Non-Native Crayfish Removal from Malibu Creek Watershed

MRT’s aquatic invasive species removal efforts focused on red swamp crayfish (Procambarus clarkii) but also include mosquito fish (Gambusia affinis), American bullfrogs (Lithobates catesbeianus), largemouth bass (Micropterus salmoides), bullhead catfish (Ameiurus spp.), common carp (Cyprinus carpio), bluegill (Lepomis macrochirus) and green sunfish (Lepomis cyanellus). Over the lifetime of the grant, MRT removed 413,976 invasive crayfish from its project sites; 205,943 from Middle Las Virgenes Creek, 6,853 from Upper Las Virgenes Creek, 171,927 from Medea Creek, and 29,253 from Lindero Creek.



In 2016 MRT successfully eradicated crayfish from upper sections of Las Virgenes Creek upstream of Hwy 101 and subsequent monitoring of these sites maintain project success to date. During biological surveys in summer 2017, MRT detected the presence of the California Red-Legged Frog (Rana draytonii) (“CRLF”) in a 0.5-mile section of Virgenes Creek above Agoura Road (upstream boundary: 34.14935, -118.69867, downstream boundary: 34.13944, -118.70333).



During two weeks in July 2017, MRT conducted a trap efficiency study comparing invasive crayfish and bycatch across 12 trap designs. The cylindrical mesh out-performed the other traps by catching the most crayfish while not catching any tadpoles.



During the grant period, MRT hosted 82 volunteer events, for 1,727 volunteers and 4,292 volunteer hours dedicated to removing aquatic invasive species.

Improve spawning and rearing habitat by remving non native species.