During Covid-19 Lockdowns, Fish Flourished in This Park

In the absence of tourists, the animals increased within Mexico’s Cabo Pulmo National Park

Diver Monitoring Coral Reef
Covid-19 lockdowns had all kinds of effects on wild populations, helping some and hindering others. In one Mexican marine park, though, the sudden lack of tourists led to an increase in the density and diversity of marine species. Manuel Olan

Scores of tropical fish, a substantial shark population and colorful coral draw thousands of tourists to Mexico’s Cabo Pulmo National Park each month. That is, except from March through August 2020, when restrictions aimed at stemming the spread of Covid-19 barred people from visiting the protected area in the Gulf of California. As it did around the world, the sudden shortfall in tourism dollars hit the local economy hard. But Covid-19 lockdowns also presented scientists with a unique opportunity: a chance to study the effects of ecotourism on the park’s wildlife. The research shows that even here, within a protected park, wildlife flourished in our absence.

“We can observe great biodiversity of fishes in Cabo Pulmo,” says Manuel Olán-González, a graduate student at Mexico’s Autonomous University of Baja California Sur. “But during the lockdown period, it was truly impressive.”

Locals spearheaded the establishment of Cabo Pulmo National Park in 1995, transforming the local economy from one saddled by years of overfishing to one reliant on ecotourism. This change let the ecosystem rebound, but the tourists who flocked to the park also meant dozens of boats idling above the reef each day, along with snorkelers and scuba divers splashing in the water.

Olán-González’s research shows that during the lull in the pandemic’s early days, fish density increased dramatically, rising to 2.5 times the normal amount. They also saw several unexpected aquatic creatures reappear in the park during the lockdown period, such as the endangered clarion angelfish, which hadn’t been seen in the area since 2005.

It’s difficult to say what exactly caused the number of fish in Cabo Pulmo to rise during the lockdown. But with ecotourism being the main annoyance within the park’s limits, the study shows that even in otherwise healthy environments where fishing is prohibited, people—with our boats, snorkels and scuba gear—can negatively affect fish.

However, Damien Olivier, a co-author of the study and a marine ecologist also at the Autonomous University of Baja California Sur, is careful to note that his and Olán-González’s research isn’t an indictment of ecotourism. It is, after all, what allowed the community and the ecosystem to stabilize in the years since the fishery collapsed. Instead, Olivier intends his work to be a starting point to look for solutions that benefit both.

For example, getting boats to slow down could reduce motor noise, which research shows alters fish behavior. Finding other interesting spots within the park to bring tourists could also provide some reprieve for fish living in the park’s more popular areas. Of course, the revenue from ecotourism is crucial to locals’ livelihoods, Olán-González says, so any changes that affect tourism within the park need to have the community’s support.

“We could even improve the system,” Olivier adds. “Cabo Pulmo is working well, that’s a fact. But it could work much better.”

Frédéric Bertucci, an eco-acoustician at the French National Research Institute for Sustainable Development, says he saw a similar situation play out in French Polynesia, where ecotourism is also common. Much like in Cabo Pulmo, Bertucci recorded a 50 percent increase in the density of adult fish during lockdown, though some fish were more affected than others.

Bertucci also isn’t against ecotourism. But he says the lockdown period was an important reminder that all human activities have an effect on wild populations.

“I hope that we will learn from this period,” Bertucci says. “I’m afraid we didn’t learn enough.”

This article is from Hakai Magazine, an online publication about science and society in coastal ecosystems. Read more stories like this at hakaimagazine.com.

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