Predicting the impacts and spread for an emerging invasion of non-native round gobies (Neogobius melanostomus) in a stream biodiversity hotspot (French Creek, Pennsylvania)
Abstract
Invasive round gobies (Neogobius melanostomus) became established in a tributary to the upper Allegheny River drainage in 2014 (French Creek, Pennsylvania). French Creek has the highest biodiversity of native bottom-dwelling fishes (16 darter species) and native unionid mussels (27 species) in Pennsylvania, and prior research indicates that both are susceptible to the impacts of round gobies. As round gobies are expanding their range downstream, there is an important need for collecting data regarding impacts on ecosystem functions in French Creek.
To achieve these goals, we have developed three objectives.
The first objective is to collect baseline data on stream macroinvertebrate communities and native benthic fish populations in three different invasion zones of French Creek (established reach, threatened reach, reference reach) for a total of nine sampling locations. We will compare these data with historical (pre-invasion) and future data (post-expansion) to determine the potential extent of round goby impacts.
The second objective is to collect baseline data on trophic niches of native darter species and round gobies in the three reach types. The trophic niche data of native darters will be inferred based on stomach contents and isotopic niche data that we collect at six sampling locations. Our final objective is to perform in situ experiments to determine whether round gobies induce food web changes in the French Creek ecosystem.
Our projects will have important implications for assessing the impacts that round gobies pose to newly invaded ecosystems with high biodiversity and high ecological value. These projects will have broad implications for the field of invasion biology and can help identify management needs and conservation priorities throughout Pennsylvania. Lastly, our proposed research will address two of Pennsylvania Sea Grant’s priority research topics on aquatic invasive species.
