Evaluation of the Efficacy of Iodophor Disinfection of Walleye and Northern Pike Eggs to Eliminate Viral Hemorrhagic Septicemia Virus

USGS Publications Warehouse

Tuttle-Lau, M.T.; Phillips, K.A.; Gaikowski, M.P.

2009-01-01

Viral hemorrhagic septicemia virus (VHSv) is a serious fish pathogen that has been responsible for large-scale fish kills in the Great Lakes since 2005. It causes high mortality and resulting outbreaks have severe economic consequences for aquaculture. Iodophor disinfection of salmonid eggs is a standard hatchery practice to reduce the risk of pathogen transfer during gamete collection ('spawning') operations and is thus a leading candidate for reducing VHSv transmission during and after spawning of nonsalmonid fishes. However, before it is incorporated by hatcheries during nonsalmonid fish spawning efforts, its safety and effectiveness needs to be evaluated. The USGS Fact Sheet 2009-3107, 'Evaluation of the Efficacy of Iodophor Disinfection of Walleye and Northern Pike Eggs to Eliminate Viral Hemorrhagic Septicemia Virus' presents the results of a study to assess the effectiveness of iodophor disinfection for eliminating VHSv (strain IVb) from fertilized eggs of walleye and northern pike intentionally challenged with VHSv following egg fertilization. Walleye and northern pike egg survival (hatch) following iodophor egg disinfection also was assessed.

Latitudinal comparisons of walleye growth in North America and factors influencing growth of walleyes in Kansas reservoirs

USGS Publications Warehouse

Quist, M.C.; Guy, C.S.; Schultz, R.D.; Stephen, J.L.

2003-01-01

We compared the growth of walleyes Stizostedion vitreum in Kansas to that of other populations throughout North America and determined the effects of the abundance of gizzard shad Dorosoma cepedianum and temperature on the growth of walleyes in Kansas reservoirs. Age was estimated from scales and otoliths collected from walleyes (N = 2,072) sampled with gill nets from eight Kansas reservoirs during fall in 1991-1999. Age-0 gizzard shad abundance was indexed based on summer seining information, and temperature data were obtained from the National Oceanic and Atmospheric Administration. Parameter estimates of von Bertalanffy growth models indicated that the growth of walleyes in Kansas was more similar to that of southern latitude populations (e.g., Mississippi and Texas) than to that of northern (e.g., Manitoba, Minnesota and South Dakota) or middle latitude (e.g., Colorado and Iowa) populations. Northern and middle latitude populations had lower mean back-calculated lengths at age 1, lower growth coefficients, and greater longevity than southern and Kansas populations. A relative growth index (RGI; [Lt/Ls ] ?? 100, where Lt is the observed length at age and Ls is the age-specific standard length derived from a pooled von Bertalanffy growth model) and standardized percentile values (percentile values of mean back-calculated lengths at age) indicated that the growth of walleyes in Kansas was above average compared with that of other populations in North America. The annual growth increments of Kansas walleyes were more variable among years than among reservoirs. The growth increments of age-0 and age-1 walleyes were positively related to the catch rates of gizzard shad smaller than 80 mm, whereas the growth of age-2 and age-3 walleyes was inversely related to mean summer air temperature. Our results provide a framework for comparing North American walleye populations, and our proposed RGI provides a simple, easily interpreted index of growth.

Functional response and capture timing in an individual-based model: predation by northern squawfish (Ptychocheilus oregonensis) on juvenile salmonids in the Columbia River

USGS Publications Warehouse

Petersen, James H.; DeAngelis, Donald L.

1992-01-01

The behavior of individual northern squawfish (Ptychocheilus oregonensis) preying on juvenile salmonids was modeled to address questions about capture rate and the timing of prey captures (random versus contagious). Prey density, predator weight, prey weight, temperature, and diel feeding pattern were first incorporated into predation equations analogous to Holling Type 2 and Type 3 functional response models. Type 2 and Type 3 equations fit field data from the Columbia River equally well, and both models predicted predation rates on five of seven independent dates. Selecting a functional response type may be complicated by variable predation rates, analytical methods, and assumptions of the model equations. Using the Type 2 functional response, random versus contagious timing of prey capture was tested using two related models. ln the simpler model, salmon captures were assumed to be controlled by a Poisson renewal process; in the second model, several salmon captures were assumed to occur during brief "feeding bouts", modeled with a compound Poisson process. Salmon captures by individual northern squawfish were clustered through time, rather than random, based on comparison of model simulations and field data. The contagious-feeding result suggests that salmonids may be encountered as patches or schools in the river.

System-Wide Significance of Predation on Juvenile Salmonids in the Columbia and Snake River Reservoirs : Annual Report of Research 1991.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Shively, R.S.

1991-01-01

We indexed consumption rates of northern squawfish (Ptychoch oregonensis) preying upon juvenile salmonids in four lower Snake River reservoirs. Stomach contents were also collected from smallmouth bass (Micropterus dolomieui), channel catfish (Ictaluris gunctatus), and walleye (Stizostedion vitreum). Northern squawfish digestive tracts were analyzed and the overall diet (% weight) was dominated by fish and crustaceans. Examination of stomach contents smallmouth bass showed that crustaceans (primarily crayfish) dominated their diets. Overall, the consumption rate of juvenile salmonids by smallmouth bass was low. The northern squawfish consumption index (CI) at Snake River locations ranged from zero at all mid-reservoir locations to 1.2more » at Lower Granite forebay. In John Day Reservoir, CI values ranged from 0.5 to 1.9 in May and from 0.9 to 3.0 in July. Consumption index values were highest in forebay and tailrace areas, and were slightly higher in BRZs than in non-restricted zones.« less

The role of density dependence in growth patterns of ceded territory walleye populations of northern Wisconsin: Effects of changing management regimes

USGS Publications Warehouse

Sass, G.G.; Hewett, S.W.; Beard, T.D.; Fayram, A.H.; Kitchell, J.F.

2004-01-01

We assessed density-related changes in growth of walleye Sander vitreus in the ceded territory of northern Wisconsin from 1977 to 1999. We used asymptotic length (Lz), growth rate near t0 (??), and body condition as measures of walleye growth to determine the relationship between growth and density. Among lakes, there was weak evidence of density-dependent growth: adult density explained only 0-6% of the variability in the growth metrics. Within lakes, growth was density dependent. Lz, ??, and body condition of walleyes changing with density for 69, 28, and 62% of the populations examined, respectively. Our results suggest that walleye growth was density dependent within individual lakes. However, growth was not coherently density dependent among lakes, which was possibly due to inherent differences in the productivity, surface area, forage base, landscape position, species composition, and management regime of lakes in the ceded territory. Densities of adult walleyes averaged 8.3 fish/ha and did not change significantly during 1990-1999. Mean Lz and body condition of walleyes were signilicantly higher before 1990 than after 1990, which may indicate an increase in density due to changes in management regimes. The observed growth changes do not appear to be a consequence of the statewide 15-in minimum size limit adopted in 1990 but rather a response to the treaty rights management regime. We conclude that walleye growth has the potential to predict regional-scale adult walleye densities if lake-specific variables are included in a model to account for regional-scale differences among walleye populations and lakes.

Impacts of Daily Bag Limit Reductions on Angler Effort in Wisconsin Walleye Lakes

USGS Publications Warehouse

Beard, T.D.; Cox, S.P.; Carpenter, S.R.

2003-01-01

Angler effort is an important factor affecting recreational fisheries. However, angler responses are rarely incorporated into recreational fisheries regulations or predictions. Few have attempted to examine how daily bag limit regulations affect total angling pressure and subsequent stock densities. Our paper develops a theoretical basis for predicting angler effort and harvest rate based on stock densities and bag limit regulations. We examined data from a management system that controls the total exploitation of walleyes Sander vitreus (formerly Stizostedion vitreum) in northern Wisconsin lakes and compared these empirical results with the predictions from a theoretical effort and harvest rate response model. The data indicated that higher general angler effort occurs on lakes regulated with a 5-walleye daily limit than on lakes regulated with either a 2- or 3-walleye daily limit. General walleye catch rates were lower on lakes with a 5-walleye limit than on lakes with either a 2- or 3-walleye daily limit. An effort response model predicted a logarithmic relationship between angler effort and adult walleye density and that an index of attractiveness would be greater on lakes with high bag limits. Predictions from the harvest rate model with constant walleye catchability indicated that harvest rates increased nonlinearly with increasing density. When the effort model was fitted to data from northern Wisconsin, we found higher lake attractiveness at 5-walleye-limit lakes. We conclude that different groups of anglers respond differently to bag limit changes and that reliance on daily bag limits may not be sufficient to maintain high walleye densities in some lakes in this region.

Factors influencing mercury concentrations in walleyes in northern Wisconsin lakes

USGS Publications Warehouse

Wiener, J.G.; Martini, R.E.; Sheffy, T.B.; Glass, G.E.

1990-01-01

The authors examined relations between mercury concentrations in walleyes Stizostedion vitreum and the characteristics of clear-water Wisconsin lakes, which spanned a broad range of pH values (5.0-8.1) and acid- neutralizing capacities (-9 to 1,017 mu eq/L). Total concentrations of mercury in axial muscle tissue of walleyes (total length, 25-56 cm) varied from 0.12 to 1.74 mu g/g wet weight. Concentrations were greatest in fish from the eight lakes with pH less than 7.0; concentrations in these fish equaled or exceeded 0.5 mu g/g in 88% of the samples analyzed and 1.0 mu g/g in 44%. In the five lakes with pH of 7.0 and above, concentrations exceeded 0.5 mu g/g in only 1 of 21 walleyes. Multiple regression revealed that lake pH and total length of fish accounted for 69% of the variation in mercury concentration in walleyes. Regression models with total length and either waterborne calcium or acid-neutralizing capacity as independent variables accounted for 67% of the variation in concentration.

Do water level fluctuations influence production of walleye and yellow perch young-of-the-year in large northern lakes?

USGS Publications Warehouse

Larson, James H.; Staples, David F.; Maki, Ryan P.; Vallazza, Jon M.; Knights, Brent C.; Peterson, Kevin E.

2016-01-01

Many ecological processes depend on the regular rise and fall of water levels (WLs), and artificial manipulations to WL regimes can impair important ecosystem services. Previous research has suggested that differences in WL between late summer and early spring may alter the suitability of shoals used by Walleyes Sander vitreus for spawning. Other species, such as the Yellow Perch Perca flavescens, are unlikely to be affected in the same way by WL fluctuations because their spawning requirements are quite different. We used 11–23 years of data from six northern Minnesota lakes to assess the effects of WL fluctuations on the abundances of young-of-the-year (age-0) Walleyes and Yellow Perch. In two lakes (Rainy Lake and Lake Kabetogama), a change in WL management occurred in 2000, after which these lakes saw increased age-0 Walleye abundance, while the other study lakes experienced decreases or no change. Rainy Lake and Lake Kabetogama also had increases in age-0 Yellow Perch, but another study lake did also. We used partial least-squares regression to assess whether WL metrics were associated with variation in age-0 Walleye and Yellow Perch abundances, but WL metrics were seldom associated with age-0 abundance for either species. Our analysis suggested a potential influence of WL regulation on age-0 Walleye abundance, but we found no evidence that early spring access to spawning shoals was the mechanism by which this occurred.

Relationships among walleye population characteristics and genetic diversity in northern Wisconsin Lakes

USGS Publications Warehouse

Waterhouse, Matthew D.; Sloss, Brian L.; Isermann, Daniel A.

2014-01-01

The maintenance of genetic integrity is an important goal of fisheries management, yet little is known regarding the effects of management actions (e.g., stocking, harvest regulations) on the genetic diversity of many important fish species. Furthermore, relationships between population characteristics and genetic diversity remain poorly understood. We examined relationships among population demographics (abundance, recruitment, sex ratio, and mean age of the breeding population), stocking intensity, and genetic characteristics (heterozygosity, effective number of alleles, allelic richness, Wright's inbreeding coefficient, effective population size [Ne], mean d2 [a measure of inbreeding], mean relatedness, and pairwise population ΦST estimates) for 15 populations of Walleye Sander vitreus in northern Wisconsin. We also tested for potential demographic and genetic influences on Walleye body condition and early growth. Combinations of demographic variables explained 47.1–79.8% of the variation in genetic diversity. Skewed sex ratios contributed to a reduction in Ne and subsequent increases in genetic drift and relatedness among individuals within populations; these factors were correlated to reductions in allelic richness and early growth rate. Levels of inbreeding were negatively related to both age-0 abundance and mean age, suggesting Ne was influenced by recruitment and generational overlap. A negative relationship between the effective number of alleles and body condition suggests stocking affected underlying genetic diversity of recipient populations and the overall productivity of the population. These relationships may result from poor performance of stocked fish, outbreeding depression, or density-dependent factors. An isolation-by-distance pattern of genetic diversity was apparent in nonstocked populations, but was disrupted in stocked populations, suggesting that stocking affected genetic structure. Overall, demographic factors were related to genetic

Validation of a side-scan sonar method for quantifying walleye spawning habitat availability in the littoral zone of northern Wisconsin Lakes

USGS Publications Warehouse

Richter, Jacob T.; Sloss, Brian L.; Isermann, Daniel A.

2016-01-01

Previous research has generally ignored the potential effects of spawning habitat availability and quality on recruitment of Walleye Sander vitreus, largely because information on spawning habitat is lacking for many lakes. Furthermore, traditional transect-based methods used to describe habitat are time and labor intensive. Our objectives were to determine if side-scan sonar could be used to accurately classify Walleye spawning habitat in the nearshore littoral zone and provide lakewide estimates of spawning habitat availability similar to estimates obtained from a transect–quadrat-based method. Based on assessments completed on 16 northern Wisconsin lakes, interpretation of side-scan sonar images resulted in correct identification of substrate size-class for 93% (177 of 191) of selected locations and all incorrect classifications were within ± 1 class of the correct substrate size-class. Gravel, cobble, and rubble substrates were incorrectly identified from side-scan images in only two instances (1% misclassification), suggesting that side-scan sonar can be used to accurately identify preferred Walleye spawning substrates. Additionally, we detected no significant differences in estimates of lakewide littoral zone substrate compositions estimated using side-scan sonar and a traditional transect–quadrat-based method. Our results indicate that side-scan sonar offers a practical, accurate, and efficient technique for assessing substrate composition and quantifying potential Walleye spawning habitat in the nearshore littoral zone of north temperate lakes.

Diet overlap and predation between largemouth bass and walleye in Wisconsin lakes using DNA barcoding to improve taxonomic resolution

USGS Publications Warehouse

Kelling, Craig J.; Isermann, Daniel A.; Sloss, Brian L.; Turnquist, Keith N.

2016-01-01

Over the last decade, the abundance of Largemouth Bass Micropterus salmoides has increased in many northern Wisconsin lakes, causing concern among anglers and biologists regarding the potential for Largemouth Bass to negatively affect populations of Walleye Sander vitreus through predation or competition for prey. Our objectives were to determine whether (1) diet overlap and predation occurred between adult Walleyes and Largemouth Bass in four northern Wisconsin lakes and (2) the use of DNA barcoding to reduce unidentifiable fish in diet samples affected conclusions regarding diet overlap. A single occurrence of Walleye predation was observed in the diets of 945 Largemouth Bass. Moderate to high diet overlap was observed between Largemouth Bass and Walleyes throughout much of the study period. The use of DNA barcoding reduced the amount of unidentified fish in diets to <1% and showed that failure to identify fish or fish parts can affect conclusions regarding diet overlap. Largemouth Bass predation is probably not a primary factor affecting Walleye abundance in the lakes we selected, but observed diet overlap suggests the potential for competition between the two species.

Temporal trends of mercury concentrations in Wisconsin walleye (Sander vitreus), 1982-2005.

PubMed

Rasmussen, Paul W; Schrank, Candy S; Campfield, Patrick A

2007-11-01

The Wisconsin Department of Natural Resources has monitored mercury (Hg) in several species of fish since the early 1970s primarily for fish consumption advisory purposes. We selected skin-on fillets of walleye (Sander vitreus) from inland lakes collected over the years 1982-2005 to assess temporal trends of Hg concentrations. While individual lakes are of interest, sample sizes, and unbalanced collections across fish lengths, seasons, or years prevent estimates of temporal trends of walleye Hg concentrations within most lakes. We evaluated temporal trends over all lakes using mixed effects models (3,024 records from 421 lakes). Relationships between Hg concentrations and a suite of lake chemistry, morphometry, and other variables were also explored. Hg concentrations generally increased with walleye length but the relationship varied among lakes. The best-fitting mixed effects models suggested that the overall rate of change in walleye Hg across all lakes in the dataset varied with latitude. Hg in walleye decreased 0.5% per year in northern lakes, increased 0.8% in southern lakes, and remained constant in middle latitude lakes over the period of 1982-2005. Season of collection was also an important predictor variable. Hg concentrations were highest in walleye captured in the spring and lowest in the fall. Other variables such as gender, lake area, and total alkalinity were also important predictors.

Influence of Physiochemical and watershed characteristics on mercury concentration in walleye, Sander vitreus, M.

USGS Publications Warehouse

Hayer, Cari-Ann; Chipps, Steven R.; Stone, James J.

2011-01-01

Elevated mercury concentration has been documented in a variety of fish and is a growing concern for human consumption. Here, we explore the influence of physiochemical and watershed attributes on mercury concentration in walleye (Sander vitreus, M.) from natural, glacial lakes in South Dakota. Regression analysis showed that water quality attributes were poor predictors of walleye mercury concentration (R2 = 0.57, p = 0.13). In contrast, models based on watershed features (e.g., lake level changes, watershed slope, agricultural land, wetlands) and local habitat features (i.e., substrate composition, maximum lake depth) explained 81% (p = 0.001) and 80% (p = 0.002) of the variation in walleye mercury concentration. Using an information theoretic approach we evaluated hypotheses related to water quality, physical habitat and watershed features. The best model explaining variation in walleye mercury concentration included local habitat features (Wi = 0.991). These results show that physical habitat and watershed features were better predictors of walleye mercury concentration than water chemistry in glacial lakes of the Northern Great Plains.

A population genetic window into the past and future of the walleye Sander vitreus: relation to historic walleye and the extinct “blue pike” S. v. “glaucus”

PubMed Central

2014-01-01

Background Conserving genetic diversity and local adaptations are management priorities for wild populations of exploited species, which increasingly are subject to climate change, habitat loss, and pollution. These constitute growing concerns for the walleye Sander vitreus, an ecologically and economically valuable North American temperate fish with large Laurentian Great Lakes' fisheries. This study compares genetic diversity and divergence patterns across its widespread native range using mitochondrial (mt) DNA control region sequences and nine nuclear DNA microsatellite (μsat) loci, examining historic and contemporary influences. We analyze the genetic and morphological characters of a putative endemic variant– “blue pike” S. v. “glaucus” –described from Lakes Erie and Ontario, which became extinct. Walleye with turquoise-colored mucus also are evaluated, since some have questioned whether these are related to the “blue pike”. Results Walleye populations are distinguished by considerable genetic divergence (mean FST mtDNA = 0.32 ± 0.01, μsat = 0.13 ± 0.00) and substantial diversity across their range (mean heterozygosity mtDNA = 0.53 ± 0.02, μsat = 0.68 ± 0.03). Southern populations markedly differ, possessing unique haplotypes and alleles, especially the Ohio/New River population that houses the oldest haplotype and has the most pronounced divergence. Northern formerly glaciated populations have greatest diversity in Lake Erie (mean heterozygosity mtDNA = 0.79 ± 0.00, μsat = 0.72 ± 0.01). Genetic diversity was much less in the historic Lake Erie samples from 1923–1949 (mean heterozygosity mtDNA = 0.05 ± 0.01, μsat = 0.47 ± 0.06) than today. The historic “blue pike” had no unique haplotypes/alleles and there is no evidence that it comprised a separate taxon from walleye. Turquoise mucus walleye also show no genetic differentiation from other sympatric walleye and

Recent changes in the walleye fishery of northern Green Bay and history of the 1943 year class

USGS Publications Warehouse

Pycha, Richard L.

1961-01-01

Production, fishing intensity, and availability of walleyes (Stizostedion vitreum vitreum) fluctuated widely in the commercial fishery of northern Green Bay in 1929-57. The catch ranged from 16,000 pounds (8 percent of average for the 1929-53 base period) in 1942 to 1,294,000 pounds (633 percent) in 1950. The index of fishing intensity ranged from 17 (1941) to 400 (1950) and that of abundance from 47 (1929) to 222 (1955). Production and fishing intensity were consistently above average in 1947-57; abundance exceeded the average in 8 of these years. The fishery statistics and records of age and size composition of commercial landings of walleyes in the spring and fall fishing seasons of 1949-58 (scale samples were taken from a total of 1,631 fish) were the basis for a study of recent changes in the walleye fishery with particular reference to the effects of fluctuations in the strength of year classes. The 1943 year class, by a wide margin, exceeded all others in the estimated total number (1,173,000 fish) and weight (3,355,000 pounds) contributed to commercial landings. This year class was a major factor in the sharp rise in production and abundance after 1945 and the all-time record catch of 1950. In contrast, certain other year classes (1945, 1946, 1948) have contributed totals as small as 16,000 to 52,000 pounds. The abundance of the 1950, 1951, and 1952 year classes approached or exceeded that of the 1943 year class at the lesser ages (through the IV group), but these more recent classes disappeared from the fishery so rapidly that their total contributions were relatively low. The indicated increase of mortality in the middle 1950's cannot be attributed to increase in the rate of commercial exploitation. Evidence is offered that the heightened mortality rate resulted from expansion of the sport fishery.

Growth and mortality of age-0 northern squawfish, Ptychocheilus oregonensis, rearing in shoreline habitats of the Columbia River Reservoir

USGS Publications Warehouse

Barfoot, C.A.; Gadomski, D.M.; Wertheimer, R.H.

1999-01-01

We investigated growth and mortality of age-0 northern squawfish during early rearing in shallow shoreline habitats. Larvae and juveniles (n=22914) were collected by weekly seining at three sample sites in the upper John Day Reservoir, Columbia River, during June through early September 1994–1996. Using a length-based ageing method, it was estimated that the exponential growth rate (G) for a common growth stanza (10–28 mm standard length SL) was significantly higher in 1994 (G=0.047) than in 1996 (G=0.037). Growth rate in 1995 could not be estimated, but was probably intermediate between 1994 and 1996 based on mean standard lengths of fish collected at the end of each sampling season (46.3, 40.0, and 32.0 mm SL in 1994, 1995, and 1996, respectively). For many fish species, variations in early growth can influence survival through size-selective mortality processes. Consistent with this possibility, our estimates of instantaneous mortality rates (Z) demonstrated that larvae and juveniles had significantly higher mortality in 1996 than in 1994 (Z=0.103 in 1994, versus Z=0.138 in 1996). Enhanced growth and lower mortality in 1994 were associated with a number of interrelated environmental conditions – comparatively low flows and turbidities, abundant instream vegetative cover, and high near-shore water temperatures.

Winter movements of four fish species near a thermal plume in northern Minnesota

DOE Office of Scientific and Technical Information (OSTI.GOV)

Ross, M.J.; Winter, J.D.

1981-01-01

During winter 1975, 17 yellow perch (Perca flavescens), 6 northern pike (Esox lucius), 3 walleyes (Stizostedion vitreum), and 2 largemouth bass (Micropterus salmoides) were equipped with radio frequency transmitters to compare their winter movements near the thermal plume of a power plant. The mean home range sizes, in hectares, were northern pike 19.0; yellow perch 13.4; largemouth bass 3.7; walleye 2.2. Northern pike and yellow perch had mean home range sizes larger than the discharge area. Mean water depths at fish locations were as follows: largemouth bass 0.8 m; northern pike 1.2 m; yellow perch 1.6 m; walleye 3.5 m.more » Largemouth bass preferred the warmest locations near the discharge point. Yellow perch were most often located in the peripheral areas of the discharge bay while walleyes were most often located in the deeper center area. Northern pike moved over the entire discharge area. All species except largemouth bass moved freely between discharge-affected and unaltered waters. The average numbers of movements per individual per week between heated and unheated areas were the following: northern pike 0.8; yellow perch 1.2; walleye 1.1; largemouth bass, 0.« less

Reevaluation of a walleye (Sander vitreus) bioenergetics model

USGS Publications Warehouse

Madenjian, Charles P.; Wang, Chunfang

2013-01-01

Walleye (Sander vitreus) is an important sport fish throughout much of North America, and walleye populations support valuable commercial fisheries in certain lakes as well. Using a corrected algorithm for balancing the energy budget, we reevaluated the performance of the Wisconsin bioenergetics model for walleye in the laboratory. Walleyes were fed rainbow smelt (Osmerus mordax) in four laboratory tanks each day during a 126-day experiment. Feeding rates ranged from 1.4 to 1.7 % of walleye body weight per day. Based on a statistical comparison of bioenergetics model predictions of monthly consumption with observed monthly consumption, we concluded that the bioenergetics model estimated food consumption by walleye without any significant bias. Similarly, based on a statistical comparison of bioenergetics model predictions of weight at the end of the monthly test period with observed weight, we concluded that the bioenergetics model predicted walleye growth without any detectable bias. In addition, the bioenergetics model predictions of cumulative consumption over the 126-day experiment differed fromobserved cumulative consumption by less than 10 %. Although additional laboratory and field testing will be needed to fully evaluate model performance, based on our laboratory results, the Wisconsin bioenergetics model for walleye appears to be providing unbiased predictions of food consumption.

Are walleye from Lake Roosevelt contaminated with mercury?

USGS Publications Warehouse

Erwin, Martha L.; Munn, Mark D.

1997-01-01

To find out, scientists from the U. S. Geological Survey (USGS) tested walleye and other sport fish from the upper Columbia River and Franklin D. Roosevelt Lake (Lake Roosevelt), the largest reservoir in Washington and a popular fishing spot.Findings:Walleye had higher concentrations of mercury than other sport fish.Larger walleye had higher mercury concentrations than smaller walleye.Mercury concentrations in walleye fillets ranged from 0.11 to 0.44 parts per million (ppm). These concentrations do not exceed the current Federal standard (1.0 ppm of mercury) designed to protect the health of people who eat small amounts of fish.After reviewing these findings, the Washington State Department of Health concluded that people who regularly consume large amounts of Lake Roosevelt walleye may be at risk of adverse health effects from mercury and should limit their consumption of these fish.

Development of a Systemwide Program: Stepwise Implementation of a Predation Index, Predator Control Fisheries and Evaluation Plan in the Columbia River Basin, Volume 1, 1992 Annual Report.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Ward, David L.

1994-06-01

Results of the second year are reported of a basinwide program to harvest northern squawfish in an effort to reduce mortality due to squawfish predation on juvenile salmonids during their migration from natal streams to the ocean. Six papers are included in this report. They are entitled: feasibility investigation of a commercial longline fishery for northern squawfish in the Columbia River downstream from Bonneville dam; evaluation of the northern squawfish sport-reward fishery in the Columbia and Snake Rivers; controlled angling for northern squawfish at selected dams on the Columbia and Snake Rivers in 1992; evaluation of harvest technology for squawfishmore » control in Columbia River reservoirs; effectiveness of predator-removal for protecting juvenile fall chinook salmon released from Bonneville Hatchery; and Northern squawfish sport-reward payments.« less

Relative contribution of stocked walleyes in Tennessee reservoirs

USGS Publications Warehouse

Vandergoot, C.S.; Bettoli, P.W.

2003-01-01

Since the mid-1950s, fisheries biologists with the Tennessee Wildlife Resources Agency have stocked walleyes Stizostedion vitreum in several tributary reservoirs of the Cumberland and Tennessee rivers to augment declining native stocks; however, the efficacy of these management actions has never been formally evaluated. The contribution of stocked walleyes in four Tennessee reservoirs was evaluated during 1999 and 2000 by marking fry and fingerlings through oxytetracycline (OTC) immersion. Stocking densities were 13-48 fingerlings/ha, and marking efficacy was high for fish marked as fry (mean = 98%; SE = 1.7%) and fingerlings (mean = 99%; SE = 0.6%). Nearly all (94-100%; N = 509) of the age-1 and age-2 walleyes collected in the four reservoirs were OTC-marked. Based on these findings, fingerling walleyes must be stocked annually to sustain the walleye populations in these tributary impoundments.

Food of young-of-the-year walleyes in Lake Erie

USGS Publications Warehouse

Wolfert, David R.

1966-01-01

Stomach contents were examined for 794 young-of-the-year (0-group) walleyes (Stizostedion vitreum vitreum) captured by trawls at 17 locations in western Lake Erie in June-November 1962. Food organisms were found in 92.5 percent of the stomachs. Food varied with geographic location and season of capture, but within areas and seasons, selection for certain species and sizes of prey was strong. Walleyes from the extreme western end of Lake Erie fed primarily on gizzard shad and alewives during the summer and shifted to emerald shiners during the fall. The stomach contents of walleyes from the Island region changed from mainly yellow perch during the summer to emerald shiners by the end of the year. Walleyes collected east of the Islands had consumed only smelt and yellow perch. The numbers of forage species caught with walleyes in trawls showed little correlation with the representation of these species in walleye stomachs. Walleyes fed on the smallest individuals of each species regardless of species preferences.

System-Wide Significance of Predation on Juvenile Salmonids in Columbia and Snake River Reservoirs : Annual Report of Research 1990.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Petersen, C.J.

1991-03-01

The consumption rates of northern squawfish (Ptychocheilus oregonensis) preying upon juvenile salmonids were indexed in four reservoirs (Bonneville, The Dalles, John Day and McNary) of the lower Columbia River. During the spring and summer of 1990, over 2000 northern squawfish were collected from dam forebays, dam tailraces and mid-reservoir locations. Gut content data, predator weight and water temperature were used to compute a consumption index (CI) for northern squawfish. Juvenile salmonids were found in 435 of 1598 northern squawfish guts analyzed. Besides salmonids and other preyfish, crustaceans formed a significant portion of the diet. The CI of northern squawfish variedmore » by season and location. At most locations, summer CI's of northern squawfish were higher than in the spring. Efforts to match sample collection with times of highest juvenile salmonid passage were successful except during July at The Dalles and Bonneville Reservoirs. Consumption indices were moderate to high at several locations even when passage was relatively low, suggesting salmonid predation rate by northern squawfish was not always a function of prey density. 19 refs., 5 figs., 12 tabs.« less

Walleye in Lake Erie and Lake St. Clair

USGS Publications Warehouse

Nepszy, S.J.; Davies, D.H.; Einhouse, D.; Hatch, R.W.; Isbell, G.; MacLennan, D.; Muth, K.M.

1991-01-01

The history and current status of walleye (Stizostedion vitreum vitreum) stocks in Lake Erie and Lake St. Clair are reviewed in relation to their exploitation by commercial and recreational fishermen, environmental factors, rehabilitation efforts, and community dynamics. Management initiatives and stock recovery under these processes are outlined. After the collapse of the fishery in 1957, the highly productive walleye stock of western Lake Erie remained depressed through the 1960s, while the eastern basin stock remained stable. Closure of the fishery for walleye from 1970-73 because of mercury contamination provided an opportunity for the development of an international interagency management plan. With quota management, the walleye stock in western Lake Erie responded well to limited exploitation, steadily increased, and expanded its range. As population expanded, growth began to decline and was more apparent in the young-of-the-year (YOY) in the 1970s, and in older walleye in the late 1970s and 1980s. At the turn of the century, commercial harvest of walleye in Lake St. Clair ranged from 12-127 tonnes annually. A relatively stable period from 1910-59 was followed by significantly increased harvests (100-150 t) in 1959-65. This increase was a result of increased commercial exploitation as well as an increased abundance of walleye. After the mercury contamination problem of 1970, angling effort and harvest was reduced but then gradually increased in Ontario waters from 37 t in 1973 to 62 t in 1988. The increased mean age of the stock during the early 1970s was due to a few strong year-classes (1970, 1972, and 1974) as well as a period of stable or reduced catch per unit effort. With the current mean age not reduced significantly, the stocks of walleye should continue to provide good yields.

Laboratory evaluation of a walleye (Sander vitreus) bioenergetics model

USGS Publications Warehouse

Madenjian, C.P.; Wang, C.; O'Brien, T. P.; Holuszko, M.J.; Ogilvie, L.M.; Stickel, R.G.

