It was 1970 when marine ecologist Dr. James Estes first came to Alaska to study marine life.
Estes flew out to the Aleutian Islands at the behest of the Atomic Energy Commission. He was hired to asses what may happen to local wildlife when the government blew up a nuclear bomb buried roughly one mile deep on a small island almost to Russia.
"In the late summer of 1971, final preparations were being made on Amchitka Island, in the remote island chain of Alaska, for project Cannikin...to proof test a warhead for the Spartan Missile of the Safeguard Ballistic Missile Program..."
That clip is from a declassified government film of the Cannikin event. The bomb packed just under five megatons and was the largest underground nuclear test conducted in the U.S. Estes remembered it was the event that launched Greenpeace.
"You know, it was a really big deal at the time...it's probably largely forgotten now in Alaska," Estes said.
While the bomb test galvanized the environmental movement, for Estes, it introduced him to the place that would serve as his lifelong research lab.
Sea otters became a main focus for Estes, and he returned year after year to the Aleutians to study the sea mammals. Estes has been a professor of ecology and evolutionary biology at UC Santa Cruz since 1978. He is now one of the world's foremost experts on sea otters and the role of top predators in ocean ecosystems.
Through long-term studies, his work established sea otters as a keystone species.
"Otters are predators on sea urchins. Sea urchins feed on kelp. When otters are abundant, they limit the sea urchin numbers to the point where kelp is not over-grazed," Estes said. "When otters are lost, urchins become very abundant, kelp forests disappear. And it's a very dramatic effect; a very, very strong manifested effect."
Starting in the early '90s, sea otter populations began to collapse.
"Really all of the evidence that we had pointed fairly strongly to killer whales being the cause of the otter decline. The more controversial part of it was why that happened," Estes said.
Estes and his colleagues developed a theory that post WWII industrial whaling in the North Pacific sharply reduced a key component of the orca diet, driving killer whales to begin preying on sea otters and seals. Fewer sea otters meant the loss of the kelp forests, and biodiversity is further eroded.
"What we have learned from the sea otters is that predators - large predatory vertebrates like sea otters and other species - have really important effects on the ecosystem," Estes said. "What we have since learned is that those kinds of processes occur in a lot of different species and a lot of different systems."
Estes recently published a new book called Serendipity, in acknowledgement of the chance encounters and random events that shaped his life's work.
What spurred him to write this particular book now?
"Well, I'm at the end of my career and I'd be working on this system, this species and a number of related things for 40 some years and I got to the point where I wanted to write about it," Estes said. "I'm a scientist, so most of my work has been has been published in the scientific literature, but I wanted to write an account that was a little more personal. So the book is in part a memoir, in part it's a chronology of the science that I did, in part it's an explanation for how the science happened.
Serendipity: An Ecologist's Quest to Understand Nature is published by UC Press.
