As Principal Restoration Ecologist and co-founder of Tidal Influence, Eric Zahn is helping to grow a constituency for the restoration and conservation of the fragmented coastal ecosystem of the San Gabriel River Estuary. Through research, monitoring, and public education, his company helps to protect and restore coastal ecosystems and one particularly fascinating species, the Pacific green sea turtle.
Jennifer Zell of AHBE Landscape Architects spoke with Eric recently about his scientific work monitoring the species and raising public awareness about the importance of conservation and restoration of their habitat.
Shortly after moving to Long Beach, I was riding my bicycle along the San Gabriel River trail when I spotted what at first I thought was a piece of carpet. I then recognized it as some sort of mysterious sea creature moving gracefully through the brackish waters. It was a Pacific green sea turtle! How did you first learn about the sea turtles in the San Gabriel River?
Back in 2009 I was teaching a class at Cal State Long Beach and one of the student group projects was to create a monitoring plan for a special status species living in the Los Cerritos Wetlands. We contacted Dan Larson at NOAA (National Oceanic and Atmospheric Administration) because we learned he was following the population of sea turtles in the San Gabriel River. We organized a tour and he showed us where he goes to see the turtles, and that was my first experience [seeing the sea turtles]. That group of students wrote a citizen scientists monitoring plan, which was tested and refined by my students the next year, and is now the monitoring plan for these turtles that is currently being used by the Aquarium of the Pacific.
What brings the turtles to this particular location?
We know a lot about these turtles, like where they are and what their ages are, mostly juveniles. But why they are here is still a big [unanswered] question. The easy answer is that they are attracted to the warm water discharged from the AES power plant, and there is some connection to sea turtles that follow a pattern of warm water. However, it is likely that the remnant estuary has always provided refuge for this species. There is an extremely active population living in nearby Anaheim Bay, which is a much larger and protected natural estuary. The other day I was doing wildlife monitoring there and took a lunch break and sea turtles were popping their heads up all over the place.
People seem to love turtles, we anthropomorphize them like “Crush” in the movie Finding Nemo. What is it about the animal that is so compelling to humans?
They are mysterious. People can’t easily interact with them and seeing one is like seeing a mermaid. You have to go with them into their native habitat. At the San Gabriel River, people wait for long periods of time to see one pop up their head for a second. People can also see them at an aquarium, but it is a rare opportunity to see them with your two eyes [in the wild]. Because of the gaps in knowledge about their life history, scientists also see the species as mysterious. We call these gaps the “Lost Years”. Scientists don’t know where the turtles go to do their breeding. We know where the females go to nest, but we don’t know where the males and females go to mate—important information to know in order to protect their breeding grounds.
Do you think the turtles gives you an audience to teach about the local wetlands ecosystem that you would not otherwise have?
Yes, 100%. They are a charismatic megafauna that can be experienced right here in the Los Cerritos Wetlands and this is a conservation species that we have adopted. We give tours and get 100 people to come out. The tours are very popular and this enthusiasm enables us to show what we are doing to actively protect and preserve the species, like what properties are actively being acquired to increase habitat. It is critically important to restore the turtle’s natural habitat and people definitely get that message on our tours.
You are passionate about edge conditions between highly urbanized landscapes and remnant pieces of coastal ecosystem habitats along the urbanized coastal zone of Southern California versus somewhere distant, like the Galápagos Islands. How does your work with Tidal Influence feed your passion?
As a resident of Long Beach, I see the needs of humans as important. I also see myself as needing to speak for species that cannot speak for themselves. As a community member, I am not coming from the outside and telling the community, “This is how this should look,” or “This should go here.” But, from my position within the community I can say, “Here is where the two – humans and wildlife – can commingle and on these edges is where that happens.”
People can come to the wetlands and see a sea turtle or heron, and they get excited. Then we are able to teach about the ecological phenomenon that is happening further at the core of the habitat, and what needs to be conserved, and which sensitive core areas need to be protected. It is during these moments people become stewards.
Is there a message, or call to action that you train your employees to include in presentations, tours, and community events?
The call to action is for people to become more aware and to learn about the Los Cerritos Wetlands, and what is down the street from their home. We have these pockets of habitats where species exist, and we want people to go out and learn how to help in the places where they live.
For years I have been trying to work up the courage to trespass and get on my standup paddle board to get an up-close look at the turtles. Do you want to go with me?
I would be happy if I never touch the river. I’ve seen the color the water turns after a rain; the San Gabriel River has become a glorified storm drain capturing pollutants from the entire watershed. The necessary BMPs have not be put in place upriver, and the rains bring trash and pollutants that you don’t see. I would love to go into the river after the upriver communities have taken the necessary steps to make the water clean and I know the sea turtles would appreciate the clean water as well.