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At least 919 records · Page 51Linked to original sources
USGS2015

Fishes of the Blackwater River Drainage, Tucker County, West Virginia

The Blackwater River, a tributary of the upper Cheat River of the Monongahela River, hosts a modest fish fauna. This relatively low diversity of fish species is partly explained by its drainage history. The Blackwater was once part of the prehistoric, northeasterly flowing St. Lawrence River. During the Pleistocene Epoch, the fauna was significantly affected by glacial advance and by proglacial lakes and their associated overflows. After the last glacial retreat, overflow channels, deposits, and scouring altered drainage courses and connected some of the tributaries of the ancient Teays and Pittsburgh drainages. These major alterations allowed the invasion of fishes from North America's more species-rich southern waters. Here we review fish distributions based on 67 surveys at 34 sites within the Blackwater River drainage, and discuss the origin and status of 37 species. Within the Blackwater River watershed, 30 species (20 native, 10 introduced) have been reported from upstream of Blackwater Falls, whereas 29 (26 native, 3 introduced) have been documented below the Falls. Acid mine drainage, historic lumbering, and human encroachment have impacted the Blackwater's ichthyofauna. The fishes that have been most affected are Salvelinus fontinalis (Brook Trout), Clinostomus elongatus (Redside Dace), Nocomis micropogon (River Chub), Hypentelium nigricans (Northern Hog Sucker), Etheostoma flabellare (Fantail Darter), and Percina maculata (Blackside Darter). The first two species incurred range reductions, whereas the latter four were probably extirpated. In the 1990s, acid remediation dramatically improved the water quality of the river below Davis. Recent surveys in the lower drainage revealed 15 fishes where none had been observed since at least the 1940s; seven of these ( Cyprinella spiloptera [Spotfin Shiner], Luxilus chrysocephalus [Striped Shiner], Notropis photogenis [Silver Shiner], N. rubellus [Rosyface Shiner]; Micropterus dolomieu [Smallmouth Bass]; and Etheostoma camurum [Bluebreast Darter] and E. variatum [Variegate Darter]) represent additions to the faunal list of the Blackwater River.

West Virginia↗
USGS2001

Flow and habitat effects on juvenile fish abundance in natural and altered flow regimes

Conserving biological resources native to large river systems increasingly depends on how flow-regulated segments of these rivers are managed. Improving management will require a better understanding of linkages between river biota and temporal variability of flow and instream habitat. However, few studies have quantified responses of native fish populations to multiyear (>2 yr) patterns of hydrologic or habitat variability in flow-regulated systems. To provide these data, we quantified young-of-year (YOY) fish abundance during four years in relation to hydrologic and habitat variability in two segments of the Tallapoosa River in the southeastern United States. One segment had an unregulated flow regime, whereas the other was flow-regulated by a peak-load generating hydropower dam. We sampled fishes annually and explored how continuously recorded flow data and physical habitat simulation models (PHABSIM) for spring (April-June) and summer (July-August) preceding each sample explained fish abundances. Patterns of YOY abundance in relation to habitat availability (median area) and habitat persistence (longest period with habitat area continuously above the long-term median area) differed between unregulated and flow-regulated sites. At the unregulated site, YOY abundances were most frequently correlated with availability of shallow-slow habitat in summer (10 species) and persistence of shallow-slow and shallow-fast habitat in spring (nine species). Additionally, abundances were negatively correlated with 1-h maximum flow in summer (five species). At the flow-regulated site, YOY abundances were more frequently correlated with persistence of shallow-water habitats (four species in spring; six species in summer) than with habitat availability or magnitude of flow extremes. The associations of YOY with habitat persistence at the flow-regulated site corresponded to the effects of flow regulation on habitat patterns. Flow regulation reduced median flows during spring and summer, which resulted in median availability of shallow-water habitats comparable to the unregulated site. However, habitat persistence was severely reduced by flow fluctuations resulting from pulsed water releases for peak-load power generation. Habitat persistence, comparable to levels in the unregulated site, only occurred during summer when low rainfall or other factors occasionally curtailed power generation. As a consequence, summer-spawning species numerically dominated the fish assemblage at the flow-regulated site; five of six spring-spawning species occurring at both study sites were significantly less abundant at the flow-regulated site. Persistence of native fishes in flow-regulated systems depends, in part, on the seasonal occurrence of stable habitat conditions that facilitate reproduction and YOY survival.