2010-01-01

Walleye (Sander vitreus) is an important game fish throughout much of North America. We evaluated the performance of the Wisconsin bioenergetics model for walleye in the laboratory. Walleyes were fed rainbow smelt (Osmerus mordax) in four laboratory tanks during a 126-day experiment. Based on a statistical comparison of bioenergetics model predictions of monthly consumption with the observed monthly consumption, we concluded that the bioenergetics model significantly underestimated food consumption by walleye in the laboratory. The degree of underestimation appeared to depend on the feeding rate. For the tank with the lowest feeding rate (1.4% of walleye body weight per day), the agreement between the bioenergetics model prediction of cumulative consumption over the entire 126-day experiment and the observed cumulative consumption was remarkably close, as the prediction was within 0.1% of the observed cumulative consumption. Feeding rates in the other three tanks ranged from 1.6% to 1.7% of walleye body weight per day, and bioenergetics model predictions of cumulative consumption over the 126-day experiment ranged between 11 and 15% less than the observed cumulative consumption. ?? 2008 Springer Science+Business Media B.V.

Development of a System-Wide Program, Volume II : Stepwise Implementation of a Predation Index, Predator Control Fisheries and Evaluation Plan in the Columbia River Basin, 1992 Annual Report.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Ward, David L.; Nigro, Anthony A.; Willis, Charles F.

1994-06-01

The authors report their results of studies to determine the extent to which northern squawfish predation on juvenile salmonids is a problem in the Columbia River Basin, and to evaluate how effectively fisheries can be used to control northern squawfish populations and reduce juvenile salmonid losses to predation. These studies were initiated as part of a basinwide program to control northern squawfish predation and reduce mortality of juvenile salmonids on their migration to the ocean. Three papers are included in this report. They are entitled: (1) Development of a Systemwide Predator Control Program: Indexing and Fisheries Evaluation; (2) Economic, Socialmore » and Legal Feasibility of Commercial Sport, and Bounty Fisheries on Northern Squawfish; (3) Columbia River Ecosystem Model (CREM): Modeling Approach for Evaluation of Control of Northern Squawfish Populations using Fisheries Exploitation.« less

Managing inherent complexity for sustainable walleye fisheries in Lake Erie

USGS Publications Warehouse

Roseman, Edward F.; Drouin, Richard; Gaden, Marc; Knight, Roger; Tyson, Jeff; Zhao, Yingming; Taylor, William W.; Lynch, Abigail J.; Léonard, Nancy J.

2012-01-01

In Lake Erie, Walleye (Sander vitreus vitreus) is king. The naturally occurring species is the foundation of commercial fishing operations on the Canadian side of the lake and is a much-prized sport fish on the American side. Management of Lake Erie walleye fisheries is complex and takes place in an inter-jurisdictional setting composed of resource agencies from the states of Michigan (MDNR), Ohio (ODNR), Pennsylvania (PFBC), and New York (NYDEC) and the province of Ontario (OMNR). The complexity of walleye management is exacerbated by interactions among environmental and ecological changes in Lake Erie, complex life-history characteristics of the species, public demand for walleye, and cultural/governance differences among managing groups and their respective constituents. Success of future management strategies will largely hinge upon our ability to understand these inherent complexities and to employ tactics that successfully accommodate stock productivity and human demand in a highly dynamic environment. In this report, we review the history of Lake Erie walleye management, outline the multi-jurisdictional process for international management of walleye, and discuss strategies to address challenges facing managers.

First-year growth, recruitment, and maturity of walleyes in western Lake Erie

USGS Publications Warehouse

Madenjian, Charles P.; Tyson, Jeffrey T.; Knight, Roger L.; Kershner, Mark W.; Hansen, Michael J.

1996-01-01

In some lakes, first-year growth of walleyes Stizostedion vitreum has been identified as an important factor governing recruitment of juveniles to the adult population. We developed a regression model for walleye recruitment in western Lake Erie by considering factors such as first-year growth, size of the spawning stock, the rate at which the lake warmed during the spring, and abundance of gizzard shad Dorosoma cepedianum. Gizzard shad abundance during the fall prior to spring walleye spawning explained over 40% of the variation in walleye recruitment. Gizzard shad are relatively high in lipids and are preferred prey for walleyes in Lake Erie. Therefore, the high degree of correlation between shad abundance and subsequent walleye recruitment supported the contention that mature females needed adequate lipid reserves during the winter to spawn the following spring. According to the regression analysis, spring warming rate and size of the parental stock also influenced walleye recruitment. Our regression model explained 92% of the variation in recruitment of age-2 fish into the Lake Erie walleye population from 1981 to 1993. The regression model is potentially valuable as a management tool because it could be used to forecast walleye recruitment to the fishery 2 years in advance. First-year growth was poorly correlated with recruitment, which may reflect the unusually low incidence of walleye cannibalism in western Lake Erie. In contrast, first-year growth was strongly linked to age at maturity.

Status and reproduction of Gulf coast strain walleye in a Tombigbee River tributary

USGS Publications Warehouse

Schramm, H.L.; Hart, J.; Hanson, L.A.

2004-01-01

Walleye (Sander vitreus [Mitchill]) are native to rivers and streams in the Mobile River basin in Mississippi and Alabama. These populations comprise a genetically unique strain (Gulf coast walleye, GCW) and represent the southernmost distribution of walleye in the United States. Luxapallila Creek was considered an important spawning site for GCW prior to and shortly after impoundment of the Tombigbee River in 1980. Extensive sampling in Luxapallila Creek in 2001 and 2002 collected only one larval walleye. Microsatellite DNA analysis suggested 14 of 16 adult walleye from Luxapallila Creek were hatchery-produced fish or their progeny. Controlled angling catch rates of adult walleye have declined since 1997. The scarcity of wild-spawned walleye and the similarity of wild-caught and hatchery broodstock walleye indicates that the GCW population in, or spawning in, Luxapallila Creek is sustained by stocking and recruitment from these stocked fish may be diminishing.

A rehabilitation plan for walleye populations and habitats in Lake Superior

USGS Publications Warehouse

Hoff, Michael H.

2003-01-01

The walleye (Stizostedion vitreum vitreum) has been historically important in regional fisheries and fish communities in large bays, estuaries, and rivers of Lake Superior. Significant negative impacts on the species caused by overharvesting, habitat degradation, and pollution during the late 1800s and early 1900s have led to the preparation of a strategic rehabilitation plan. The lakewide goal is to maintain, enhance, and rehabilitate habitat for walleye and to establish self-sustaining populations in areas where walleyes historically lived. Population objectives that support the goal are to increase the abundance of juvenile and adult walleyes in selected areas. Habitat objectives that support the goal include increasing spawning and nursery habitat in four areas: enhancing fish passage, reducing sedimentation, increasing water quality, and reducing contaminants in walleyes. Progress toward achieving the habitat objectives should be measured by documenting increases in spawning and nursery habitats, resolving fish-passage issues, reducing sediments in rivers, and reducing contaminant levels in walleyes. Stocking various life stages of walleye should be considered to rehabilitate certain degraded populations. Total annual mortality of walleye populations should be less than 45% to allow populations to either increase or be maintained at target levels of abundance. Routine assessments should focus on gathering the data necessary to evaluate abundance and mortality and on taking inventories of spawning and nursery habitats. Research should be conducted to understand the specific habitat requirements for Lake Superior walleye populations and the habitat-abundance relationships for populations and for the lake as a whole.

Sex difference in polybrominated diphenyl ether concentrations of walleyes

USGS Publications Warehouse

Madenjian, Charles P.; Trombka, Autumn W.; Rediske, Richard R.; Jude, David J.; O'Keefe, James P.

2012-01-01

Polybrominated diphenyl ether (PBDE) concentrations were determined for mature male and mature female walleyes (Sander vitreus) sampled from the Saginaw Bay population during 2007. PBDE concentrations in prey fish caught in the Saginaw River, the primary tributary to Saginaw Bay, and in Saginaw Bay during 2005 and 2007 also were determined. Mature male and mature female walleyes averaged 70.3 ng/g and 24.8 ng/g, respectively, in ΣPBDE, which was equal to the sum of concentrations of six PBDE congeners (BDE-28, BDE-47, BDE-99, BDE-100, BDE-153, and BDE-154). This sex difference was likely due to males spending more time in the Saginaw River system than females. Prey fish captured in the Saginaw River were roughly ten times higher in ΣPBDE than those caught in Saginaw Bay. BDE-47 was the predominant congener in both walleyes and prey fish, and this congener contributed about 50%, on average, to ΣPBDE. Congener profiles differed significantly between the two sexes of walleyes. In contrast, congener profiles of the prey fish did not differ significantly between the river-caught fish and the bay-caught fish. One plausible explanation for these congener profile results was that net trophic transfer efficiencies of PBDEs to walleyes from their prey were similar for all congeners except BDE-28, and that diet composition differed between the two sexes of walleyes.

Selective food preferences of walleyes of the 1959 year class in Lake Erie

USGS Publications Warehouse

Parsons, John W.

1971-01-01

Stomachs were examined from 1,473 walleyes (Stizostedion vitreum vitreum) of the 1959 year class collected in western Lake Erie from June 1959 to October 1960. In the same period, the relative abundance and lengths of potential forage species were determined from trawl catches. The walleye fed almost entirely on fish. In 1959 the food was dominated first (in June and July) by yellow perch (Perca flavescens) and then, in sequence, by spottail shiners (Notropis hudsonius) and emerald shiners (Notropis atherinoides). In 1960, the walleyes fed mostly on yearling spottail shiners and emerald shiners in the spring and summer but young alewives (Alosa pseudoharengus) became the dominant food in the fall. The length of forage fish increased with the length of walleyes and walleyes of a given length usually ate forage fish within a restricted range of lengths. This size preference was shown by walleyes of the same length in the same and different months. The increased in length of forage fish with length of walleye was not proportionate. Walleyes 2.5 inches long ate forage fish 0.44 times their length whereas walleyes 15.5 inches long ate forage fish only 0.28 times their length. The diet of the walleyes changed according to species and lengths of forage fish available. Since young of several species hatched in different months and grew at different rates, abundance and suitability as forage sometimes changed rapidly.

Genetic contribution of hatchery fish to walleye stocks in Saginaw Bay, Michigan

USGS Publications Warehouse

Todd, Thomas N.; Haas, Robert C.; Schramm, Harold L.; Piper, Robert G.

1995-01-01

Stocks of walleye (Stizostedion vitreum) were severely depressed in Saginaw Bay in the 1970s. In 1979, the Michigan Department of Natural Resources began intensive stocking of walleye fingerlings to bolster fish populations. Subsequent to stocking, the walleye fishery has recovered. The study objective was to determine if recovery was due to the stocking program or natural reproduction. Inherent genetic differences between hatchery fish and endemic walleyes were used to determine the effect and contribution of hatchery fish to Saginaw Bay.

Feeding Activity, Rate of Consumption, Daily Ration and Prey Selection of Major Predators in the John Day Pool. 1982 Annual Report.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Gray, Gerard A.; United States. Bonneville Power Administration

1984-03-01

This study was initiated to determine the extent of predation by resident populations of native and introduced fish on juvenile salmonids in main stem Columbia River Reservoirs. The John Day Reservoir and tailrace was selected as the study area. First year objectives were: (1) determine whether native and introduced predators preyed on juvenile salmonids; (2) determine which species were major predators; and (3) locate areas where predation was most intense. Results indicated that juvenile salmonids were consumed by all four predatory fish species studied: northern squawfish (Ptychocheilus oregonensis), walleye (Stizostedion vitreum vitreum), smallmouth bass (Micropterus dolomieu), and channel catfish (Ictalurusmore » punctatus). However, degree of predation varied among predators as a function of spatial distribution, apparent abundance, size, and temporal feeding behavior. 15 figs., 16 tabs.« less

Influence of variable rainbow smelt and gizzard shad abundance on walleye diets and growth

USGS Publications Warehouse

Fincel, Mark J.; Dembkowski, Daniel J.; Chipps, Steven R.

2014-01-01

Prey availability influences growth and condition of walleye (Sander vitreus) in large systems. In Lake Oahe, South Dakota, rainbow smelt (Osmerus mordax) and gizzard shad (Dorosoma cepedianum) are primary prey of walleye, but their abundance varies substantially year to year. To evaluate the influence of gizzard shad and rainbow smelt on walleye diets and growth in Lake Oahe, we compared recent estimates of walleye diets and growth in 2008 through 2010 with those from the late 1990s and early 2000s. Walleye diets differed seasonally with increased piscivory in July and October. In 2008, gizzard shad were the dominant prey item of walleye, representing about 60% of the diets by weight; however, by 2009, gizzard shad declined appreciably in the diet (22%) and were completely absent from walleye diets by 2010. Conversely, rainbow smelt abundance represented 12%, 27%, and 90% of walleye diets by weight in 2008, 2009 and 2010, respectively. Changes in growth corresponded to changes in diets, with the slowest growth occurring when gizzard shad were dominant in the diets and increasing growth every year thereafter. Because gizzard shad are only available during short periods (<3 months) in late summer, walleye can only achieve about 50% of their annual maintenance energy requirements from this prey source. Conversely, rainbow smelt, which are available and consumed year round, provide a continuous energy source that contributes to high growth rates. Nonetheless, when abundant, gizzard shad may provide an important subsidy to Lake Oahe walleye during periods of low rainbow smelt abundance.

First evidence of egg deposition by walleye (Sander vitreus) in the Detroit River

USGS Publications Warehouse

Manny, B.A.; Kennedy, G.W.; Allen, J.D.; French, J. R. P.

2007-01-01

The importance of fish spawning habitat in channels connecting the Great Lakes to fishery productivity in those lakes is poorly understood and has not been adequately documented. The Detroit River is a reputed spawning and nursery area for many fish, including walleye (Sander vitreus) that migrate between adjacent Lakes Erie and St. Clair. During April–May 2004, near the head of the Detroit River, we collected 136 fish eggs from the bottom of the river on egg mats. We incubated the eggs at the Great Lakes Science Center until they hatched. All eleven larvae that hatched from the eggs were identified as walleye. These eggs and larvae are the first credible scientific evidence that walleye spawn in the Detroit River. Their origin might be a stock of river-spawning walleye. Such a stock of walleye could potentially add resilience to production by walleye stocks that spawn and are harvested in adjacent waters.

Thiamine and fatty acid content of walleye tissue from three southern U.S. reservoirs

USGS Publications Warehouse

Honeyfield, D.C.; Vandergoot, C.S.; Bettoli, P.W.; Hinterkopf, J.P.; Zajicek, J.L.

2007-01-01

We determined the thiamine concentration in egg, muscle, and liver tissues of walleyes Sander vitreus and the fatty acid content of walleye eggs from three southern U.S. reservoirs. In two Tennessee reservoirs (Dale Hollow and Center Hill), in which there were alewives Alosa pseudoharengus in the forage base, natural recruitment of walleyes was not occurring; by contrast in Lake James Reservoir, North Carolina, where there were no alewives, the walleye population was sustained via natural recruitment. Female walleye tissues were collected and assayed for thiamine (vitamin B1) and fatty acid content. Thiamine pyrophosphate was found to be the predominant form of thiamine in walleye eggs. In 2000, mean total egg thiamine concentrations were similar among Center Hill, Dale Hollow, and Lake James reservoirs (2.13, 3.14, and 2.77 nmol thiamine/g, respectively). Egg thiamine concentration increased as maternal muscle (r 2 = 0.73) and liver (r2 = 0.68) thiamine concentration increased. Walleye egg thiamine does not appear to be connected to poor natural reproduction in Tennessee walleyes. Threadfin shad Dorosoma petenense, which are found in all three reservoirs, had higher thiaminase activity than alewives. Six fatty acids differed among the walleye eggs for the three reservoirs. Two were physiologically important fatty acids, arachidonic acid (20:4[n-6]) and docosahexaenoic acid (22:6[n-3]), which are important eicosanoid precursors involved in the regulation of biological functions, such as immune response and reproduction. ?? Copyright by the American Fisheries Society 2007.

Identification, movement, growth, mortality, and exploitation of walleye stocks in Lake St. Clair and the western basin of Lake Erie

USGS Publications Warehouse

Haas, Robert C.; Fabrizio, Mary C.; Todd, Thomas N.

1988-01-01

two stocks are the western basin of Lake Erie and Lake St. Clair stocks. No further subdivision of stocks was possible based on the genetic analysis of 21 loci. These genetically different stocks intermix in the northern waters of this system. Based on a consideration of the results of the genetic analysis, catch-at-age analysis, and tag-recapture study we recommend independent but coordinated management of the walleye populations in Lake St. Clair and Lake Erie.

Acoustic telemetry reveals large-scale migration patterns of walleye in Lake Huron

USGS Publications Warehouse

Hayden, Todd A.; Holbrook, Christopher; Fielder, David G.; Vandergoot, Christopher S.; Bergstedt, Roger A.; Dettmers, John M.; Krueger, Charles C.; Cooke, Steven J.

2014-01-01

Fish migration in large freshwater lacustrine systems such as the Laurentian Great Lakes is not well understood. The walleye (Sander vitreus) is an economically and ecologically important native fish species throughout the Great Lakes. In Lake Huron walleye has recently undergone a population expansion as a result of recovery of the primary stock, stemming from changing food web dynamics. During 2011 and 2012, we used acoustic telemetry to document the timing and spatial scale of walleye migration in Lake Huron and Saginaw Bay. Spawning walleye (n = 199) collected from a tributary of Saginaw Bay were implanted with acoustic tags and their migrations were documented using acoustic receivers (n = 140) deployed throughout U.S. nearshore waters of Lake Huron. Three migration pathways were described using multistate mark-recapture models. Models were evaluated using the Akaike Information Criterion. Fish sex did not influence migratory behavior but did affect migration rate and walleye were detected on all acoustic receiver lines. Most (95%) tagged fish migrated downstream from the riverine tagging and release location to Saginaw Bay, and 37% of these fish emigrated from Saginaw Bay into Lake Huron. Remarkably, 8% of walleye that emigrated from Saginaw Bay were detected at the acoustic receiver line located farthest from the release location more than 350 km away. Most (64%) walleye returned to the Saginaw River in 2012, presumably for spawning. Our findings reveal that fish from this stock use virtually the entirety of U.S. nearshore waters of Lake Huron.

Acoustic telemetry reveals large-scale migration patterns of walleye in Lake Huron.

PubMed

Hayden, Todd A; Holbrook, Christopher M; Fielder, David G; Vandergoot, Christopher S; Bergstedt, Roger A; Dettmers, John M; Krueger, Charles C; Cooke, Steven J

2014-01-01

Fish migration in large freshwater lacustrine systems such as the Laurentian Great Lakes is not well understood. The walleye (Sander vitreus) is an economically and ecologically important native fish species throughout the Great Lakes. In Lake Huron walleye has recently undergone a population expansion as a result of recovery of the primary stock, stemming from changing food web dynamics. During 2011 and 2012, we used acoustic telemetry to document the timing and spatial scale of walleye migration in Lake Huron and Saginaw Bay. Spawning walleye (n = 199) collected from a tributary of Saginaw Bay were implanted with acoustic tags and their migrations were documented using acoustic receivers (n = 140) deployed throughout U.S. nearshore waters of Lake Huron. Three migration pathways were described using multistate mark-recapture models. Models were evaluated using the Akaike Information Criterion. Fish sex did not influence migratory behavior but did affect migration rate and walleye were detected on all acoustic receiver lines. Most (95%) tagged fish migrated downstream from the riverine tagging and release location to Saginaw Bay, and 37% of these fish emigrated from Saginaw Bay into Lake Huron. Remarkably, 8% of walleye that emigrated from Saginaw Bay were detected at the acoustic receiver line located farthest from the release location more than 350 km away. Most (64%) walleye returned to the Saginaw River in 2012, presumably for spawning. Our findings reveal that fish from this stock use virtually the entirety of U.S. nearshore waters of Lake Huron.

Predation on walleye eggs by fish on reefs in western Lake Erie

USGS Publications Warehouse

Roseman, E.F.; Taylor, W.W.; Hayes, D.B.; Jones, A.L.; Francis, J.T.

2006-01-01

We examined diets of fishes from gillnet and egg pump collections conducted on reefs in western Lake Erie during walleye (Sander vitreus) egg incubation periods from 1994–1999 and 2004 to assess incidence of walleye eggs in fish diets. We collected no potential egg predators in samples taken in 1994 but from 1995–1999 and in 2004 we caught 22 different species of fish on reefs in addition to spawning walleye. In most years, white perch (Morone americana) stomachs contained more walleye eggs than any other species on the reefs averaging 253 eggs per stomach. We also found lower numbers of walleye eggs in the stomachs of channel catfish (Ictalurus punctatus; 53 eggs/stomach), johnny darter (Etheostoma nigrum; 2 eggs/stomach), logperch (Percina caprodes; 10 eggs/stomach), quillback (Carpiodes cyprinus; 184 eggs/stomach), rock bass (Ambloplites rupestris; 3 eggs/stomach), round goby (Neogobius melanostomus; 4 eggs/stomach), sculpin (Cottidae; 21 eggs/stomach), silver chub (Macrhybopsis storeriana; 3 eggs/stomach), spottail shiner (Notropis hudsonius; 14 eggs/stomach), trout-perch (Percopsis omiscomaycus; 30 eggs/stomach), white sucker (Catastomus commersonii; 20 eggs/stomach), and yellow perch (Perca flavescens; 181 eggs/stomach). Similar to other studies of predation on walleye eggs, our results indicate that prolonged incubation periods increase the potential for egg loss due to predation.

Acoustic Telemetry Reveals Large-Scale Migration Patterns of Walleye in Lake Huron

PubMed Central

Hayden, Todd A.; Holbrook, Christopher M.; Fielder, David G.; Vandergoot, Christopher S.; Bergstedt, Roger A.; Dettmers, John M.; Krueger, Charles C.; Cooke, Steven J.

2014-01-01

Fish migration in large freshwater lacustrine systems such as the Laurentian Great Lakes is not well understood. The walleye (Sander vitreus) is an economically and ecologically important native fish species throughout the Great Lakes. In Lake Huron walleye has recently undergone a population expansion as a result of recovery of the primary stock, stemming from changing food web dynamics. During 2011 and 2012, we used acoustic telemetry to document the timing and spatial scale of walleye migration in Lake Huron and Saginaw Bay. Spawning walleye (n = 199) collected from a tributary of Saginaw Bay were implanted with acoustic tags and their migrations were documented using acoustic receivers (n = 140) deployed throughout U.S. nearshore waters of Lake Huron. Three migration pathways were described using multistate mark-recapture models. Models were evaluated using the Akaike Information Criterion. Fish sex did not influence migratory behavior but did affect migration rate and walleye were detected on all acoustic receiver lines. Most (95%) tagged fish migrated downstream from the riverine tagging and release location to Saginaw Bay, and 37% of these fish emigrated from Saginaw Bay into Lake Huron. Remarkably, 8% of walleye that emigrated from Saginaw Bay were detected at the acoustic receiver line located farthest from the release location more than 350 km away. Most (64%) walleye returned to the Saginaw River in 2012, presumably for spawning. Our findings reveal that fish from this stock use virtually the entirety of U.S. nearshore waters of Lake Huron. PMID:25506913

Development of eighteen microsatellite loci in walleye (Sander vitreus)

USGS Publications Warehouse

Coykendall, D. Katharine; Morrison, Cheryl L.; Stott, Wendylee; Springmann, Marcus J.

2014-01-01

A suite of tri- and tetra-nucleotide microsatellite loci were developed for walleye (Sander vitreus) from 454 pyrosequencing data. Eighteen of the 50 primer sets tested amplified consistently in 35 walleye from two lakes on Isle Royale, Lake Superior: Chickenbone Lake and Whittlesey Lake. The loci displayed moderate levels of allelic diversity (average 5.5 alleles/locus) and heterozygosity (average 35.8 %). Levels of genetic diversity were sufficient to produce unique multi-locus genotypes and detect phylogeographic structuring as individuals assigned back to their population of origin. Cross-species amplification within S. canadensis(sauger) was successful for 15 loci, and 11 loci were diagnostic to species. The loci characterized here will be useful for detecting fine-scale spatial structuring, resolving the taxonomic status of Sander species and sub-species, and detecting walleye/sauger hybrids.

Seasonal thermal ecology of adult walleye (Sander vitreus) in Lake Huron and Lake Erie.

PubMed

Peat, Tyler B; Hayden, Todd A; Gutowsky, Lee F G; Vandergoot, Christopher S; Fielder, David G; Madenjian, Charles P; Murchie, Karen J; Dettmers, John M; Krueger, Charles C; Cooke, Steven J

2015-10-01

The purpose of this study was to characterize thermal patterns and generate occupancy models for adult walleye from lakes Erie and Huron with internally implanted biologgers coupled with a telemetry study to assess the effects of sex, fish size, diel periods, and lake. Sex, size, and diel periods had no effect on thermal occupancy of adult walleye in either lake. Thermal occupancy differed between lakes and seasons. Walleye from Lake Erie generally experienced higher temperatures throughout the spring and summer months than did walleye in Lake Huron, due to limnological differences between the lakes. Tagged walleye that remained in Saginaw Bay, Lake Huron (i.e., adjacent to the release location), as opposed to those migrating to the main basin of Lake Huron, experienced higher temperatures, and thus accumulated more thermal units (the amount of temperature units amassed over time) throughout the year. Walleye that migrated toward the southern end of Lake Huron occupied higher temperatures than those that moved toward the north. Consequently, walleye that emigrated from Saginaw Bay experienced thermal environments that were more favorable for growth as they spent more time within their thermal optimas than those that remained in Saginaw Bay. Results presented in this paper provide information on the thermal experience of wild fish in a large lake, and could be used to refine sex- and lake-specific bioenergetics models of walleye in the Great Lakes to enable the testing of ecological hypotheses. Copyright © 2015 Elsevier Ltd. All rights reserved.

Seasonal thermal ecology of adult walleye (Sander vitreus) in Lake Huron and Lake Erie

USGS Publications Warehouse

Peat, Tyler B; Hayden, Todd A.; Gutowsky, Lee F G; Vandergoot, Christopher S.; Fielder, David G.; Madenjian, Charles P.; Murchie, Karen J; Dettmers, John M.; Krueger, Charles C.; Cooke, Steven J.

2015-01-01

The purpose of this study was to characterize thermal patterns and generate occupancy models for adult walleye from lakes Erie and Huron with internally implanted biologgers coupled with a telemetry study to assess the effects of sex, fish size, diel periods, and lake. Sex, size, and diel periods had no effect on thermal occupancy of adult walleye in either lake. Thermal occupancy differed between lakes and seasons. Walleye from Lake Erie generally experienced higher temperatures throughout the spring and summer months than did walleye in Lake Huron, due to limnological differences between the lakes. Tagged walleye that remained in Saginaw Bay, Lake Huron (i.e., adjacent to the release location), as opposed to those migrating to the main basin of Lake Huron, experienced higher temperatures, and thus accumulated more thermal units (the amount of temperature units amassed over time) throughout the year. Walleye that migrated toward the southern end of Lake Huron occupied higher temperatures than those that moved toward the north. Consequently, walleye that emigrated from Saginaw Bay experienced thermal environments that were more favorable for growth as they spent more time within their thermal optimas than those that remained in Saginaw Bay. Results presented in this paper provide information on the thermal experience of wild fish in a large lake, and could be used to refine sex- and lake-specific bioenergetics models of walleye in the Great Lakes to enable the testing of ecological hypotheses.

Environmental DNA assays for the sister taxa sauger (Sander canadensis) and walleye (Sander vitreus)

PubMed Central

Carim, Kellie J.; Ruggles, Michael; McKelvey, Kevin S.; Young, Michael K.; Schwartz, Michael K.

2017-01-01

Sauger (Sander canadensis) and walleye (S. vitreus) are percid fishes that naturally co-occur throughout much of the eastern United States. The native range of sauger extends into the upper Missouri River drainage where walleye did not historically occur, but have been stocked as a sport fish. Sauger populations have been declining due to habitat loss, fragmentation, and competition with non-native species, such as walleye. To effectively manage sauger populations, it is necessary to identify areas where sauger occur, and particularly where they co-occur with walleye. We developed quantitative PCR assays that can detect sauger and walleye DNA in filtered water samples. Each assay efficiently detected low quantities of target DNA and failed to detect DNA of non-target species with which they commonly co-occur. PMID:28441436

Consumption estimates of walleye stocked as fry to suppress fathead minnow populations in west-central Minnesota wetlands

USGS Publications Warehouse

Ward, M.C.; Willis, D.W.; Herwig, B.R.; Chipps, S.R.; Parsons, B.G.; Reed, J.R.; Hanson, M.A.

2008-01-01

Fisheries managers throughout the Prairie Pothole Region of Minnesota often use semi-permanent and permanent wetland basins to extensively culture walleye Sander vitreus fry. Waterfowl managers have expressed concern over this practice because of the potential influence that fish have on food resources used by waterfowl during development and migration. It is well known that native fathead minnows Pimephales promelas can have detrimental effects on macroinvertebrates, zooplankton, water clarity, epiphyton, and macrophytes in wetlands. Because walleye commonly become piscivorous as soon as mouth gape allows, walleye fry may suppress fathead minnow populations and improve wetland conditions for waterfowl. In this study, we quantify consumption estimates, specifically predation on fathead minnows, by age-0 and age-1 walleye reared in natural wetland basins. Six wetlands were stocked in mid-May 2001 and 2002 at a rate of 12,000 walleye fry ha-1. Age-0 walleye were sampled bi-weekly from mid-June through mid-September 2001. Age-0 and age-1 walleye were sampled monthly from mid-May through mid-September 2002. A generalised diet shift from zooplankton to fish to macroinvertebrates was observed in 2001, whereas diets of juvenile walleye contained primarily macroinvertebrates in 2002. Stocked walleye quickly reduced fathead minnow populations in 2001 and suppression was maintained throughout 2002. Although walleye consumed primarily macroinvertebrates once prey fish populations became suppressed, consumption estimates of invertebrates by walleye were substantially less than those documented for fathead minnow populations. Thus, stocking age-0 walleye was an effective biomanipulation tool that substantially reduced fathead minnow densities and influenced lower trophic levels in these aquatic communities. ?? 2007 Blackwell Munksgaard.

System-Wide Significance of Predation on Juvenile Salmonids in Columbia and Snake River Reservoirs : Annual Report 1992.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Petersen, James H.; Poe, Thomas P.

1993-12-01

Northern squawfish (Ptychocheilus oregonensis) predation on juvenile salmonids was characterized during 1992 at ten locations in the Columbia River below Bonneville Dam and at three locations in John Day Reservoir. During the spring and summer, 1,487 northern squawfish were collected in the lower Columbia River and 202 squawfish were sampled in John Day Reservoir. Gut content data, predator weight, and water temperature were used to compute a consumption index (CI) for northern squawfish, and overall diet was also described. In the Columbia River below Bonneville Dam, northern squawfish diet was primarily fish (spring 69%; summer 53%), most of which weremore » salmonids. Salmonids were also the primary diet component in the Bonneville Dam tailrace, John Day Dam forebay, and the McNary Dam tailrace. Crustaceans were the dominant diet item at the John Day mid-reservoir location, although sample sizes were small. About half of the non-salmonid preyfish were sculpins. The consumption index (CI) of northern squawfish was generally higher during summer than during spring. The highest CI`s were observed during summer in the tailrace boat restricted zones of Bonneville Dam (CI = 7.8) and McNary Dam (CI = 4.6). At locations below Bonneville Dam, CI`s were relatively low near Covert`s Landing and Rooster Rock, higher at four locations between Blue Lake and St. Helens, and low again at three downriver sites (Kalama, Ranier, and Jones Beach). Northern squawfish catches and CI`s were noticeably higher throughout the lower Columbia compared to mid-reservoir sites further upriver sampled during 1990--92. Predation may be especially intense in the free-flowing section of the Columbia River below Bonneville Dam. Smallmouth bass (Micropterus dolomieui; N = 198) ate mostly fish -- 25% salmonids, 29% sculpins, and 46% other fish. Highest catches of smallmouth bass were in the John Day Dam forebay.« less

A reexamination of the relationship between electrofishing catch rate and age-0 walleye density in northern Wisconsin lakes

Treesearch

Michael J. Hansen; Steven P. Newman; Clayton J. Edwards

2004-01-01

We quantified the relationship between the population density (number/acre) of age-0 walleyes Sander vitreus (formerly Stizostedion vitreum) and electrofishing catch per effort (CPE; number/mi) in 19 Wisconsin lakes to update a 1982 analysis by Serns, who used linear regression through the origin to develop a model from a small...

Factors associated with mortality of walleyes and saugers caught in live-release tournaments

USGS Publications Warehouse

Schramm, Harold; Vondracek, Bruce C.; French, William E.; Gerard, Patrick D.

