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Creek CleanupFishin for Crawdads
October 3, 2013 - By Rosi Dagit, Sr. Conservation Biologist, RCDSMM
PHOTO BY LISA WARD
Kids helping the Stream Team on Saturday morning, Sept. 21, catch invasive crayfish that eat our native frogs, tadpoles, newts and fish.
The Second Annual Coastal Cleanup Day Crayfish Removal Roundup in Topanga Creek was a great success!
In less than two hours on Sept. 21, more than 50 volunteers dipped their nets and hotdogs tied to strings and captured 224 crayfish in a 100-meter long reach.
Led by the Topanga Creek Stream Team, local Brownies, Girl Scouts, Cub Scouts, Palisades High School students, Topanga Elementary School families, Westside Waldorf families and Topanga Homeschool families helped capture the only invasive aquatic species found in Topanga Creek.
Introduced into Topanga Creek in 2002 by a fisherman who did not want to buy more bait, the population of red swamp crayfish has exploded during the past two dry years. These fierce predators eat our native frogs, tadpoles, newts and fish. They reproduce and grow quickly, taking over habitat and gobbling up all the food.
PHOTO COURTESY OF ROSI DAGIT
Kids and community volunteers gather at Topanga Creek on Sept. 21 to round up invasive crawdads.
Since 2001, Topanga Creek has been closed to fishing to protect the endangered steelhead trout that have made somewhat of a comeback. Removal events, such as this one, are allowed only under the supervision of permitted biologists and anyone otherwise found fishing in Topanga Creek risks a heavy fine. The Resource Conservation District of the Santa Monica Mountains (RCDSMM) has been organizing these events with interested school groups with a permitted biologist present to make sure no fish are trapped or harmed. Everyone has a great time and is eager to help whenever we can find funding for the project. Grant writing is in progress!
In addition to catching the crayfish, the volunteers helped measure them and noted the sex. We found 114 females that ranged in size from 6-16 cm, and 110 males that were slightly smaller on average (8 cm). None of the females had eggs, which is different from last year, when we found several reproducing for a second time. Learning more about the biology of these creek invaders will help us understand the impact they have on our native species.
PHOTO COURTESY OF ROSI DAGIT
Using hotdogs on the ends of their lines, local Topanga kids and community volunteers gather at Topanga Creek on Sept. 21 to round up invasive crawdads.
Research in Trancas Creek, coordinated by Dr. Lee Kats of Pepperdine University, suggests that crayfish populations increase during dry times and are suppressed when large rain events swoosh them out to sea. All of the creeks are so dry this year that the crayfish are able to take over.
All of the captured crayfish have been frozen and will be donated to The Nature of Wildworks to help feed their critters.