Alabama, Georgia↗
USGS2001

Effects of a test flood on fishes of the Colorado River in Grand Canyon, Arizona

A beach/habitat-building flow (i.e., test flood) of 1274 m 3 /s, released from Glen Canyon Dam down the Colorado River through Grand Canyon, had little effect on distribution, abundance, or movement of native fishes, and only short-term effects on densities of some nonnative species. Shoreline and backwater catch rates of native fishes, including juvenile humpback chub ( Gila cypha ), flannelmouth suckers ( Catostomus latipinnis ), and bluehead suckers ( C. discobolus ), and all ages of speckled dace ( Rhinichthys osculus ), were not significantly different before and after the flood. Annual spring spawning migrations of flannelmouth suckers into the Paria River and endangered humpback chub into the Little Colorado River (LCR) took place during and after the flood, indicating no impediment to fish migrations. Pre-spawning adults staged in large slack water pools formed at the mouths of these tributaries during the flood. Net movement and habitat used by nine radio-tagged adult humpback chub during the flood were not significantly different from prior observations. Diet composition of adult humpback chub varied, but total biomass did not differ significantly before, during, and after the flood, indicating opportunistic feeding for a larger array of available food items displaced by the flood. Numbers of nonnative rainbow trout ( Oncorhynchus mykiss ) <152 mm total length decreased by ∼8% in electrofishing samples from the dam tailwaters (0–25 km downstream of the dam) during the flood. Increased catch rates in the vicinity of the LCR (125 km downstream of the dam) and Hell's Hollow (314 km downstream of the dam) suggest that these young trout were displaced downstream by the flood, although displacement distance was unknown since some fish could have originated from local populations associated with intervening tributaries. Abundance, catch rate, body condition, and diet of adult rainbow trout in the dam tailwaters were not significantly affected by the flood, and the flood did not detrimentally affect spawning success; catch of young-of-year increased by 20% in summer following the flood. Post-flood catch rates of nonnative fathead minnows ( Pimephales promelas ) in shorelines and backwaters, and plains killifish ( Fundulus zebrinus ) in backwaters decreased in the vicinity of the LCR, and fathead minnows increased near Hell's Hollow, suggesting that the flood displaced this nonnative species. Densities of rainbow trout and fathead minnows recovered to pre-flood levels eight months after the flood by reinvasion from tributaries and reproduction in backwaters. We concluded that the flood was of insufficient magnitude to substantially reduce populations of nonnative fishes, but that similar managed floods can disadvantage alien predators and competitors and enhance survival of native fishes.

Arizona↗
USGS2008

Evidence for fish dispersal from spatial analysis of stream network topology

Developing spatially explicit conservation strategies for stream fishes requires an understanding of the spatial structure of dispersal within stream networks. We explored spatial patterns of stream fish dispersal by evaluating how the size and proximity of connected streams (i.e., stream network topology) explained variation in fish assemblage structure and how this relationship varied with local stream size. We used data from the US Environmental Protection Agency's Environmental Monitoring and Assessment Program in wadeable streams of the Mid-Atlantic Highlands region (n = 308 sites). We quantified stream network topology with a continuous analysis based on the rate of downstream flow accumulation from sites and with a discrete analysis based on the presence of mainstem river confluences (i.e., basin area >250 km2) within 20 fluvial km (fkm) from sites. Continuous variation in stream network topology was related to local species richness within a distance of ???10 fkm, suggesting an influence of fish dispersal within this spatial grain. This effect was explained largely by catostomid species, cyprinid species, and riverine species, but was not explained by zoogeographic regions, ecoregions, sampling period, or spatial autocorrelation. Sites near mainstem river confluences supported greater species richness and abundance of catostomid, cyprinid, and ictalurid fishes than did sites >20 fkm from such confluences. Assemblages at sites on the smallest streams were not related to stream network topology, consistent with the hypothesis that local stream size regulates the influence of regional dispersal. These results demonstrate that the size and proximity of connected streams influence the spatial distribution of fish and suggest that these influences can be incorporated into the designs of stream bioassessments and reserves to enhance management efficacy. ?? 2008 by The North American Benthological Society.

