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Aquatic food web changes to invasive Flathead Catfish along a natural invasion gradient

Biological invasions have the potential to significantly alter the structure and function of aquatic communities. Invasive predatory fish species are known to restructure food webs – since predatory fishes have a dominant influence on community structure in freshwater systems. The Flathead Catfish Pylodictis olivaris is a large piscivorous catfish that is invasive in many parts […]

Population and pollutant estimates for invasive snails in Presque Isle State Park

Invasive species can have direct and indirect negative impacts on native communities. Freshwater snails—because of their diet variety, association with water and sediment, rapid reproduction rates, and obscure life history—can significantly impact the communities they invade. Our preliminary work has shown that Presque Isle State Park (PISP), located along Lake Erie’s shores, is now home […]

Status of Exotic Round Goby and Tubenose Goby in Pennsylvania

The purposes of this study was to report on the status of the Round Goby, Neogobius melanostomu, in the Lake Erie watershed of Pennsylvania, to determine if there was a shift in diet of the native fishes when Round Goby were present in selected Pennsylvania tributaries of Lake Erie, and to compare the diet of the Tubenose […]

Rusty Crayfish and Smallmouth Bass in the Susquehanna River: Who’s Eating Whom?

Two nonnative crayfish species, Rusty Crayfish (Faxonius rusticus) and the Allegheny Crayfish (Faxonius. obscurus), are currently found in the Susquehanna River.  In 2015, we hand collected crayfish from among six sites spanning almost 115 river miles. Thirty stomachs were dissected from similarly sized individuals at each of the six sites; two of the sites had […]

Genomic Application for Mutational Analysis of Skin Tumor Formation in the Bioindicator Bottom Feeder Brown Bullhead Fish in Presque Isle Bay

Genome sequence comparison of tumor and non-tumor samples obtained from brown bullhead fish from Presque Isle State Park was undertaken to identify regions of DNA mutations in tumor samples. DNA primer sets were constructed to amplify and examine eight of these regions in greater detail, all of which successfully amplified the region targeted. Three genome […]

PCR Tracking of Predation on Non-native Species in Lake Erie

Lake Erie’s ecology is disrupted by aquatic invasive species (AIS), such as the round goby (Neogobius melanostomus) tubenose goby (Proterorhinus semilunaris). The impact of the tubenose goby on the Great Lakes ecosystem is relatively unstudied. Our current studies focus on discovering which species of fish prey upon these invasive gobies. We use polymerase chain reaction […]

Development of a Real-time PCR Method for Early Detection of Aquatic Invasive in Pennsylvania Watersheds

The widespread occurrence of aquatic invasive species is a worldwide issue threatening the environment and impacting the intended use of water. Conventional methods for the identification of aquatic invasive species are laborious and time-consuming, preventing the timely application of eradication measures. On the contrary, molecular biology methods based on the detection of specific DNA sequences […]

Didymosphenia Geminata in Pennsylvania: an Investigation of Current and Historic Distribution, Habitat Suitability, and Nutritional Content

Didymosphenia geminata (Lyngbye) M.Schmidt (herein referred to as didymo) is a benthic freshwater diatom capable of producing nuisance blooms that impact the recreational, ecological, and aesthetic value of freshwater ecosystems. Recently, didymo has expanded its range and ecological tolerances leading to massive blooms in areas where it was previously undocumented or had existed in low […]

Preliminary Determination of Density and Distribution of Flathead Catfish (Pylodictis Olivaris) in the Susquehanna River and Select Tributaries

Flathead Catfish records in the Atlantic Slope drainage of Pennsylvania date back to the early 1990s; however, large-scale range expansion and population increases were not realized until the late 1990s in the Delaware River drainage and the early 2000s in the Susquehanna River drainage. The impacts of introduced Flathead Catfish on migratory and resident fishes […]

Investigation of Chemical Signals for Improving Trapping Efficiency and Preventing Further Expansion of Invasive Crayfish Species

Invasive crustacean species disturb existing food webs, macrophyte, benthic invertebrate and fish populations, and negatively affect overall ecosystem function (Hill and Lodge, 1999; Khulman and Hazelton, 2007). In Central Pennyslvania, the invasive Orconectes rusticus and Orconectes obscurus have invaded aquatic habitats, dominating the Susquehanna River and many of its tributaries while displacing native species (Lieb […]

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