September 18, 2014

First Crayfish Roundup

 

PHOTO BY ROSI DAGIT

First Crayfish Roundup

In less than two hours, volunteers captured 77 crayfish, the only non-native species in Topanga Creek.

On Saturday, Sept. 15, more than 60 people gathered at the bridge on Topanga Canyon Boulevard for the First Annual Crayfish Roundup.

Each year, since 1995, the Topanga Creek Stream Team, under the auspices of the Resource Conservation District of the Santa Monica Mountains (RCDSMM), has participated in Coastal Clean-Up Day.

This has involved everything from trash removal (two to four each time), weeding and planting in Lower Topanga Creek, and this year, for the first time, Crayfish removal.

Because RCDSMM has federally listed endangered species in this reach of the creek, there is no fishing permitted—for anything! It holds special permits and made special arrangements with the National Marine Fisheries Service and CA Department of Fish and Game to get permission to conduct this effort.

Ken Wheeland and Rebecca Barkin helped volunteers from the Topanga Brownies, CSUN Geography Club, Palisades High School Envirothon Team, and longtime volunteers, like the deRecat family, make their fishing lines with string, washers (for weight) and bait. The group did a loose experiment with the kinds of bait that worked best—hot dogs, chicken and dog biscuits all were successful!

RCDSMM biologists Jenna Krug and Steve Williams, along with Ken Wheeland, led the teams down the creek to slowly, quietly and stealthily sneak up on the crayfish.

The group’s effort was to remove this invasive species, native to Louisiana, from Topanga Creek because they are devouring our native frogs, newts and fishes.

The source of this invasion was a misguided release of leftover bait into the creek near Highvale Road in the late 1990’s. For many years, students from Topanga Elementary were able to keep the population under control, but by 2004, more and more crayfish have been seen in the stream south of town. This is the same part of the creek that has the most diversity of native amphibians, reptiles, fish, bugs and birds.

To date, crayfish are the only non-native animal species in Topanga Creek, which is one of the reasons why there are still 28 of the possible 32 amphibian and reptile species found in the Santa Monica Mountains, as well as all three native fish species, living in the creek.

Not only do crayfish prey upon many life stages of our native species, they also dig burrows and alter habitat. While these survival traits are all wonderful in their native bayous, they are very destructive here in our southern California habitats. Crayfish are now found in creeks and streams throughout the Santa Monica Mountains, and in many of those invaded, have made a significant impact on local species survival.

In less than two hours, the dedicated volunteers captured 77 crayfish. Most were adults between 3-5 inches long. We gently sacrificed these tasty morsels by freezing them in bags ready to feed the wild critters at Nature of Wildworks. At least they will not go to waste.

DON’T RELEASE, REHOME

While it may seem humane to release pets of all kinds into the wild, it really is not good, either for the pet or the native ecosystem. If you have unwanted turtles, frogs, lizards or snakes, please find them a good home rather than set them free in our local creek. Topanga has a sensitive and delicately balanced suite of natives and many of these newcomers are real problems. The RCDSMM can direct you to a local adoption program if you need help finding a home for your bait or pets. For more information, contact them at http://www.rcdsmm.org/