum and his team work seasonally. Photo Credit: Marla Tomorug)
Large-scale industrial fisheries are relentless and powerful due to their financial resources. Globally, they exert significant influence on local governments, and Mexico is no exception. This control over fisheries management leaves local artisanal fishers with no leverage and often overlooked entirely. Artisanal fishermen use sustainable methods, like hook and line, which are passed down through generations. Their method is more like an art form, requiring detailed knowledge of specific rocks and seamounts. However, some opportunistic local fishermen use destructive gill nets, which are depleting fish populations as well.
And this is not to mention, climate change exacerbates these issues. The Gulf of California is experiencing tropicalization, with warmer waters affecting species distribution. Black corals and sea fans, once thriving, are now dead. Fish are migrating to cooler waters, disrupting local ecosystems. If we don’t protect this marine haven on earth, we are looking at a bleak future for the generations to come.
(FiLos Islotes sea lion colony of 600+ in the Sea of Cortez. Photo Credit: Marla Tomorug)
A MESSAGE TO THE WORLD
Despite these challenges, there is hope. Today, we have advanced tools and technology to support conservation, like Global Fishing Watch and artificial intelligence. These can accelerate the creation of MPAs and provide critical data for conservation efforts. Using these tools, we can identify hotspots of abundance and diversity to establish new MPAs, such as the migratory corridor from Loreto to Espiritu Santo and Cabo Pulmo.
The world needs to know that more MPAs are essential. They need to know what a MPA can do for a region. But, we must avoid being sucked in by blue washing. MPAs should be backed by science, supported by local communities, and require sufficient funding and management enforcement to ensure their success. Only feasible, well-supported no-take zones will be effective in protecting our oceans, especially here in the Gulf of California where real damage has been done.
(Tagging a silky shark on expedition with Dr. James Ketchum and his team. Photo Credit: Marla Tomorug)
It’s up to my generation to make a commitment to try to restore the Gulf of California to what it used to be. The next generation is inheriting this completely changed ocean, with a baseline far different from ours. It’s up to us to support our youth counterparts, and leverage our shared knowledge to restore our shared home for as long as we can.
As told to Andi Cross in June 2024.