Journal of the North American Benthological Societ↗
USGS2008

Fisheries and aquatic resources—fish health

Fish health research at Leetown had its origin in the 1930’s when the Leetown Fish Hatchery and Experiment Station was constructed. In 1978, the National Fish Health Research Laboratory, now a component of the Leetown Science Center, was established to solve emerging and known disease problems affecting fish and other aquatic organisms critical to species restoration programs. Center scientists develop methods for the isolation, detection, and identification of fish pathogens and for prevention and control of fish diseases.

Fact Sheet↗
USGS2018

Cooperative Fish and Wildlife Research Units Program—2017 year in review

The Cooperative Fish and Wildlife Research Units Program was involved in a number of notable events during 2017, many concerning our personnel. Dr. Barry Grand left his position as Leader of the Alabama Cooperative Fish and Wildlife Research Unit to become the Cooperative Units Program Supervisor for the South, replacing Dr. Kevin Whalen who took over as Supervisor for the West. We welcomed Dr. Sarah Converse who left the Patuxent Wildlife Research Center to become Leader of the Washington Cooperative Fish and Wildlife Research Unit. Dr. Amanda Rosenberger joined the Tennessee Cooperative Fishery Research Unit as Assistant Leader, transferring from the Missouri Cooperative Unit. Dr. Scott Carleton left his position as Assistant Unit Leader in New Mexico to become Chief of the Region 2 Migratory Bird Program of the U.S. Fish and Wildlife Service. We said farewell to many colleagues who retired. Their departure is bittersweet as we wish them health, happiness, and wellness in retirement. We will miss their companionship and the extraordinary contributions they have made to the Cooperative Fish and Wildlife Research Units Program and conservation. The Cooperative Fish and Wildlife Research Units Program has a record high number of vacant scientist positions due to a combination of retirements and base funding short-falls. These issues are affecting our ability to meet cooperator needs. Yet, we remain highly productive. For example, this year we released a report ( https://doi.org/10.3133/cir1427 ) containing abstracts of nearly 600 of our research projects, covering thematic areas ranging from advanced technologies to wildlife diseases. We provided highly competent, trained scientists and natural resource managers for our cooperators’ workforce. We delivered technical training and guidance to professional practitioners. We provided critical information to cooperators for decisions on species status assessments and management of species of greatest conservation need. This year we had an active presence at major national meetings, including the North American Wildlife and Natural Resources Conference where we co-sponsored a workshop on continuing education as a means to bridge the gap between science and management. During the coming year, with support from the U.S. Geological Survey and our cooperators, we intend to reduce the number of vacancies in the program. It will take time and active support of our cooperators to get back to full strength, but I am committed to this goal and encouraged by the resolve of our partners. We look forward to an even more productive year in 2018!

Circular↗
USGS2005

Host Fish Identification and Early Life Thermal Requirements for the Federal Endangered Winged Mapleleaf Mussel

The winged mapleleaf mussel (Quadrula fragosa, WML) is a Federal endangered species historically inhabiting at least 34 river systems in 12 Midwestern states. Only four populations are currently known to exist, including one confirmed reproducing population in the St. Croix National Scenic Riverway (NSR) bordering Minnesota and Wisconsin. Recovery efforts are limited by a lack of life history information, particularly which species of fish serve as host to the mussel's parasitic larvae (glochidia). Since 1997, biologists at the University of Minnesota have tried to identify host fish for the WML. Department of the Interior colleagues working in western Wisconsin at the U.S. Fish and Wildlife Service's La Crosse Fishery Resources Office and Genoa National Fish Hatchery, the National Park Service's St. Croix NSR, and the U.S. Geological Survey's Upper Midwest Environmental Sciences Center (UMESC) in La Crosse joined the team in 2001 to expand and accelerate the laboratory host fish identification program by making use of the well-equipped aquatic research facilities at UMESC. We report on several WML early life history investigations conducted at UMESC since autumn 2003 to identify suitable host fish species and evaluate thermal requisites for the development of glochidia into free-living juvenile mussels.