2010-01-01

We measured the initial mortality (fish judged nonreleasable at weigh-in), prerelease mortality (fish judged nonreleasable 1–2 h after weigh-in [which includes initial mortality]), and postrelease mortality (fish that died during a 5-d retention in net-pens) in 14 live-release tournaments for walleye Sander vitreus conducted in April–October 2006 and April–July 2007 in lakes and rivers in Michigan, Minnesota, North Dakota, South Dakota, and Wisconsin. Among the 14 events, initial mortality was 0–28%, prerelease mortality was 3–54%, and postrelease mortality was 0–100%; the mortality of reference fish (walleyes ≥31 cm long that were captured by electrofishing and held in net-pens with tournament-caught walleyes to measure postrelease mortality) was 0–97%. Mortality was generally low in events conducted when water temperatures were below 14°C but substantially higher in events when water temperatures were above 18°C. The mortality of reference fish suggests that capture by electrofishing and minimal handling when the water temperature exceeds 19°C results in high mortality of walleyes that is largely the result of the thermal conditions immediately after capture. Mortality was not related to the size of the tournaments (number of boats), the total number or weight of walleyes weighed in, or the mean number or weight of walleyes weighed in per boat. Mortality was positively related to the depth at which walleyes were caught and the live-well temperature and negatively related to the live-well dissolved oxygen concentration. Surface water temperature was the best predictor of mortality, and models were developed to predict the probability of prerelease and postrelease mortality of 10, 20, and 30% or less of tournament-caught walleyes due to water temperature.

Factors associated with initial mortality of Walleye and Sauger caught in live-release tournaments

USGS Publications Warehouse

Schramm, Harold L.; Vondracek, Bruce C.; French, William E.; Gerard, Patrick D.

2010-01-01

We measured the initial mortality (fish judged nonreleasable at weigh-in), prerelease mortality (fish judged nonreleasable 1–2 h after weigh-in [which includes initial mortality]), and postrelease mortality (fish that died during a 5-d retention in net-pens) in 14 live-release tournaments for walleye Sander vitreus conducted in April–October 2006 and April–July 2007 in lakes and rivers in Michigan, Minnesota, North Dakota, South Dakota, and Wisconsin. Among the 14 events, initial mortality was 0–28%, prerelease mortality was 3–54%, and postrelease mortality was 0–100%; the mortality of reference fish (walleyes ≥31 cm long that were captured by electrofishing and held in net-pens with tournament-caught walleyes to measure postrelease mortality) was 0–97%. Mortality was generally low in events conducted when water temperatures were below 14°C but substantially higher in events when water temperatures were above 18°C. The mortality of reference fish suggests that capture by electrofishing and minimal handling when the water temperature exceeds 19°C results in high mortality of walleyes that is largely the result of the thermal conditions immediately after capture. Mortality was not related to the size of the tournaments (number of boats), the total number or weight of walleyes weighed in, or the mean number or weight of walleyes weighed in per boat. Mortality was positively related to the depth at which walleyes were caught and the live-well temperature and negatively related to the live-well dissolved oxygen concentration. Surface water temperature was the best predictor of mortality, and models were developed to predict the probability of prerelease and postrelease mortality of 10, 20, and 30% or less of tournament-caught walleyes due to water temperature.

Gender difference in walleye PCB concentrations persists following remedial dredging

USGS Publications Warehouse

Madenjian, Charles P.; Jude, David J.; Rediske, Richard R.; O'Keefe, James P.; Noguchi, George E.

2009-01-01

Eleven male walleyes (Sander vitreus) and 10 female walleyes from the Saginaw Bay (Lake Huron) population were caught during the spawning run at Dow Dam (Midland, Michigan) in the Tittabawassee River during April 1996, and individual whole-fish polychlorinated biphenyl (PCB) determinations were made. Total PCB concentrations averaged 7.95 and 3.17??mg/kg for males and females, respectively. As part of the Natural Resource Damage Assessment remediation process, contaminated sediments from the Saginaw River, the main tributary to Saginaw Bay, were removed during 2000 and 2001. Total PCB concentrations of 10 male and 10 female walleyes caught at Dow Dam during April 2007 averaged 1.58 and 0.55??mg/kg, respectively. Thus, dredging of the Saginaw River appeared to be effective in reducing PCB concentrations of Saginaw Bay adult walleyes, as both males and females decreased in PCB concentration by more than 80% between 1996 and 2007. However, the ratio of male PCB concentration to female PCB concentration did not decline between 1996 and 2007. This persistent gender difference in PCB concentrations was apparently due to a gender difference in habitat utilization coupled with a persistent spatial gradient in prey fish PCB concentrations from the Saginaw River to Lake Huron.

Magnitude and Dynamics of Predation on Juvenile Salmonids in Columbia and Snake River Reservoirs, Annual Report of Research, 1989-1990.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Petersen, J.H.

1990-07-01

Three aspects of predation upon juvenile salmonids in the Columbia River are addressed in this report: (1) Indexing predator consumption. During 1989--1990, two indices of northern squawfish consumption upon juvenile salmonids were developed for use throughout the Columbia River Basin. The direct Consumption Index (CI) is based upon the concept of meal turnover time and takes into account number of salmonids, temperature, total gut content weight and predator weight. A Bioenergetics Index (BI) for consumption indexing was also developed to complement the direct CI. In the BI, growth, consumption, excretion/evacuation and respiration processes are modeled to predict the consumption requiredmore » to produce an observed growth increment. (2) Studies on predator-smolt dynamics. Northern squawfish consumption data were collected in the McNary Dam tailrace during nine days in July 1988 to improve our understanding of the predator-smolt functional response. (3) Selective predation by northern squawfish. Laboratory and field protocols were developed to evaluate northern squawfish selection and prey vulnerability. Results from laboratory studies suggest that northern squawfish prefer dead over live prey and that descaled prey may be more vulnerable to predation than non-descaled prey. Stressed and unstressed prey were consumed in equal proportions when predation occurred for 6 or 24 h. Physiological and behavioral effects of stress on juvenile salmon are presented. 100 refs., 13 figs., 12 tabs.« less

Sexual difference in polychlorinated biphenyl accumulation rates of walleye (Stizostedion vitreum)

USGS Publications Warehouse

Madenjian, Charles P.; Noguchi, George E.; Haas, Robert C.; Schrouder, Kathrin S.

1998-01-01

Adult male walleye (Stizostedion vitreum) exhibited significantly higher polychlorinated biphenyl (PCB) concentrations than similarly aged female walleye from Saginaw Bay (Lake Huron). To explain this difference, we tested the following three hypotheses: (i) females showed a considerably greater reduction in PCB concentration immediately following spawning than males, (ii) females grew at a faster rate and therefore exhibited lower PCB concentrations than males, and (iii) males spent more time in the Saginaw River system than females, and therefore received a greater exposure to PCBs. The first hypothesis was tested by comparing PCB concentration in gonadal tissue with whole-body concentration, the second hypothesis was tested via bioenergetics modeling, and we used mark-recapture data from the Saginaw Bay walleye fishery to address the third hypothesis. The only plausible explanation for the observed difference in PCB accumulation rate was that males spent substantially more time in the highly contaminated Saginaw River system than females, and therefore were exposed to greater environmental concentrations of PCBs. Based on the results of our study, we strongly recommend a stratified random sampling design for monitoring PCB concentration in Saginaw Bay walleye, with fixed numbers of females and males sampled each year.

The effect of oil sands tailings pond sediments on embryo-larval walleye (Sander vitreus).

PubMed

Raine, J C; Turcotte, D; Tumber, V; Peru, K M; Wang, Z; Yang, C; Headley, J V; Parrott, J L

2017-10-01

Walleye (Sander vitreus) are a commercially important North American fish species that inhabit the Athabasca River. This river flows through the Athabasca oil sands where natural sources of bitumen erode from the McMurray formation. Little information is available on responses of walleye embryos to oil sands tailings pond sediments in a laboratory setting. The current study describes the design and implementation of a daily-renewal bioassay to assess the potential effects of tailings pond sediments from the Athabasca oil sands area on walleye development. Developing walleye embryos were exposed to increasing concentrations of two tailings pond sediments (collected in the Athabasca oil sands area) until the completion of yolk absorption in control fish. Sediments from the tailings pond represent a mixture of polycyclic aromatic hydrocarbons (PAHs) and alkylated PAHs. During the 31 day exposure, the walleye were examined for mortalities, weight, length and developmental abnormalities to provide an initial evaluation of the effects of the oil sands tailings pond sediments. Walleye embryo survival differed between the tailings pond sediments, and survival decreased with increasing sediment concentration. Alkylated PAH content differed between the two tailings pond sediments and lower embryo survival corresponded to higher total and alkylated PAH content. Tailings pond sediment-exposed walleye exhibited a delay in development, as well as increased percentages of larvae with heart and yolk sac edema, and cranial and spinal malformations. These abnormalities in development are often associated with PAH and alkylated PAH exposure. This study provides an exposure design that can be used to assess sediment toxicity to early developmental stages of a fish species not commonly tested in the lab, and lays the groundwork for future studies with this and other difficult-to-culture species. These results offer information on the potential effects of tailings pond sediments

Factors influencing recruitment of walleye and white bass to three distinct early ontogenetic stages

USGS Publications Warehouse

DeBoer, Jason A.; Pope, Kevin L.

2015-01-01

Determining the factors that influence recruitment to sequential ontogenetic stages is critical for understanding recruitment dynamics of fish and for effective management of sportfish, particularly in dynamic and unpredictable environments. We sampled walleye (Sander vitreus) and white bass (Morone chrysops) at 3 ontogenetic stages (age 0 during spring: ‘age-0 larval’; age 0 during autumn: ‘age-0 juvenile’; and age 1 during autumn: ‘age-1 juvenile’) from 3 reservoirs. We developed multiple linear regression models to describe factors influencing age-0 larval, age-0 juvenile and age-1 juvenile walleye and white bass abundance indices. Our models explained 40–80% (68 ± 9%; mean ± SE) and 71%–97% (81 ± 6%) of the variability in catch for walleye and white bass respectively. For walleye, gizzard shad were present in the candidate model sets for all three ontogenetic stages we assessed. For white bass, there was no unifying variable in all three stage-specific candidate model sets, although walleye abundance was present in two of the three white bass candidate model sets. We were able to determine several factors affecting walleye and white bass year-class strength at multiple ontogenetic stages; comprehensive analyses of factors influencing recruitment to multiple early ontogenetic stages are seemingly rare in the literature. Our models demonstrate the interdependency among early ontogenetic stages and the complexities involved with sportfish recruitment.

Variation in annual production of copepods, euphausiids, and juvenile walleye pollock in the southeastern Bering Sea

NASA Astrophysics Data System (ADS)

Sigler, Michael F.; Napp, Jeffrey M.; Stabeno, Phyllis J.; Heintz, Ronald A.; Lomas, Michael W.; Hunt, George L.

2016-12-01

We synthesize recent research on variation in annual production of copepods (Calanus spp.), euphausiids (Thysanoessa spp.), and juvenile walleye pollock (Gadus chalcogrammus) in the southeastern Bering Sea. We reach five conclusions: 1) the timing of the spring bloom is more important than the amount of annual primary production for the transfer of primary to secondary production (i.e., timing matters); 2) summer and fall, not just spring, matter: organisms must maximize energy intake devoted to somatic growth and storage of lipids and minimize energy expenditures during each season; 3) stored lipids are important for the overwinter survival of both zooplankton and age-0 walleye pollock; 4) variation in ice extent and timing of ice retreat affect the spatial distributions of phytoplankton, zooplankton, and age-0 walleye pollock; when these spatial distributions match in late-ice-retreat years, the annual production of copepods, euphausiids, and juvenile walleye pollock often increases (i.e., location matters); 5) if years with late ice retreat, which favor copepod, euphausiid, and juvenile walleye pollock production, occur in succession, top-down control increases. These conclusions help to explain annual variation in production of copepods, euphausiids and juvenile walleye pollock. Copepods and euphausiids often are more abundant in cold years with late ice retreat than in warm years with early ice retreat due to bloom timing and the availability of ice algae during years with late ice retreat. As a consequence, age-0 walleye pollock consume lipid-enriched prey in cold years, better preparing them for their first winter and their overwinter survival is greater. In addition, there is a spatial match of primary production, zooplankton, and age-0 walleye pollock in cold years and a mismatch in warm years.

PCBs, liver lesions, and biomarker responses in adult walleye (Stizostedium vitreum vitreum) collected from Green Bay, Wisconsin

USGS Publications Warehouse

Barron, Mace G.; Anderson, Michael J.; Cacela, Dave; Lipton, Joshua; Teh, Swee J.; Hinton, David E.; Zelikoff, Judith T.; Dikkeboom, Audrey L.; Tillitt, Donald E.; Holey, Mark; Denslow, Nancy

2000-01-01

Adult walleye were collected from several locations in the Lower Fox River and Green Bay, Wisconsin (the assessment area) and two relatively uncontaminated reference locations (Lake Winnebago and Patten Lake, Wisconsin) between July and October in 1996 and 1997. Whole body and liver samples collected in 1996 were analyzed for total PCBs, PCB congeners, and liver histological lesions. Follow-up sampling in 1997 included examination of liver histopathology, PCBs in liver samples, measurement of ethoxyresorufin-O-deethylase (EROD) activity, immunological evaluation of kidney and blood samples, measurement of plasma vitellogenin, and examination of tissues for parasites as well as bacterial and viral infections. Mean PCB concentrations in whole body and liver samples were elevated in assessment area walleye (4.6 to 8.6 and 3.6 to 6.4 mg/kg wet weight, respectively) compared to PCB concentrations in reference areas (0.04 mg/kg in walleye fillets from Lake Winnebago). A significant (p < 0.01) elevation was observed in the prevalence (26%) of hepatic preneoplastic foci of cellular alteration (FCA) and neoplasms in 5 to 8 year old walleye collected from the assessment area, compared to reference area fish (6% prevalence). Walleye from the assessment area also contained multiple FCA and hepatic tumors per liver sample, whereas no tumors and a reduced prevalence of FCA were observed in reference area walleye. Both tumors and FCA were more prevalent in female fish than in male fish within the 5 to 8 year age classes. There were no remarkable effects on immunological parameters in assessment area walleye, although hematocrit was elevated and blood monocyte counts were 40% lower than those of reference area fish. The data did not show any clear distinctions in the prevalence of disease between reference and assessment area walleye. EROD activity was similar in assessment area and reference area walleye. Plasma vitellogenin was elevated in female walleye from eastern Green Bay

Diet Overlap and Predation between Smallmouth Bass and Walleye in a North Temperate Lake

Treesearch

Aaron P. Frey; Michael A. Bozek; Clayton J. Edwards; Steve P. Newman

2003-01-01

Walleye (Stizostedion vitreum vitreum) and smallmouth bass (Micropterus dolomieu) diets from Big Crooked Lake, Wisconsin were examined to assess the degree of diet overlap and predation occurring between these species in an attempt to deternine whether walleye influence smallmouth bass recruitment, which is consistently low...

Effects of simulated angler capture and live-release tournaments on walleye survival

USGS Publications Warehouse

Loomis, John H.; Schramm, Harold L.; Vondracek, Bruce C.; Gerard, Patrick D.; Chizinski, Christopher J.

2015-01-01

We examined the effects of acclimation water temperature,live-well (LW) water temperature,and LW dissolved oxygen (DO) concentration on survival of adult WalleyesSander vitreus subjected to simulated tournament conditions (angling,LW confinement,and weigh-in procedures) under controlled laboratory conditions. We tested three acclimation temperatures (12,18,and 24°C),and three LW temperature differentials (ΔT = −4,0,and +4°C) were tested at each acclimation temperature. Survival was monitored after 8 h of LW confinement and during a 5-d retention period in 1,700-L tanks. None of the Walleyes that were acclimated to 24°C and subjected to simulated tournament procedures survived the 5-d retention period; for fish subjected only to simulated angling at 24°C,survival during the 5-d retention period was 29%. Five-day survival was generally over 70% at acclimation temperatures of 12°C and 18°C,and we observed a significant interaction between acclimation temperature and ΔT; survival was greatest in LWs at −4°C ΔT for fish acclimated to 18°C and in LWs at +4°C ΔT for fish acclimated to 12°C. Best survival of Walleyes subjected to the stress of angling and tournament procedures was obtained at temperatures 6–8°C below the optimum temperature for adult Walleyes (i.e.,optimum = 20–22°C). Five-day survival exceeded 70% when LW DO was 5 or 12–15 mg/L (at an acclimation and LW temperature of 18°C),but survival was 0% when DO was 2 mg/L. Anglers may increase survival of Walleyes through careful manipulation of LW temperature and DO when ambient temperature is at or below 18°C,but high mortality of angled and LW-retained Walleyes should be expected when ambient water temperatures are 24°C or greater.

Toxicity of TFM lampricide to early life stages of walleye

USGS Publications Warehouse

Seelye, J.G.; Marking, L.L.; King, E.L.; Hanson, L.H.; Bills, T.D.

1987-01-01

The authors studied the effects of the lampricide 3-trifluoromethyl-4-nitrophenol (TFM) on gametes, newly fertilized eggs, eyed eggs, larvae, and swim-up fry of the walleye Stizostedion vitreum . When gametes from sexually mature walleyes were stripped into solutions of TFM, no effects were observed during the fertilization process at concentrations up to 3.0 mg/L - three times the concentration lethal to 99.9% of larval sea lampreys Petromyzon marinus held 12 h (LC99.9) under the same test conditions. Newly fertilized eggs likewise were unaffected during water hardening by concentrations of TFM that were lethal to sea lamprey ammocoetes. Eyed eggs, sac fry, and swim-up fry yielded LC25 values that were 2.5 to 5 times greater than the 12-h LC99.9 for sea lamprey ammocoetes. The data thus indicated that all of the early life stages of walleyes tested were considerably more resistant than sea lamprey ammocoetes to TFM, and that it is unlikely they would be adversely affected by standard stream treatments to kill sea lamprey ammocoetes.

Walleye population and fishery responses after elimination of legal harvest on Escanaba Lake, Wisconsin

USGS Publications Warehouse

Haglund, Justin M.; Isermann, Daniel A.; Sass, Greg G.

2016-01-01

Implementing harvest regulations to eliminate or substantially reduce (≥90%) the exploitation of Walleyes Sander vitreus in recreational fisheries may increase population size structure, but these measures also could reduce angler effort because many Walleye anglers are harvest oriented. We analyzed data collected during 1995–2015 to determine whether Walleye population and fishery metrics in Escanaba Lake, Wisconsin, changed after a minimum TL limit of 71 cm with a one-fish daily bag limit was implemented in 2003. This change eliminated the legal harvest of Walleyes after several decades during which annual exploitation averaged 34%. We detected a significant increase in the loge density of adult females after the regulation change, but the loge density of all adults and adult males did not differ between periods. Mean TL of adult males was significantly greater after the regulation change, but the mean TL of females and the proportional size distribution of preferred-length fish (≥51 cm TL) were similar between periods. Sex-specific mean TLs at age 5 did not differ between periods. Loge density of age-0 Walleyes did not change after 2003, but variation in age-0 density was lower. Total angler effort and the effort for anglers targeting Walleyes were significantly lower (35% and 60% declines, respectively) after the regulation change, whereas catch rates for both angler categories did not differ between periods. Our results suggest that implementing highly restrictive regulations that greatly reduce or eliminate legal harvest will not always increase angler catch rates and population size structure. Highly restrictive regulations may also deter anglers from using a fishery when many other fisheries are available. Our findings are useful for fishery managers who may work with anglers holding the belief that lower exploitation is a potential remedy for low Walleye size structure, even when density and growth suggest that there is limited potential for

Selection of prey by walleyes in the Ohio waters of the central basin of Lake Erie, 1985-1987

USGS Publications Warehouse

Wolfert, David R.; Bur, Michael T.

1992-01-01

Walleyes (Stizostedion vitreum vitreum) were collected at five locations in the central basin of Lake Erie in 1985-87. The contents of the fishes' stomachs were examined to identify the species of prey. The seasonal availability of potential prey was determined from sampling with trawl tows. Food electivity indexes for young-of-the-year (YOY) and older walleyes were calculated. Electivity indexes changed monthly in YOY walleyes that consumed mostly YOY gizzard shads (Dorosoma cepedianum) in July and fed moderately on gizzard shads, but more on smelts (Osmerus mordax), in August. In September and October YOY walleyes did not consume YOY white perch (Morone americana). During October, they continued to eat YOY gizzard shads moderately but consumed mostly emerald shiners (Notropis atherinoides). Older walleys were highly partial to YOY gizzard shads, emerald shiners, and smelts and consumed no YOY white perch. The numbers of YOY yellow perch (Perca flavescens) in stomachs were limited. Prey selection by walleyes in the central basin was species-specific irrespective of abundance of prey.

Efficacy of oxytetracycline hydrochloride bath immersion to control external columnaris disease on walleye and channel catfish fingerlings

USGS Publications Warehouse

Rach, J.J.; Johnson, Aaron H.; Rudacille, J.B.; Schleis, S.M.

2008-01-01

The efficacy of oxytetracycline hydrochloride (OTC-HCl) in controlling external columnaris disease caused by Flavobacterium columnare on fingerling walleyes Sander vitreus and channel catfish Ictalurus punctatus was evaluated in two on-site hatchery trials. Microscopic examination of skin scrapings before treatment confirmed the presence of bacteria with characteristics indicative of F. columnare.in separate trials, walleyes (4.4 g) and channel catfish (1.5 g) were exposed to 60-min static bath treatments of OTC-HCl at 0, 10, and 20 mg/L (walleyes) or 0, 10, 20, and 40 mg/L (channel catfish) on three consecutive days. Each treatment regimen was tested in triplicate, and each replicate contained either 30 walleyes or 55 channel catfish. Posttreatment presumptive disease diagnosis indicated that F. columnare was the disease agent causing the mortality in both species of fish. Walleye survival at 10 d posttreatment was greater in the 10- and 20-mg/L treatment groups than in the control group; however, only the 10-mg/L treatment significantly (P < 0.05) increased walleye survival in comparison with controls. In the channel catfish trial, survival at 10 d posttreatment was significantly (P < 0.05) greater for all OTC-HCl treatment groups relative to controls. Results from these trials indicated that OTC-HCl treatments effectively reduced mortality in walleyes (10 mg/L only) and channel catfish infected with F. columnare. ?? Copyright by the American Fisheries Society 2008.

Distribution and population genetics of walleye and sauger

USGS Publications Warehouse

Haponski, Amanda E.; Sloss, Brian L.

2014-01-01

Conserving genetic diversity and local adaptations are management priorities for wild populations of exploited species, which increasingly are subject to climate change, habitat loss, and pollution. These constitute growing concerns for the walleye Sander vitreus, an ecologically and economically valuable North American temperate fish with large Laurentian Great Lakes' fisheries. This study compares genetic diversity and divergence patterns across its widespread native range using mitochondrial (mt) DNA control region sequences and nine nuclear DNA microsatellite (μsat) loci, examining historic and contemporary influences. We analyze the genetic and morphological characters of a putative endemic variant– “blue pike” S. v. “glaucus” –described from Lakes Erie and Ontario, which became extinct. Walleye with turquoise-colored mucus also are evaluated, since some have questioned whether these are related to the “blue pike”.

Sexual difference in PCB concentrations of walleyes (Sander vitreus) from a pristine lake

USGS Publications Warehouse

Madenjian, C.P.; Hanchin, P.A.; Chernyak, S.M.; Begnoche, L.J.

2009-01-01

We determined polychlorinated biphenyl (PCB) concentrations in 15 adult female walleyes (Sander vitreus) and 15 adult male walleyes from South Manistique Lake (Michigan, United States), a relatively pristine lake with no point source inputs of PCBs. By measuring PCB concentration in gonads and in somatic tissue of the South Manistique Lake fish, we also estimated the expected change in PCB concentration due to spawning for both sexes. To determine whether gross growth efficiency differed between the sexes, we applied bioenergetics modeling. Results showed that, on average, adult males were 34% higher in PCB concentration than adult females in South Manistique Lake. Results from the PCB determinations of the gonads and somatic tissues revealed that shedding of the gametes led to 1% and 5% increases in PCB concentration for males and females, respectively. Therefore, shedding of the gametes could not explain the higher PCB concentration in adult male walleyes. Bioenergetics modeling results indicated that the sexual difference in PCB concentrations of South Manistique Lake walleyes was attributable, at least in part, to a sexual difference in gross growth efficiency (GGE). Adult female GGE was estimated to be up to 17% greater than adult male GGE.

Spawning site fidelity and apparent annual survival of walleye (Sander vitreus) differ between a Lake Huron and Lake Erie tributary

USGS Publications Warehouse

Hayden, Todd A.; Binder, Thomas; Holbrook, Christopher; Vandergoot, Christopher; Fielder, David G.; Cooke, Steven J.; Dettmers, John M.; Krueger, Charles C.

2018-01-01

Fidelity to spawning habitats can maximise reproductive success of fish by synchronising movements to sites of previous recruitment. To determine the role of reproductive fidelity in structuring walleye Sander vitreus populations in the Laurentian Great Lakes, we used acoustic telemetry combined with Cormack–Jolly–Seber capture–recapture models to estimate spawning site fidelity and apparent annual survival for the Tittabawassee River in Lake Huron and Maumee River in Lake Erie. Walleye in spawning condition were tagged from the Tittabawassee River in Lake Huron and Maumee River in Lake Erie in 2011–2012. Site fidelity and apparent annual survival were estimated from return of individuals to the stream where tagged. Site fidelity estimates were higher in the Tittabawassee River (95%) than the Maumee River (70%) and were not related to sex or fish length at tagging. Apparent annual survival of walleye tagged in the Tittabawassee did not differ among spawning seasons but was higher for female than male walleye and decreased linearly as fish length increased. Apparent annual survival of walleye tagged in the Maumee River did not differ among spawning seasons but was higher for female walleye than male walleye and increased linearly as fish length increased. Greater fidelity of walleye tagged in the Tittabawassee River than walleye tagged in the Maumee River may be related to the close proximity to the Maumee River of other spawning aggregations and multiple spawning sites in Lake Erie. As spawning site fidelity increases, management actions to conserve population structure require an increasing focus on individual stocks.

Age structure and mortality of walleyes in Kansas reservoirs: Use of mortality caps to establish realistic management objectives

USGS Publications Warehouse

Quist, M.C.; Stephen, J.L.; Guy, C.S.; Schultz, R.D.

2004-01-01

Age structure, total annual mortality, and mortality caps (maximum mortality thresholds established by managers) were investigated for walleye Sander vitreus (formerly Stizostedion vitreum) populations sampled from eight Kansas reservoirs during 1991-1999. We assessed age structure by examining the relative frequency of different ages in the population; total annual mortality of age-2 and older walleyes was estimated by use of a weighted catch curve. To evaluate the utility of mortality caps, we modeled threshold values of mortality by varying growth rates and management objectives. Estimated mortality thresholds were then compared with observed growth and mortality rates. The maximum age of walleyes varied from 5 to 11 years across reservoirs. Age structure was dominated (???72%) by walleyes age 3 and younger in all reservoirs, corresponding to ages that were not yet vulnerable to harvest. Total annual mortality rates varied from 40.7% to 59.5% across reservoirs and averaged 51.1% overall (SE = 2.3). Analysis of mortality caps indicated that a management objective of 500 mm for the mean length of walleyes harvested by anglers was realistic for all reservoirs with a 457-mm minimum length limit but not for those with a 381-mm minimum length limit. For a 500-mm mean length objective to be realized for reservoirs with a 381-mm length limit, managers must either reduce mortality rates (e.g., through restrictive harvest regulations) or increase growth of walleyes. When the assumed objective was to maintain the mean length of harvested walleyes at current levels, the observed annual mortality rates were below the mortality cap for all reservoirs except one. Mortality caps also provided insight on management objectives expressed in terms of proportional stock density (PSD). Results indicated that a PSD objective of 20-40 was realistic for most reservoirs. This study provides important walleye mortality information that can be used for monitoring or for inclusion into

Cormorant predation and the population dynamics of walleye and yellow perch in Oneida Lake

USGS Publications Warehouse

Rudstam, L. G.; VanDeValk, A.J.; Adams, C.M.; Coleman, J.T.H.; Forney, J.L.; Richmond, M.E.

2004-01-01

Double-crested Cormorants (Phalacrocorax auritus) increased dramatically in North America during the 1990s, providing the opportunity to study the effects of an increase of a top predator on an existing predator-prey system. In Oneida Lake, New York, USA, Double-crested Cormorants were first observed nesting in 1984 and had increased to over 360 nesting pairs by 2000. Concomitant with this increase in piscivorous birds was a decrease in the adult walleye (Stizostedion vitreum) and yellow perch (Perca flavescens) populations. Analysis of a 40-yr data series shows higher mortality of subadults (age 1-2 yr perch and age 1-3 yr walleye) for both species in the 1990s compared to the previous three decades. Cormorant diet was investigated from 1995 to 2000 using a combination of cast pellets, regurgitants, and stomach analysis. Walleye and yellow perch were a major portion of the cormorant diet during these years (40-82% by number). The number of subadult walleye and yellow perch consumed by cormorants suggests that the increase in subadult mortality can be explained by predation from cormorants. Mean mortality rates of adult percids attributed to cormorant predation were 1.1% per year for walleye and 7.7% per year for yellow perch. Our analysis suggests that predation by cormorants on subadult percids is a major factor contributing to the decline in both the walleye and the yellow perch populations in Oneida Lake. Other ecosystem changes (zebra mussels, lower nutrient loading, decrease in alternate prey) are not likely explanations because the potential mechanisms involved are not consistent with auxiliary data from the lake and would not affect subadult mortality. The likely impact of bird predation on percid populations in Oneida Lake occurs because cormorants feed on larger fish that are beyond the size range where compensatory mechanisms are important.

The Effects of Simulated Live-release Walleye Tournaments on Survival and Blood Chemistry

USGS Publications Warehouse

Loomis, John H.; Schramm, Harold L.; Vondracek, Bruce C.; Gerard, Patrick D.; Chizinski, Christopher J.

2013-01-01

We examined the effects of acclimation water temperature,live-well (LW) water temperature,and LW dissolved oxygen (DO) concentration on survival of adult WalleyesSander vitreus subjected to simulated tournament conditions (angling,LW confinement,and weigh-in procedures) under controlled laboratory conditions. We tested three acclimation temperatures (12,18,and 24°C),and three LW temperature differentials (ΔT = −4,0,and +4°C) were tested at each acclimation temperature. Survival was monitored after 8 h of LW confinement and during a 5-d retention period in 1,700-L tanks. None of the Walleyes that were acclimated to 24°C and subjected to simulated tournament procedures survived the 5-d retention period; for fish subjected only to simulated angling at 24°C,survival during the 5-d retention period was 29%. Five-day survival was generally over 70% at acclimation temperatures of 12°C and 18°C,and we observed a significant interaction between acclimation temperature and ΔT; survival was greatest in LWs at −4°C ΔT for fish acclimated to 18°C and in LWs at +4°C ΔT for fish acclimated to 12°C. Best survival of Walleyes subjected to the stress of angling and tournament procedures was obtained at temperatures 6–8°C below the optimum temperature for adult Walleyes (i.e.,optimum = 20–22°C). Five-day survival exceeded 70% when LW DO was 5 or 12–15 mg/L (at an acclimation and LW temperature of 18°C),but survival was 0% when DO was 2 mg/L. Anglers may increase survival of Walleyes through careful manipulation of LW temperature and DO when ambient temperature is at or below 18°C,but high mortality of angled and LW-retained Walleyes should be expected when ambient water temperatures are 24°C or greater.

Response of walleye and yellow perch to water-level fluctuations in glacial lakes

USGS Publications Warehouse

Dembkowski, D.J.; Chipps, Steven R.; Blackwell, B. G.

2014-01-01

The influence of water levels on population characteristics of yellow perch, Perca flavescens (Mitchill), and walleye, Sander vitreus (Mitchill), was evaluated across a range of glacial lakes in north-eastern South Dakota, USA. Results showed that natural variation in water levels had an important influence on frequently measured fish population characteristics. Yellow perch abundance was significantly (P<0.10) greater during elevated water levels. Yellow perch size structure, as indexed by the proportional size distribution of quality- and preferred-length fish (PSD and PSD-P), was significantly greater during low-water years, as was walleye PSD. Mean relative weight of walleye increased significantly during high-water periods. The dynamic and unpredictable nature of water-level fluctuations in glacial lakes ultimately adds complexity to management of these systems.

Does behavioural thermoregulation underlie seasonal movements in Lake Erie walleye?

USGS Publications Warehouse

Raby, Graham D.; Vandergoot, Christopher; Hayden, Todd A.; Faust, Matthew D.; Kraus, Richard T.; Dettmers, John M.; Cooke, Steven J.; Zhao, Yingming; Fisk, Aaron T.; Krueger, Charles C.

