Aquatic Ecosystem Health

A team of USGS scientists is currently working with the MDNR, ODNR, USFWS, and academic institutions to evaluate the use of grass carp baits and attractants as a tool for resource managers. The science team aims to integrate the use of baits and attractants to increase aggregation of grass carp near targeted capture sites to enhance the multi-jurisdictional removal program associated with the Lake...

No current technology can specifically target Grass Carp Ctenopharyngodon idella for control within aquatic ecosystems. Other than TFM (3-trifluoromethyl-4-nitrophenol) for Sea Lamprey Petromyzon marinus control, available control chemicals used in aquatic invasive species management programs are non‐selective and typically applied throughout the entire water column, resulting in equal exposure of...

Recently there has been an increased removal effort of adult Grass Carp Ctenopharyngodon idella from the Lake Erie Basin through traditional capture methods (Herbst et al. 2021). Use of chemical control tools such as a general or ingestible pesticide to support this removal effort has been identified as a potential management option (Robinson et al. 2021).

The Winged Mapleleaf mussel ( Quadrula fragosa) is only known to inhabit five locations in the U.S., and the population in the St. Croix National Scenic Riverway is isolated both physically and genetically from the other populations. In 2000, the U.S. Fish and Wildlife Service (USFWS) issued Reasonable and Prudent Measures, which required the U.S. Army Corps of Engineers (USACE) to establish...

The St. Croix National Scenic Riverway (SACN) is one of the last refuges for rapidly declining populations of native unionid mussels in the United States and supports the only known self-sustaining population of the federally endangered Winged Mapleleaf mussel ( Quadrula fragosa) in the upper Mississippi River basin. The Channel Catfish ( Ictalurus punctatus) is the only known host for Winged...

Native freshwater mussels play a critical role in aquatic environments and are considered “ecosystem engineers” and indicators of water quality by constantly filtering water. Populations of native freshwater mussels have declined in recent years, and this decline has been attributed to factors such as habitat degradation, pollution, and invasive species, among others. The importance of these...

Dreissenid mussels have posed an aquatic invasive species challenge in the United States since their arrival in the Great Lakes in the 1980s. Zebra ( Dreissena polymorpha) and Quagga ( D. bugensis) mussels are filter feeders with high reproductive capacity. Their behaviors result in altered nutrient cycles, shifts in trophic structures, and extirpation of some native species in systems where they...

As invasive zebra and quagga mussels ( Dreissena polymorpha and D. rostriformis bugensis, respectively), known as dreissenid mussels, continue their expansion throughout North America, the need to develop selective control tools has become critical for resource managers. Registered molluscicides for dreissenid control are limited, and often must be applied within or under a barrier to achieve...

USGS researchers are investigating novel methods for the use of copper in dreissenid mussel (zebra and quagga mussels) control. Our research includes laboratory assays and field applications with a focus on understanding influences on efficacy and quantifying nontarget impacts. Our research has been and is conducted in collaboration with academic institutions, such as the University of Minnesota’s...

Nitrogen and phosphorus are plant essential nutrients that are currently in excess in many aquatic ecosystems due to runoff from urban and agricultural areas. In high amounts, these nutrients are detrimental to aquatic ecosystem health, because elevated nutrients promote excessive growth or “blooms” of algae and other nuisance species. Many species that cause blooms can produce toxins which are...

Nutrients lost from agricultural areas in watersheds of the Great Lakes cause harmful algal blooms and hypoxia in some areas of the Great Lakes. Substantial efforts are being made in these watersheds to reduce the amount of nutrients entering the streams and rivers; however, additional work is needed to further reduce nutrient loads to meet international water quality standards. Limited research...

Rivers have a natural capacity to improve water quality when they are connected to their natural floodplains and are not overloaded with sediment and nutrient runoff. Where rivers have been disconnected from their historical floodplains and channelized to eliminate backwater areas, increased flow and nutrient loads have contributed to local and downstream problems of excessive nutrient enrichment...