Fact Sheet↗
USGS2007

Determination of total mercury in fillets of sport fishes collected from Folsom and New Melones Reservoirs, California, 2004

This report presents the results of a study by the U.S. Geological Survey, done in cooperation with the U.S. Bureau of Reclamation, to determine mercury concentrations in selected sport fishes from Folsom and New Melones Reservoirs in California. Fillets were collected from each fish sample, and after homogenization and lyophilization of fish fillets, mercury concentrations were determined with a direct mercury analyzer utilizing the process of thermal combustion-gold amalgamation atomic absorption spectroscopy. Mercury concentrations in fish fillets from Folsom Reservoir ranged from 0.09 to 1.16 micrograms per gram wet weight, and from New Melones Reservoir ranged from 0.03 to 0.94 microgram per gram wet weight. Most of the fish fillets from Folsom Reservoir (87 percent) and 27 percent of the fillets from New Melones Reservoir exceeded the U.S. Environmental Protection Agency's fish consumption advisory of 0.30 microgram per gram wet weight.

Open-File Report↗
USGS2009

Composition of Age-0 Fish Assemblages in the Apalachicola River, River Styx, and Battle Bend, Florida

Light traps were used to sample the age-0 year class of fish communities in the Apalachicola River and associated floodplain water bodies of River Styx and Battle Bend, Florida, in 2006-2007. A total of 629 light traps were deployed during the spring and early summer months (341 between March 15 and June 6, 2006; 288 between March 9 and July 3, 2007). For combined years, 13.8 percent of traps were empty and a total of 20,813 age-0 fish were captured representing at least 40 taxa of 29 genera and 16 families. Trap catches were dominated by relatively few species, with the most abundant groups represented by cyprinids, centrarchids, percids, and catostomids. Six taxa accounted for about 80 percent of all fish collected: Micropterus spp. (28.9 percent), Notropis texanus (28.9 percent), Lepomis macrochirus (7.9 percent), Carpiodes cyprinus (6.2 percent), Cyprinidae sp. (4.6 percent), and Minytrema melanops (4.2 percent). Based on chronological appearance in light traps and catch-per-unit effort, including data from previous years of sampling, peak spawning periods for most species occurred between early March and mid-June. A complementary telemetry study of pre-reproductive adults of select target species (Micropterus spp., Lepomis spp., and M. melanops) revealed distinct patterns of habitat use, with some individual fish exclusively utilizing mainstem river habitat or floodplain habitat during spawning and post-spawning periods, and other individuals migrating between habitats. A comparison of light-trap catches between a pre-enhancement, high-water year (2003) and post-enhancement, low-water year (2007) for the oxbow at Battle Bend revealed some difference in community composition, with slightly greater values of diversity and evenness indices in 2007. Two dominant species, Lepomis macrochirus and Micropterus salmoides, were substantially greater in relative abundance among all age-0 fish collected in 2007 in comparison to 2003. Excavation of sediments at the mouth of Battle Bend improved river-floodplain connectivity during low flows such as occurred in 2007 and likely provided greater access and availability of fish spawning and nursery habitats.

