The recent discoveries of damaging quagga mussels and zebra mussels in California reservoirs have water managers scrambling to prevent the costly havoc that these exotics have wreaked in the Great Lakes. A UC Davis expert on invasive species says this result could have been avoided -- if the responsible state agencies had heeded repeated warnings throughout the past decade. Contact: Ted Grosholz, Environmental Science and Policy, (530) 752-9151, tedgrosholz@ucdavis.edu. (Editor's note: A high-resolution photo of quagga mussels and zebra mussels is available from Sylvia Wright, swright@ucdavis.edu.)