The extinct mammal that may have shaped California’s kelp forests

“You look at these animals that live along the coast – they must have had a huge impact,” Dr Sampson said.

Another co-author of the paper, Roxanne Banker, an ecologist at the California Academy of Sciences, added that ecosystems “are made up of species that influence each other and interact in very non-linear ways.”

She continued, “Sometimes adding a room will change how another room works.”

Together, the co-authors created a simplified mathematical model of the kelp forest ecosystem, simulating an alternate reality where Steller’s sea cow did not become extinct and lived under conditions similar to the status quo.

The model showed that sea cow grazing would thin the kelp forest canopy. Sunlight would reach deeper into the water, and a more robust algal understory would form and serve as an alternate feeding option for the sea urchins. Under warming waters and debilitating starfish disease, the model showed that this ecosystem grazed by sea cows would rebound faster than the existing ecosystem.

Perhaps this resilience could be replicated in conservation efforts, or at least inform conservationists of what might work. “What we’re advocating here is a thoughtful way of partnering with nature to bring health back to these places,” Dr. Sampson said.

Laura Rogers-Bennett, a marine biologist at the University of California, Davis, who was not involved in the research, said that while it’s helpful to create these kinds of simplified models, people should be careful before to draw firm conclusions. . Ecosystems are so complex and delicate that even a small change could turn things upside down.

She added that modern kelp forests often have diverse algal understory, and the interconnected web of living and dead, dynamic and inert, large and small, is difficult to model. “Thinking about what the habitat looked like back then, I would say we don’t even know what the habitat looks like now,” she said.

The paper’s authors acknowledged these drawbacks, but, Dr. Roopnarine said, “We will always be limited in terms of having enough knowledge about all of these species in the system.” He added: “Frankly, we’re running out of time to really understand these systems.”