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A New Perspective on Yosemite: Under the Rocks, Little Creatures

September 5, 2008

Alejandro Miró Co remembers his parents, both doctors, telling him not to play in the dirt – he’d get sick. He’s come a long way from those days to his current work in the UC Merced Research Experiences for Undergraduates (REU) program, turning over rocks in the Merced River in Yosemite National Park, looking for aquatic macroinvertebrates to catalog using ultra-modern DNA barcoding techniques.

His fellow student on the project, UC Riverside student Cymphonee Robinson of San Bernardino, came to REU looking to get more connected to the environment – and you can’t get much more connected than sitting on a river rock, sifting through mosses looking for bugs.

Their advisor is REU director Professor Benoit Dayrat of the UC Merced School of Natural Sciences.

The diversity of species in a river, Dayrat says, is an important indicator of water quality. In addition, a thorough survey of species is necessary as a benchmarking tool.

“Ten years from now, we need to be able to come back to this system and study it again, having a baseline to compare it to,” said Dayrat. “Then we can see if factors like climate change are affecting these species.

These kinds of concerns mean a lot to Miró Co, who changed from pre-med to environmental science at the University of Puerto Rico last year. He’s hoping to absorb information from Yosemite to apply to wilderness management back on the island where he was born. (He was reared mostly in Texas, then chose to return to Puerto Rico for college.)

“It’s a completely different system,” said Miró Co, “It’s impressive. On an island, there’s not much mammalian life. Here, I’ve seen bobcats, wolves, deer. It’s fascinating to think of a system that supports so many layers.”

That kind of impact was part of Dayrat’s aim with the REU program.

“If, after this program, our students get really into environmental science and we have a major impact on their career, that’s the kind of effect we want to have,” he said.

His enthusiasm is contagious. After their last sampling trip, Miró Co and Robinson stayed in the lab late into the night, sorting and analyzing the tiny larvae, mites, nematodes, aquatic beetles and flatworms they found in the river.

“I got a water penny!” Dayrat called out as they sampled species near Happy Isle in Yosemite Valley. “I love these guys.”

Miró Co and Robinson gathered around to see the small, brown aquatic beetle whose legs move elegantly under a highly modified round carapace decorated with detailed black markings.

“You should have seen him when he found a gastropod,” Robinson said.

In spite of a little good-natured ribbing, enthusiasm and motivation are hallmarks of the carefully selected REU students. The REU experience may even help bring passionate students like Miró Co to California to study. “I’ve been thinking about it,” he said. “I imagine I’ll be applying to UC Merced for grad school.”