Open-File Report↗
USGS2010

Colorado River fish monitoring in Grand Canyon, Arizona; 2000 to 2009 summary

Long-term fish monitoring in the Colorado River below Glen Canyon Dam is an essential component of the Glen Canyon Dam Adaptive Management Program (GCDAMP). The GCDAMP is a federally authorized initiative to ensure that the primary mandate of the Grand Canyon Protection Act of 1992 to protect resources downstream from Glen Canyon Dam is met. The U.S. Geological Survey's Grand Canyon Monitoring and Research Center is responsible for the program's long-term fish monitoring, which is implemented in cooperation with the Arizona Game and Fish Department, U.S. Fish and Wildlife Service, SWCA Environmental Consultants, and others. Electrofishing and tagging protocols have been developed and implemented for standardized annual monitoring of Colorado River fishes since 2000. In 2009, sampling occurred throughout the river between Lees Ferry and Lake Mead for 38 nights over two trips. During the two trips, scientists captured 6,826 fish representing 11 species. Based on catch-per-unit-effort, salmonids (for example, rainbow trout (Oncorhynchus mykiss) and brown trout (Salmo trutta)) increased eightfold between 2006 and 2009. Flannelmouth sucker (Catostomus latipinnis) catch rates were twice as high in 2009 as in 2006. Humpback chub (Gila cypha) catches were low throughout the 10-year sampling period.

Open-File Report↗
USGS2026

Summary of fish communities in Underwood Creek, Milwaukee, Wisconsin, April 2021

Portions of Underwood Creek in Milwaukee County, Wisconsin were reconstructed beginning in 2010 to allow for improved fish habitat and better management of streamflow during storm events. Four reaches of Underwood Creek were sampled in April 2021 for fish abundance by species to evaluate the status of fish communities after reconstruction efforts were completed. A total of 25 fish species were collected during the April 2021 sampling events. Reach D, a recently restored reach, contained the most fish species (14) and individuals (391). White suckers ( Catostomus commersonii ) were present in three of four reaches, fulfilling one of the success metrics outlined in the Underwood Creek restoration plan. Another success metric, collection of young of year northern pike ( Esox lucius ), was not met in this sampling event. However, spawning steelhead ( Oncorhynchus mykiss ) were observed in several reaches, indicating that reconstruction allowed for suitable habitat and passage for some migratory fish.

Wisconsin↗
USGS1996

Organochlorine compounds and trace elements in fish tissue and ancillary data for the Connecticut, Housatonic, and Thames river basins study unit, 1992-94

Concentrations of organochlorine compounds and trace elements were assayed in fish tissue collected from the Connecticut, Housatonic, and Thames River Basins Study Unit, 1992-94. These data were collected to determine the occurrence and distribution of organochlorine compounds and trace elements in the study unit. Ancillary data included are land-use categories by percentage of the sampling-site basins and the size, gender, and age of the individual fish collected for this study. Concentrations of 28 organochlorine compounds in composited whole fish samples were measured at 32 sites, and concentrations of 22 trace elements in composited fish liver samples were measured at 14 of the 32 sites. Most frequently detected organochlorines were DDT related compounds at 31 sites, total PCBs at 28 sites, and chlordane related compounds at 25 sites. Concentrations of total PCBs in fish tissue were generally higher at the large river sites than at the smaller tributary sites. Concentrations of chlordane-related compounds in fish tissue were higher at sites from more urbanized basins than at sites from predominately agriculture and forested basins. Concentrations of the DDT related compounds were undifferentiated among sites comprising different land uses. Trace elements detected at all 14 sites included boron, copper, iron, manganese, molybdenum, selenium, and zinc. Trace elements detected at 10 or more sites included arsenic, mercury, silver, strontium, and vanadium. Antimony, beryllium, and uranium were not detected at any site.

Open-File Report↗
USGS2005

Biomonitoring of Environmental Status and Trends (BEST) Program: Environmental contaminants and their effects on fish in the Columbia River Basin

This project examined and analyzed 560 fish representing eight species from 16 sites in the Columbia River Basin (CRB) from September 1997 to April 1998. Ten of the 16 sampling locations were historical National Contaminant Biomonitoring Program (NCBP) sites where organochlorine and elemental contaminants in fish had been monitored from 1969 through 1986. Five sites were co-located at U.S. Geological Survey (USGS)-National Stream Quality Accounting Network (NASQAN) stations at which water quality is monitored. The sampling location at Marine Park in Vancouver, Washington did not correspond to either of the established monitoring programs. Eight of the sampling locations were located on the Columbia River; three were on the Snake River; two were on the Willamette River, and one site was on each of the Yakima, Salmon and Flathead Rivers. Common carp ( Cyprinus carpio ), black basses ( Micropterus sp. ), and largescale sucker ( Catostomus macrocheilus ) together accounted for 80% of the fish sampled during the study. Fish were weighed and measured then field-examined for external and internal lesions, and liver, spleen, and gonads were weighed to compute somatic indices. Selected tissues and fluids were obtained and preserved for analysis of fish health and reproductive biomarkers. Composite samples of whole fish from each station were grouped by species and gender and analyzed for persistent organic and inorganic contaminants and for dioxin-like activity using H4IIE rat hepatoma cell bioassay.