2018-01-01

Thermoregulation is presumed to be a widespread determinant of behaviour in fishes, but has not often been investigated as a mechanism shaping long-distance migrations. We used acoustic telemetry and animal-borne thermal loggers to test the hypothesis that seasonal migration in adult walleye (Sander vitreus) in Lake Erie is size- and (or) sex-specific and related to behavioural thermoregulation. Female walleye migrated out of the warm, shallow western basin earlier than did males and were 1.8 times more likely to be detected on acoustic receivers in the deeper and cooler eastern basin. The few fish that remained in the western basin were restricted to a smaller range of higher temperatures (≥20 °C) than those that migrated to the central and eastern basins (∼16–21 °C). However, temperature records from walleye in the central basin were nearly indistinguishable from those in the eastern basin, suggesting thermal preferences alone could not explain migration to the eastern basin. As such, our effort to understand the mechanisms that cause migratory behaviours has generated mixed evidence on the role of temperature and that factors like foraging opportunities may have synergistic roles in the migration.

Environmental DNA assays for the sister taxa aauger (Sander canadensis) and walleye (Sander vitreus)

Treesearch

Joseph C. Dysthe; Kellie J. Carim; Michael Ruggles; Kevin S. McKelvey; Michael K. Young; Michael K. Schwartz

2017-01-01

Sauger (Sander canadensis) and walleye (S. vitreus) are percid fishes that naturally co-occur throughout much of the eastern United States. The native range of sauger extends into the upper Missouri River drainage where walleye did not historically occur, but have been stocked as a sport fish. Sauger populations have been declining due to habitat loss, fragmentation,...

Interactions between walleyes and smallmouth bass in a Missouri River reservoir with consideration of the influence of temperature and prey

USGS Publications Warehouse

Wuellner, Melissa R.; Chipps, Steven R.; Willis, David W.; Adams, Wells E.

2010-01-01

Walleyes Sander vitreus are the most popular fish among South Dakota anglers, but smallmouth bass Micropterus dolomieu were introduced to provide new angling opportunities. Some walleye anglers have reported reductions in the quality of walleye fisheries since the introduction of smallmouth bass and attribute this to the consumption of young walleyes by smallmouth bass and competition for shared prey resources. We quantified the diets of walleyes and smallmouth bass in the lower reaches of Lake Sharpe (a Missouri River reservoir), calculated the diet overlap between the two predators, and determined whether they partitioned shared prey based on size. We also quantified walleye diets in the upper reach of the reservoir, which has a different prey base and allowed us to compare the growth rates of walleyes within Lake Sharpe. Age-0 gizzard shad Dorosoma cepedianum composed a substantial proportion of the diets of both predators, regardless of location, for most of the growing season; the patterns in shad vulnerability appeared to drive the observed patterns in diet overlap. Smallmouth bass appeared to consume a smaller size range of gizzard shad than did walleyes, which consumed a wide range. Smallmouth bass consumed Sander spp. in some months, but in very low quantities. Given that global climate change is expected to alter the population and community dynamics in Great Plains reservoirs, we also used a bioenergetics approach to predict the potential effects of limiting prey availability (specifically, the absence of gizzard shad and rainbow smelt Osmerus mordax) and increased water temperatures (as projected from global climate change models) on walleye and smallmouth bass growth. The models indicated that the absence of rainbow smelt from the diets of walleyes in upper Lake Sharpe would reduce growth but that the absence of gizzard shad would have a more marked negative effect on both predators at both locations. The models also indicated that higher

Spatial and temporal genetic analysis of Walleyes in the Ohio River

USGS Publications Warehouse

Page, Kevin S.; Zweifela, Richard D.; Stott, Wendylee

2017-01-01

Previous genetic analyses have shown that Walleyes Sander vitreus in the upper Ohio River comprise two distinct genetic strains: (1) fish of Great Lakes origin that were stocked into the Ohio River basin and (2) a remnant native strain (Highlands strain). Resource agencies are developing management strategies to conserve and restore the native strain within the upper reaches of the Ohio River. Hybridization between strains has impacted the genetic integrity of the native strain. To better understand the extent and effects of hybridization on the native strain, we used mitochondrial DNA and microsatellite markers to evaluate the spatial (river sections) and temporal (pre- and poststocking) genetic diversity of Ohio River Walleyes. Contemporary Lake Erie Walleyes and archival museum specimens collected from the Ohio River basin were used for comparison to contemporary Ohio River samples. Although there was evidence of hybridization between strains, most of the genetic diversity within the Ohio River was partitioned by basin of origin (Great Lakes versus the Ohio River), with greater similarity among river sections than between strains within the same section. Results also suggested that the native strain has diverged from historical populations. Furthermore, notable decreases in measures of genetic diversity and increased relatedness among native-strain Walleyes within two sections of the Ohio River may be related to stocking aimed at restoration of the Highlands strain. Our results suggest that although the Highlands strain persists within the Ohio River, it has diverged over time, and managers should consider the potential impacts of future management practices on the genetic diversity of this native strain.

Changes in growth and maturity of walleyes associated with stock rehabilitation in western Lake Erie, 1964-1983

USGS Publications Warehouse

Muth, Kenneth M.; Wolfert, David R.

1986-01-01

The precipitous decline in abundance of walleyes (Stizostedion vitreum vitreum) in western Lake Erie during the 1960s caused major concerns for the future of this resource. Mercury contamination in walleyes in 1970 resulted in a moratorium on commercial fishing in United States and Canadian waters. The opportunity arose for resource agencies to develop a plan for rehabilitation of the walleye stocks, and quota management for walleyes was begun in 1976. After 8 years, the resource had recovered dramatically and the estimated standing stock in 1983 was more than three times that in 1976. In the mid-1970s, however, certain detrimental changes suggested that self-regulatory mechanisms were occurring. The growth rate declined gradually but rather consistently. Growth changes were most evident for young-of-the-year (YOY), yearlings, and 2-year-old fish, which usually constituted more than 80% of the standing stock in 1976-1983. Average lengths of YOY fish decreased by nearly 50 mm (from about 240 mm in 1961 to 190 mm in 1983). Average lengths and weights of yearling and older fish began to decline after 1975 and decreased markedly after 1980. Historically, growth of walleyes in western Lake Erie exceeded that reported for many walleye populations in other waters. Another sign of self-regulation was an increasing delay in the onset of maturity. Most (usually more than 90%) of the yearling males were sexually mature each fall before 1979, but this percentage decreased to only 32 by fall 1983. Usually 80% or more of the age-II females were mature each fall during the 1960s and early 1970s, but this percentage decreased rapidly to only 7 by fall 1983. Prey fish populations declined somewhat in the early 1980s, and their ability to sustain the high abundance of walleyes is a great concern to resource managers.

Selectivity evaluation for two experimental gill-net configurations used to sample Lake Erie walleyes

USGS Publications Warehouse

Vandergoot, Christopher S.; Kocovsky, Patrick M.; Brenden, Travis O.; Liu, Weihai

2011-01-01

We used length frequencies of captured walleyes Sander vitreus to indirectly estimate and compare selectivity between two experimental gill-net configurations used to sample fish in Lake Erie: (1) a multifilament configuration currently used by the Ohio Department of Natural Resources (ODNR) with stretched-measure mesh sizes ranging from 51 to 127 mm and a constant filament diameter (0.37 mm); and (2) a monofilament configuration with mesh sizes ranging from 38 to 178 mm and varying filament diameter (range = 0.20–0.33 mm). Paired sampling with the two configurations revealed that the catch of walleyes smaller than 250 mm and larger than 600 mm was greater in the monofilament configuration than in the multifilament configuration, but the catch of 250–600-mm fish was greater in the multifilament configuration. Binormal selectivity functions yielded the best fit to observed walleye catches for both gill-net configurations based on model deviances. Incorporation of deviation terms in the binormal selectivity functions (i.e., to relax the assumption of geometric similarity) further improved the fit to observed catches. The final fitted selectivity functions produced results similar to those from the length-based catch comparisons: the monofilament configuration had greater selectivity for small and large walleyes and the multifilament configuration had greater selectivity for mid-sized walleyes. Computer simulations that incorporated the fitted binormal selectivity functions indicated that both nets were likely to result in some bias in age composition estimates and that the degree of bias would ultimately be determined by the underlying condition, mortality rate, and growth rate of the Lake Erie walleye population. Before the ODNR switches its survey gear, additional comparisons of the different gill-net configurations, such as fishing the net pairs across a greater range of depths and at more locations in the lake, should be conducted to maintain congruence in

Quantity, structure, and habitat selection of natural spawning reefs by walleyes in a north temperate lake: A multiscale analysis

USGS Publications Warehouse

Raabe, Joshua K.; Bozek, Michael A.

2012-01-01

Spawning habitat, the cornerstone of self-sustaining, naturally reproducing walleyeSander vitreus populations, has received limited quantitative research. Our goal was to quantitatively describe the structure and quantity of natural walleye spawning habitat and evaluate potential selection of habitat in Big Crooked Lake, Wisconsin. In 2004 and 2005, we located and delineated walleye egg deposition polygons through visual snorkel and scuba surveys. We also delineated recently deposited, adhesive egg patches daily along one spawning reef in 2005. To determine habitat selection, we quantified and compared spawning and lakewide available habitat at different scales. In both years, walleyes used similar spawning habitat, including three geomorphic types: linear shorelines, a point bar, and an island. Walleyes used only 14% of the entire lake shoreline and 39% of the shoreline comprised of gravel (6.4–76.0 mm), cobble (76.1–149.9 mm), or coarser substrates for spawning in 2005, indicating selection of specific spawning habitat. Lakewide, walleyes spawned close to shore (outer egg deposition polygon boundary mean distance = 2.7 m), in shallow water (outer egg deposition polygon boundary mean depth = 0.3 m), and over gravel substrate (percent coverage mean = 64.3) having low embeddedness (mean = 1.30). Our best nearshore (0–13-m) resource selection function predicted an increase in the relative probability of egg deposition with the increasing abundance of gravel, cobble, and rubble (150.0–303.9-mm) substrates and a decrease with increasing distance from shore and water depth (89.9% overall correct classification). Adhesive egg patches confirmed that walleyes actively chose nearshore, shallow-water, and coarse-substrate spawning habitat. The quantitative habitat information and predictive models will assist biologists in developing walleye spawning reef protection strategies and potentially aid in designing and evaluating artificial spawning reefs.

A biophysical model of Lake Erie walleye (Sander vitreus) explains interannual variations in recruitment

USGS Publications Warehouse

Zhao, Yingming; Jones, Michael L.; Shuter, Brian J.; Roseman, Edward F.

2009-01-01

We used a three-dimensional coupled hydrodynamic-ecological model to investigate how lake currents can affect walleye (Sander vitreus) recruitment in western Lake Erie. Four years were selected based on a fall recruitment index: two high recruitment years (i.e., 1996 and 1999) and two low recruitment years (i.e., 1995 and 1998). During the low recruitment years, the model predicted that (i) walleye spawning grounds experienced destructive bottom currents capable of dislodging eggs from suitable habitats (reefs) to unsuitable habitats (i.e., muddy bottom), and (ii) the majority of newly hatched larvae were transported away from the known suitable nursery grounds at the start of their first feeding. Conversely, during two high recruitment years, predicted bottom currents at the spawning grounds were relatively weak, and the predicted movement of newly hatched larvae was toward suitable nursery grounds. Thus, low disturbance-based egg mortality and a temporal and spatial match between walleye first feeding larvae and their food resources were predicted for the two high recruitment years, and high egg mortality plus a mismatch of larvae with their food resources was predicted for the two low recruitment years. In general, mild westerly or southwesterly winds during the spawning-nursery period should favour walleye recruitment in the lake.

Spatial heterogeneity of mercury bioaccumulation by walleye in Franklin D. Roosevelt Lake and the upper Columbia River, Washington

USGS Publications Warehouse

Munn, M.D.; Short, T.M.

1997-01-01

We examined mercury concentration in muscle of walleye Stizostedion vitreum from three reaches in Franklin D. Roosevelt Lake, a reservoir on the Columbia River, and from the upper Columbia River, an area contaminated by wastes from metal mining and associated processing activities. Our objectives were to describe the relation between size and age of walleyes and tissue concentrations of mercury and to compare mercury concentrations within a single reservoir system among spatially segregated cohorts. Overall, mercury concentrations in walleye muscle ranged from 0.11 to 0.44 mg/kg (wet weight) and were positively correlated with age, weight, and length of the fish. Mercury concentrations in walleyes varied spatially within the system; the highest concentrations were in fish from the lower and middle reaches of the reservoir. Condition factor of age-2+ fish was inversely related to tissue concentration of mercury and was lower in fish from the lower and middle reaches than in fish from the upper reach. Spatial patterns in condition factor and mercury in walleyes were unrelated to concentrations of total mercury in surficial bed sediments, which ranged from less than 0.05 to 2.8 mg/kg (dry weight). We suggest that the observed spatial differences in the concentrations of mercury in walleyes may be attributed to the fish preferring to spawn and forage in specific areas where the bioavailability of mercury varies due to local differences in the physical and chemical environment.

Walleye age estimation using otoliths and dorsal spines: Preparation techniques and sampling guidelines based on sex and total length

USGS Publications Warehouse

Dembkowski, Daniel J.; Isermann, Daniel A.; Koenigs, Ryan P.

2017-01-01

We used dorsal spines and otoliths from 735 Walleye Sander vitreus collected from 35 Wisconsin water bodies to evaluate whether 1) otolith and dorsal spine cross sections provided age estimates similar to simpler methods of preparation (e.g., whole otoliths and dorsal spines, cracked otoliths); and 2) between-reader precision and differences between spine and otolith ages varied in relation to total length (TL), sex, and growth rate. Ages estimated from structures prepared using simpler techniques were generally similar to ages estimated using thin sections of dorsal spines and otoliths, suggesting that, in some instances, much of the additional processing time and specialized equipment associated with thin sectioning could be avoided. Overall, between-reader precision was higher for sectioned otoliths (mean coefficient of variation [CV] = 3.28%; standard error [SE] = 0.33%) than for sectioned dorsal spines (mean CV = 9.20%; SE = 0.56%). When using sectioned otoliths for age assignment, between-reader precision did not vary between sexes or growth categories (i.e., fast, moderate, slow), but between-reader precision was higher for females than males when using sectioned dorsal spines. Dorsal spines were generally effective at replicating otolith ages for male Walleye <450 mm TL and female Walleye <600 mm TL, suggesting that dorsal spines can be used to estimate ages for male Walleye <450 mm TL and female Walleye <600 mm TL. If sex is unknown, we suggest dorsal spines be used to estimate ages for Walleye <450 mm TL, but that otoliths be used for fish >450 mm TL. Our results provide useful guidance on structure and preparation technique selection for Walleye age estimation, thereby allowing biologists to develop sampling guidelines that could be implemented using information that is always (TL) or often (sex) available at the time of fish collection.

Habitat selection and spawning success of walleye in a tributary to Owasco Lake, New York

USGS Publications Warehouse

Chalupnicki, Marc A.; Johnson, James H.; McKenna, James E.; Dittman, Dawn E.

2010-01-01

Walleyes Sander vitreus are stocked into Owasco Lake, New York, to provide a sport fishery, but the population must be sustained by annual hatchery supplementation despite the presence of appropriate habitat. Therefore, we evaluated walleye spawning success in Dutch Hollow Brook, a tributary of Owasco Lake, to determine whether early survival limited recruitment. Spawning success during spring 2006 and 2007 was evaluated by estimating egg densities from samples collected in the lower 725 m of the stream. Environmental variables were also recorded to characterize the selected spawning habitat. Drift nets were set downstream of the spawning section to assess egg survival and larval drift. We estimated that 162,596 larvae hatched in 2006. For 2007, we estimated that 360,026 eggs were deposited, with a hatch of 127,500 larvae and hatching success of 35.4%. Egg density was significantly correlated to percent cover, substrate type, and depth : velocity ratio. Two sections had significantly higher egg deposition than other areas. Adult spawning walleyes selected shallow, slow habitats with some cover and gravel substrate in the accessible reaches of Dutch Hollow Brook. Our results show that walleyes found suitable spawning habitat in Dutch Hollow Brook and that egg and larval development does not appear to limit natural reproduction.

Sequence and Transcriptional Analyses of the Fish Retroviruses Walleye Epidermal Hyperplasia Virus Types 1 and 2: Evidence for a Gene Duplication

PubMed Central

LaPierre, Lorie A.; Holzschu, Donald L.; Bowser, Paul R.; Casey, James W.

1999-01-01

Walleye epidermal hyperplasia virus types 1 and 2 (WEHV1 and WEHV2, respectively) are associated with a hyperproliferative skin lesion on walleyes that appears and regresses seasonally. We have determined the complete nucleotide sequences and transcriptional profiles of these viruses. WEHV1 and WEHV2 are large, complex retroviruses of 12,999 and 13,125 kb in length, respectively, that are closely related to one another and to walleye dermal sarcoma virus (WDSV). These walleye retroviruses contain three open reading frames, orfA, orfB, and orfC, in addition to gag, pol, and env. orfA and orfB are adjacent to one another and located downstream of env. The OrfA proteins were previously identified as cyclin D homologs that may contribute to the induction of cell proliferation leading to epidermal hyperplasia and dermal sarcoma. The sequence analysis of WEHV1 and WEHV2 revealed that the OrfB proteins are distantly related to the OrfA proteins, suggesting that orfB arose by gene duplication. Presuming that the precursor of orfA and orfB was derived from a cellular cyclin, these genes are the first accessory genes of complex retroviruses that can be traced to a cellular origin. WEHV1, WEHV2, and WDSV are the only retroviruses that have an open reading frame, orfC, of considerable size (ca. 130 amino acids) in the leader region preceding gag. While we were unable to predict a function for the OrfC proteins, they are more conserved than OrfA and OrfB, suggesting that they may be biologically important to the viruses. The transcriptional profiles of WEHV1 and WEHV2 were also similar to that of WDSV; Northern blot analyses detected only low levels of the orfA transcripts in developing lesions, whereas abundant levels of genomic, env, orfA, and orfB transcripts were detected in regressing lesions. The splice donors and acceptors of individual transcripts were identified by reverse transcriptase PCR. The similarities of WEHV1, WEHV2, and WDSV suggest that these viruses use

Do walleye pollock exhibit flexibility in where or when they spawn based on variability in water temperature?

NASA Astrophysics Data System (ADS)

Bacheler, Nathan M.; Ciannelli, Lorenzo; Bailey, Kevin M.; Bartolino, Valerio

2012-06-01

Environmental variability is increasingly recognized as a primary determinant of year-class strength of marine fishes by directly or indirectly influencing egg and larval development, growth, and survival. Here we examined the role of annual water temperature variability in determining when and where walleye pollock (Theragra chalcogramma) spawn in the eastern Bering Sea. Walleye pollock spawning was examined using both long-term ichthyoplankton data (N=19 years), as well as with historical spatially explicit, foreign-reported, commercial catch data occurring during the primary walleye pollock spawning season (February-May) each year (N=22 years in total). We constructed variable-coefficient generalized additive models (GAMs) to relate the spatially explicit egg or adult catch-per-unit-effort (CPUE) to predictor variables including spawning stock biomass, season, position, and water temperature. The adjusted R2 value was 63.1% for the egg CPUE model and 35.5% for the adult CPUE model. Both egg and adult GAMs suggest that spawning progresses seasonally from Bogoslof Island in February and March to Outer Domain waters between the Pribilof and Unimak Islands by May. Most importantly, walleye pollock egg and adult CPUE was predicted to generally increase throughout the study area as mean annual water temperature increased. These results suggest low interannual variability in the spatial and temporal dynamics of walleye pollock spawning regardless of changes in environmental conditions, at least at the spatial scale examined in this study and within the time frame of decades.

Fall diets of red-breasted merganser (Mergus serrator) and walleye (Sander vitreus) in Sandusky Bay and adjacent waters of western Lake Erie

USGS Publications Warehouse

Bur, M.T.; Stapanian, M.A.; Bernhardt, G.; Turner, M.W.

2008-01-01

Although published studies indicate the contrary, there is concern among many sport anglers that migrating red-breasted mergansers (Mergus serrator) and other waterbirds pose a competitive threat to sport fish species such as walleye (Sander vitreus) in Lake Erie. We quantified the diet of autumn-migrant mergansers and walleye during 1998-2000 in Sandusky Bay and adjacent waters of western Lake Erie. We hypothesized that the diets of both predators would be similar in species composition, but because of different foraging ecologies their diets would differ markedly in size of prey consumed. In addition to predator samples, we used trawl data from the same general area as an index of prey availability. We found that mergansers fed almost exclusively on fish (nine species). Gizzard shad (Dorosoma cepedianum), emerald shiner (Notropis atherinoides) and round goby (Neogobius melanostomus) were consumed in the greatest numbers, most frequently and comprised the greatest biomass. Walleye fed exclusively on fish: gizzard shad, alewife (Alosa psuedoharengus) and emerald shiner were consumed in the greatest numbers, most frequently and comprised the greatest biomass. Diet overlap between mergansers and walleye was 67% by weight and 66% by species frequency. Mean total lengths of gizzard shad, emerald shiner and round goby found in walleye stomachs exceeded those captured in trawls by 47%, on average. Mean total lengths of gizzard shad, emerald shiner and round goby were greater in walleye stomachs than in merganser stomachs. Mean total lengths of emerald shiner and round goby were less in merganser stomachs than in trawls. Our results suggest that although the diets of walleye and mergansers overlapped considerably, mergansers generally consumed smaller fish than walleye. Given the abundance and diversity of prey species available, and the transient nature of mergansers on Lake Erie during migration, we conclude that competition for food between these species is minimal.

Walleye recruitment success is less resilient to warming water temperatures in lakes with abundant largemouth bass populations

USGS Publications Warehouse

Hansen, Gretchen J. A.; Midway, Stephen R.; Wagner, Tyler

2018-01-01

Lakes respond heterogeneously to climate, with implications for fisheries management. We analyzed walleye (Sander vitreus) recruitment to age-0 in 359 lakes in Wisconsin, USA, to (i) quantify the relationship between annual water temperature degree days (DD) and walleye recruitment success and (ii) identify the influence of lake characteristics — area, conductivity, largemouth bass (Micropterus salmoides) catch rates, and mean DD — on this relationship. The relationship between walleye recruitment and annual DD varied among lakes and was not distinguishable from zero overall (posterior mean = −0.11, 90% CI = −0.34, 0.15). DD effects on recruitment were negative in 198 lakes (55%) and positive in 161 (45%). The effect of annual DD was most negative in lakes with high largemouth bass densities, and, on average, the probability of recruitment was highest in large lakes with low largemouth bass densities. Conductivity and mean DD influenced neither recruitment nor the effect of annual DD. Walleye recruitment was most resilient to warming in lakes with few largemouth bass, suggesting that the effects of climate change depend on lake-specific food-web and habitat contexts.

Toxicity of inorganic contaminants, individually and in environmental mixtures, to three endangered fishes (Colorado squawfish, bonytail, and razorback sucker)

USGS Publications Warehouse

Buhl, Kevin J.; Hamilton, S.J.

1996-01-01

Two life stages of three federally-listed endangered fishes, Colorado squawfish (Ptychocheilus lucius), bonytail (Gila elegans), and razorback sucker (Xyrauchen texanus) were exposed to copper, selenate, selenite, and zinc individually, and to mixtures of nine inorganics in a reconstituted water that simulated the water quality of the middle Green River, Utah. The mixtures simulated environmental ratios of arsenate, boron, copper, molybdenum, selenate, selenite, uranium, vanadium, and zinc in two tributaries, Ashley Creek and Stewart Lake outlet, of the middle Green River. The rank order of toxicity of the individual inorganics, from most to least toxic, was: copper > zinc > selenite > selenate. Colorado squawfish larvae were more sensitive to all four inorganics and the two mixtures than the juveniles, whereas there was no consistent response between the two life stages for the other two species. There was no consistent difference in sensitivity to the inorganics among the three endangered fishes. Both mixtures exhibited either additive or greater than additive toxicity to these fishes. The primary toxic components in the mixtures, based on toxic units, were copper and zinc. Acute toxicity values were compared to measured environmental concentrations in the two tributaries to derive margins of uncertainty. Margins of uncertainty were low for both mixtures (9–22 for the Stewart Lake outlet mixture, and 12–32 for the Ashley Creek mixture), indicating that mixtures of inorganics derived from irrigation activities may pose a hazard to endangered fishes in the Green River.

A method to directly measure maximum volume of fish stomachs or digestive tracts

USGS Publications Warehouse

Burley, C.C.; Vigg, S.

1989-01-01

A new method for measuring maximum stomach or digestive tract volume of fish incorporates air injection at constant pressure with water displacement to measure directly the internal volume of a stomach or analogous structure. The method was tested with coho salmon, Oncorhynchus kisutch (Walbaum), which has a true stomach, and northern squawfish, Ptychocheilus oregonensis(Richardson), which has a modified foregut as a functional analogue. Both species were collected during July-October 1987 from the Columbia River, U.S.A. Relationships between fish weight (= volume) and maximum volume of the digestive organ were best fitted for coho salmon by an allometric model and for northern squawfish by an exponential model. Least squares regression analysis of individual measurements showed less variability in the volume of coho salmon stomachs (R2= 0.85) than in the total digestive tracts (R2= 0.55) and foreguts (R2= 0.61) of northern squawfish, relative to fish size. Compared to previous methods, the new technique has the advantage of accurately measuring the internal volume of a wide range of digestive organ shapes and sizes.

Development of a stock-recruitment model and assessment of biological reference points for the Lake Erie walleye fishery

USGS Publications Warehouse

Zhao, Yingming; Kocovsky, Patrick M.; Madenjian, Charles P.

2013-01-01

We developed an updated stock–recruitment relationship for Lake Erie Walleye Sander vitreus using the Akaike information criterion model selection approach. Our best stock–recruitment relationship was a Ricker spawner–recruit function to which spring warming rate was added as an environmental variable, and this regression model explained 39% of the variability in Walleye recruitment over the 1978 through 2006 year-classes. Thus, most of the variability in Lake Erie Walleye recruitment appeared to be attributable to factors other than spawning stock size and spring warming rate. The abundance of age-0 Gizzard Shad Dorosoma cepedianum, which was an important term in previous models, may still be an important factor for Walleye recruitment, but poorer ability to monitor Gizzard Shad since the late 1990s could have led to that term failing to appear in our best model. Secondly, we used numerical simulation to demonstrate how to use the stock recruitment relationship to characterize the population dynamics (such as stable age structure, carrying capacity, and maximum sustainable yield) and some biological reference points (such as fishing rates at different important biomass or harvest levels) for an age-structured population in a deterministic way.

Fecundity of walleyes in western Lake Erie, 1966 and 1990-91

USGS Publications Warehouse

Muth, Kenneth M.; Ickes, Brian S.

1993-01-01

Ovaries were collected from walleyes (Stizostedion vitreum vitreum) in western Lake Erie just prior to spawning in 1990 and 1991 to determine current fecundity. Results were compared with fecundity determined in 1966 prior to stock rehabilitation when walleye abundance was lower and fish size at age was greater. Fecundity estimates determined from 121 fish aged 3-10 ranged from 53,000 to 426,000 eggs per female. Increases in egg production correlated with increases in length and weight, and weight accounting for most of the variability. In 1990-91 the mean egg production of the dominant age groups of spawners (ages 4 to 8) was approximately 25% lower than fishes of similar age in 1966. The mean egg diameter in 1990-91 (1.63 mm) was not related to the size or age of the fish and was not significantly smaller than the egg diameter in 1966 (1.72 mm).

Walleye Sander vitreus performance, water quality, and waste production in replicated recirculation aquaculture systems when feeding a low phosphorus diet without fishmeal versus a traditional fishmeal-based diet

USDA-ARS?s Scientific Manuscript database

Walleye Sander vitreus is a popular sport- and food-fish in areas surrounding the Great Lakes. Walleye are mainly provided as food-fish by limited capture fisheries, but have potential for profitable production to market-size in recirculation aquaculture systems (RAS). Walleye are piscivorous with a...

Histopathology of repeated, intermittent exposure of chloramine-T to walleye (Sander vitreum) and (Ictalurus punctalus) channel catfish

USGS Publications Warehouse

Gaikowski, M.P.; Densmore, Christine L.; Blazer, V.S.

2009-01-01

Chloramine-T (Cl-T) has been used safely and effectively to control bacterial gill disease in salmonids at a maximum exposure regimen of up to four consecutive, once-daily exposures administered for 60??min at 20??mg/L. However, data to document safe treatment concentrations of Cl-T are lacking for freshwater-reared fish other than salmonids. We report the histopathology resultant from the administration of 12 consecutive, once-daily, 180-min static immersion baths of 0, 20, 50, or 80??mg Cl-T/L to walleye (20????C) and channel catfish (27????C). Twelve fish of each species were euthanized immediately before the first exposure (initial controls) and then after the twelfth exposure and 7 and 14??days after the twelfth exposure. Only initial controls and fish euthanized immediately after the twelfth exposure were processed for histological review because of the general lack of exposure-related lesions in exposed fish. The only exposure-related histological changes were in the spleen where significantly greater erythrocyte swelling and necrosis was observed in channel catfish exposed at 80??mg/L relative to exposure at 0??mg/L; similar histological changes were insignificant for walleye, though there appeared to be a shift in the general category of histological change with degenerative changes (necrosis, etc.) observed following exposure at 50 or 80??mg/L compared to the inflammatory and hemodynamic changes (congestion, leukocyte infiltrate, etc.) observed in walleye exposed at 0 or 20??mg/L. The only significant change in peripheral blood cytology was that walleye fingerlings exposed at 80??mg/L had significantly fewer mature red blood cells and significantly more immature red blood cells per oil-immersion field than controls. The histopathological changes observed following exposure to Cl-T under an exaggerated exposure regimen suggest that walleye or channel catfish therapeutically exposed to Cl-T will not have treatment-related histological changes.

Efficacy of hydrogen peroxide in controlling mortality associated with saprolegniasis on walleye, white sucker, and paddlefish eggs

USGS Publications Warehouse

Gaikowski, M.P.; Rach, J.J.; Drobish, M.; Hamilton, J.; Harder, T.; Lee, L.A.; Moen, C.; Moore, A.

2003-01-01

The efficacy of hydrogen peroxide in controlling saprolegniasis on eggs of walleye Stizostedion vitreum, white sucker Catostomus commersoni, and paddlefish Polyodon spathula was evaluated at four private, state, and federal production hatcheries participating in an Investigational New Animal Drug efficacy study (experiment 1; walleyes) and in a laboratory-based miniature egg jar incubation system (experiment 2; walleyes, white suckers, and paddlefish). Naturally occurring fungal infestations (saprolegniasis) were observed on eggs in both experiments. Confirmatory diagnosis of infested eggs from one hatchery in experiment 1 identified the pathogen as Saprolegnia parasitica. During experiment 1, eggs were treated daily for 15 min with either 0, 500, or 750 mg/L of hydrogen peroxide, and one trial compared a 500-mg/L hydrogen peroxide treatment with a formalin treatment at 1,667 mg/L. Saprolegniasis infestation was observed in control egg jars, whereas treatment with either formalin or hydrogen peroxide virtually eliminated the infestation. Hydrogen peroxide treatments of 500 mg/L either increased egg hatch or were as effective as physical removal of infested eggs in controlling mortality. Although treatment with formalin at 1,667 mg/L significantly increased the percent eye-up of walleye eggs compared with that of those treated with hydrogen peroxide at 500 mg/L, the difference was only 1.9-2.6%. In experiment 2, noneyed eggs were treated for 15 min every other day with 0, 283, 565, or 1,130 mg/L of hydrogen peroxide until the viable eggs hatched. Saprolegniasis infestation engulfed most control eggs, whereas infestation of treated eggs was either reduced or not visible. Hydrogen peroxide significantly increased egg hatch for all three species tested in experiment 2. Although hydrogen peroxide treatments as low as 283 mg/L significantly increased walleye and white sucker hatch, treatments between 500 and 1,000 mg/L are more likely to be effective in production egg

Dynamics of the recovery of the western Lake Erie walleye (Stizostedion vitreum vitreum) stock

USGS Publications Warehouse

Hatch, Richard W.; Nepszy, Stephen J.; Muth, Kenneth M.; Baker, Carl T.

