Event Title

Invasion of the Middle Creek Watershed by the Rusty Crayfish (Orconectes rusticus)

Presenter Information

David Zinn, Susquehanna University

Faculty Advisor

Michael Bilger

Start Date

25-4-2017 5:00 PM

End Date

25-4-2017 6:00 PM

Description

Understanding how the introduction of invasive species affects not only native populations, but also the local ecosystem, is essential for determining the total impact of these species. In addition, examining how physical barriers and environmental barriers affect invasive species may be beneficial when deciding how to allocate resources to protect native populations. Our study conducted in the fall of 2016 seeks to determine the effects of two Central Pennsylvania reservoirs (Walker and Faylor Lakes) on the invasion of Rusty Crayfish (Orconectes rusticus) and the effects of drought on the crayfish populations of Middle Creek (Snyder County, Pennsylvania). We used a one-square meter frame net to sample ten stream sites above and below Walker and Faylor Lakes over several weeks. Three sites on each reservoir were sampled with modified minnow traps. All individuals were measured to the nearest mm in order to determine size class. Representatives of each size class were dissected in order to determine diets. Initial results indicate only individuals of the native Appalachian Brook Crayfish (Cambarus bartonii bartonii) were found in one site above Walker Lake, indicating this reservoir could be a barrier to invasion. Based on previous results of rusty crayfish diets, we expect to see younger age classes of crayfish eating primarily benthic macroinvertebrates while older age classes will likely consume primarily a plant and organic matter based diet. Understanding the impacts of aquatic invasive species such as Rusty Crayfish can help us better understand how these species disrupt ecosystems and alter food webs.

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Apr 25th, 5:00 PM Apr 25th, 6:00 PM

Invasion of the Middle Creek Watershed by the Rusty Crayfish (Orconectes rusticus)

Understanding how the introduction of invasive species affects not only native populations, but also the local ecosystem, is essential for determining the total impact of these species. In addition, examining how physical barriers and environmental barriers affect invasive species may be beneficial when deciding how to allocate resources to protect native populations. Our study conducted in the fall of 2016 seeks to determine the effects of two Central Pennsylvania reservoirs (Walker and Faylor Lakes) on the invasion of Rusty Crayfish (Orconectes rusticus) and the effects of drought on the crayfish populations of Middle Creek (Snyder County, Pennsylvania). We used a one-square meter frame net to sample ten stream sites above and below Walker and Faylor Lakes over several weeks. Three sites on each reservoir were sampled with modified minnow traps. All individuals were measured to the nearest mm in order to determine size class. Representatives of each size class were dissected in order to determine diets. Initial results indicate only individuals of the native Appalachian Brook Crayfish (Cambarus bartonii bartonii) were found in one site above Walker Lake, indicating this reservoir could be a barrier to invasion. Based on previous results of rusty crayfish diets, we expect to see younger age classes of crayfish eating primarily benthic macroinvertebrates while older age classes will likely consume primarily a plant and organic matter based diet. Understanding the impacts of aquatic invasive species such as Rusty Crayfish can help us better understand how these species disrupt ecosystems and alter food webs.