Presentation Type
Poster
Presentation Type
Submission
Keywords
Mathematics, Biology
Department
Mathematics
Major
Mathematics
Abstract
The red swamp crayfish, Procambarus clarkii, is an invasive species introduced into several streams within the Santa Monica Mountains (SMM) in Southern California. Crayfish predation decimates native aquatic species. Thus, the Mountains Restoration Trust (MRT) and Environmental Restoration Group have worked to remove crayfish through regular trapping in Malibu Creek.
To aid conservation efforts, former SURB students William Milligan and Dev Patel developed mathematical models of crayfish removal efficacy. Milligan created a differential equation model of how crayfish removal affects local newt populations. Patel expanded Milligan’s crayfish model by creating a discrete model of the crayfish life cycle that newly accounted for cannibalism but was not yet parameterized to stream data. We expand Patel’s model to better predict the efficacy of crayfish removal efforts in the SMM. We separate crayfish based upon life stage and total length: eggs, two monthly juvenile stages, small (4-5 cm) non-reproductive adults, medium (6-7 cm) adults, and large (8+ cm) adults.
We construct and parameterize this preliminary predictive discrete model of crayfish population levels with and without trapping. We use literature and crayfish removal data provided by MRT to fit the model to the Middle Las Virgenes (MLV) portion of Malibu Creek. We numerically simulate how the crayfish population changes over time and find that the model dynamics are highly sensitive to juvenile monthly survivorship. We determine the best crayfish life stages to trap to most efficiently decrease crayfish population size; specifically, model predictions suggest that a smaller mesh size that traps juveniles in addition to adults is necessary to reduce crayfish populations to local extinction.
Faculty Mentor
Dr. Courtney Davis
Funding Source or Research Program
Academic Year Undergraduate Research Initiative, Summer Undergraduate Research in Biology
Location
Waves Cafeteria
Start Date
22-3-2024 1:30 PM
End Date
22-3-2024 2:30 PM
Included in
Mathematically modeling how trapping regimes that target specific crayfish life stages impact removal efficacy
Waves Cafeteria
The red swamp crayfish, Procambarus clarkii, is an invasive species introduced into several streams within the Santa Monica Mountains (SMM) in Southern California. Crayfish predation decimates native aquatic species. Thus, the Mountains Restoration Trust (MRT) and Environmental Restoration Group have worked to remove crayfish through regular trapping in Malibu Creek.
To aid conservation efforts, former SURB students William Milligan and Dev Patel developed mathematical models of crayfish removal efficacy. Milligan created a differential equation model of how crayfish removal affects local newt populations. Patel expanded Milligan’s crayfish model by creating a discrete model of the crayfish life cycle that newly accounted for cannibalism but was not yet parameterized to stream data. We expand Patel’s model to better predict the efficacy of crayfish removal efforts in the SMM. We separate crayfish based upon life stage and total length: eggs, two monthly juvenile stages, small (4-5 cm) non-reproductive adults, medium (6-7 cm) adults, and large (8+ cm) adults.
We construct and parameterize this preliminary predictive discrete model of crayfish population levels with and without trapping. We use literature and crayfish removal data provided by MRT to fit the model to the Middle Las Virgenes (MLV) portion of Malibu Creek. We numerically simulate how the crayfish population changes over time and find that the model dynamics are highly sensitive to juvenile monthly survivorship. We determine the best crayfish life stages to trap to most efficiently decrease crayfish population size; specifically, model predictions suggest that a smaller mesh size that traps juveniles in addition to adults is necessary to reduce crayfish populations to local extinction.