ResearchTopic: Invasive Species

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 […]

Determination of Invasive Round Goby Populations Within the Main Stem of French Creek and Their Potential Impact on Benthic Fishes

The introduction of Round Gobies (Neogobius melanostomus) in the French Creek Watershed (Lake LeBoeuf) was probably via bait bucket and were first discovered in 2014. This was the first documented invasion outside of the Lake Erie Basin in Pennsylvania. This was alarming in large part because the Round Goby has become the most abundant benthic […]

Impacts of Introduced Round Goby on Aquatic Community Structure in Pennsylvania Watersheds

Round Goby diet analysis was based on 177 fish; 15 fish were not included in analysis due to empty stomachs or fully digested organisms that could not be identified. Round Gobies consumed both benthic aquatic macroinvertebrates, unionid mussels, and sphaeriids. Chironomids comprised a large percentage (greater than 24%) in all size classes. Chironomids were found […]

Comparison of Age and Growth Patterns of Flathead Catfish in Invasive and Native Populations: A Meta-analysis with Implications for Invasive Species Management

Flathead Catfish are a long-lived apex predator native to the Gulf Coast drainage including the Ohio Basin in Pennsylvania; however, they are invasive in the Atlantic Slope of Pennsylvania. 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 […]

Evaluating the Effects of the Recently Discovered Non-Native, Parasitic Copepods Salmincola Edwardsii and S. Californiensis on Brook Trout and Rainbow Trout, Respectively in Pennsylvania Inland Streams and Lake Erie Tributaries

The primary focus of this project is to determine the distribution, prevalence, and genetic composition of non-native Salmincola spp. (commonly referred to as gill lice) and the potential impacts that Salmincola spp. are having on the Commonwealth’s wild trout populations. Of particular concern are the impacts of Salmincola spp. on Pennsylvania’s wild Brook Trout and […]

Diet Composition of Invasive Flathead Catfish in the Susquehanna River Basin: Quantifying Impacts on Native and Migratory Fishes and Recreational Fisheries

Flathead Catfish Pylodictis olivaris are an indiscriminate predator of other fish and an expanding invader to large river systems outside of its native range, including the Susquehanna River Basin in Pennsylvania. Research efforts are beginning to provide insight on the distribution of this invader in the Susquehanna River Basin, however, there is considerable uncertainty about […]

ResearchTopic: Invasive Species

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