1987-01-01

After its 1957 collapse under intensive fishing and environmental stresses, the walleye (Stizostedion vitreum vitreum) stock of western Lake Erie remained low throughout the 1960s. A moratorium on both sport and commercial fishing, resulting from the 1970 discovery of mercury concentrations in walleye flesh, provided an opportunity for the development of an international interagency management plan. The quota management plan developed depended on sequential projection of the fishable stock on the basis of estimated annual recruitment and reports of total withdrawals from the stock. The fishery reopened gradually and quota management (including allocation among jurisdictions) was implemented in 1976. The stock, which had been gradually increasing as a result of relatively strong year-classes produced in 1970, 1972, and 1974, responded well to limited exploitation and produced a record year-class in 1977. Quotas were exceeded in 1978-80, but the stock continued to improve to the extent that the recommended rate of exploitation was increased in 1980 and again in 1981. As the population expanded, growth began to decline; the decline became apparent in young-of-the-year in the early 1970s and in older walleyes in the late 1970s. This trend toward progressively slower growth, which continued in the 1977 and subsequent year-classes, was accompanied by an increase in length at sexual maturity and a decrease in the percentage of female walleyes reaching sexual maturity at age III. As a net result of these changes, the proportion of mature females in the stock (an index of stock fecundity) decreased slightly during the interval 1975-84, while the estimated biomass of the standing stock rose from 9 000 to nearly 26 000 t. Both sport and commercial catches increased markedly after 1980 in Lake Erie's central basin.

Relationships among condition indices, feeding and growth of walleye in Lake Erie

USGS Publications Warehouse

Hartman, K.J.; Margraf, F.J.

2006-01-01

Condition indices are often used as surrogates of fish health, growth, and feeding and to compare ecological well-being among fish populations. In an effort to identify easily measured indices, growth and food consumption were compared with gonadal-somatic index, liver-somatic index (LSI), fat-somatic index and relative weight (Wr) for ages 1-3 walleye, Sander vitreus (Mitchill), in Lake Erie from 1986 to 1988. The LSI and Wr were significantly correlated with growth rate or food consumption, but correlations were too small to be considered biologically meaningful. Furthermore, no consistent relationships between condition indices and growth or consumption were found among combinations of fish age and season. None of the indices are considered reliable surrogates for more laborious estimates of growth and food consumption for Lake Erie walleye. Significant relationships between Wr and relative abundance of key prey species warrant further investigation. ?? 2006 Blackwell Publishing Ltd.

Feeding ecology of the walleye (Percidae, Sander vitreus), a resurgent piscivore in Lake Huron (Laurentian Great Lakes) after shifts in the prey community

USGS Publications Warehouse

Pothoven, Steven A.; Madenjian, Charles P.; Höök, Tomas O.

2017-01-01

Recovering populations of piscivores can challenge understanding of ecosystem function due to impacts on prey and to potentially altered food webs supporting their production. Stocks of walleye (Percidae, Sander vitreus), an apex predator in the Laurentian Great Lakes, crashed in the mid‐1900s. Management efforts led to recovery by 2009, but recovery coincided with environmental and fish community changes that also had implications for the feeding ecology of walleye. To evaluate potential changes in feeding ecology for this apex predator, we assessed diets in the main basin of Lake Huron and in Saginaw Bay, a large embayment of Lake Huron, during 2009–2011. Walleye switched their diets differently in the main basin and Saginaw Bay, with non‐native round goby (Gobiidae, Neogobius melanostomus) and rainbow smelt (Osmeridae, Osmerus mordax) more prevalent in diets in the main basin, and invertebrates, yellow perch (Percidae,Perca flavescens) and gizzard shad (Clupeidae, Dorosoma cepedianum) more prevalent in diets in the bay. Feeding strategy plots indicated that there was a high degree of individual specialisation by walleye in the bay and the main basin. Bioenergetic simulations indicated that walleye in Saginaw Bay need to consume 10%–18% more food than a walleye that spends part or all of the year in the main basin, respectively, in order to achieve the same growth rate. The differences in diets between the bay and main basin highlight the flexibility of this apex predator in the face of environmental changes, but changes in diet can alter energy pathways supporting piscivore production.

Walleye dermal sarcoma virus: expression of a full-length clone or the rv-cyclin (orf a) gene is cytopathic to the host and human tumor cells.

PubMed

Xu, Kun; Zhang, Ting Ting; Wang, Ling; Zhang, Cun Fang; Zhang, Long; Ma, Li Xia; Xin, Ying; Ren, Chong Hua; Zhang, Zhi Qiang; Yan, Qiang; Martineau, Daniel; Zhang, Zhi Ying

2013-02-01

Walleye dermal sarcoma virus (WDSV) is etiologically associated with a skin tumor, walleye dermal sarcoma (WDS), which develops in the fall and regresses in the spring. WDSV genome contains, in addition to gag, pol and env, three open reading frames (orfs) designated orf a (rv-cyclin), orf b and orf c. Unintegrated linear WDSV provirus DNA isolated from infected tumor cells was used to construct a full-length WDSV provirus clone pWDSV, while orf a was cloned into pSVK3 to construct the expression vector porfA. Stable co-transfection of a walleye cell line (W12) with pWDSV and pcDNA3 generated fewer and smaller G418-resistant colonies compared to the control. By Northern blot analysis, several small transcripts (2.8, 1.8, 1.2, and 0.8 kb) were detected using a WDSV LTR-specific probe. By RT-PCR and Southern blot analysis, three cDNAs (2.4, 1.6 and 0.8 kb) were identified, including both orf a and orf b messenger. Furthermore stable co-transfection of both a human lung adenocarcinoma cell line (SPC-A-1) and a cervical cancer cell line (HeLa) with pcDNA3 and ether porfA or pWDSV also generated fewer and smaller G418-resistant colonies. We conclude that expression of the full-length WDSV clone or the orf a gene inhibits the host fish and human tumor cell growth, and Orf A protein maybe a potential factor which contributes to the seasonal tumor development and regression. This is the first fish provirus clone that has been expressed in cell culture system, which will provide a new in vitro model for tumor research and oncotherapy study.

Walleye dermal sarcoma virus Orf B functions through receptor for activated C kinase (RACK1) and protein kinase C

DOE Office of Scientific and Technical Information (OSTI.GOV)

Daniels, Candelaria C.; Rovnak, Joel; Quackenbush, Sandra L.

2008-06-05

Walleye dermal sarcoma virus is a complex retrovirus that is associated with walleye dermal sarcomas that are seasonal in nature. Fall developing tumors contain low levels of spliced accessory gene transcripts A and B, suggesting a role for the encoded proteins, Orf A and Orf B, in oncogenesis. In explanted tumor cells the 35 kDa Orf B accessory protein is localized to the cell periphery in structures similar to focal adhesions and along actin stress fibers. Similar localization was observed in mammalian cells. The cellular protein, receptor for activated C kinase 1 (RACK1), bound Orf B in yeast two-hybrid assaysmore » and in cell culture. Sequence analysis of walleye RACK1 demonstrated high conservation to other known RACK1 sequences. RACK1 binds to activated protein kinase C (PKC). Orf B associates with PKC{alpha}, which is constitutively activated and localized at the membrane. Activated PKC promoted cell survival, proliferation, and increased cell viability in Orf B-expressing cells.« less

Squamous epithelial proliferation induced by walleye dermal sarcoma retrovirus cyclin in transgenic mice

PubMed Central

Lairmore, Michael D.; Stanley, James R.; Weber, Stacy A.; Holzschu, Donald L.

2000-01-01

Walleye dermal sarcoma (WDS) is a common disease of walleye fish in the United States and Canada. These proliferative lesions are present autumn through winter and regress in the spring. Walleye dermal sarcoma virus (WDSV), a retrovirus distantly related to other members of the family Retroviridae, has been etiologically linked to the development of WDS. We have reported that the D-cyclin homologue [retroviral (rv) cyclin] encoded by WDSV rescues yeast conditionally deficient for cyclin synthesis from growth arrest and that WDSV-cyclin mRNA is present in developing tumors. These data strongly suggest that the rv-cyclin plays a central role in the development of WDS. To test the ability of the WDSV rv-cyclin to induce cell proliferation, we have generated transgenic mice expressing the rv-cyclin in squamous epithelia from the bovine keratin-5 promoter. The transgenic animals were smaller than littermates, had reduced numbers of hair follicles, and transgenic females did not lactate properly. Following injury the transgenic animals developed severe squamous epithelial hyperplasia and dysplasia with ultrastructural characteristics of neoplastic squamous epithelium. Immunocytochemistry studies demonstrated that the hyperplastic epithelium stained positive for cytokeratin and were abnormally differentiated. Furthermore, the rv-cyclin protein was detected in the thickened basal cell layers of the proliferating lesions. These data are the first to indicate that the highly divergent WDSV rv-cyclin is a very potent stimulator of eukaryotic cell proliferation and to demonstrate the potential of a cyclin homologue encoded by a retrovirus to induce hyperplastic skin lesions. PMID:10811912

Effects of light conditions and temperature gradients on vertical migration behavior of larval Arctic cod (Boreogadus saida) and walleye pollock (Gadus chalcogramma)

NASA Astrophysics Data System (ADS)

Flanders, K. R.; Laurel, B.

2016-02-01

Early life stages of marine fishes must maximize growth while minimizing vulnerability to predators. Larval stages in particular are subject to ocean currents, but encounter favorable habitats by adjusting their vertical position in the water column. The investigation of environmental cues that change larval fish behavior is therefore crucial to understanding larval drift and dispersal modeling, and subsequently population structure and connectivity. In this study, the behavioral responses of larval Arctic cod (Boreogadus saida) and walleye pollock (Gadus chalcogramma) in a vertical water column were examined. Two prominent environmental variables, light and temperature, were manipulated over 3 h during observational trials. Light intensity was studied at two levels (1.484 x 101 μE m-2 s-1 ; 2.54 x102 μE m-2 s-1), and a diel effect was studied through the removal of light after 2 h. Light intensity did not significantly impact the position of either species in a vertical water column. However, a significant difference by species was apparent when all light levels were considered: the mean position of Arctic cod was closer to the surface of the water than that of walleye pollock. The effect of temperature through the introduction of a thermocline (range 5.6°C - 1.5°C) was limited to walleye pollock given the Arctic cod larvae were surface oriented across all light treatments. However, the thermocline did not significantly impact the relative change in position from light to dark in walleye pollock, likely because they were also surface oriented in control treatments. These results could be incorporated into future larval dispersal and survival models, particularly in Alaskan and Arctic waters, to investigate changes in species distributions resulting from global warming impacts. These results also indicate population structures of Arctic cod and walleye pollock could be affected, which may be reflected in ecosystem and trophic interactions. Because Arctic cod

To Harvest a Walleye. Student Guide and Teacher Guide. OEAGLS Investigation 16.

ERIC Educational Resources Information Center

Leach, Susan; And Others

Designed to introduce basic ecological relationships in a lake community, this investigation uses a Lake Erie food chain involving people and walleye as an example. The first activity is a board game in the form of a biomass pyramid; students begin with 1000 kilograms of algae and attempt to reach the "harvest" with at least a kilogram…

Predation by Resident Fish on Juvenile Salmonids in John Day Reservoir: Final Report, 1983-1986: Volume 1, Final Report of Research.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Poe, Thomas P.; Rieman, Bruce E.

1988-07-01

In 1982 the NPPC included in its Fish and Wildlife Program a measure that called for studies ''... to investigate juvenile salmon and steelhead losses to predators while these fish are migrating through Columbia and Snake River reservoirs.'' In the same year the Bonneville Power Administration (BPA) funded ODFW and FWS to conduct collaborative studies to estimate the number of juvenile salmonids lost to predators in John Day Reservoir. Also included as study objectives were: (1) a description of the importance of predation losses relative to mortality at the dam and total reservoir mortality; (2) a description of how predationmore » losses might vary (spatially and temporally); and (3) recommendations of measures to control predation on smolts. We studied four species of predator: northern squawfish, walleye, smallmouth bass, and channel catfish. We selected John Day Reservoir as the study site because the following factors led us to believe if predation was a problem in any reservoir, it would be most obvious there because: (1) the reservoir is an important subyearling chinook rearing area; (2) passage and residualism of juvenile salmonids were considered a problem there; and (3) substantial populations of predators were known to reside in the reservoir. Individual reports were processed separately for the data base.« less

Lake Sturgeon, Lake Whitefish, and Walleye egg deposition patterns with response to fish spawning substrate restoration in the St. Clair–Detroit River system

USGS Publications Warehouse

Fischer, Jason L.; Pritt, Jeremy J.; Roseman, Edward; Prichard, Carson G.; Craig, Jaquelyn M.; Kennedy, Gregory W.; Manny, Bruce A.

2018-01-01

Egg deposition and use of restored spawning substrates by lithophilic fishes (e.g., Lake Sturgeon Acipenser fulvescens, Lake Whitefish Coregonus clupeaformis, and Walleye Sander vitreus) were assessed throughout the St. Clair–Detroit River system from 2005 to 2016. Bayesian models were used to quantify egg abundance and presence/absence relative to site-specific variables (e.g., depth, velocity, and artificial spawning reef presence) and temperature to evaluate fish use of restored artificial spawning reefs and assess patterns in egg deposition. Lake Whitefish and Walleye egg abundance, probability of detection, and probability of occupancy were assessed with detection-adjusted methods; Lake Sturgeon egg abundance and probability of occurrence were assessed using delta-lognormal methods. The models indicated that the probability of Walleye eggs occupying a site increased with water velocity and that the rate of increase decreased with depth, whereas Lake Whitefish egg occupancy was not correlated with any of the attributes considered. Egg deposition by Lake Whitefish and Walleyes was greater at sites with high water velocities and was lower over artificial spawning reefs. Lake Sturgeon eggs were collected least frequently but were more likely to be collected over artificial spawning reefs and in greater abundances than elsewhere. Detection-adjusted egg abundances were not greater over artificial spawning reefs, indicating that these projects may not directly benefit spawning Walleyes and Lake Whitefish. However, 98% of the Lake Sturgeon eggs observed were collected over artificial spawning reefs, supporting the hypothesis that the reefs provided spawning sites for Lake Sturgeon and could mitigate historic losses of Lake Sturgeon spawning habitat.

Managing Ich infections of walleye cultured in a surface water supply with copper sulfate

USDA-ARS?s Scientific Manuscript database

Ichthyophthirius multifiliis infests walleye during growout at Rathbun Fish Hatchery (RFH). Daily flow-through formalin treatments (45-50 ppm for 9 h) were applied to prevent Ich outbreaks, and this contributed to 25% ($35,000) of fish production costs during the grow-out period. Research to decre...

Comparison of two viewing methods for estimating largemouth bass and walleye ages from sectioned otoliths and dorsal spines

USGS Publications Warehouse

Wegleitner, Eric J.; Isermann, Daniel A.

2017-01-01

Many biologists use digital images for estimating ages of fish, but the use of images could lead to differences in age estimates and precision because image capture can produce changes in light and clarity compared to directly viewing structures through a microscope. We used sectioned sagittal otoliths from 132 Largemouth Bass Micropterus salmoides and sectioned dorsal spines and otoliths from 157 Walleyes Sander vitreus to determine whether age estimates and among‐reader precision were similar when annuli were enumerated directly through a microscope or from digital images. Agreement of ages between viewing methods for three readers were highest for Largemouth Bass otoliths (75–89% among readers), followed by Walleye otoliths (63–70%) and Walleye dorsal spines (47–64%). Most discrepancies (72–96%) were ±1 year, and differences were more prevalent for age‐5 and older fish. With few exceptions, mean ages estimated from digital images were similar to ages estimated via directly viewing the structures through the microscope, and among‐reader precision did not vary between viewing methods for each structure. However, the number of disagreements we observed suggests that biologists should assess potential differences in age structure that could arise if images of calcified structures are used in the age estimation process.

Comparisons between consumption estimates from bioenergetics simulations and field measurements for walleyes from Oneida Lake, New York

USGS Publications Warehouse

Lantry, B.F.; Rudstam, L. G.; Forney, J.L.; VanDeValk, A.J.; Mills, E.L.; Stewart, D.J.; Adams, J.V.

2008-01-01

Daily consumption was estimated from the stomach contents of walleyes Sander vitreus collected weekly from Oneida Lake, New York, during June-October 1975, 1992, 1993, and 1994 for one to four age-groups per year. Field rations were highly variable between weeks, and trends in ration size varied both seasonally and annually. The coefficient of variation for weekly field rations within years and ages ranged from 45% to 97%. Field estimates were compared with simulated consumption from a bioenergetics model. The simulation averages of daily ration deviated from those of the field estimates by -20.1% to +70.3%, with a mean across all simulations of +14.3%. The deviations for each time step were much greater than those for the simulation averages, ranging from -92.8% to +363.6%. A systematic trend in the deviations was observed, the model producing overpredictions at rations less than 3.7% of body weight. Analysis of variance indicated that the deviations were affected by sample year and week but not age. Multiple linear regression using backwards selection procedures and Akaike's information criterion indicated that walleye weight, walleye growth, lake temperature, prey energy density, and the proportion of gizzard shad Dorosoma cepedianum in the diet significantly affected the deviations between simulated and field rations and explained 32% of the variance. ?? Copyright by the American Fisheries Society 2008.

Infection of the walleye, Stizostedion v. vitreum, of western Lake Erie with Bothriocephalus cuspidatus (Cooper)

USGS Publications Warehouse

Wolfert, David R.; Applegate, Vernon C.; Allison, Leonard N.

1967-01-01

In recent years appreciable changes have taken place in the biota and physiochemical conditions in Lake Erie. The accelerated eutrophication of the lake has been accompanied by the near disappearance of several fish species, e.g., blue pike (Stizostedion vitreum glaucum), lake herring (Coregonus artedi), lake trout (Salvelinus namaycush), sauger (Stizostedion canadense), and whitefish (Coregonus clupeaformis). Interest in the biology of the remaining species has increased as means have been sought to preserve their numbers in the lake. This report, which describes the caecal and intestinal parasites of the walleye, Stizostedion vitreum vitreum, is a contribution to the natural history of this fish in western Lake Erie. This study concerns: the type and degree of intestinal parasitic infestations in a single year class of walleyes during their first 3 years of life; seasonal changes in the incidence and maturity of the dominant parasite Bothriocephalus cuspidatus; and the effects of the infestations on the physical condition of the host.

Neurocysticercosis presenting as isolated wall-eyed monocular internuclear ophthalmoplegia with contraversive ocular tilt reaction.

PubMed

Chandran, Suresh R; Balakrishnan, Rojith K; Umakanthan, K; Govindarajan, K

2012-01-01

Neurocysticercosis is a common tropical infection presenting with neurological signs. It commonly presents as seizures but various other focal neurological presentations have been reported. Though neurocysticercosis have been reported to present as isolated internuclear ophthalmoplegia, we report the first case of neurocysticercosis presenting as wall-eyed monoocular internuclear ophthalmoplegia syndrome with contraversive ocular tilt reaction.

Neurocysticercosis presenting as isolated wall-eyed monocular internuclear ophthalmoplegia with contraversive ocular tilt reaction

PubMed Central

Chandran, Suresh R; Balakrishnan, Rojith K; Umakanthan, K; Govindarajan, K

2012-01-01

Neurocysticercosis is a common tropical infection presenting with neurological signs. It commonly presents as seizures but various other focal neurological presentations have been reported. Though neurocysticercosis have been reported to present as isolated internuclear ophthalmoplegia, we report the first case of neurocysticercosis presenting as wall-eyed monoocular internuclear ophthalmoplegia syndrome with contraversive ocular tilt reaction. PMID:22346205

Safety of oxytetracycline (Terramycin TM-100F) administered in feed to hybrid striped bass, walleyes, and yellow perch

USGS Publications Warehouse

Gaikowski, M.P.; Wolf, J.C.; Schleis, S.M.; Gingerich, W.H.

2003-01-01

Oxytetracycline (Terramycin TM-100F, a medicated premix containing oxytetracycline at 220 g/kg) is approved in the United States to control certain systemic bacterial diseases of salmon and catfish when fed at a rate of 55-82.5 mg per kilogram of bodyweight per day for 10 d. Although oxytetracycline may also control certain systemic bacterial infections in coolwater or scaled warmwater fish, no safety data for such species are available. Our objective was to determine the safety of oxytetracycline administered in feed at nominal doses of 0, 82.5, 248, or 413 mg??kg-1??d-1 to yellow perch Perca flavescens and hybrid striped bass (striped bass Morone saxatilis x white bass M. chrysops) for 10 d and to walleye Sander vitreus (formerly Stizostedion vitreum) for 20 d. Yellow perch and hybrid striped bass consumed 50% to 100% of the diet, whereas walleye feed consumption was occasionally less than 50% of the diet. Feed or fecal material was present in the gastrointestinal tract of all necropsied walleyes except for one control fish. The single growth effect was that hybrid striped bass offered a nominal dose of 413 mg??kg-1??d-1 were significantly smaller than untreated controls. Oxytetracycline-related histopathological findings were limited to walleyes and were of low severity. The histopathological findings included decreased hematopoietic-lymphopoietic (H&L) tissue in the anterior kidneys, diffuse hyperplasia of the gill filament epithelium, and a decreased prevalence of fish with eosinophilic droplets in their renal tubular epithelial cells. Although the incidence of decreased H&L tissue tended to increase in proportion to oxytetracycline dose, this finding was statistically significant only for fish that received a nominal dose of 413 mg??kg-1??d-1. Given the pathogenicity of the types of bacteria that are controlled by oxytetracycline treatment and the long history of its use in major aquaculture species, the relative risk of the minor oxytetracycline

HOT CELL BUILDING, TRA632. CONTEXTUAL VIEW ALONG WALLEYE AVENUE, CAMERA ...

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

HOT CELL BUILDING, TRA-632. CONTEXTUAL VIEW ALONG WALLEYE AVENUE, CAMERA FACING EASTERLY. HOT CELL BUILDING IS AT CENTER LEFT OF VIEW; THE LOW-BAY PROJECTION WITH LADDER IS THE TEST TRAIN ASSEMBLY FACILITY, ADDED IN 1968. MTR BUILDING IS IN LEFT OF VIEW. HIGH-BAY BUILDING AT RIGHT IS THE ENGINEERING TEST REACTOR BUILDING, TRA-642. INL NEGATIVE NO. HD46-32-1. Mike Crane, Photographer, 4/2005 - Idaho National Engineering Laboratory, Test Reactor Area, Materials & Engineering Test Reactors, Scoville, Butte County, ID

Competitive interactions between walleye (Sander vitreus) and smallmouth bass (Micropterus dolomieu) under various controlled conditions

USGS Publications Warehouse

Wuellner, M.R.; Graeb, B.D.S.; Willis, D.W.; Galster, B.J.; Selch, T.M.; Chipps, S.R.

2011-01-01

The range of smallmouth bass (Micropterus dolomieu) is expanding northward, creating new interactions with native predators, including walleye (Sander vitreus). We used a series of experiments to investigate competition between walleye (WAE) and smallmouth bass (SMB) at different life stages and light conditions, identified behaviors that allowed one fish to outcompete another, and evaluated whether prey switching mitigated competitive interactions. Juvenile and adult SMB appeared to outcompete WAE when fed during the daytime; neither species dominated when fed near dusk. Attack rates and capture efficiencies of both species were similar with an intra- or interspecific competitor, but SMB often exploited prey before the competitor had a chance to feed (exploitative competition) or displayed agonistic behaviors toward a potential competitor (interference competition). Prey selectivity of WAE or SMB did not differ when by themselves or with a potential competitor. These results indicate that SMB could outcompete WAE under limiting prey conditions due to the aggressive nature of SMB, but resources may be partitioned at least along a temporal scale. ?? 2011 Taylor & Francis.

Non-lethal sampling of walleye for stable isotope analysis: a comparison of three tissues

USGS Publications Warehouse

Chipps, Steven R.; VanDeHey, J.A.; Fincel, M.J.

2012-01-01

Stable isotope analysis of fishes is often performed using muscle or organ tissues that require sacrificing animals. Non-lethal sampling provides an alternative for evaluating isotopic composition for species of concern or individuals of exceptional value. Stable isotope values of white muscle (lethal) were compared with those from fins and scales (non-lethal) in walleye, Sander vitreus (Mitchill), from multiple systems, size classes and across a range of isotopic values. Isotopic variability was also compared among populations to determine the potential of non-lethal tissues for diet-variability analyses. Muscle-derived isotope values were enriched compared with fins and depleted relative to scales. A split-sample validation technique and linear regression found that isotopic composition of walleye fins and scales was significantly related to that in muscle tissue for both δ13C and δ15N (r2 = 0.79–0.93). However, isotopic variability was significantly different between tissue types in two of six populations for δ15N and three of six populations for δ13C. Although species and population specific, these findings indicate that isotopic measures obtained from non-lethal tissues are indicative of those obtained from muscle.

ALTERED SERUM SEX STEROIDS AND VITELLOGENIN INDUCTION IN WALLEYE (STIZOSTEDION VITREUM) COLLECTED NEAR A METROPOLITAN SEWAGE TREATMENT PLANT

EPA Science Inventory

Feral, male walleye collected from the Mississippi River below the St. Paul metropolitan sewage treatment plant (STP) contained measurable levels of the estrogen-inducible, female egg protein, vitellogenin. These same fish showed significantly decreased serum androgen and signifi...

Interannual and Spatial Variability in Maturity of Walleye Pollock Gadus chalcogrammus and Implications for Spawning Stock Biomass Estimates in the Gulf of Alaska

PubMed Central

Kruse, Gordon H.; Dorn, Martin W.

2016-01-01

Catch quotas for walleye pollock Gadus chalcogrammus, the dominant species in the groundfish fishery off Alaska, are set by applying harvest control rules to annual estimates of spawning stock biomass (SSB) from age-structured stock assessments. Adult walleye pollock abundance and maturity status have been monitored in early spring in Shelikof Strait in the Gulf of Alaska for almost three decades. The sampling strategy for maturity status is largely characterized as targeted, albeit opportunistic, sampling of trawl tows made during hydroacoustic surveys. Trawl sampling during pre-spawning biomass surveys, which do not adequately account for spatial patterns in the distribution of immature and mature fish, can bias estimated maturity ogives from which SSB is calculated. Utilizing these maturity data, we developed mixed-effects generalized additive models to examine spatial and temporal patterns in walleye pollock maturity and the influence of these patterns on estimates of SSB. Current stock assessment practice is to estimate SSB as the product of annual estimates of numbers at age, weight at age, and mean maturity at age for 1983-present. In practice, we found this strategy to be conservative for a time period from 2003–2013 as, on average, it underestimates SSB by a 4.7 to 11.9% difference when compared to our estimates of SSB that account for spatial structure or both temporal and spatial structure. Inclusion of spatially explicit information for walleye pollock maturity has implications for understanding stock reproductive biology and thus the setting of sustainable harvest rates used to manage this valuable fishery. PMID:27736982

Using cumulative diet data and stable isotope analysis to determine trophic position of walleye Sander vitreus in a large, complex system

USGS Publications Warehouse

Fincel, Mark J.; James, Daniel A.; Chipps, Steven R.; Davis, Blake A.

2014-01-01

Diet studies have traditionally been used to determine prey use and food web dynamics, while stable isotope analysis provides for a time-integrated approach to evaluate food web dynamics and characterize energy flow in aquatic systems. Direct comparison of the two techniques is rare and difficult to conduct in large, species rich systems. We compared changes in walleye Sander vitreus trophic position (TP) derived from paired diet content and stable isotope analysis. Individual diet-derived TP estimates were dissimilar to stable isotope-derived TP estimates. However, cumulative diet-derived TP estimates integrated from May 2001 to May 2002 corresponded to May 2002 isotope-derived estimates of TP. Average walleye TP estimates from the spring season appear representative of feeding throughout the entire previous year.

Water-quality assessment of the Upper Mississippi River Basin, Minnesota and Wisconsin- Polychlorinated biphenyls in common carp and walleye fillets, 1975-95

USGS Publications Warehouse

Lee, Kathy E.; Anderson, Jesse P.

1998-01-01

Median PCB concentrations in common carp and walleye at individual sites were greatest during 1975-79 and 1980-87, and least during 1988-95 at most sites. Most of the river segments exhibited over 80 percent decline in median PCB concentrations in common carp and walleye between the 1975-79 and 1988-95 time periods. The results from these temporal analyses were similar to those of other studies in the United States and in Minnesota and Wisconsin that reported a significant downward trend in PCB concentrations in fish. Although, PCB concentrations have decreased during 1975-95, low concentrations of PCBs still remain in the aquatic environment despite the fact that PCBs were banned nearly 20 years ago.

Including independent estimates and uncertainty to quantify total abundance of fish migrating in a large river system: walleye (Sander vitreus) in the Maumee River, Ohio

USGS Publications Warehouse

Pritt, Jeremy J.; DuFour, Mark R.; Mayer, Christine M.; Kocovsky, Patrick M.; Tyson, Jeffrey T.; Weimer, Eric J.; Vandergoot, Christopher S.

2013-01-01

Walleye (Sander vitreus) in Lake Erie is a valuable and migratory species that spawns in tributaries. We used hydroacoustic sampling, gill net sampling, and Bayesian state-space modeling to estimate the spawning stock abundance, characterize size and sex structure, and explore environmental factors cuing migration of walleye in the Maumee River for 2011 and 2012. We estimated the spawning stock abundance to be between 431,000 and 1,446,000 individuals in 2011 and between 386,400 and 857,200 individuals in 2012 (95% Bayesian credible intervals). A back-calculation from a concurrent larval fish study produced an estimate of 78,000 to 237,000 spawners for 2011. The sex ratio was skewed towards males early in the spawning season but approached 1:1 later, and larger individuals entered the river earlier in the season than smaller individuals. Walleye migration was greater during low river discharge and intermediate temperatures. Our approach to estimating absolute abundance and uncertainty as well as characterization of the spawning stock could improve assessment and management of this species, and our methodology is applicable to other diadromous populations.

Significance of Selective Predation and Development of Prey Protection Measures for Juvenile Salmonids in the Columbia and Snake River Reservoirs: Annual Progress Report, February 1993-February 1994.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Poe, Thomas P.

1994-08-01

This report addresses the problem of predator-prey interactions of juvenile salmonids in the Columbia and Snake River. Six papers are included on selective predation and prey protection. Attention is focused on monitoring the movements, the distribution, and the behavior of juvenile chinook salmon and northern squawfish.

Comparative population genetic structure and diversity of Yellow Perch and Walleye: Broad- and fine-scale patterns across North America

USDA-ARS?s Scientific Manuscript database

The yellow perch Perca flavescens and the walleye Sander vitreus are native North American percid fishes, which have considerable fishery and ecological importance across their wide geographic ranges. Over the past century, they were stocked into new habitats, often with relative disregard for conse...

Before-after, control-impact analysis of evidence for the impacts of water level on Walleye, Northern Pike and Yellow Perch in lakes of the Rainy-Namakan complex (MN, USA and ON, CA).

PubMed

Larson, James H; Maki, Ryan P; Vondra, Benjamin A; Peterson, Kevin E

2018-01-01

Water level (WL) fluctuations in lakes influence many aspects of ecosystem processes. Concern about the potential impact of WL fluctuations on fisheries was one of the factors that motivated the decision in 2000 to alter the management of WL in the Rainy-Namakan reservoir complex (on the border between the U.S. state of Minnesota and the Canadian province of Ontario). We used a Before-After, Control-Impact (BACI) framework to identify potential impacts of the change in WL management to Walleye, Northern Pike and Yellow Perch catch per unit effort (CPUE). The CPUE of these species from 1990-1999 and from 2005-2014 were compared in four impact lakes (Lake Kabetogama, Namakan Lake, Rainy Lake and Sand Point Lake) and two control lakes (Lake of the Woods and Lake Vermilion) using a simple Bayesian model. Changes in fish CPUE in the impact lakes were often similar to changes that occurred in at least one control lake. The only change that was not similar to changes in control lakes was an increase of Yellow Perch in Lake Kabetogama. The two control lakes often differed substantially from each other, such that if only one had been available our conclusions about the role of WL management on fisheries would be very different. In general, identifying cause-and-effect relationships in observational field data is very difficult, and the BACI analysis used here does not specify a causative mechanism, so co-occurring environmental and management changes may obscure the effect of WL management.

Effect of diet processing method and ingredient substitution on feed characteristics and survival of larval walleye, Sander vitreus

USGS Publications Warehouse

Barrows, F.T.; Lellis, W.A.

