Approximately six months later we observed juvenile trout in the lower section of Devil Canyon. These fish were clearly from the group further upstream and genetic analysis would prove that. Unfortunately, this group was located in the last watered pool in the creek and only yards from the San Mateo Creek confluence, home of the exotic predators. After monitoring the juvenile trout for a month, a small rainstorm moved through and washed them down into San Mateo, where they were probably preyed upon by the non-native fish. We continued to monitor the adult trout in Devil Canyon until there was only one left. That last fish, a male, was last seen in September of 2003 in a small pool in Devil Canyon Creek. From their discovery in 1999 to the
fall of 2003, resident trout, the offspring of sea-run steelhead, inhabited the wetted sections of San Mateo Creek and Devil Canyon Creek. We determined that anadromous adults had entered the creek in 1997, made their way to Devil Canyon and spawned. Some of those offspring emigrated out of the creek during a high water event in 1999 and were discovered. The remainder stayed in Devil Canyon and spawned the following year, leaving juveniles that likely never made it out of the drainage. The last of the Devil Canyon trout were observed on the drainage in 2003.
A DIFFICULT PLACE TO SPAWN The regular steelhead runs that Southern California used to experience in the 1940s and ’50s began to decline
28 California Sportsman APRIL 2018 | calsportsmanmag.com
Biologists are concerned that steelhead might never recover in Southern California, but they continue to survey creeks like San Mateo in hopes of ﬁnding specimens. Aligned against the sea-run trout is a grab bag of invasive species, development and dropping water tables affecting stream ﬂows. (TIM E. HOVEY)
sharply when stream access became inconsistent for returning spawning adults. Increased development taxing groundwater, dams and drainage channelization all contributed to a reduced stream flow, limiting or eliminating ocean access. Occasional access to natal streams may be available during heavy winter storms, when returning steelhead will take advantage of these opportunities to migrate up these creeks to spawn.