MALIBU – A new study of the streams in the Santa Monica Mountains shows that even protected areas such as national and state parks are being altered by urbanization, making them unsuitable for native frogs and salamanders. The federally funded study found that urban streams were missing native amphibians such as California newts and tree frogs, but were rife with introduced, invasive species including crawfish, bass, bluegill and bullfrogs. “The more urbanized streams were transformed from babbling brooks to sand and mud-filled trenches that were missing native species but full of non-native invaders,” Seth Riley, a National Park Service wildlife ecologist and lead author of the study, said Tuesday. The results are scheduled to be published in the December issue of the scientific journal Conservation Biology. AD Quality Auto 360p 720p 1080p Top articles1/5READ MOREWalnut’s Malik Khouzam voted Southern California Boys Athlete of the Week “Amphibians have gotten a lot of attention because they seem to be disappearing on several continents,” said Lee Kats, a biology professor at Pepperdine University and another of the study’s authors, said. “Amphibians represent a fragile group of animals in Southern California and elsewhere, and this study suggests that even minimal urbanization can contribute to their disappearance.” Previous studies from other parts of the United States indicated that, when 15 to 20 percent of a watershed is developed, stream organisms begin to suffer. But this study showed that as little as 8 percent urbanization resulted in habitat changes that made streams unsuitable for native amphibians, officials said. Southern California streams typically dry up in late summer and in dry years, but some fed by urban runoff flow year-round, every year. In these, urban-related changes provide opportunities for invasion by non-native animals that compete with or prey upon the native amphibians, officials said. “If we start adding water because of runoff and urbanization, it becomes suitable for the invasives,” Kats said. “The invasives are eating the native insects and eating the native amphibians. “I was concerned going into this and am more concerned now because the trend we’re seeing is that they are disappearing from one stream after another,” he said. The study involved biologists from Pepperdine, the National Park Service, the U.S. Geological Survey and the Resource Conservation District of the Santa Monica Mountains. The 35 streams involved were all in the Santa Monica Mountains and Simi Hills. Eric Leach, (805) 583-7602 firstname.lastname@example.org 160Want local news?Sign up for the Localist and stay informed Something went wrong. Please try again.subscribeCongratulations! You’re all set!