2006-01-01

Two methods were developed for the production of larval fish diets. The first method, microextrusion marumerization (MEM), has been tested in laboratory feeding trials for many years and produces particles that are palatable and water stable. The second method, particle-assisted rotational agglomeration (PARA), produced diets that have lower density than diets produced by MEM. Each method was used to produce diets in the 250- to 400- and 400- to 700-??m range and compared with a reference diet (Fry Feed Kyowa* [FFK]) for feeding larval walleye in two experiments. The effect of substituting 4% of the fish meal with freeze-dried artemia fines was also investigated. In the first experiment, 30-d survival was greater (P < 0.05) for fish fed a diet produced by PARA without Artemia (49.1.0%) than for fish fed the same diet produced by MEM (27.6%). The addition of Artemia to a diet produced by MEM did not increase survival of larval walleye. Fish fed the reference diet had 24.4% survival. In the second experiment, there was an effect of both processing method and Artemia supplementation, and an interaction of these effects, on survival. Fish fed a diet produced by PARA without Artemia supplementation had 48.4% survival, and fish fed the same diet produced by MEM had only 19.6% survival. Inclusion of 4% freeze-dried Artemia improved (P < 0.04) survival of fish fed MEM particles but not those fed PARA particles. Fish fed FFK had greater weight gain than fish fed other diets in both experiments. Data indicate that the PARA method of diet processing produces smaller, lower density particles than the MEM process and that diets produced by the PARA process support higher survival of larval walleye with low capital and operating costs. ?? Copyright by the World Aquaculture Society 2006.

Winter movements of four fish species near a thermal plume in northern Minnesota

DOE Office of Scientific and Technical Information (OSTI.GOV)

Ross, M.J.; Winter, J.D.

1981-01-01

Four fish species were studied during the winter of 1975 to compare their winter movements near the thermal plume of a power plant. Seventeen yellow perch (Perca flavescens), six northern pike (Esox lucius), three walleyes (Stizostedion vitreum), and two largemouth bass (Micropterus salmoides) were equipped with radio frequency transmitters. The spatial distributions differed among species. Only the largemouth bass confined their movements to heated water areas. The yellow perch, which was of particular interest, do not seem to be attracted to warm winter waters, and thus locate themselves in the peripheral areas of the discharge bay and fail to reproduce.more » This finding is contrary to those of previous studies.« less

Environmental factors affecting the strength of walleye (Stizostedion vitreum vitreum) year-classes in western Lake Erie, 1960-70

USGS Publications Warehouse

Busch, Wolf-Dieter N.; Scholl, Russell L.; Hartman, Wilbur L.

1975-01-01

Commercial production of walleyes (Stizostedion vitreum vitreum) from western Lake Erie declined from 5.9 million pounds in 1956 to 140,000 pounds by 1969. Since 1956, marked irregularity in year-class success has developed. Only four year-classes were considered good during 1959–70. The rate and regularity of water warming during the spring spawning and incubation periods in 1960–70 had a positive effect on the density of egg deposits and the resulting year-class strength. Rates of warming were not themselves detrimental, but rather the extended length of the incubation period in cool springs increased the exposure of eggs to such negative influences as dislodgment from the spawning reefs by strong current action generated by spring storms, or siltation and low oxygen tensions. The annual brood stock size had much less influence on year-class strength than did water temperature. Reproductive success was unrelated to fluctuations in size of suitable reef spawning area caused by changes in water level. Apparently the usable spawning area at any water level is more than adequate to serve the limited walleye brood stocks.

Climate and Physiography Predict Mercury Concentrations in Game Fish Species in Quebec Lakes Better than Anthropogenic Disturbances.

PubMed

Lucotte, Marc; Paquet, Serge; Moingt, Matthieu

2016-05-01

The fluctuations of mercury levels (Hg) in fish consumed by sport fishers in North-Eastern America depend upon a plethora of interrelated biological and abiological factors. To identify the dominant factors ultimately controlling fish Hg concentrations, we compiled mercury levels (Hg) during the 1976-2010 period in 90 large natural lakes in Quebec (Canada) for two major game species: northern pike (Esox lucius) and walleye (Sander vitreus). Our statistical analysis included 28 geographic information system variables and 15 climatic variables, including sulfate deposition. Higher winter temperatures explained 36% of the variability in higher walleye growth rates, in turn accounting for 54% of the variability in lower Hg concentrations. For northern pike, the dominance of a flat topography in the watershed explained 31% of the variability in lower Hg concentrations. Higher mean annual temperatures explained 27% of the variability in higher pike Hg concentrations. Pelagic versus littoral preferred habitats for walleye and pike respectively could explain the contrasted effect of temperature between the two species. Heavy logging could only explain 2% of the increase in walleye Hg concentrations. The influence of mining on fish Hg concentrations appeared to be masked by climatic effects.

Consumption dynamics of the adult piscivorous fish community in Spirit Lake, Iowa

USGS Publications Warehouse

Liao, H.; Pierce, C.L.; Larscheid, J.G.

2004-01-01

At Spirit Lake, one of Iowa's most important fisheries, walleye Sander vitreus (formerly Stizostedion vitreum) is one of the most popular species with anglers. Despite a century of walleye stocking and management in Spirit Lake, walleye growth rate, size structure, and angler harvest continue to decline. Our purpose was to determine the magnitude and dynamics of walleye population consumption relative to those of other piscivorous species in Spirit Lake, which would allow managers to judge the feasibility of increasing the abundance, growth rate, and size structure of the walleye population. We quantified food consumption by the adult piscivorous fish community in Spirit Lake over a 3-year period. Data on population dynamics, diet, energy density, and water temperature from 1995 to 1997 were used in bioenergetics models to estimate total consumption by walleye, yellow perch Perca flavescens, smallmouth bass Micropterus dolomieu, largemouth bass Micropterus salmoides, black crappie Pomoxis nigromaculatus, and northern pike Esox lucius. Estimated annual consumption by the piscivorous community varied roughly fourfold, ranging from 154,752 kg in 1995 to 662,776 kg in 1997. Walleyes dominated total consumption, accounting for 68, 73, and 90% (1995-1997, respectively) of total food consumption. Walleyes were also the dominant consumers of fish, accounting for 76, 86, and 97% of piscivorous consumption; yellow perch followed, accounting for 16% of piscivorous consumption in 1995 and 12% in 1996. Yellow perch were the predominant fish prey species in all 3 years, accounting for 68, 52, and 36% of the total prey consumed. Natural reproduction is weak, so high walleye densities are maintained by intensive stocking. Walleye stocking drives piscivorous consumption in Spirit Lake, and yearly variation in the cannibalism of stocked walleye fry may be an important determinant of walleye year-class strength and angler success. Reducing walleye stocking intensity, varying stocking

Concentrations of mercury and other trace elements in walleye, smallmouth bass, and rainbow trout in Franklin D. Roosevelt Lake and the upper Columbia River, Washington, 1994

USGS Publications Warehouse

Munn, M.D.; Cox, S.E.; Dean, C.J.

1995-01-01

Three species of sportfish--walleye, smallmouth bass, and rainbow trout--were collected from Franklin D. Roosevelt Lake and the upstream reach of the Columbia River within the state of Washington, to determine the concentrations of mercury and other selected trace elements in fish tissue. Concentrations of total mercury in walleye fillets ranged from 0.11 to 0.44 milligram per kilogram, with the higher concentrations in the larger fish. Fillets of smallmouth bass and rainbow trout also contained mercury, but generally at lower concentrations. Other selected trace elements were found in fillet samples, but the concentrations were generally low depending on species and the specific trace element. The trace elements cadmium, copper, lead, and zinc were found in liver tissue of these same species with zinc consistently present in the highest concentration.

Contaminant trends in lake trout and walleye from the Laurentian Great Lakes

USGS Publications Warehouse

DeVault, David S.; Hesselberg, Robert J.; Rodgers, Paul W.; Feist, Timothy J.

1996-01-01

Trends in PCBs, DDT, and other contaminants have been monitored in Great Lakes lake trout and walleye since the 1970s using composite samples of whole fish. Dramatic declines have been observed in concentrations of PCB, ΣDDT, dieldrin, and oxychlordane, with declines initially following first order loss kinetics. Mean PCB concentrations in Lake Michigan lake trout increased from 13 μg/g in 1972 to 23 μg/g in 1974, then declined to 2.6 μg/g by 1986. Between 1986 and 1992 there was little change in concentration, with 3.5 μg/g observed in 1992. ΣDDT in Lake Michigan trout followed a similar trend, decreasing from 19.2 μg/g in 1970 to 1.1 μg/g in 1986, and 1.2 μg/g in 1992. Similar trends were observed for PCBs and ΣDDT in lake trout from Lakes Superior, Huron and Ontario. Concentrations of both PCB and ΣDDT in Lake Erie walleye declined between 1977 and 1982, after which concentrations were relatively constant through 1990. When originally implemented it was assumed that trends in the mean contaminant concentrations in open-lake fish would serve as cost effective surrogates to trends in the water column. While water column data are still extremely limited it appears that for PCBs in lakes Michigan and Superior, trends in lake trout do reasonably mimic those in the water column over the long term. Hypotheses to explain the trends in contaminant concentrations are briefly reviewed. The original first order loss kinetics used to describe the initial decline do not explain the more recent leveling off of contaminant concentrations. Recent theories have examined the possibilities of multiple contaminant pools. We suggest another hypothesis, that changes in the food web may have resulted in increased bioaccumulation. However, a preliminary exploration of this hypothesis using a change point analysis was inconclusive.

Interactions between commercial fishing and walleye pollock aggregations

NASA Astrophysics Data System (ADS)

Stienessen, Sarah; Wilson, Chris D.; Hallowed, Anne B.

2002-05-01

Scientists with the Alaska Fisheries Science Center are conducting a multiyear field experiment off the eastern side of Kodiak Island in the Gulf of Alaska to determine whether commercial fishing activities significantly affect the distribution and abundance of walleye pollock (Theragra chalcogramma), an important prey species of endangered Steller sea lions (Eumetopias jubatus). In support of this activity, spatio-temporal patterns were described for pollock aggregations. Acoustic-trawl surveys were conducted in two adjacent submarine troughs in August 2001. One trough served as a control site where fishing was prohibited and the other as a treatment site where fishing was allowed. Software, which included patch recognition algorithms, was used to extract acoustic data and generate patch size and shape-related variables to analyze fish aggregations. Important patch related descriptors included skewness, kurtosis, length, height, and density. Estimates of patch fractal dimensions, which relate school perimeter to school area, were less for juvenile than for adult aggregations, indicating a more complex school shape for adults. Comparisons of other patch descriptors were made between troughs and in the presence and absence of the fishery to determine whether trends in pollock aggregation dynamics were a result of the fishery or of naturally occurring events.

Life-history plasticity and sustainable exploitation: a theory of growth compensation applied to walleye management.

PubMed

Lester, Nigel P; Shuter, Brian J; Venturelli, Paul; Nadeau, Daniel

2014-01-01

A simple population model was developed to evaluate the role of plastic and evolutionary life-history changes on sustainable exploitation rates. Plastic changes are embodied in density-dependent compensatory adjustments to somatic growth rate and larval/juvenile survival, which can compensate for the reductions in reproductive lifetime and mean population fecundity that accompany the higher adult mortality imposed by exploitation. Evolutionary changes are embodied in the selective pressures that higher adult mortality imposes on age at maturity, length at maturity, and reproductive investment. Analytical development, based on a biphasic growth model, led to simple equations that show explicitly how sustainable exploitation rates are bounded by each of these effects. We show that density-dependent growth combined with a fixed length at maturity and fixed reproductive investment can support exploitation-driven mortality that is 80% of the level supported by evolutionary changes in maturation and reproductive investment. Sustainable fishing mortality is proportional to natural mortality (M) times the degree of density-dependent growth, as modified by both the degree of density-dependent early survival and the minimum harvestable length. We applied this model to estimate sustainable exploitation rates for North American walleye populations (Sander vitreus). Our analysis of demographic data from walleye populations spread across a broad latitudinal range indicates that density-dependent variation in growth rate can vary by a factor of 2. Implications of this growth response are generally consistent with empirical studies suggesting that optimal fishing mortality is approximately 0.75M for teleosts. This approach can be adapted to the management of other species, particularly when significant exploitation is imposed on many, widely distributed, but geographically isolated populations.

Maternal influences on thiamine status of walleye Sander vitreus ova.

PubMed

Wiegand, M D; Johnston, T A; Brown, L R; Brown, S B; Casselman, J M; Leggett, W C

2011-03-01

Concentrations of the various forms of thiamine (vitamin B(1) ) were determined in walleye Sander vitreus ova from three central North American lakes. Total thiamine concentrations in ova from Lake Winnipeg S. vitreus were approximately three times greater (mean 12 nmol g(-1) ) than in those from Lakes Erie or Ontario. The percentage of thiamine in the active form (thiamine pyrophosphate, TPP) was highest in Lake Ontario ova (mean 88%) and lowest in those from Lake Winnipeg (mean 70%). Neither ova total thiamine concentration nor per cent ova thiamine as TPP showed any consistent relationships with maternal age, size, morphometric condition, somatic lipid concentrations or liver lipid concentrations. Ova total thiamine concentration, however, was negatively related to ovum size in some populations, as well as among populations, and was positively related to liver total thiamine concentration. Maternal transfer of thiamine to ova appears to be independent of female ontogenetic or conditional state in S. vitreus. © 2011 The Authors. Journal of Fish Biology © 2011 The Fisheries Society of the British Isles.

Gill tissue reactions in walleye Stizostedion vitreum vitreum and common carp Cyprinus carpio to glochidia of the freshwater mussel Lampsilis radiata siliquoidea

USGS Publications Warehouse

Waller, D.L.; Mitchell, L.G.

1989-01-01

The glochidia of many freshwater mussels, which are obligate parasites on the gills, fins, and other body parts of specific fishes, attach to a suitable host, become encapsulated, and develop to the free-living juvenile stage. Using light and electron microscopy we compared gill tissue reactions in a suitable host (walleye Stizostedion vitreum vitreum) and unsuitable host (common carp Cyprinus carpio) infected with Lampsilis radiata siliquoidea. Encapsulation of glochidia on walleye gills was completed by 6 h post-infection at 20 to 22°C. Capsular formation and compaction were accompanied by a general increase in epithelioid cells. Fibrotic material appeared in capsules at about 48 h and virtually filled capsular cells from about Day 5 to Day 11 post-infection. Liberation of juvenile mussels was accompanied by thinning of the capsule from about Day 11 to Day l7. Although glochidia attached to the gills of common carp, few became encapsulated. By 48 h post-infection, preliminary capsular growth was evident and necrotic cells and cellular debris appeared at the edges of the growth. However, all glochidia were sloughed from carp gills by 60 h. Host specificity of L. radiata siliquoidea apparently depended on a combination of the attachment response of glochidia, differences in the encapsulation process, and tissue reactions in the fish.

Stock-specific advection of larval walleye (Sander vitreus) in western Lake Erie: Implications for larval growth, mixing, and stock discrimination

USGS Publications Warehouse

Fraker, Michael E.; Anderson, Eric J.; May, Cassandra J.; Chen, Kuan-Yu; Davis, Jeremiah J.; DeVanna, Kristen M.; DuFour, Mark R.; Marschall, Elizabeth A.; Mayer, Christine M.; Miner, Jeffery G.; Pangle, Kevin L.; Pritt, Jeremy J.; Roseman, Edward F.; Tyson, Jeffrey T.; Zhao, Yingming; Ludsin, Stuart A

2015-01-01

Physical processes can generate spatiotemporal heterogeneity in habitat quality for fish and also influence the overlap of pre-recruit individuals (e.g., larvae) with high-quality habitat through hydrodynamic advection. In turn, individuals from different stocks that are produced in different spawning locations or at different times may experience dissimilar habitat conditions, which can underlie within- and among-stock variability in larval growth and survival. While such physically-mediated variation has been shown to be important in driving intra- and inter-annual patterns in recruitment in marine ecosystems, its role in governing larval advection, growth, survival, and recruitment has received less attention in large lake ecosystems such as the Laurentian Great Lakes. Herein, we used a hydrodynamic model linked to a larval walleye (Sander vitreus) individual-based model to explore how the timing and location of larval walleye emergence from several spawning sites in western Lake Erie (Maumee, Sandusky, and Detroit rivers; Ohio reef complex) can influence advection pathways and mixing among these local spawning populations (stocks), and how spatiotemporal variation in thermal habitat can influence stock-specific larval growth. While basin-wide advection patterns were fairly similar during 2011 and 2012, smaller scale advection patterns and the degree of stock mixing varied both within and between years. Additionally, differences in larval growth were evident among stocks and among cohorts within stocks which were attributed to spatiotemporal differences in water temperature. Using these findings, we discuss the value of linked physical–biological models for understanding the recruitment process and addressing fisheries management problems in the world's Great Lakes.

Fluctuations in production and abundance of commercial species in the Red Lakes, Minnesota, with special reference to changes in the walleye population

USGS Publications Warehouse

Smith, Lloyd L.; Krefting, Laurits W.

1954-01-01

The Red Lakes in northwestern Minnesota comprise 275,000 acres of water which support a commercial fishery producing up to 1.5 million pounds of fish per year. Walleye, Stizostedion vitreum vitreum (Mitchill), and yellow perch, Perca flavescens (Mitchill), are the principal species. Statistics for the past 37 years have been analyzed and fluctuations in the abundance of the important species calculated for the 24-year period, 1930–1953. The fishing is carried on exclusively with 3 1/2-inch-mesh (extension measure) gill nets by Chippewa Indians and the catch is marketed through a cooperative fishery enterprise. There have been wide fluctuations in the abundance of principal species but, although fishing effort has increased greatly during the past few years no trends have developed. Changes in walleye abundance have been shown to be independent of changes or levels of fishing effort, and to be determined by strength of individual year classes. Gear competition has no effect on abundance estimates. Strength of year classes is not correlated with size of brood stock, abundance of competing species, or amount of hatchery fish planted. Weather conditions cannot be correlated with observed changes in strength of year classes. Implications for management include provision of adequate prediction of abundance, and annual adjustment of fishing practices to make greatest use of the available stock. Gear limitations should be designed to secure harvest at optimum size of fish and to provide a suitable economic status for the fisherman.

Localization and seasonal variation of blue pigment (sandercyanin) in walleye (Sander vitreus)

USGS Publications Warehouse

Schaefer, Wayne; Schmitz, Mark; Blazer, Vicki S.; Ehlinger, Tim; Berges, John

2015-01-01

Several fish species, including the walleye (Sander vitreus), have “yellow” and “blue” color morphs. In S. vitreus, one source of the blue color has been identified as a bili-binding protein pigment (sandercyanin), found in surface mucus of the fish. Little is known about the production of the pigment or about its functions. We examined the anatomical localization and seasonal variation of sandercyanin in S. vitreus from a population in McKim Lake, northwestern Ontario, Canada. Skin sections were collected from 20 fish and examined histologically. Mucus was collected from 306 fish over 6 years, and the amount of sandercyanin was quantified spectrophotometrically. Sandercyanin was found solely on dorsal surfaces of the fish and was localized to novel cells in the epidermis, similar in appearance to secretory sacciform cells. Sandercyanin concentrations were significantly higher in fish collected in summer versus other seasons. Yellow and blue morphs did not differ in amounts of sandercyanin, suggesting that the observed blue color, in fact, arises from lack of yellow pigmentation in blue morphs. The function of the sandercyanin remains unclear, but roles in photoprotection and countershading are consistent with available data.

Temporal changes in mercury concentrations of large-bodied fishes in the boreal shield ecoregion of northern Ontario, Canada.

PubMed

Tang, Rex W K; Johnston, Thomas A; Gunn, John M; Bhavsar, Satyendra P

2013-02-01

Much of the mercury (Hg) in freshwater fish of the boreal shield ecoregion is believed to originate from atmospheric deposition. As such, declines in fish Hg concentrations would be expected in response to recent declines in atmospheric Hg deposition in this ecoregion. We compared recent (2005-2010) and historic (1974-1981) muscle total mercury concentrations ([THg], standardized to a fish body mass of 1 kg) in seven fish species (five piscivores, two benthivores) from 73 lakes in northern Ontario (Canada) using a paired-comparisons approach. The rate of bioaccumulation (i.e., slopes of log(e)[THg] vs log(e) total length relationship) increased for walleye (Sander vitreus) but did not change significantly for any other species. There was no significant decline in mean [THg] between recent and historic time periods for any species. In fact, recent mean [THg] were slightly higher (<0.08 ppm) than historic mean [THg] for all species, and this difference was significant for northern pike (Esox lucius). The magnitude of the temporal change in northern pike declined significantly from south to north over the study area but there were no discernible geographic patterns in the temporal change in [THg] for any other species. This study shows that [THg] of most large-bodied fish species in boreal shield lakes are not declining in response to the decline in atmospheric Hg deposition. Crown Copyright © 2012. Published by Elsevier B.V. All rights reserved.

Prototype water reuse system

USGS Publications Warehouse

Lucchetti, G.; Gray, G.A.

1988-01-01

A small-scale water reuse system (150 L/min) was developed to create an environment for observing fish under a variety of temperature regimes. Key concerns of disease control, water quality, temperature control, and efficiency and case of operation were addressed. Northern squawfish (Ptychocheilus oregonensis) were held at loading densities ranging from 0.11 to 0.97 kg/L per minute and at temperatures from 10 to 20°C for 6 months with no disease problems or degradation ofwater quality in the system. The system required little maintenance during 2 years of operation.

Concentration of elements in whole-body fish, fish fillets, fish muscle plugs, and fish eggs from the 2008 Missouri Department of Conservation General Contaminant Monitoring Program

USGS Publications Warehouse

May, Thomas W.; Walther, Michael J.; Brumbaugh, William G.; McKee, Michael J.

2009-01-01

This report presents the results of a contaminant monitoring survey conducted annually by the Missouri Department of Conservation to examine the levels of selected elemental contaminants in whole-body fish, fish fillets, fish muscle plugs, and fish eggs. Whole-body, fillet, or egg samples of catfish (Ictalurus punctatus, Ictalurus furcatus, Pylodictis olivaris), largemouth bass (Micropterus salmoides), walleye (Sander vitreus), crappie (Pomoxis annularis, Pomoxis nigromaculatus), shovelnose sturgeon (Scaphirhynchus platorynchus), northern hog sucker (Hypentelium nigricans), and Missouri saddled darter (Etheostoma tetrazonum) were collected from 23 sites as part of the Missouri Department of Conservation's Fish Contaminant Monitoring Program. Fish dorsal muscle plugs also were collected from walleye (Sander vitreus) at one of the sites.

Effects of anesthesia and surgery on serial blood gas values and lactate concentrations in yellow perch (Perca flavescens), walleye pike (Sander vitreus), and koi (Cyprinus carpio).

PubMed

Hanley, Christopher S; Clyde, Victoria L; Wallace, Roberta S; Paul-Murphy, Joanne; Patterson, Tamatha A; Keuler, Nicholas S; Sladky, Kurt K

2010-05-15

OBJECTIVE-To evaluate serial blood gas values and lactate concentrations in 3 fish species undergoing surgery and to compare blood lactate concentrations between fish that survived and those that died during the short-term postoperative period. DESIGN-Prospective cohort study. Animals-10 yellow perch, 5 walleye pike, and 8 koi. PROCEDURES-Blood samples were collected from each fish at 3 time points: before anesthesia, during anesthesia, and immediately after surgery. Blood gas values and blood lactate concentrations were measured. Fish were monitored for 2 weeks postoperatively. RESULTS-All walleye and koi survived, but 2 perch died. Blood pH significantly decreased in perch from before to during anesthesia, but increased back to preanesthesia baseline values after surgery. Blood Pco(2) decreased significantly in perch from before anesthesia to immediately after surgery, and also from during anesthesia to immediately after surgery, whereas blood Pco(2) decreased significantly in koi from before to during anesthesia. Blood Po(2) increased significantly in both perch and koi from before to during anesthesia, and also in koi from before anesthesia to immediately after surgery. For all 3 species, blood lactate concentrations increased significantly from before anesthesia to immediately after surgery. Blood lactate concentration (mean +/- SD) immediately after surgery for the 8 surviving perch was 6.06 +/- 1.47 mmol/L, which was significantly lower than blood lactate concentrations in the 2 nonsurviving perch (10.58 and 10.72 mmol/L). CONCLUSIONS AND CLINICAL RELEVANCE-High blood lactate concentrations following surgery in fish may be predictive of a poor short-term postoperative survival rate.

Summer diet composition of walleye pollock and predator-prey relationships with copepods and euphausiids in the eastern Bering Sea, 1987-2011

NASA Astrophysics Data System (ADS)

Buckley, Troy W.; Ortiz, Ivonne; Kotwicki, Stan; Aydin, Kerim

2016-12-01

The composition of walleye pollock diets from the eastern Bering Sea continental shelf was determined from 25 years of sampling during summer surveys from 1987 through 2011. Substantial differences in the stomach contents of walleye pollock were found among the sizes and geographic strata that correspond to geographic distribution of the prey. With increasing pollock size, copepods decreased in importance in middle and outer shelf areas while mysids decreased in importance in the inner shelf. Euphausiids increased in importance with increasing pollock size in southeastern areas of the shelf, and fishes and shrimp increased in importance with increasing pollock size in northeastern areas of the middle and outer shelf. The biomass-weighted average diet composition of eastern Bering Sea pollock in each year's survey indicated perennial but variable importance of euphausiids and copepods as prey. An index of partial fullness indicated an interannual pattern of below-average consumption of copepods by the surveyed pollock from 1993 to 2004, but during this period the amount of euphausiids consumed continued to fluctuate about a mean that was similar to years surveyed before and after that period. The summer feeding success, as indicated by average stomach fullness, of intermediate sizes of pollock appears to be closely related to the consumption of copepods (especially for pollock 30-39 cm fork length (FL)) and prey other than euphausiids (especially for pollock 40-49 cm FL). Length-specific predator-prey relationships with copepods and euphausiids correspond to patterns in pollock feeding migrations. Interannual trends in the biomass of copepods in the EBS are reflected most closely in the diet of 20-29 cm FL pollock, and trends in the biomass of euphausiids in the EBS are reflected most closely in the diet of the largest pollock (60+ cm FL). Climate-mediated changes in the zooplankton community will likely have differential impacts across the demographic spectrum of

Diel and distributional abundance patterns of fish embryos and larvae in the lower Columbia and Deschutes rivers

USGS Publications Warehouse

Gadomski, D.M.; Barfoot, C.A.

1998-01-01

Diel and distributional abundance patterns of free embryos and larvae of fishes in the lower Columbia River Basin were investigated. Ichthyoplankton samples were collected in 1993 during day and night in the main-channel and a backwater of the lower Columbia River, and in a tributary, the Deschutes River. Fish embryos and larvae collected in the main-channel Columbia River were primarily (85.6%) of native taxa (peamouth Mylocheilus caurinus, northern squawfish Ptychocheilus oregonensis, suckers Catostomus spp., and sculpins Cottus spp.), with two introduced species (American shad Alosa sapidissima and common carp Cyprinus carpio) comprising a smaller percentage of the catch (13.3%). Similarly, in the Deschutes River native taxa [lampreys (Petromyzontidae), minnows (Cyprinidae), and suckers Catostomus spp.] dominated collections (99.5% of the catch). In contrast, 83.5% of embryos and larvae in the Columbia River backwater were of introduced taxa [American shad, common carp, and sunfishes (Centrarchidae)]. In all locations, all dominant taxa except sculpins were collected in significantly greater proportions at night. Taxon-specific differences in proportions of embryos and larvae collected at night can in some instances be related to life history styles. In the main-channel Columbia River, northern squawfish and peamouth were strongly nocturnal and high proportions still had yolksacs, suggesting that they had recently hatched and were drifting downriver to rearing areas. In contrast, sculpin abundances were similar during day and night, and sculpins mostly had depleted yolksacs, indicating sculpins were feeding and rearing in offshore limnetic habitats. Taxon-specific diel abundance patterns and their causes must be considered when designing effective sampling programs for fish embryos and larvae.

Fish mercury levels appear to be increasing lately: a report from 40 years of monitoring in the province of Ontario, Canada.

PubMed

Gandhi, Nilima; Tang, Rex W K; Bhavsar, Satyendra P; Arhonditsis, George B

2014-05-20

Recent mercury levels and trends reported for North America suggest a mixed (positive/negative) outlook for the environmental mercury problem. Using one of the largest consistent monitoring data sets in the world, here we present long-term and recent mercury trends in Walleye, Northern Pike, and Lake Trout from the Province of Ontario, Canada, which contains about one-third of the world's fresh water and covers a wide geographical area (1.5 and 3 times larger than France and Germany, respectively). Overall, the results indicate that the fish mercury levels either declined (0.01-0.07 μg/g decade) or remained stable between the 1970s and 2012. The rates of mercury decline were substantially greater (mostly 0.05-0.31 μg/g decade) during the 1970s/80s possibly in response to reductions in mercury emissions. However, Walleye and Pike levels have generally increased (0.01-0.27 μg/g decade) in recent years (1995-2012), especially for northern Ontario (effect sizes for differences between the two periods ranged from 0.39 to 1.04). Proportions of Walleye and Pike locations showing a flat or increasing trend increased from 26-44% to 59-73% between the 1970s/80s and 1995-2012. Mercury emissions in North America have declined over the last few decades, and as such it is logical to expect recovery in fish mercury levels; however, other factors such as global emissions, climate change, invasive species, and local geochemistry are likely affecting the response time and magnitude.

Factors related to commercial production of the walleye in Red Lakes, Minnesota

USGS Publications Warehouse

Smith, Lloyd L.; Pycha, Richard L.

1961-01-01

Growth of the walleye (Stizostedion vitreum vitreum) in Red Lakes, Minnesota, over a 17-year period was slower than in other waters of the Great Lakes region and fluctuated annually from 30.7 percent above to 42.2 percent below mean growth. Individual year classes varied considerably in growth rate. Age distribution in 3 1/2-inch stretch-measure commercial nets varied extremely in 9 years' collections and was related to year-class strength and fishing intensity during periods when classes were available for catch. Abundance of different classes varied 23-fold. Annulus formation and resumption of growth occurred from mid-June to late July. Effective growing season did not exceed 4 months and for some individuals in some years was 2 months or less. The catch contained age-groups II-XII but consisted principally of groups IV-VIII. Seasonal changes in age distribution were dependent on growth rate and fishing effort. Total catch was strongly influenced by growth and seasonal distribution of fishing effort. Maximum availability to commercial nets was at a total length of 15.1 inches, but a large percentage of the catch was smaller fish. Total annual mortality rate after fish attained 15.1 inches total length was 0.66, but continued recruitment through group VIII caused apparent change in mortality rate with increasing age up to IX. Maximum harvest could be attained by concentrating fishing effort in the latter part of the growing season. Abundance indices derived from commercial catch will be strongly influenced by the seasonal pattern of fishing.

ENSO events in the northern Gulf of Alaska, and effects on selected marine fisheries

USGS Publications Warehouse

Bailey, K.M.; Macklin, S.A.; Reed, R.K.; Brodeur, R.D.; Ingraham, W.J.; Piatt, John F.; Shima, M.; Francis, R.C.; Anderson, P.J.; Royer, T.C.; Hollowed, A.; Somerton, D.A.; Wooster, W.S.

1995-01-01

The 1991-93 El Nino-Southern Oscillation (ENSO) event first appeared in the northern Gulf of Alaska in autumn 1991 with warm sea-surface temperatures. In winter 1992, there were pulses of increased sea level and anomalous circulation. El Nino conditions persisted at least through summer 1993. The effects of this ENSO event on major groundfish species and Pacific herring in the northern Gulf of Alaska were examined and compared with the effects of previous ENSO events. There is little evidence that the 1991-93 or 1982-83 ENSO events affected landings of walleye pollock, Pacific cod, Pacific halibut, or arrowtooth flounder. Some changes in distribution of groundfish species were observed in 1993, but the effect was similar to changes observed in non-ENSO warm years. In general, warm ocean conditions have a positive effect on recruitment of northern stocks, but ENSO events appear to have an inconsistent effect on year-class strength within species and among different species. For example, strong year classes of halibut and arrowtooth flounder sometimes, but not always, coincide with ENSO events; ENSO events are associated with moderate to weak year classes of cod and pollock. However, post-ENSO warm years often are associated with strong recruitment of many groundfish species. Major changes have occurred in the Gulf of Alaska ecosystem since 1977. The influence of the 1976 ENSO event in precipitating these changes and the role of the frequency or strength of subsequent El Nino events is presently unknown. Herring and other stocks of small pelagic fishes may be more affected by ENSO events. In particular, decreased catches, recruitment, and weight-at-age of herring are sometimes associated with ENSO events. Furthermore, a variety of seabirds which feed mostly on pelagic forage fishes or the pelagic juvenile stages of groundfish suffered widespread mortalities and breeding failures in the Gulf of Alaska during the ENSO years of 1983 and 1993. These effects on seabirds

The scavenging of free radical and oxygen species activities and hydration capacity of collagen hydrolysates from walleye pollock ( Theragra chalcogramma) skin

NASA Astrophysics Data System (ADS)

Zhuang, Yongliang; Li, Bafang; Zhao, Xue

2009-06-01

Fish skin collagen hydrolysates (FSCH) were prepared from walleye pollock ( Theragra chalcogramma) using a mixture of enzymes, namely trypsin and flavourzyme. The degree of hydrolysis of the skin collagen was 27.3%. FSCH was mainly composed of low-molecular-weight peptides and the relative proportion of <1000Da fraction was 70.6%. Free radical and oxygen species scavenging activities of FSCH were investigated in four model systems, including diphenylpicrylhy-drazyl radical (DPPH), superoxide anion radical, hydroxyl radical and hydrogen peroxide model, and compared with that of a native antioxidant, reduced glutathione (GSH). FSCH was also evaluated by water-absorbing and water-holding capacity. The results showed that FSCH was able to scavenge free radical and oxygen species significantly and to enhance water-absorbing and water-holding capacity remarkably. Therefore, FSCH may have potential applications in the medicine and food industries.

