Unexpected variety of insects found by study
Sunday, April 1, 2001 - Napa Valley Register
By NATHAN
CRABBE
Register
Staff Writer
NAPA
Maybe they'll call it Baumenella chrismalanus.
Friends of the Napa River last week announced it found a number of rare and possibly new species in its study of the Napa River and more than 30 tributaries.
Study director Charley Dewberry said an "astounding" variety of aquatic insects were discovered, including several rare types of blind crustaceans and a unique stone fly.
Dewberry said the stone fly is either a new species or a species previously found only once before in Alameda County, called Baumenella alameda.
As the collecting group, Friends of the Napa River, will be able to name any new species found.
"You might want to brush up on your Latin," Dewberry said.
The first and part of subsequent years of the study are being funded by the environmental foundation of Peter Mennen, former St. Helena postmaster and shaving-equipment fortune heir.
Mennen suggested naming the stone fly after Chris Malan, the area's most outspoken environmental activist, who organized the stream sampling.
Dewberry said the diversity of species found, much greater than the number found in the Russian River, surprised researchers.
"I'm not aware of anybody knowing ... that was the case for Napa," he said.
He said aquatic insects in the watershed are unique because they are both diverse and resistant to sediment and other consequences of streamside development.
"On the one hand, we have very high diversity. On the other hand, we have very high tolerance," he said.
The high diversity and tolerance are consequences of Napa's geographical location. The valley lies between coastal- and Mediterranean-type areas.
While coastal species are highly sensitive, Dewberry said, Mediterranean species are highly tolerant
The study of aquatic insects is helpful in determining the health of the watershed, he said. The variety and number of species in samples can be used to measure the effect of human development, pesticides and other agricultural runoff on the surrounding environment.
Dewberry declined to specifically name which of the more than 30 test sites spread through the county had the lowest number of samples.
"Clearly, there are some poor sites and clearly there are some very good sites within the watershed," he said.
County Supervisor Mike Rippey was among those attending a presentation of the study's results Thursday at the Napa Public Library.
Rippey said the information could be used in conjunction with existing studies of vegetation and satellite photos as a map to guide development.
The study is the first comprehensive look at aquatic insects in streams of the Napa River watershed, scheduled to last five years.
After several years of data, researchers will be able to have a baseline figure that can be used as a point of comparison in studying the effects of future development.
The group originally planned to compare their results to the Russian River watershed, but found it was not a good comparison.
Groups testing the Russian found any sample with more than 36 species to be highly diverse, while only two of 33 Napa samples had less than that amount.
The local samples ranged from 34-90 species.
Samples were collected by members of Friends of the Napa River and other volunteers. The group is looking for additional help for the next round of sampling, set to begin April 17.
Marine biologist Leighton Taylor said the diversity of the watershed is good news, but should be weighed against the fact the area likely was much more so before human development.
"It's like the Mona Lisa: It's beautiful now but you should have seen it when Leonardo painted it," Taylor said.
Mennen said the report gives him hope that fish will be able to propagate if dams and other water diversions are removed from area streams.
"What this really means ... is somehow we have to get enough water back," Mennen said.