Columbia River Basin↗
USGS2005

The fishes of Wilson's Creek National Battlefield, Missouri, 2003

An inventory of fishes of Wilson's Creek National Battlefield was conducted at eight sites on three streams, two springs, a pond, and within a cave. Fish were sampled using conventional electrofishing equipment during July 2003. Approximately 325 fish were collected and identified from five of the eight sampling sites. A total of 30 species of fish was collected from the eight sampling sites. The number of species collected at the sampling sites ranged from 0 to 23. Many of the 'most commonly' collected fish species are typical of Ozark streams. A preliminary expected species list incorrectly listed 12 species because of incorrect species range or habitat requirements. A thirteenth species (the Ozark cavefish, Amblyopsis rosae) is listed as 'unexpected.' However, this designation is uncertain because Ozark cavefish have been reported from several caves and springs in Greene County. Upon revising the list of expected species, the inventory yielded 30 of the 53 species (57 percent). Ten of the 30 fish species collected in this inventory previously had not been collected at Wilson's Creek National Battlefield. However, eight species collected in one or more of the two previous inventories were not collected in this effort. It is unknown if any change in environmental conditions has occurred that is responsible for the absence of these species. Although none of the species collected in this study are federally-listed threatened or endangered species, five species collected at Wilson's Creek National Battlefield may be of special interest to National Park Service managers and others because they are endemic to the Ozark Plateaus. The duskystripe shiner (Luxilus pilsbryi), Ozark bass (Ambloplites constellatus), Ozark chub (Erimystax harryi), and stippled darter (Etheostoma punctulatum) are common and found throughout much of the Ozark Plateaus. However, the Ozark sculpin (Cottus hypselurus) has a more limited range and more specific habitat requirements.

Scientific Investigations Report↗
USGS2005

The fishes of Pea Ridge National Military Park, Arkansas, 2003

A fish inventory was conducted at Pea Ridge National Military Park, Arkansas, during base-flow conditions in September 2003. Six sites including four streams and two ponds were sampled using conventional electrofishing equipment (a seine also was used at one site). There were 653 individuals collected comprising 18 species (plus 1 hybrid) and 15 genera. The number of species collected at the four stream sites ranged from 1 16. Most fish species collected generally are associated with small streams in the Ozark Plateaus. The two most common species were the banded sculpin and the southern redbelly dace. Three species and a sunfish hybrid were collected from the quarry pond. No fish were collected from the unnamed pond. A preliminary expected species list incorrectly listed 42 species because of incorrect species range or habitat requirements. One species not on the original list was added to the revised list. Upon revising this list, the inventory yielded 18 the 40 species (45 percent) and 1 hybrid. No previous fish inventories have been completed for park but some observations can be made relative to species distributions. There were only five fish species collected in three headwater streams, and it is unlikely that many other species would occur in these three streams because of constraints imposed on the fish community by stream size. Little Sugar Creek, a medium-sized stream, had the most species collected, and it is likely that additional species would be collected from this stream if additional sampling were to occur. Distribution records indicate that all 18 species occur in the general area. Although no species collected in this study are federallylisted threatened or endangered species, three species collected at Pea Ridge National Military Park may be of some special interest to National Park Service managers and others. Two the species collected (cardinal shiner and stippled darter) are endemic to the Ozark Plateaus; both are rather common in certain parts of the Ozark Plateaus. The white sucker has a restricted range in Arkansas because northern Arkansas is at southern edge of the white sucker's distributional range.