Diet dynamics of the adult piscivorous fish community in Spirit Lake, Iowa, USA 1995-1997

USGS Publications Warehouse

Liao, H.; Pierce, C.L.; Larscheid, J.G.

2002-01-01

Diets of adults of six important piscivorous fish species, black crappie Pomoxis nigromaculatus, largemouth bass Micropterus salmoides, northern pike Esox lucius, smallmouth bass Micropterus dolomieui, walleye Stizostedion vitreum, and yellow perch Perca flavescens were quantified in Spirit Lake, Iowa, USA from May to October in 1995-1997. Forty-one prey taxa were found in the diets of these species, including 19 species of fish. The most important prey taxa overall were yellow perch, amphipods and dipterans. Diets of northern pike and walleye were dominated by yellow perch. Largemouth bass diets included large percentages of both yellow perch and black bullhead Ameiurus melas. Smallmouth bass diets included large percentages of both yellow perch and crayfish. Black crappie and yellow perch diets were dominated by invertebrates, primarily amphipods and dipterans. There were pronounced differences in diets among species, among size classes within species and over time. Most of the dominant prey taxa we documented in the diets of piscivorous species were in accordance with previous studies, but a few deviated significantly from expectations. Many of the temporal diet changes were asynchronous among piscivorous species and size classes, suggesting different responses to common prey resources over time.

Predation on ruffe by native fishes of the St. Louis River Estuary, Lake Superior, 1989-1991

USGS Publications Warehouse

Ogle, Derek H.; Selgeby, James H.; Savino, Jacqueline F.; Newman, Raymond M.; Henry, Mary G.

1996-01-01

The ruffe Gymnocephalus cernuus, an exotic Eurasian percid, recently became established in the St. Louis River estuary, Lake Superior, after accidental introduction. Management actions (catch regulations and stockings) were enacted in 1989 to increase the density of top-level predators in the estuary, and thus to increase predation on ruffe. We conducted a field and laboratory study to determine if, and to what extent, native piscivores consume ruffe. Stomachs of 3,669 predators were examined in 1989–1991. Ruffe occurred in 6.7% of burbot Lota lota, 5.8% of bullheads Ictalurus spp., 4.7% of smallmouth bass Micropterus dolomieu, 2.6% of northern pike Esox lucius, 2.6% of black crappiesPomoxis nigromaculatus, and 1.3% of yellow perch Perca flavescens (4.5% after 1989) captured during the 3-year study. No ruffe were found in 967 stomachs of walleyesStizostedion vitreum examined. Ruffe were 22.7%, of the diet (by weight) of bullheads (during the only year bullheads were captured) and 0.1–17.9% of the diet of northern pike. Ruffe were 0.9–24.5% of the diet of smallmouth bass that contained fish, 1.5–6.9% of yellow perch that contained fish, and 0.0–10.9% of black crappies that contained fish. Most ruffe eaten were age-0 or small age- 1 fish. In the laboratory, walleyes that were first fed soft-rayed prey or that were also offered soft-rayed prey consumed very few ruffe, whereas walleyes that were first fed spiny-rayed yellow perch or were also offered yellow perch consumed about equal numbers of ruffe and yellow perch. Northern pike and burbot consumed about equal numbers of ruffe and yellow perch in the laboratory. It is unlikely that predation will effectively control the initial expansion of ruffe in other areas of the Great Lakes because native predators initially consume few ruffe, especially if more preferred soft-rayed prey are available.

Mercury and omega-3 fatty acid profiles in freshwater fish of the Dehcho Region, Northwest Territories: Informing risk benefit assessments.

PubMed

Laird, Matthew J; Henao, Juan J Aristizabal; Reyes, Ellen S; Stark, Ken D; Low, George; Swanson, Heidi K; Laird, Brian D

2018-10-01

Traditional foods have significant nutritional, sociocultural and economic value in subarctic First Nations communities of the Northwest Territories, and play a crucial role in promoting cultural continuity and sovereignty. Omega-3 polyunsaturated fatty acids (N-3 PUFAs), including eicosapentaenoic (EPA) and docosahexaenoic acid (DHA), carry significant benefits for neurocognitive development and cardiovascular health. However, the health risks posed by methylmercury may serve to undermine the benefits of fish consumption in Northern Indigenous communities. The objective of this study was to characterize profiles for mercury (Hg) and fatty acids in fish species harvested across lakes of the Dehcho Region, in the Mackenzie Valley of the Northwest Territories, to better understand the risks and benefits associated with traditional foods. Hg levels increased with trophic position, with the highest levels found in Burbot, Lake Trout, Walleye, and Northern Pike. Lake Trout, along with planktivorous species including Lake Whitefish, Cisco, and Sucker, demonstrated higher N-3 PUFAs than other species. Negative associations were observed between Hg and N-3 PUFAs in Lake Trout, Northern Pike, Walleye and Burbot. Further stratifying these relationships revealed significant interactions by lake. Significant differences observed in fatty acid and Hg profiles across lakes underscore the importance of considering both species- and lake-specific findings. This growing dataset of freshwater fish of the Dehcho will inform future efforts to characterize human Hg exposure profiles using probabilistic dose reconstruction models. Copyright © 2018 Elsevier B.V. All rights reserved.

Trends of chlorinated organic contaminants in Great Lakes trout and walleye from 1970-1998

USGS Publications Warehouse

Hickey, J.P.; Batterman, S.A.; Chernyak, S.M.

2006-01-01

Levels of chlorinated organic contaminants in predator fish have been monitored annually in each of the Great Lakes since the 1970s. This article updates earlier reports with data from 1991 to 1998 for lake trout (Salvelinus namaycush) and (Lake Erie only) walleye (Sander vitreus) to provide a record that now extends nearly 30 years. Whole fish were analyzed for a number of industrial contaminants and pesticides, including polychlorinated biphenyls (PCBs), dichloro-diphenyl-trichloroethane (DDT), dieldrin, toxaphene, and mirex, and contaminant trends were quantified using multicompartment models. As in the past, fish from Lakes Michigan, Ontario, and Huron have the highest levels of PCBs, DDT, and dieldrin; Superior has the highest levels of toxaphene; and Ontario has the highest levels of mirex. In the period after curtailment of chemical use, concentrations rapidly decreased, represented by relatively short half-lives from approximately 1 to 9 years. Although trends depend on both the contaminant and the lake, in many cases the rate of decline has been decreasing, and concentrations are gradually approaching an irreducible concentration. For dioxin-like PCBs, levels have not been decreasing during the most recent 5-year period (1994 to 1998). In some cases, the year-to-year variation in contaminant levels is large, mainly because of food-web dynamics. Although this variation sometimes obscures long-term trends, the general pattern of a rapid decrease followed by slowing or leveling-off of the downward trend seems consistent across the Great Lakes, and future improvements of the magnitude seen in the 1970s and early 1980s likely will take much longer.

Survival of cool and warm freshwater fish following chloramine-T exposure

USGS Publications Warehouse

Gaikowski, M.P.; Larson, W.J.; Gingerich, W.H.

2008-01-01

Chloramine-T is presently available in the USA to control mortalities associated with bacterial gill disease or external columnaris only through an Investigational New Animal Drug Permit authorized by the US Food and Drug Administration (FDA). Its US approval hinges on FDA's acceptance of several key data, including those describing animal safety. Chloramine-T is presently applied in US aquaculture, by permit only, once daily on consecutive or alternate days for 1??h at 10 to 20??mg/L to control mortalities associated with bacterial gill disease or external columnaris. Our objective was to determine the safety of chloramine-T bath exposures at multiples of the proposed maximum treatment concentration (i.e., 0, 20, 60, 100, and 200??mg/L) administered on four consecutive days at 20????C to lake sturgeon Acipenser fulvescens, northern pike Esox lucius, and walleye Sander vitreum, or at 27????C to channel catfish Ictalurus punctatus, and largemouth bass Micropterus salmoides. All fish were tested as five to eight week old fry except for walleye and channel catfish which were tested as both fry and fingerling (fingerlings were at least four weeks older than the fry tested). Walleye and channel catfish were selected to evaluate the effects of life stage (fry vs. fingerling), temperature (walleye - 15, 20, or 25????C; channel catfish - 22, 27, or 32????C), exposure duration (60 vs. 180??min), and water chemistry (walleye only - reconstituted soft water vs. well water). Except for channel catfish fry, survival was significantly reduced only when fish were treated at 100 or 200??mg/L. Channel catfish fry survival was significantly reduced when exposed at 60??mg/L for 180??min at 27????C. Based on our mortality data, chloramine-T administered once daily for 60??min on four consecutive days at concentrations of up to 20??mg/L is not likely to adversely affect survival of cool or warmwater fish cultured in freshwater. Crown Copyright ?? 2007.

Diet breadth and variability in Sander spp. inferred from stable isotopes

USGS Publications Warehouse

Fincel, M.J.; Chipps, Steven R.; Graeb, B.D.S.; Brown, M.L.

2016-01-01

We used stable isotopes of carbon and nitrogen to evaluate trophic similarity between sauger Sander canadensis and walleye S. vitreus in three Missouri River impoundments characterized by unique differences in riverine habitat. Mean δ15N was similar for sauger and walleye in each reservoir ranging from 15.7 to 17.8‰ for sauger and 15.2 to 17.7‰ for walleye. However, mean δ13C was greater for sauger (−24‰) than for walleye (−25‰) in Lake Oahe (lacustrine habitat), where rainbow smelt Osmerus mordax is an important prey species for walleye. Variation in δ15N and δ13C values was similar between walleye and sauger in Lewis and Clark Lake (riverine habitat), but was greater for sauger than for walleye in Lake Oahe, implying that in pelagic environments, sauger exhibit a larger diet breadth and lower diet consistency compared with walleyes. Isotope analyses support observations from traditional gut content studies that diet overlap between sauger and walleye varies with environmental conditions and is more similar in riverine food webs than in large lakes and impoundments.

Comparison of potential fecundity models for walleye pollock Gadus chalcogrammus in the Pacific waters off Hokkaido, Japan.

PubMed

Tanaka, H; Hamatsu, T; Mori, K

2017-01-01

Potential fecundity models of walleye or Alaska pollock Gadus chalcogrammus in the Pacific waters off Hokkaido, Japan, were developed. They were compared using a generalized linear model with using either standard body length (L S ) or total body mass (M T ) as a main covariate along with Fulton's condition factor (K) and mean diameter of oocytes (D O ) as additional potential covariates to account for maternal conditions and maturity stage. The results of model selection showed that M T was a better single predictor of potential fecundity (F P ) than L S . The biological importance of K on F P was obscure, because it was statistically significant when used in the predictor with L S (i.e. length-based model), but not significant when used with M T (i.e. mass-based model). Meanwhile, D O was statistically significant in both length and mass-based models, suggesting the importance of downregulation on the number of oocytes with advancing maturation. Among all candidate models, the model with M T and D O in the predictor had the lowest Akaike's information criterion value, suggesting its better predictive power. These newly developed models will improve future comparisons of the potential fecundity within and among stocks by excluding potential biases other than body size. © 2016 The Fisheries Society of the British Isles.

Distribution and relative abundance of fishes in littoral areas of Chief Joseph Reservoir, Columbia River

USGS Publications Warehouse

Gadomski, Dena M.; Venditti, David A.; Robinson, T. Craig; Beeman, John W.; Maule, Alec G.

2004-01-01

We surveyed fish assemblages in littoral areas of Chief Joseph Reservoir of the upper Columbia River to aid in understanding this ecosystem. Fish distributions and abundances were examined during April-July 1999 in relation to environmental conditions in the reservoir. We also compared the fish assemblages in Chief Joseph reservoir in 1999 to a past study conducted during 1974-1975, and to assemblages in other areas of the Columbia River. During 67 hr of electrofishing and 78 beach seine hauls in Chief Joseph Reservoir, 7460 fishes representing 8 families were collected. The majority of the catch was native – northern pikeminnow; redside shiners; longnose, bridgelip, and largescale suckers; and sculpins. The most abundant introduced species was walleye, and one species, rainbow trout, was mostly of net-pen origin. Larger sizes of suckers and northern pikeminnow were most abundant in the upper reservoir, likely due to upstream spawning migrations. The lower reservoir contained greater abundances of smaller fishes, and this area had lower flows, smaller substrates, and more complex shorelines that offered these fishes refugia. Only adult suckers displayed significant differences in abundances related to substrate. The relative abundances of species appeared to have changed since the 1970s, when the dominant fishes were northern pikeminnow, peamouth, largescale suckers, and walleye. Fish assemblage differences between Chief Joseph Reservoir and lower Columbia River reservoirs were also evident due to the morphology of the reservoir, its more northerly location, and the lack of fish passage facilities at Chief Joseph Dam. Our study is one of the few descriptions of fishes in the upper Columbia Rivers.

A comparison of the physics of the northern and southern shelves of the eastern Bering Sea and some implications for the ecosystem

NASA Astrophysics Data System (ADS)

Stabeno, Phyllis J.; Farley, Edward V., Jr.; Kachel, Nancy B.; Moore, Sue; Mordy, Calvin W.; Napp, Jeffrey M.; Overland, James E.; Pinchuk, Alexei I.; Sigler, Michael F.

2012-06-01

Sufficient oceanographic measurements have been made in recent years to describe the latitudinal variation in the physics of the eastern Bering Sea shelf and the potential impact of climate change on the species assemblages in the two ecosystems (north and south). Many of the predicted ecosystem changes will result from alterations in the timing and extent of sea ice. It is predicted that the sea ice in the northern Bering Sea will be less common in May, but will continue to be extensive through April. In contrast, the southern shelf will have, on average, much less sea ice than currently observed, but with large interannual and multiyear variability until at least 2050. Thus, even under current climate warming scenarios, bottom temperatures on the northern shelf will remain cold. Based on biophysical measurements, the southern and northern ecosystems were divided by a North-South Transition at ˜60°N. The northern middle shelf was characterized by a freshwater lens at the surface, cold bottom temperatures, and a thicker pycnocline than found on the southern shelf. Subsurface phytoplankton blooms were common. In contrast, the southern shelf stratification was largely determined by temperature alone; the pycnocline was thin (often<3 m) and subsurface blooms were uncommon. Biological responses to climate warming could include greater north-south differences in zooplankton community structure, the transport of large Outer Shelf Domain crustacean zooplankton to the middle shelf, and the disappearance of two principal prey taxa (Calanus spp. and Thysanoessa spp.) of planktivorous fish, seabirds and whales. The response of commercially and ecologically important fish species is predicted to vary. Some species of fish (e.g., juvenile sockeye salmon, Oncorhynchus nerka) may expand their summer range into the northern Bering Sea; some (e.g., pink salmon, O. gorbuscha) may increase in abundance while still other species (e.g., walleye pollock and arrowtooth flounder

Understanding the influence of predation on introduced fishes on juvenile salmonids in the Columbia River Basin: Closing some knowledge gaps. Late summer and fall diet and condition of smallmouth bass, walleye, and channel catfish in the middle Columbia River, USA. Interim Report of Research 2011.

USGS Publications Warehouse

Rose, Brien P.; Hansen, Gabriel S.; Weaver,; Ayers, David; Van Dyke, Erick S.; Mesa, Matthew G.

2012-01-01

American shad Alosa sapidissima in the middle Columbia River (MCR)—a high energy food available in the summer and fall—may be contributing to the increased growth and enhanced condition of nonnative piscivores. To test this hypothesis we quantified the late summer and autumn diets of smallmouth bass Micropterus dolomieu, walleye Sander vitreus, and channel catfish Ictalurus punctatus in the three lowermost reservoirs on the Columbia River (Bonneville [BON], The Dalles [TDA], and John Day [JDA]). The diet of smallmouth bass (SMB) was fairly similar among reservoirs, with crustaceans (52–82%) and fish (13–38%) being the dominant prey groups by percent mass. Cottidae were usually the dominant fish prey in the diet of SMB at all areas and the contribution of juvenile shad ranged from 0–8.2%. Fish (mostly Cyprinidae and Cottidae) were always the dominant prey item for walleye (WAL) at all areas and at all times, ranging from 70–100% of their diet by mass. Juvenile American shad composed from 10–27% (by mass) of the diet of walleye, depending on area and month. For channel catfish (CHC), the most common prey items consumed were crustaceans (20%–80% by mass) and unidentified items (30%–80%). Fish represented a relatively small component (< 4%) of their diet. We also evaluated the condition of SMB and WAL by determining relative weights (Wr) and hepatosomatic indices (HSI). Mean Wr for SMB greater than 300 mm ranged from 0.89 to 0.94 depending on area and month and showed a significant increase from August to September for fish in BON only. Overall, mean Wr of WAL was similar at all areas, ranging from 0.89–0.91, and increased significantly from September to mid-October and November for fish in TDA only. Overall, mean HSI of SMB ranged from 1.18 to 1.48, did not differ between fish in different reservoirs, and increased significantly from September to mid-October and November for fish from the lower JDA only. Mean HSI of WAL was significantly higher in

Tumor frequencies in walleye (Stizostedion vitreum) and brown bullhead (Ictalurus nebulosus) and sediment contaminants in tributaries of the Laurentian Great Lakes

USGS Publications Warehouse

Baumann, Paul C.; Mac, Michael J.; Smith, Stephen B.; Harshbarger, John C.

1991-01-01

To better characterize neoplasm epizootics in the Great Lakes basin and their association with families of contaminants, we sampled five locations: the Fox and Menominee rivers, Lake Michigan; Munuscong Lake, St. Mary's River; and the Black and Cuyahoga rivers, Lake Erie. Frequencies of external and liver tumors were determined for brown bullhead (Ictalurus nebulosus) from all locations except the Black River and for walleye (Stizostedion vitreum) from the Lake Michigan and St. Mary's River sites. Sediment samples were analyzed for metals, polychlorinated aromatics, and polynuclear aromatic hydrocarbons (PAH). Liver neoplasms occurred in brown bullhead from the Cuyahoga River and Munuscong Lake; brown bullhead captured from Munuscong Lake were older than those collected from the other locations. Brown bullhead from these same two rivers had elevated hepatosomatic indexes. No liver neoplasms were found in brown bullhead from the Fox and Menominee rivers, although polychlorinated aromatics were highest in both Fox River sediment and Fox and Menominee brown bullhead, and arsenic was highest in Menominee River sediment and fish. Liver neoplasms in brown bullhead from the Cuyahoga River fit the prevailing hypothesis that elevated PAH in sediment can induce cancer in wild fish. The cause of the liver neoplasms in Munuscong Lake brown bullhead is undetermined.

Sport fishery potential of power plant cooling ponds: Final report

DOE Office of Scientific and Technical Information (OSTI.GOV)

Heidinger, R.C.; Lewis, W.M.

1986-10-01

This research was undertaken to determine if cooling ponds could serve as habitat for several coolwater fish species and also to evaluate the potential use of cooling ponds as nursery areas for receiving waters. The work was conducted on two cooling ponds in northern Illinois. Walleye (Stizostedion vitreum), muskellunge (Esox masquinongy), striped bass (Morone saxatilis) fingerlings, and adult threadfin shad (Dorosoma petenense) were stocked into both cooling ponds. The hybrids between the striped bass and white bass (M. chrysops) had been previously stocked into Collins Pond. Smallmouth bass (Micropterus dolomieui) fingerlings and larval striped bass and walleye were stocked inmore » Dresden Pond. Several sampling techniques including seining, electrofishing, and rotenoning were used to monitor growth and survival of stocked species. In addition, escapement of stocked and indigenous species was monitored at the Dresden Pond spillway. Walleye, muskellunge, striped bass and hybrid striped bass exhibited excellent growth in Collins Pond as did smallmouth bass in Dresden Pond. One of the primary differences between an open system (such as Dresden Pond) and a closed system (such as Collins Pond) is the potential that the open system has to serve as a fish nursery area for receiving waters. The stocking of ''coolwater'' species in a closed type system such as Collins Pond is an effective way to control and maintain selected sport species. Dresden Pond was not open to public fishing during this study, but Collins Pond developed an excellent sport fishery as a result of these stockings.« less

Northern Studies at Northern Universities.

ERIC Educational Resources Information Center

Northern Review: A Multidisciplinary Journal of the Arts and Social Sciences of the North, 1994

1994-01-01

Describes college programs and research projects focused on the Arctic, northern studies, or northern concerns at Athabasca University (Alberta), the University of British Columbia, the University of Alaska Anchorage, the University of Alaska Fairbanks, the Scott Polar Institute at the University of Cambridge (England), and Kent State University…

Assessing native and introduced fish predation on migrating juvenile salmon in Priest Rapids and Wanapum Reservoirs, Columbia River, Washington, 2009--11

USGS Publications Warehouse

Counihan, Timothy D.; Hardiman, Jill M.; Burgess, Dave S.; Simmons, Katrina E.; Holmberg, Glen S.; Rogala, Josh A.; Polacek, Rochelle R.

2012-01-01

We used the catch and diet data collected in 2009 and 2010 to estimate relative abundance, consumption, and predation indices for northern pikeminnow and smallmouth bass. Despite extensive sampling in the study area in 2009 and 2010, very few channel catfish and walleye were captured. The mean total lengths of northern pikeminnow were much lower than those observed in 1993; suggesting that efforts to remove northern pikeminnow in the study area may be shifting the population towards smaller fish. The northern pikeminnow predation index values were lower in 2009 than in the 1993 study. The reduced predation levels observed may be due to the prevalence of smaller pikeminnow in our catches than in catches reported in 1993. Predation by smallmouth bass was lower in 2009 than in 2010, and generally was greater than predation for northern pikeminnow. Predation for northern pikeminnow was concentrated in the tailrace areas of Priest Rapids, Wanapum, and Rock Island Dams; predation for smallmouth bass was concentrated in the forebay and mid-reservoir sections of the study area. Our results indicate areas where control measures for smallmouth bass could be concentrated to reduce predation in the Priest Rapids Project.

Diphyllobothriasis: update on human cases, foci, patterns and sources of human infections and future considerations.

PubMed

Dick, T A; Nelson, P A; Choudhury, A

2001-01-01

Diphylobothriasis is a well documented disease of humans. On a world scale new infections are reported regularly, especially from Russia and parts of Japan. Globally, new species have been discovered and the etiology of the disease may be changing. Human infections appear to be in decline but it is not clear if the sources of infection are also in decline or if public health awareness has improved. In North America there has been a decline in human cases while in South America an increase in reports from fish, especially salmonids suggests high levels in these fish species. The history of human infections of Diphyllobothrium latum is primarily associated with the consumption of the northern circumpolar distributed pike and percids and is often considered a parasite of humans only. Indeed some researchers believe that D. latum was introduced to North America by northern European immigrants. The more benign human infections of D. dendriticum appears to be primarily associated with salmonids and coregonid fishes and fish eating birds. Although the early cases of diphyllobothriasis in the 1930s in North America came from fish originating in Lake Winnipeg, Manitoba, there was general belief that it was declining in fish populations and therefore of little significance to humans in the area. However, high levels of a plerocercoid in the flesh of walleyes and pike led to rejection of commercially harvested walleye and pike in Manitoba and northern Ontario, Canada, and a financial loss to Aboriginal fishers. D. latum is widely distributed in fishes of Manitoba and is infective to humans where it is not pathogenic and has a life span up to 4.5 years. The distribution and potential infection routes has not changed in a century and is still well established in natural hosts in the boreal regions of North America. Evidence is building for an old pre-European presence in North America, involving the Beringian land bridge and later involvement of susceptible hosts (northern

Projected shifts in fish species dominance in Wisconsin lakes under climate change.

PubMed

Hansen, Gretchen J A; Read, Jordan S; Hansen, Jonathan F; Winslow, Luke A

2017-04-01

Temperate lakes may contain both coolwater fish species such as walleye (Sander vitreus) and warmwater fish species such as largemouth bass (Micropterus salmoides). Recent declining walleye and increasing largemouth bass populations have raised questions regarding the future trajectories and management actions for these species. We developed a thermodynamic model of water temperatures driven by downscaled climate data and lake-specific characteristics to estimate daily water temperature profiles for 2148 lakes in Wisconsin, US, under contemporary (1989-2014) and future (2040-2064 and 2065-2089) conditions. We correlated contemporary walleye recruitment and largemouth bass relative abundance to modeled water temperature, lake morphometry, and lake productivity, and projected lake-specific changes in each species under future climate conditions. Walleye recruitment success was negatively related and largemouth bass abundance was positively related to water temperature degree days. Both species exhibited a threshold response at the same degree day value, albeit in opposite directions. Degree days were predicted to increase in the future, although the magnitude of increase varied among lakes, time periods, and global circulation models (GCMs). Under future conditions, we predicted a loss of walleye recruitment in 33-75% of lakes where recruitment is currently supported and a 27-60% increase in the number of lakes suitable for high largemouth bass abundance. The percentage of lakes capable of supporting abundant largemouth bass but failed walleye recruitment was predicted to increase from 58% in contemporary conditions to 86% by mid-century and to 91% of lakes by late century, based on median projections across GCMs. Conversely, the percentage of lakes with successful walleye recruitment and low largemouth bass abundance was predicted to decline from 9% of lakes in contemporary conditions to only 1% of lakes in both future periods. Importantly, we identify up to 85

Projected shifts in fish species dominance in Wisconsin lakes under climate change

USGS Publications Warehouse

Hansen, Gretchen JA; Read, Jordan S.; Hansen, Jonathan F.; Winslow, Luke

2016-01-01

Temperate lakes may contain both coolwater fish species such as walleye (Sander vitreus) and warmwater fish species such as largemouth bass (Micropterus salmoides). Recent declining walleye and increasing largemouth bass populations have raised questions regarding the future trajectories and management actions for these species. We developed a thermodynamic model of water temperatures driven by downscaled climate data and lake-specific characteristics to estimate daily water temperature profiles for 2148 lakes in Wisconsin, US, under contemporary (1989–2014) and future (2040–2064 and 2065–2089) conditions. We correlated contemporary walleye recruitment and largemouth bass relative abundance to modeled water temperature, lake morphometry, and lake productivity, and projected lake-specific changes in each species under future climate conditions. Walleye recruitment success was negatively related and largemouth bass abundance was positively related to water temperature degree days. Both species exhibited a threshold response at the same degree day value, albeit in opposite directions. Degree days were predicted to increase in the future, although the magnitude of increase varied among lakes, time periods, and global circulation models (GCMs). Under future conditions, we predicted a loss of walleye recruitment in 33–75% of lakes where recruitment is currently supported and a 27–60% increase in the number of lakes suitable for high largemouth bass abundance. The percentage of lakes capable of supporting abundant largemouth bass but failed walleye recruitment was predicted to increase from 58% in contemporary conditions to 86% by mid-century and to 91% of lakes by late century, based on median projections across GCMs. Conversely, the percentage of lakes with successful walleye recruitment and low largemouth bass abundance was predicted to decline from 9% of lakes in contemporary conditions to only 1% of lakes in both future periods. Importantly, we identify up

Lake Roosevelt Fisheries Evaluation Program; Evaluation of Limiting Factors for Stocked Kokanee and Rainbow Trout in Lake Roosevelt, Washington, 1999 Annual Report.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Baldwin, Casey; Polacek, Matt

2009-03-01

Hatchery supplementation of kokanee Oncorhynchus nerka and rainbow trout O. mykiss has been the primary mitigation provided by Bonneville Power Administration for loss of anadromous fish to the waters above Grand Coulee Dam (GCD). The hatchery program for rainbow trout has consistently met management goals and provided a substantial contribution to the fishery; however, spawner returns and creel survey results for kokanee have been below management goals. Our objective was to identify factors that limit limnetic fish production in Lake Roosevelt by evaluating abiotic conditions, food limitations, piscivory, and entrainment. Dissolved oxygen concentration was adequate throughout most of the year;more » however, levels dropped to near 6 mg/L in late July. For kokanee, warm water temperatures during mid-late summer limited their nocturnal distribution to 80-100 m in the lower section of the reservoir. Kokanee spawner length was consistently several centimeters longer than in other Pacific Northwest systems, and the relative weights of rainbow trout and large kokanee were comparable to national averages. Large bodied daphnia (> 1.7 mm) were present in the zooplankton community during all seasons indicating that top down effects were not limiting secondary productivity. Walleye Stizostedion vitreum were the primary piscivore of salmonids in 1998 and 1999. Burbot Lota lota smallmouth bass Micropterus dolomieui, and northern pikeminnow Ptychocheilus oregonensis preyed on salmonids to a lesser degree. Age 3 and 4 walleye were responsible for the majority (65%) of the total walleye consumption of salmonids. Bioenergetics modeling indicated that reservoir wide consumption by walleye could account for a 31-39% loss of stocked kokanee but only 6-12% of rainbow trout. Size at release was the primary reason for differential mortality rates due to predation. Entrainment ranged from 2% to 16% of the monthly abundance estimates of limnetic fish, and could account for 30% of total

ASSESSING CONTAMINANT SENSITIVITY OF ENDANGERED AND THREATENED SPECIES: EFFLUENT TOXICITY TESTS

EPA Science Inventory

Toxicity tests using standard effluent test procedures were conducted (EPA 1994) with Ceriodaphnia dubia and fathead minnows and four endangered fish species: bonytail chub (Gila elegans), Colorado squawfish (Ptychocheilus lucias ), razorback sucker (Xyrauchen texanus) and Gila t...

Lake Roosevelt Fisheries Evaluation Program, Part C; Lake Roosevelt Pelagic Fish Study: Washington Department of Fish and Wildlife, 1998 Annual Report.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Baldwin, Casey; Polacek, Matt; Bonar, Scott

2002-11-01

Pelagic fishes, such as kokanee and rainbow trout, provide an important fishery in Lake Roosevelt; however, spawner returns and creel results have been below management goals in recent years. Our objective was to identify factors that potentially limit pelagic fish production in Lake Roosevelt including entrainment, food limitation, piscivory, and other abiotic factors. We estimated the ratio of total fish entrained through Grand Coulee Dam to the pelagic fish abundance for September and October, 1998. If the majority of these fish were pelagic species, then entrainment averaged 10-13% of pelagic fish abundance each month. This rate of entrainment could imposemore » considerable losses to pelagic fish populations on an annual basis. Therefore, estimates of species composition of entrained fish will be important in upcoming years to estimate the proportion of stocked pelagic fish lost through the dam. Food was not limiting for kokanee or rainbow trout populations since growth rates were high and large zooplankton were present in the reservoir. Estimates of survival for kokanee were low (< 0.01 annual) and unknown for rainbow trout. We estimated that the 1997 standing stock biomass of large (>1.1 mm) Daphnia could have supported 0.08 annual survival by kokanee and rainbow trout before fish consumption would have exceeded available biomass during late winter and early spring. Therefore, if recruitment goals are met in the future there may be a bottleneck in food supply for pelagic planktivores. Walleye and northern pikeminnow were the primary piscivores of salmonids in 1996 and 1997. Predation on salmonid prey was rare for rainbow trout and not detected for burbot or smallmouth bass. Northern pikeminnow had the greatest individual potential as a salmonid predator due to their high consumptive demand; however, their overall impact was limited because of their low relative abundance. We modeled the predation impact of 273,524 walleye in 1996, and 39,075 northern

Interrelationships between fish tissue mercury concentrations and water quality for South Dakota natural lakes and impoundments

USGS Publications Warehouse

Chipps, Steven R.; Stetler, Larry; Stone, James J.; McCutcheon, Cindy M.

