UC Davis researchers continue in Sea of Cortez

Two decades of pioneering research on desert-island ecosystems in Mexico's Sea of Cortez did not end when UC Davis ecologist Gary Polis died in the waters there six months ago.

Three postgraduate researchers who worked closely with Polis-Francisco "Paco" Sánchez-Piñero, Paul Stapp and Gary Huxel- are continuing the research on the islands off Baja California.

Huxel is a survivor of the March 26 boat accident that claimed the lives of Polis, postgraduate researcher Michael Rose and three visiting Japanese scientists.

The other two researchers collaborating with Huxel both were long-standing members of Polis' research group-Sánchez-Piñero for four of the last six years and Stapp for three years.

Huxel and Sánchez-Piñero have been named as lead investigators for about $550,000 in grants Polis obtained from the National Science Foundation. Included in that funding is a $400,000, four-year grant that Polis had applied for last winter and the NSF awarded after his death. Stapp who will be returning to UC Davis in October will be the principal investigator on one of the grants.

"I think it's the least we can do," said Sánchez-Piñero, who first worked with Polis at Vanderbilt University and rejoined his team when Polis came to UC Davis in two years ago.

Polis, an internationally renowned expert on scorpions and spiders, was studying complex food webs and how the sea subsidized life on the desert islands.

Among the topics he was addressing was how dramatic fluctuations in annual rain-from a fraction of an inch during a drought to more than 17 inches during the 1997-98 El Niño-affected entire populations of plants, insects, mice, lizards, birds and other life.

Unlike other deserts, where levels of nitrogen and phosphorous are low, the islands are fertilized by seabird guano and detritus washed ashore-leading to 10- to 160-fold increases in plants in wet years.

That in turn leads to huge ups and downs in creatures that depend on those plants and the species that in turn feed on those organisms.

For example, spiders increase rapidly in number the first El Niño year. The following year sees an eruption of wasps that feed on flower nectar when young but prey on spiders. The spider population subsequently drops, followed by a decrease in wasps in the third year.

The latest studies involve experiments that look at how those cycles vary with changes in the both quality and quantity of food.

His work, funded for at least nine years by the National Science Foundation, was considered important by other ecologists because it showed connections between two environments-in the sea and on land.

Discussions about continuing the research began in the Environmental Science and Policy Department within a week or two after the accident, Sánchez-Piñero said.

He and Huxel said they felt it was important to continue the research for a combination of emotional and scientific reasons. They wished to honor Polis' memory, as well as advance research in which they each have much personal investment.

"It's hard because it's a place where you know that some of your friends and people you really appreciate lost their lives," Sánchez-Piñero said. "But also, I think it's necessary to do it. I do think it would be bad if we just stopped working down there with such a tragic end."

Added Huxel: "There's a lot more to be done there. We still see Baha as a place that has a lot of opportunity to do some good scientific research."

The first few months after the accident were occupied largely by paperwork-transferring the NSF grants, obtaining needed permits from Mexico and making travel arrangements.

In June, Huxel, Sánchez-Piñero, Stapp and a handful of graduate students and other researchers made their first trip back to Bahia de Los Angeles. Another two-week expedition followed in July. They plan a third trip next month.

The sea was calm and the weather beautiful during their summer trips, but the pair said their perceptions of the area are forever changed.

"Now Baja has another side. Before it was like going home," said Sánchez-Piñero, a native of Spain. "After the accident, it was still this gorgeous place that was so neat. But now we know it's so treacherous too."

Huxel said he found it difficult to return to the area, but worthwhile for "the same reasons we got started." However, he said, some of the other three accident survivors are not ready to go back.

"It's been a special place for a long time for a lot of people," Huxel said. "It's also a place where we have very strong memories.

"It's paradoxical. On the one hand, it's a great place. And on the other hand, it's potentially a very dangerous and tragic place as well."

Polis was president last year of the American Society of Naturalists.

In August, a symposium that Polis had organized for the Ecological Society of America annual meeting last month in Utah became a memorial in Polis' honor.

Alan Hastings, professor of UC Davis Department of Environmental Science and Policy and a close friend of Polis', is also organizing a workshop in his honor at the annual meeting of the American Association for the Advancement of Science in San Francisco next February.

This fall, UC Davis plans to hold a ceremony to plant five memorial trees-one for each scientist who died-in the arboretum near Putah Creek Lodge. A date for the ceremony is pending.

Environmental horticulture department chair Dave Burger, who helped select the trees, said a desert willow that bears burgundy flowers in the summer will be planted for Polis. Polis, who would have turned 54 in August, also conducted research in deserts in California and Namibia.

A "Flame" variety of the North American redbud, which comes from the Midwest, was chosen to honor Michael Rose, who grew up in Illinois.

A Japanese variety of magnolia will be planted in memory of each of the University of Kyoto scientists who died-Takuya Abe, Masahiko Higashi and Shigeru Nakano.

Faculty members in the Environmental Science and Policy Department, where Polis had been chair, were pleased Huxel and Sánchez-Piñero were continuing Polis' research.

"It's what Gary would have wanted," Hastings said.

Huxel, who also worked under Hastings, said he and Sánchez-Piñero received widespread support that extended far beyond the campus.

"Other scientists around the world contacted us and said, whatever resources we would need, they would help," he said. "There is a strong desire by the scientific community to keep Gary's work going."

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Amy Agronis, Dateline, (530) 752-1932, abagronis@ucdavis.edu

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