Scientific Investigations Report↗
USGS2006

Organic Compounds and Trace Elements in Fish Tissue and Bed Sediment in the Delaware River Basin, New Jersey, Pennsylvania, New York, and Delaware, 1998-2000

As part of the National Water-Quality Assessment (NAWQA) program activities in the Delaware River Basin (DELR), samples of fish tissue from 21 sites and samples of bed sediment from 35 sites were analyzed for a suite of organic compounds and trace elements. The sampling sites, within subbasins ranging in size from 11 to 600 square miles, were selected to represent 5 main land-use categories in the DELR -forest, low-agricultural, agricultural, urban, and mixed use. Samples of both fish tissue and bed sediment were also collected from 4 'large-river' sites that represented drainage areas ranging from 1,300 to 6,800 square miles, areas in which the land is used for a variety of purposes. One or more of the organochlorine compounds-DDT and chlordane metabolites, polychlorinated biphenyls (total PCBs), and dieldrin- were detected frequently in samples collected over a wide geographic area. One or more of these compounds were detected in fish-tissue samples from 92 percent of the sites and in bed-sediment samples from 82 percent of the sites. Concentrations of total DDT, total chlordanes, total PCBs, and dieldrin in whole white suckers and in bed sediment were significantly related to urban/industrial basin characteristics, such as percentage of urban land use and population density. Semi-volatile organic compounds (SVOCs)-total polycyclic aromatic hydrocarbons (PAHs), total phthalates, and phenols- were detected frequently in bed-sediment samples. All three types of SVOCs were detected in samples from at least one site in each land-use category. The highest detection rates and concentrations typically were in samples from sites in the urban and mixed land-use categories, as well as from the large-river sites. Concentrations of total PAHs and total phthalates in bed-sediment samples were found to be statistically related to percentages of urban land use and to population density in the drainage areas represented by the sampling sites. The samples of fish tissue and bed sediment collected throughout the DELR were analyzed for a large suite of trace elements, but results of the analyses for eight elements-arsenic, cadmium, chromium, copper, lead, nickel, mercury, and zinc- that are considered contaminants of concern are described in this report. One or more of the eight trace elements were detected in samples from every fish tissue and bed-sediment sampling site, and all of the trace elements were detected in samples from 97 percent of the bed-sediment sites. The concentrations of organic compounds and trace elements in the DELR samples were compared to applicable guidelines for the protection of wildlife and other biological organisms. Concentrations of total DDT, total chlordanes, total PCBs, and dieldrin in fish-tissue samples from 14 sites exceeded one or more of the Wildlife Protective Guidelines established by the New York State Department of Environmental Conservation. Concentrations of one or more organic compounds in samples from 16 bed-sediment sites exceeded the Threshold Effects Concentrations (TEC) of the Canadian Sediment Quality Guidelines, and concentrations of one or more of the eight trace elements in samples from 38 bed-sediment sites exceeded the TEC. (The TEC is the concentration below which adverse biological effects in freshwater ecosystems are expected to be rare.) Concentrations of organic compounds in samples from some bed-sediment sites exceeded the Canadian Probable Effects Concentrations (PEC), and concentrations of trace elements in samples from 18 sites exceeded the PEC. (The PEC is the concentration above which adverse effects to biological organisms are expected to occur frequently). Concentrations of organic compounds and trace elements in samples from the DELR were compared to similar data from other NAWQA study units in the northeastern United States and also data from the Mobile River (Alabama) Basin and the Northern Rockies Intermontane Basin study units. Median concentrations of to

Scientific Investigations Report↗
USGS2010

Polychlorinated biphenyls in aquatic invertebrates and fish and observations about nitrogen and carbon isotope composition in relation to trophic structure and bioaccumulation patterns, Lake Worth and Meandering Road Creek, Fort Worth, Texas, 2007-08

