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Native fish sanctuaries of the Lower Colorado River: Cibola High Levee Pond Desert Pupfish Pond

Historically, the Colorado River was one of the most formidable rivers in the world. Each spring, melting snow from the mountains scoured the desert landscape moving millions of tons of sediment to the sea. The Grand Canyon lays testament to its erosive nature. Summer heat would bring seasonal droughts, reducing the river to a trickle impacting More...

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Relations between and among contaminant concentrations and biomarkers in black bass (Micropterus spp.) and common carp (Cyprinus carpio) from large U.S. rivers, 1995-2004

Environmental contaminant and biomarker monitoring data from major U.S. river basins were summarized for black bass (Micropterus spp.) and common carp (Cyprinus carpio) sampled over a nine year period. Cumulative frequency distributions revealed taxon differences for many organochlorine residue concentrations, elemental contaminant concentrations, More...

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Evaluation of Potentially Nonlethal Sampling Methods for Monitoring Mercury Concentrations in Smallmouth Bass (Micropterus dolomieu)

This project is an evaluation of three potentially nonlethal alternatives to fillet sampling for the determination of mercury (Hg) concentrations in smallmouth bass (Micropterus dolomieu) to monitor mercury concentrations in smallmouth bass (micropterus dolomieu) from six sites in southern Missouri were captured by electrofishing. Blood samples More...

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Biomonitoring of Environmental Status and Trends (BEST) Program: Environmental Contaminants, Health Indicators, and Reproductive Biomarkers in Fish from the Colorado River Basin

This report documents the spatial trends in the concentrations of accumulative contaminants and assesses the contaminant effects on the fish from the Colorado River Basin.

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Case of the Red Shiner: What Happens When a Fish Goes Bad?

The red shiner (Cyprinella lutrensis) is a hardy, widespread minnow native to the middle and southwestern United States and Mexico. Its native range encompasses the lowland tributaries of the Mississippi River and western Gulf slope drainages to the Rio Grande River. The red shiner peripherally occurs in the southeastern United States, inhabiting More...

  • Male red shiner in near-peak spawning coloration (46 mm Standard Length).

Asian Carp Invasion of the Upper Mississippi River System

The Long Term Resource Monitoring Program (LTRMP) has been collecting Asian carp from the Upper Mississippi River System (UMRS) and documenting changes in abundance and size structure. This research summary shows the annual increase in number of catches since 1990 and compares habitat type and collecting gear types to the percentage of catches.

  • Upper Mississippi River System and locations of Long Term Resource Monitoring Program trend analysis

Paddlefish Study Project

Paddlefish (Polyodon spathula) have been lost from four states and Canada, and 11 of 22 states within the remaining species range now list the paddlefish as endangered, threatened, or a species of special concern. Restoration of paddlefish populations is a shared goal of many state and federal agencies. UMESC scientists, in collaboration with the More...

  • Image of a Paddlefish (Polyodon spathula)

Salinity Tolerance of Hemichromis letourneuxi

The African jewelfish (Hemichromis letourneuxi) has been established in canals surrounding the Miami area since the 1960s. With changes in water delivery to the park, the species has recently (2000) entered Everglades National Park and expanded its range westward through Big Cypress National Preserve. Simultaneously, African jewelfish from a More...

  • African jewelfish (Hemichromis letourneuxi)

Effects of salinity on survival, growth and reproduction of non-native Nile tilapia (Oreochromis niloticus) from southern Mississippi

The Nile tilapia (Oreochromis niloticus) is commonly used in aquaculture worldwide. Feral populations exist in many regions where individuals escape culture and establish in natural habitats. In Mississippi, Nile tilapia are established in at least three distinct localities (fig. 1): the lower Pascagoula and Escatawpa river drainages, and a More...

  • Image of Nile tilapia (Oreochromis niloticus)

Bioaccumulation of Mercury by Fish and Fish-forage Organisms in Camp Far West Reservoir, Yuba and Placer Counties, California

Mercury contamination from historic gold mining operations is widespread in many rivers, lakes, and reservoirs on the western slopes of the Sierra Nevada. A multidisciplinary investigation by USGS is attempting to better understand mercury dynamics and to identify hot spots within Camp Far West Reservoir in order to determine if remediation More...

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Persistence of organochlorine chemical residues in fish from the Tombigbee River (Alabama, USA): Continuing risk to wildlife from a former DDT manufacturing facility

Organochlorine pesticide and total polychlorinated biphenyl (PCB) concentrations were measured in largemouth bass from the Tombigbee River near a former DDT manufacturing facility at McIntosh, Alabama. Concentrations of DDT isomers in McIntosh bass remained unchanged from 1974 to 2004 and were four times greater than contemporary concentrations More...

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Effects of Swimming and Exhaustive Stess in Pacific Lamprey (Lampetra tridentata): Implications for Upstream Migrations Past Dams

This research summary reports on the decline of Pacific lampreys (Lampetra tridentata) in the Columbia River Basin. Their numbers have declined to only a remnant of their pre-1940's populations. One factor that could be detrimental to lamprey production is the amount of energy they expend negotiating upstream fish passage facilities at dams. An More...

  • Aerial view of Bonneville Dam