Friday, July 8, 2011

Stream Survey in Temescal Canyon

Can you believe this waterfall is only 30 minutes up a trail in Los Angeles (technically Pacific Palisades)?

The stream survey involves surveying 250 meters of stream for amphibians and other creatures. Many of our streams have been heavily impacted by urbanization and channelization but this one, in Temescal Canyon, is still incredibly beautiful and diverse.
Even though the camera is foggy, you can still see that I am very happy to be holding an adult California salamander (Taricha tarosa).

About ten years ago Seth, Lee Katz, Ray Sauvajot, crazy Robert Fisher, Rosi Dagit and a few other folks got together in the Santa Monica Mountains to figure out how to study possible impacts of urbanization on stream communities in our area. They started surveying streams for amphibians and stream invertebrates and they've been doing it ever since. They've published one paper on their findings (that a watershed with more than 11% urbanization has reduced native diversity and more invasive species such as crayfish, fish, and bullfrogs. Also that streams that no longer dry up in the summer have more invasive species. And of course, invasive species appear to have large negative impacts on native species such as frogs and salamanders. Crayfish are brutal predators.)

These guys are continuing their work and starting to look at other factors like long-term trends in population sizes and diversity, impacts of fires, and possible impacts of vineyard development within watersheds. Katy Delaney is running the NPS part of the program now with Seth and yesterday she took Lena and I out to do a stream survey in Temescal Canyon. Steve Bustamante was there as the actual field assistant while Lena took data and I helped look for creatures.

It was super neat and it was amazing how beautiful and wild this stream is considering how close it is to Los Angeles. We parked in the Temescal Canyon parking lot in Pacific Palisades and hiked in about 30 minutes on a dirt trail. Then we hopped into the stream and spent a couple of hours hiking up the stream. It was very quiet with only bird song and the sound of the stream. We heard lots of Pacific slope flycatchers, Spotted Towhees, Jays, Wrentits and Canyon wrens. It was sunny and warm and the water was cool. We saw adult California salamanders, larval salamanders, larval frogs, and lots of dragon fly larva and toe-biters.

I hope we can keep streams like this in good shape because they really are an amazing resource. We saw lots of people of all ages and ethnicities out enjoying the beauty of the area.

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