During 2007-08 the U.S. Geological Survey, in cooperation with the U.S. Air Force, evaluated the concentration of polychlorinated biphenyls (PCBs) in aquatic invertebrates and fish from one site in the main body of Lake Worth, two sites in a small inlet in Lake Worth (upper and lower Woods Inlet), and one site in Meandering Road Creek in Fort Worth, Texas. The four sites sampled during 2007-08 were located at or near sites where surficial bed-sediment samples had been collected and analyzed for PCBs during previous U.S. Geological Survey studies so that PCB concentrations in aquatic invertebrates and fish and PCB concentrations in surficial bed-sediment samples could be compared. Stable nitrogen and carbon isotopes were used to help assess differences in the amount of these isotopes by species and sampling location. The sum of 15 PCB-congener concentrations was highest for aquatic invertebrates and fish from the upper Woods Inlet site and lowest for the same aquatic invertebrates and fish from Lake Worth site, where PCBs historically had not been detected in lake bed sediment. An increase in the ratio of the heavier nitrogen-15 (15N) isotope to the lighter nitrogen-14 (14N) isotope, referred to as enrichment of 15N, was highest in largemouth bass (representing the highest trophic level sampled) at all sites and lowest for true midge larvae inhabiting surficial bed sediment in the lake (representing the lowest trophic level sampled). Enrichment of 15N was less variable in largemouth bass and other fish from the highest trophic level compared with shorter lived, primary consumer invertebrates from lower trophic levels, such as true midge larvae, mayfly nymphs, and zooplankton. The delta carbon-13 (delta13C) values measured in true midge larvae collected at the Lake Worth and upper and lower Woods Inlet sites were more negative compared with the delta13C values measured for all other taxa, indicating true midge larvae were more depleted of carbon-13 (13C) compared with all other aquatic invertebrate and fish. The relative depletion of 13C might indicate the carbon sources consumed by true midge larvae are different from the carbon sources consumed by all other taxon that were sampled. Ratios of stable nitrogen isotopes nitrogen-15 to nitrogen-14 (delta15N) were similar between taxa from the Lake Worth site and Woods Inlet sites. The sum of 15 PCB-congener concentrations, however, was an order of magnitude higher in largemouth bass from the upper Woods Inlet site, indicating that PCB-congener concentrations in lake bed sediment likely controls biomagnification within the lake because of the similarities in trophic structure of the resident aquatic community. The biota at the Lake Worth reference site, where PCBs were not detected in the surficial sediment during previous studies, were less contaminated than the biota at sites where PCBs had been detected in the surficial sediment. The highest trophic-level consumers (as evidenced by the most 15N-enriched delta15N values) showed the maximum bioaccumulation.

Lake Worth↗
USGS2017

Egg deposition by lithophilic-spawning fishes in the Detroit and Saint Clair Rivers, 2005–14

A long-term, multiseason, fish egg sampling program conducted annually on the Detroit (2005–14) and Saint Clair (2010–14) Rivers was summarized to identify where productive fish spawning habitat currently exists. Egg mats were placed on the river bottom during the spring and fall at historic spawning areas and candidate fish spawning habitat restoration sites throughout both rivers. Widespread evidence was found of lithophilic spawning by numerous native fish species, including walleye ( Sander vitreus ), lake whitefish ( Coregonus clupeaformis ), lake sturgeon ( Acipenser fulvescens ), suckers (Catostomidae spp.), and trout-perch ( Percopsis omiscomaycus ). Walleye, lake whitefish, and suckers spp. spawned in nearly every region of each river in all years on both reef and nonreef substrates. Lake sturgeon eggs were collected almost exclusively over constructed reefs. Catch-per-unit effort of walleye, lake whitefish, and sucker eggs was much greater in the Detroit River than in the Saint Clair River, while Saint Clair River sites supported the greatest collections of lake sturgeon eggs. Collections during this study of lake sturgeon eggs on man-made spawning reefs suggest that artificial reefs may be an effective tool for restoring fish populations in the Detroit and Saint Clair Rivers; however, the quick response of lake sturgeon to spawn on newly constructed reefs and the fact that walleye, lake whitefish, and sucker eggs were often collected over substrate with little interstitial space to protect eggs from siltation and predators suggests that lack of suitable spawning habitat may continue to limit reproduction of lithophilic-spawning fish species in the Saint Clair-Detroit River System.

Michigan↗