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Status of Aquatic Non-indigenous Species in the St. Louis River System
Citation:
TREBITZ, A. S., G. S. PETERSON, J. HOFFMAN, J. R. KELLY, AND C. W. WEST. Status of Aquatic Non-indigenous Species in the St. Louis River System. Presented at St. Louis River Estuary Summit, Superior, WI, February 07 - 08, 2011.
Impact/Purpose:
s part of a study to develop recommendations for aquatic non-indigenous species (NIS) monitoring in Great Lakes areas at risk of invasion, we conducted comprehensive, multi-gear sampling in the lower St. Louis River in 2005-2007. This effort represents the most spatially and taxonomically comprehensive NIS survey of this complex, invasion-vulnerable Great Lakes subsystem to date. In this poster, we identify the NIS and their invasion timeline, describe their abundance and distribution, and evaluate which sampling gears were most effective in finding them. Our study confirms that this major shipping port remains a NIS invasion “hotspot”
Description:
As part of a study to develop recommendations for aquatic non-indigenous species (NIS) monitoring in Great Lakes areas at risk of invasion, we conducted comprehensive, multi-gear sampling in the lower St. Louis River in 2005-2007. This effort represents the most spatially and taxonomically comprehensive NIS survey of this complex, invasion-vulnerable Great Lakes subsystem to date. In this poster, we identify the NIS and their invasion timeline, describe their abundance and distribution, and evaluate which sampling gears were most effective in finding them. Our study confirms that this major shipping port remains a NIS invasion “hotspot”. Ten of the 41 fish species and 19 of the ~240 benthic invertebrate taxa recorded were non-indigenous. Eight of the benthic invertebrates, including the New Zealand mud snail (Potamopyrgus antipodarum), a Eurasian-origin amphipod (Echinogammarus ischnus), and the quagga mussel (Dreissena bugensis), were first-detection records. Notably, zebra mussel (Dreissena polymorpha), round goby (Neogobius melanostomus), and Eurasian ruffe (Gymnocephalus cernuus) were abundant and widespread in the system (potentially “invasive”), while other NIS were less common and more localized (“non-invasive”, at present). A few NIS were extremely rare and required considerable sampling effort to detect. Because the sampling gear differed substantially in the habitats covered and the species composition recovered, monitoring multiple habitats with multiple gear types provided the most complete and nuanced picture of aquatic NIS status.