San Francisco beats Los Angeles in international City Nature Challenge

CBS News

16-05-2025

Each winter in the town of Princeton-by-the-Sea, south of San Francisco and off the coast of Pillar Point, the massive waves at the legendary Mavericks draw elite surfers from around the world.
But what lies hidden beneath these cold waters, where the land meets the Pacific Ocean, is equally jaw-dropping. Seen only at low tide, it's a whole different kind of world teeming with treasure and life.
"This place is one of the places that you can come at low tide, and you can see the greatest diversity of life," said Professor Rebecca Johnson.
Dr. Johnson is the director of biodiversity and community science at the California Academy of Sciences. Jessica Carver is the associate manager of community service and works with Dr. Johnson at the academy.
"Every time is so amazing. It's always so different," Carver remarked as she surveyed the massive reef, with multiple tide pools.
Recently, at the crack of dawn, a group including Johnson, Carver, and volunteer community scientist Kristi Brakken gathered in the parking lot at Mavericks Beach to document wildlife and participate in the City Nature Challenge. Joining Brakken was her daughter, Kelly.
The City Nature Challenge began 10 years ago as a friendly competition between two cities: San Francisco and Los Angeles. Today, it's an international event that involves almost 670 cities and metro areas across six continents. Johnson is a co-founder.
The idea is that volunteers around the world photograph as many wild plants and animals as possible in their own communities, on four designated days.
"People have made over seven million observations of nature. This gives us an ongoing annual census of where species are across the globe," Johnson explained.
She called the location at Mavericks "magical."
"You can see this huge diversity of things: you can see seaweeds, crabs, shrimps, sponges, anemones," she said.
There's a lot to look at: 650 different species live in the tide pools alone, including ochre sea stars, crabs, California mussels, and all kinds of barnacles and seaweed. But perhaps the most mesmerizing find is the vibrantly colored creatures known as nudibranchs.
"This place is an amazing hot spot for diversity," noted Olivia VanDamme, a community science coordinator with the academy.
Kelly came to catch and glimpse and was not disappointed.
"This officially has made the trip worthwhile," she said as she pointed at one tiny nudibranch and laughed.
Kelly Brakken
Armed with smartphones, the team snapped pictures of all the wildlife they saw. On their phones, they downloaded a free special app known as iNaturalist. The app allows all the participants to record their observations. The program identified the species and then tallied and shared their findings with all involved in the challenge.
The data is important for scientists who study long-term trends.
"It's like an early warning system, often in what is going on in these very delicate ecosystems," Lizzy Edson explained.
Edson is the biodiversity data manager for the Center of Biodiversity Sciences at the academy and also works with Johnson. After a few hours, the team noticed the rising tides and realized it was time to wrap up their observations and leave.
The Brakkens left with a new appreciation.
"With the current changing climate, we don't know how long we'll have the ability to see these creatures and see them prospering unless we can make really rapid changes," Kelly said.
"So that we can be more aware and take better care of our earth," added her mom, Kristi.
The competition ended on April 28. The winners included La Paz, Bolivia, for the most observations and the most participants; Cochabamba in Central Bolivia recorded the highest number of species; and San Francisco beat L.A. in all three categories: observations, participants, and recorded species.
But the biggest winner, according to Johnson, is our understanding of nature where or near people live, which is really important for protecting, understanding, and conserving the world's biodiversity.