2011-01-01

The purpose of this study was to determine whether water quality parameters commonly associated with primary productivity may be used to predict the susceptibility of a specific water body to exceed proposed fish consumption advisory limitation of 0.3 mg kg−1. South Dakota currently has nine lakes and impoundments that exceed fish tissue mercury advisory limits of 1.0 mg kg−1 total mercury, far exceeding US Environmental Protection Agency and Food and Drug Administration 0.3 mg kg−1 consumption criteria. Previous studies suggest that increased aquatic productivity may mitigate the effects of biological production and subsequent uptake of methyl mercury through bio-dilution; however, it is uncertain whether these trends may exist within highly alkaline and highly productive aquatic conditions common to South Dakota lakes and impoundments. Water quality parameters and fish tissue mercury data for northern pike and walleye were collected and assessed using existing South Dakota Department of Environment and Natural Resources and Game Fish and Parks data. The data was initially screened using both parametric linear regression and non-parametric Mann–Whitney rank sum comparisons and further assessed using binary logistic regression and stepwise logistic regression methodology. Three separate phosphorus measurements (total, total dissolved, and Trophic State Index) and pH were determined to significantly correlate with increased mercury concentrations for the northern pike-in-impoundments model. However, phosphorus surprisingly was not a strong predictor for the remaining scenarios modeled. For the northern pike-in-natural lakes models, alkalinity was the most significant water quality parameter predicting increased mercury concentrations. Mercury concentrations for the walleye-in-natural lakes models were further influenced by pH and alkalinity. The water quality and fish tissue mercury interrelationships determined within this study suggest aquatic

Spatial match-mismatch between juvenile fish and prey provides a mechanism for recruitment variability across contrasting climate conditions in the eastern Bering Sea.

PubMed

Siddon, Elizabeth Calvert; Kristiansen, Trond; Mueter, Franz J; Holsman, Kirstin K; Heintz, Ron A; Farley, Edward V

2013-01-01

Understanding mechanisms behind variability in early life survival of marine fishes through modeling efforts can improve predictive capabilities for recruitment success under changing climate conditions. Walleye pollock (Theragra chalcogramma) support the largest single-species commercial fishery in the United States and represent an ecologically important component of the Bering Sea ecosystem. Variability in walleye pollock growth and survival is structured in part by climate-driven bottom-up control of zooplankton composition. We used two modeling approaches, informed by observations, to understand the roles of prey quality, prey composition, and water temperature on juvenile walleye pollock growth: (1) a bioenergetics model that included local predator and prey energy densities, and (2) an individual-based model that included a mechanistic feeding component dependent on larval development and behavior, local prey densities and size, and physical oceanographic conditions. Prey composition in late-summer shifted from predominantly smaller copepod species in the warmer 2005 season to larger species in the cooler 2010 season, reflecting differences in zooplankton composition between years. In 2010, the main prey of juvenile walleye pollock were more abundant, had greater biomass, and higher mean energy density, resulting in better growth conditions. Moreover, spatial patterns in prey composition and water temperature lead to areas of enhanced growth, or growth 'hot spots', for juvenile walleye pollock and survival may be enhanced when fish overlap with these areas. This study provides evidence that a spatial mismatch between juvenile walleye pollock and growth 'hot spots' in 2005 contributed to poor recruitment while a higher degree of overlap in 2010 resulted in improved recruitment. Our results indicate that climate-driven changes in prey quality and composition can impact growth of juvenile walleye pollock, potentially severely affecting recruitment variability.

Patterns in prey use among fur seals and seabirds in the Pribilof Islands

NASA Astrophysics Data System (ADS)

Sinclair, E. H.; Vlietstra, L. S.; Johnson, D. S.; Zeppelin, T. K.; Byrd, G. V.; Springer, A. M.; Ream, R. R.; Hunt, G. L., Jr.

2008-08-01

We explored correlation in diet trends for five piscivorous predators that reproduce on the Pribilof Islands as illustrative of the shifting structure of the Bering Sea ecosystem. We evaluated the size and species of prey consumed by adult female and juvenile northern fur seals ( Callorhinus ursinus) and adults and chicks of black-legged kittiwakes ( Rissa tridactyla), red-legged kittiwakes ( Rissa brevirostris), thick-billed murres ( Uria lomvia), and common murres ( Uria aalge) from data collected between July and October 1960-2000. Sample sources included stomachs from seals and seabirds collected on pelagic foraging grounds in the eastern Bering Sea, seal scats from rookeries and seabird regurgitations and whole prey from nest sites on St. Paul and St. George Islands of the Pribilof Island archipelago. Typical prey included small fish and invertebrates (⩽20 cm for seals and ⩽12 cm for seabirds) that concentrate along frontal boundaries of the continental shelf/slope and in the epi-pelagic zone. Squids and fishes including walleye pollock ( Theragra chalcogramma), capelin ( Mallotus villosus), and sand lance ( Ammodytes hexapterus) were variably important in the diet of all five predators. Some prey, such as capelin, were principal in predator diets during the 1960s (seals) and into the early 1980s (seabirds), but declined or disappeared from all predator diets thereafter while others, such as walleye pollock, occurred with increasing frequency from the 1970s forward. As the number of individuals consuming walleye pollock increased, the overall volume of pollock in seabird diets declined. This decline was coincident with a decrease in the age and body size of pollock consumed by both seabirds and fur seals. Squid and pollock were negatively correlated in the diets of their primary consumers, northern fur seals (Pearson's coefficient -0.71, p=0.016) and thick-billed murres (Pearson's coefficient=-0.74, p=0.015) from the 1970s forward. Inter-island variation

Northern forests, Chapter 7

Treesearch

L.H. Pardo; C.L. Goodale; E.A. Lilleskov; L.H. Geiser

2011-01-01

The Northern Forests ecological region spans much of Canada, from Saskatchewan to Newfoundland; its southern portion extends into the northern United States (CEC 1997). The U.S. component includes the northern hardwood and spruce-fir forest types and encompasses parts of the Northeast (mountainous regions in Pennsylvania, New York, New Jersey, Connecticut,...

The effects of regional angling effort, angler behavior, and harvesting efficiency on landscape patterns of overfishing.

PubMed

Hunt, Len M; Arlinghaus, Robert; Lester, Nigel; Kushneriuk, Rob

2011-10-01

We used a coupled social-ecological model to study the landscape-scale patterns emerging from a mobile population of anglers exploiting a spatially structured walleye (Sander vitreus) fishery. We systematically examined how variations in angler behaviors (i.e., relative importance of walleye catch rate in guiding fishing site choices), harvesting efficiency (as implied by varying degrees of inverse density-dependent catchability of walleye), and angler population size affected the depletion of walleye stocks across 157 lakes located near Thunder Bay (Ontario, Canada). Walleye production biology was calibrated using lake-specific morphometric and edaphic features, and angler fishing site choices were modeled using an empirically grounded multi-attribute utility function. We found support for the hypothesis of sequential collapses of walleye stocks across the landscape in inverse proportionality of travel cost from the urban residence of anglers. This pattern was less pronounced when the regional angler population was low, density-dependent catchability was absent or low, and angler choices of lakes in the landscape were strongly determined by catch rather than non-catch-related attributes. Thus, our study revealed a systematic pattern of high catch importance reducing overfishing potential at low and aggravating overfishing potential at high angler population sizes. The analyses also suggested that density-dependent catchability might have more serious consequences for regional overfishing states than variations in angler behavior. We found little support for the hypotheses of systematic overexploitation of the most productive walleye stocks and homogenized catch-related qualities among lakes sharing similar access costs to anglers. Therefore, one should not expect anglers to systematically exploit the most productive fisheries or to equalize catch rates among lakes through their mobility and other behaviors. This study underscores that understanding landscape

Invading species in the Eel River, California: Successes, failures, and relationships with resident species

USGS Publications Warehouse

Brown, L.R.; Moyle, P.B.

1997-01-01

We examined invasions of non-native fishes into the Eel River, California. At least 16 species of fish have been introduced into the drainage which originally supported 12-14 fish species. Our study was prompted by the unauthorized introduction in 1979 of Sacramento squawfish, Ptychocheilus grandis, a large predatory cyprinid. From 1986 to 1990, we conducted growth and diet studies of squaw fish, conducted intensive surveys of the distribution and habitat associations of both native and introduced species, and examined the nature of species-habitat and interspecies relationships. We found no evidence for increased growth or expanded feeding habits, compared to native populations, of Sacramento squawfish as they invaded the Eel River drainage. Ten of the introduced species were well established, with four species limited to a reservoir and six species established in streams. The success or failure of introductions of stream species appeared to be a function of the ability of a species to survive the fluctuating, highly seasonal, flow regime. The present mixture of native and exotic species has not formed stable fish assemblages but it seems likely that four habitat-associated assemblages will develop. The overall effect of the successful species introductions has been to assemble a group of species, with some exceptions, that are native to and occur together in many California streams. The assemblages now forming are similar to those found in other California streams. The assemblage characterized by squawfish and suckers is likely to be resistant to invasion, in the absence of human caused habitat modifications.

Historical and Contemporary Patterns of Mercury in a Hydroelectric Reservoir and Downstream Fishery: Concentration Decline in Water and Fishes.

PubMed

Green, Derek J; Duffy, Mark; Janz, David M; McCullum, Kevin; Carrière, Gary; Jardine, Timothy D

2016-08-01

Mercury (Hg) contamination can pose risks to human and animal health as well as commercial fisheries. Reservoir construction in riverine systems produces flooded conditions amenable to Hg(II)-methylating bacteria, which can transform this relatively benign environmental contaminant into the bioaccumulative, environmentally relevant, and neurotoxic methyl-Hg (MeHg). Hg concentrations ([Hg]) in fishes from reservoirs can take decades to decrease to pre-dam levels, but less is known about Hg exported downstream and its dynamics within downstream fish populations. We examined and compared the multidecadal rates of biotic [Hg] decrease and contemporary factors affecting [Hg] in fish collected from a hydroelectric reservoir (Tobin Lake) and a related downstream fishery (Cumberland Lake) along the Saskatchewan River, Canada. Rates of [Hg] decrease were considered in four species-northern pike (Esox lucius), sauger (Sander canadensis), goldeye (Hiodon alosoides), and walleye (S. vitreus)-all of which showed a significant decrease over time (p < 0.001) and are now lower than Health Canada consumption guidelines (0.5 μg/g). Rates of decrease ranged from 0.5 to 3.9 %/year and were similar between sites in the cases of northern pike and sauger. Contemporary factors affecting [Hg] in walleye collected downstream include fish length (p < 0.001), fish age (p < 0.001), and trophic magnification through the food web (p < 0.001), and relationships between [Hg] and trophic level in predatory and prey fish are now similar to those found in non-Hg-inundated systems at a similar latitude. Together, these results suggest connected contamination between the two sites and delineate the timeline during which [Hg] in a variety of fish species decreased to nontoxic levels in both locations.

Concentrations of elements in fish fillets, fish muscle plugs, and crayfish from the 2007 Missouri Department of Conservation General Contaminant Monitoring Program

USGS Publications Warehouse

May, Thomas W.; Walther, Michael J.; Brumbaugh, William G.; McKee, Michael J.

2009-01-01

This report presents the results of a contaminant monitoring survey conducted annually by the Missouri Department of Conservation to examine the levels of selected elemental contaminants in fish fillets, fish muscle plugs, and crayfish. Fillets of channel catfish (Ictalurus punctatus), bass (Micropterus salmoides, Micropterus dolomieu, Morone chrysops), walleye (Sander vitreus), common carp (Cyprinus carpio), lake sturgeon (Acipenser fulvescens), northern hog sucker (Hypentelium nigricans), and rainbow trout (Oncorhynchus mykiss) were collected from 21 sites as part of the Department's Fish Contaminant Monitoring Program. Long-pincered crayfish (Orconectes longidigitus) were collected from one site to assess trophic transfer of metals to fish. Fish muscle plugs were collected from smallmouth bass (Micropterus dolomieu) at two different locations from one site.

Development of a walleye spleen stromal cell line sensitive to viral hemorrhagic septicemia virus (VHSV IVb) and to protection by synthetic dsRNA.

PubMed

Vo, Nguyen T K; Bender, Aaron W; Ammendolia, Dustin A; Lumsden, John S; Dixon, Brian; Bols, Niels C

2015-07-01

A cell line, WE-spleen6, has been developed from the stromal layer of primary spleen cell cultures. On conventional plastic, WE-spleen6 cells had a spindle-shaped morphology at low cell density but grew to become epithelial-like at confluency. On the commercial extracellular matrix (ECM), Matrigel, the cells remained spindle-shaped and formed lumen-like structures. WE-spleen6 cells had intermediate filament protein, vimentin and the ECM protein, collagen I, but not smooth muscle α-actin (SMA) and von Willebrand factor (vWF) and lacked alkaline phosphatase and phagocytic activities. WE-spleen6 was more susceptible to infection with VHSV IVb than a fibroblast and epithelial cell lines from the walleye caudal fin, WE-cfin11f and WE-cfin11e, respectively. Viral transcripts and proteins appeared earlier in WE-spleen6 cultures as did cytopathic effect (CPE) and significant virus production. The synthetic double-stranded RNA (dsRNA), polyinosinic: polycytidylic acid (pIC), induced the antiviral protein Mx in both cell lines. Treating WE-spleen6 cultures with pIC prior to infection with VHSV IVb inhibited the early accumulation of viral transcripts and proteins and delayed the appearance of CPE and significant viral production. Of particular note, pIC caused the disappearance of viral P protein 2 days post infection. WE-spleen6 should be useful for investigating the impact of VHSV IVb on hematopoietic organs and the actions of pIC on the rhabdovirus life cycle. Copyright © 2015 Elsevier Ltd. All rights reserved.

Assessment of the Fishery Improvement Opportunities on the Pend Oreille River: Recommendations for Fisheries Enhancement: Final Report.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Ashe, Becky L.; Scholz, Allan T.

1992-03-01

population in the river is stunted and therefore not popular with anglers. Pumpkinseed composed 16% of the total catch, followed by tenth (9%), largemouth bass (8%), mountain whitefish (6%), largescale sucker (5%), northern squawfish (4%) and longnose sucker (3%).« less

Ecological risk of methylmercury to piscivorous fish of the Great Lakes region.

PubMed

Sandheinrich, Mark B; Bhavsar, Satyendra P; Bodaly, R A; Drevnick, Paul E; Paul, Eric A

2011-10-01

Contamination of fish populations with methylmercury is common in the region of the Laurentian Great Lakes as a result of atmospheric deposition and methylation of inorganic mercury. Using fish mercury monitoring data from natural resource agencies and information on tissue concentrations injurious to fish, we conducted a screening-level risk assessment of mercury to sexually mature female walleye (Sander vitreus), northern pike (Esox lucius), smallmouth bass (Micropterus dolomieu), and largemouth bass (Micropterus salmoides) in the Great Lakes and in interior lakes, impoundments, and rivers of the Great Lakes region. The assessment included more than 43,000 measurements of mercury in fish from more than 2000 locations. Sexually mature female fish that exceeded threshold-effect tissue concentrations of 0.20 μg g(-1) wet weight in the whole body occurred at 8% (largemouth bass) to 43% (walleye) of sites. Fish at 3% to 18% of sites were at risk of injury and exceeded 0.30 μg g(-1) where an alteration in reproduction or survival is predicted to occur. Most fish at increased risk were from interior lakes and impoundments. In the Great Lakes, no sites had sexually mature fish that exceeded threshold-effect concentrations. Results of this screening-level assessment indicate that fish at a substantive number of locations within the Great Lakes region are potentially at risk from methylmercury contamination and would benefit from reduction in mercury concentrations.

Titan's Stratospheric Condensibles at High Northern Latitudes During Northern Winter

NASA Technical Reports Server (NTRS)

Anderson, Carrie; Samuelson, R.; Achterberg, R.

2012-01-01

The Infrared Interferometer Spectrometer (IRIS) instrument on board Voyager 1 caught the first glimpse of an unidentified particulate feature in Titan's stratosphere that spectrally peaks at 221 per centimeter. Until recently, this feature that we have termed 'the haystack,' has been seen persistently at high northern latitudes with the Composite Infrared Spectrometer (CIRS) instrument onboard Cassini, The strength of the haystack emission feature diminishes rapidly with season, becoming drastically reduced at high northern latitudes, as Titan transitions from northern winter into spring, In contrast to IRIS whose shortest wavenumber was 200 per centimeter, CIRS extends down to 10 per centimeter, thus revealing an entirely unexplored spectral region in which nitrile ices have numerous broad lattice vibration features, Unlike the haystack, which is only found at high northern latitudes during northern winter/early northern spring, this geometrically thin nitrile cloud pervades Titan's lower stratosphere, spectrally peaking at 160 per centimeter, and is almost global in extent spanning latitudes 85 N to 600 S, The inference of nitrile ices are consistent with the highly restricted altitude ranges over which these features are observed, and appear to be dominated by a mixture of HCN and HC3N, The narrow range in altitude over which the nitrile ices extend is unlike the haystack, whose vertical distribution is significantly broader, spanning roughly 70 kilometers in altitude in Titan's lower stratosphere, The nitrile clouds that CIRS observes are located in a dynamically stable region of Titan's atmosphere, whereas CH4 clouds, which ordinarily form in the troposphere, form in a more dynamically unstable region, where convective cloud systems tend to occur. In the unusual situation where Titan's tropopause cools significantly from the HASI 70.5K temperature minimum, CH4 should condense in Titan's lower stratosphere, just like the aforementioned nitrile clouds, although

Northern Pintail

USGS Publications Warehouse

Clark, Robert G.; Fleskes, Joseph P.; Guyn, Karla L.; Haukos, David A.; Austin, Jane E.; Miller, Michael R.

2014-01-01

This medium-sized dabbling duck of slender, elegant lines and conservative plumage coloration is circumpolar in distribution and abundant in North America, with core nesting habitat in Alaska and the Prairie Pothole Region of southern Canada and the northern Great Plains. Breeders favor shallow wetlands interspersed throughout prairie grasslands or arctic tundra. An early fall migrant, the species arrives on wintering areas beginning in August, after wing molt, often forming large roosting and feeding flocks on open, shallow wetlands and flooded agricultural fields. The birds consume grains, marsh plant seeds, and aquatic invertebrates throughout fall and winter.Northern Pintails are among the earliest nesting ducks in North America, beginning shortly after ice-out in many northern areas. Individuals form new pair bonds each winter but are highly promiscuous during the nesting season, with mated and unmated males often involved in vigorous, acrobatic Pursuit Flights. Annual nest success and productivity vary with water conditions, predation, and weather. Females build nests on the ground, often far from water. Only the female incubates; her mate leaves shortly after incubation begins. Ducklings hatch together in one day, follow the female to water after a day in the nest, and fledge by July or August. Adults and ducklings consume mainly aquatic invertebrates during the breeding season.Predators and farming operations destroy many thousands of Northern Pintail nests annually; farming has also greatly reduced the amount of quality nesting cover available. Winter habitats are threatened by water shortages, agricultural development, contamination, and urbanization. Periods of extended drought in prairie nesting regions have caused dramatic population declines, usually followed by periods of recovery. Over the long term, however, the continental population of Northern Pintails has declined significantly from 6 million birds in the early 1970s to less than 3 million in

Landscape prediction and mapping of game fish biomass, an ecosystem service of Michigan rivers

USGS Publications Warehouse

Esselman, Peter C.; Stevenson, R Jan; Lupi, Frank; Riseng, Catherine M.; Wiley, Michael J.

2015-01-01

The increased integration of ecosystem service concepts into natural resource management places renewed emphasis on prediction and mapping of fish biomass as a major provisioning service of rivers. The goals of this study were to predict and map patterns of fish biomass as a proxy for the availability of catchable fish for anglers in rivers and to identify the strongest landscape constraints on fish productivity. We examined hypotheses about fish responses to total phosphorus (TP), as TP is a growth-limiting nutrient known to cause increases (subsidy response) and/or decreases (stress response) in fish biomass depending on its concentration and the species being considered. Boosted regression trees were used to define nonlinear functions that predicted the standing crops of Brook Trout Salvelinus fontinalis, Brown Trout Salmo trutta, Smallmouth Bass Micropterus dolomieu, panfishes (seven centrarchid species), and Walleye Sander vitreus by using landscape and modeled local-scale predictors. Fitted models were highly significant and explained 22–56% of the variation in validation data sets. Nonlinear and threshold responses were apparent for numerous predictors, including TP concentration, which had significant effects on all except the Walleye fishery. Brook Trout and Smallmouth Bass exhibited both subsidy and stress responses, panfish biomass exhibited a subsidy response only, and Brown Trout exhibited a stress response. Maps of reach-specific standing crop predictions showed patterns of predicted fish biomass that corresponded to spatial patterns in catchment area, water temperature, land cover, and nutrient availability. Maps illustrated predictions of higher trout biomass in coldwater streams draining glacial till in northern Michigan, higher Smallmouth Bass and panfish biomasses in warmwater systems of southern Michigan, and high Walleye biomass in large main-stem rivers throughout the state. Our results allow fisheries managers to examine the biomass

Comparison of northern goshawk nesting habitat in Appalachian oak and northern hardwood forests of Pennsylvania

Treesearch

J.T. Kimmel; R.H. Yahner

1991-01-01

The Northern Goshawk (Accipiter gentilis) is a rare to uncommon woodland raptor in Pennsylvania. Although it is primarily a boreal species, the goshawk nests in Northern Hardwoods and Appalachian oak forests along the southern margin of its range in Pennsylvania. This study compared the nesting habitat of goshawks in Appalachian oak and Northern...

Trophic ecology of largemouth bass and northern pike in allopatric and sympatric assemblages in northern boreal lakes

USGS Publications Warehouse

Soupir, Craig A.; Brown, Michael L.; Kallemeyn, Larry W.

2000-01-01

Largemouth bass (Micropterus salmoides) and northern pike (Esox lucius) are top predators in the food chain in most aquatic environments that they occupy; however, limited information exists on species interactions in the northern reaches of largemouth bass distribution. We investigated the seasonal food habits of allopatric and sympatric assemblages of largemouth bass and northern pike in six interior lakes within Voyageurs National Park, Minnesota. Percentages of empty stomachs were variable for largemouth bass (38-54%) and northern pike (34.7-66.7%). Fishes (mainly yellow perch, Perca flavescens) comprised greater than 60% (mean percent mass, MPM) of the northern pike diet during all seasons in both allopatric and sympatric assemblages. Aquatic insects (primarily Odonata and Hemiptera) were important in the diets of largemouth bass in all communities (0.0-79.7 MPM). Although largemouth bass were observed in the diet of northern pike, largemouth bass apparently did not prey on northern pike. Seasonal differences were observed in the proportion of aquatic insects (P = 0.010) and fishes (P = 0.023) in the diets of northern pike and largemouth bass. Based on three food categories, jackknifed classifications correctly classified 77 and 92% of northern pike and largemouth bass values, respectively. Percent resource overlap values were biologically significant (greater than 60%) during at least one season in each sympatric assemblage, suggesting some diet overlap.

Assessment of smolt condition: Biological and environmental interactions -- The impact of prey and predators on juvenile salmonids

USGS Publications Warehouse

Sauter, Sally T.; Schrock, Robin M.; Petersen, James H.; Maule, Alec G.

2004-01-01

The Bonneville Power Administration (BPA) has funded the Assessment of Smolt Condition project since 1987. During that time the project changed frequently to meet the information needs of fish managers by conducting studies throughout the Columbia River basin. Past research has examined the influence of smolt physiological development and health on migration rate; differences in development and migration rates of smolts of hatchery or wild origins; and the impacts of hatchery practices on smolt development. The Smolt Assessment Project will not continue beyond 2004, and here we report on the final study of the project in which we used bioenergetics modeling to investigate predation on juvenile salmonids by northern pikeminnow, smallmouth bass, and walleye in the lower Columbia River reservoirs.

Survival and growth of planted northern red oak in northern West Virginia

Treesearch

Charles A. McNeel; David M. Hix; Edwin C. Townsend

1993-01-01

The survival and growth of northern red oak (Quercus rubra L.) seedlings planted beneath a shelterwood in northern West Virginia were evaluated one year after planting. The use of 1.5 m (5 ft) tall TUBEX tree shelters on planted seedlings was also examined. The study was conducted on both excellent and good sites (site indices of 27 m (89 ft) and 22...

Response of nesting northern goshawks to logging truck noise in northern Arizona

Treesearch

Teryl G. Grubb; Larry L. Pater; Angela E. Gatto; David K. Delaney

2013-01-01

We recorded 94 sound-response events at 3 adult-occupied northern goshawk (Accipiter gentilis) nests 78 m, 143 m, and 167m from the nearest United States Forest Service maintenance level 3, improved gravel road on the Kaibab Plateau in northern Arizona. During 4 test sessions on 7, 8, 10, and 11 June 2010, we recorded 60 experimentally controlled logging trucks; 30 non...

Fertilization of Northern Hardwoods

Treesearch

R. Lea; D.G. Brockway

1986-01-01

Northern hardwoods grow over a considerable range of climatic and edaphic conditions and exhibit a wide range in productivity.Many northern hardwood forests are capable of high production relative to other forest types, but are often slow to reach maximum productivity because of low nutrient availability.Altering the patterns of biomass accumulation so that managers...

Compensatory Feeding Following a Predator Removal Program : Detection and Mechanisms, 1982-1996 Progress Report.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Petersen, James H.

2002-02-28

Predator removal is one of the oldest management tools in existence, with evidence that ancient Greeks used a bounty reward for wolves over 3,000 years ago (Anonymous 1964). Efforts to control predators on fish have been documented in scientific journals for at least 60 years (Eschmeyer 1937; Lagler 1939; Foerster and Ricker 1941; Smith and Swingle 1941; Jeppson and Platts 1959), and has likely been attempted for much longer. Complete eradication of a target species from a body of water has rarely been the objective of predator removal programs, which instead have attempted to eliminate predators from specific areas, tomore » reduce the density or standing stock of predators, or to kill the largest individuals in the population (Meronek et al. 1996). In evaluating management programs that remove only part of a predator population, the compensatory response(s) of the remaining predators must be considered. Some potential compensatory responses by remaining individuals include increased reproductive output, increased growth rate, or increased consumption of certain prey species (Jude et al. 1987). If compensation by predators that remain in the system following a removal effort occurs, it may reduce the effectiveness of the predator control program. Northern pike-minnow Ptychocheilus oregonensis (formerly called northern squawfish) consume juvenile salmon in rivers, lakes, and reservoirs in British Columbia, Washington, Idaho, Oregon, and California. Northern pikeminnow have been estimated to consume about 11% of all juvenile salmon that migrate through John Day Reservoir on the Columbia River (Rieman et al. 1991). Modeling studies suggested that removal of 20% of the northern pikeminnow population in John Day Reservoir would result in a 50% decrease in predation-related mortality of juvenile salmon migrating through this reach (Beamesderfer et al. 1991). Since the early 1940's, other programs have been implemented to remove northern pikeminnow, with hopes of

Adaptability of black walnut, black cherry, and Northern red oak to Northern California

Treesearch

Philip M. McDonald

1987-01-01

When planted in sheltered sites in northern California, only 49% of black walnut (Juglans nigra L.) and 58% of black cherry (Prunus serotina Ehrh.) survived for 15 years, and 20% of northern red oak (Quercus rubra L.) survived for 10 years. The black walnut trees averaged 0.6 inches diameter at breast...

From the Northern Eurasia Earth Science Partnership Initiative to the Northern Eurasia Future Initiative

NASA Astrophysics Data System (ADS)

Streletskiy, D. A.; Groisman, P. Y.; Shugart, H. H., Jr.; Gulev, S.; Maksyutov, S. S.; Qi, J.

2017-12-01

Since 2004, the Northern Eurasia Earth Science Partnership Initiative (NEESPI) - an interdisciplinary program of internationally-supported Earth systems and science research - has addressed large-scale and long-term manifestations of climate and environmental changes over Northern Eurasia and their impact on the Global Earth system. With 40 books and more than 1500 peer-reviewed journal publications to its credit, NEESPI's output can now be used to directly support decision-making for societal needs. Specifically, it was decided to shift gradually the foci of regional studies in Northern Eurasia towards applications with the following major Science Question: "What dynamic and interactive change(s) will affect societal well-being, activities, and health, and what might be the mitigation and adaptation strategies that could support sustainable development and decision-making activities in Northern Eurasia?" To answer this question requires a stronger socio-economic component in the ongoing and future regional studies focused on sustainable societal development under changing climatic and environmental conditions. The NEESPI Research Team has reorganized itself into "Northern Eurasia Future Initiative" (NEFI) and developed a new Science Plan released in June 2016. The Plan underwent a 6-month-long public review and was finalized at the end of 2016. Its description was thereafter split between two review papers: Groisman et al. (2017) and Monier et al. (2017). The first paper describes the Plan rationale and a new set of topical questions. The second paper describes a major modeling approach that will be employed in addressing the "what to do" questions of the NEFI Research (cf., presentation by Monier et al. at this Session). In the current presentation, we outline the new NEFI research foci and present latest NEFI findings including international projects in the Eurasian Arctic, boreal zone, and the Dry Land Belt of Northern Eurasia (cf., also presentations at sister

Movements of a polar bear from northern Alaska to northern Greenland

USGS Publications Warehouse

Durner, George M.; Amstrup, Steven C.

1995-01-01

Using satellite telemetry, we monitored the movements of an adult female polar bear (Ursus maritimus) as she traveled from the Alaskan Beaufort Sea coast to northern Greenland. She is the first polar bear known to depart the Beaufort Sea region for an extended period, and the first polar bear known to move between Alaska and Greenland. This bear traveled for four months across the polar basin and came within 2 degrees of the North Pole. During the first year following her capture, she traveled 5256 km. Evidence to suggest her use of maternity dens in northern Alaska and in northern Greenland demonstrates the potential for genetic exchange between two widely separate populations of polar bears. The long life spans of polar bears and the rarity of their long-range movements means the significance of interpopulation movement can be assessed after long-term monitoring of individuals.

What are northern hardwoods?

Treesearch

Richard M. Godman

1992-01-01

The term "northern hardwoods" was used in the early 1900's to separate the hardwoods of the northern region from those growing in the South. With continued usage in the North the term now represents all dense hardwood species both in the Lake States and Northeast. Unfortunately, this has complicated describing and applying silvicultural practices for...

Northern homelands, northern frontier: linking culture and economic security in contemporary livelihoods in boreal and cold temperate forest communities in northern Canada

Treesearch

Andrew J. Chapeskie

2001-01-01

This paper highlights the environmental pressures that have historically been brought to bear on the northern forests of Canada. It then presents the idea of the northern frontier forests of Canada as Indigenous landscapes whose ecological diversity and abundance have historically been nurtured in no small measure by their original inhabitants. It then proposes how...

Survey of larval fish in the Michigan waters of Lake Erie, 1975 and 1976. Final report, 1975-1978

DOE Office of Scientific and Technical Information (OSTI.GOV)

Waybrant, R.C.; Shauver, J.M.

1979-08-01

Surveys in 1975 and 1976 in the Michigan waters of Lake Erie assessed the relative abundance and distribution of larval fish. Seasonal fluctuations, patterns of distribution, and depth preferences were noted for the 24 larval fish taxa identified. Special emphasis was placed on four target species, walleye (Stizostedion vitreum), yellow perch (Perca flavescens), white bass (Morone chrysops) and channel catfish (Ictalurus punctatus). Of these 4 species only yellow perch and white bass were found more than occasionally. Of the remaining 20 species collected during the study only 5 were regularly captured. The northern and southern extremes of the study areamore » held many more fish than the central portion. The 0- to 12-ft depth zone had the largest concentrations of larval fish and concentrations gradually decreased as the depth increased.« less

Movement and Harvest of Fish in Lake Saint Clair, Saint Clair River, and Detroit River

DTIC Science & Technology

1985-01-01

a creel survey of the angling fishery , a trap net survey, and a tagging study of the adult fish community . The study area encompassed all of...River does not support a winter walleye fishery (C. Baker, ODNR, personal communication ). Yellow perch,-Yellow perch, like walleyes, are considered best...two basic forms: affecting the adult fish community directly, or interfering with the winter angling fishery . The fish community might be affected

Comparison of individual-based model output to data using a model of walleye pollock early life history in the Gulf of Alaska

NASA Astrophysics Data System (ADS)

Hinckley, Sarah; Parada, Carolina; Horne, John K.; Mazur, Michael; Woillez, Mathieu

2016-10-01

Biophysical individual-based models (IBMs) have been used to study aspects of early life history of marine fishes such as recruitment, connectivity of spawning and nursery areas, and marine reserve design. However, there is no consistent approach to validating the spatial outputs of these models. In this study, we hope to rectify this gap. We document additions to an existing individual-based biophysical model for Alaska walleye pollock (Gadus chalcogrammus), some simulations made with this model and methods that were used to describe and compare spatial output of the model versus field data derived from ichthyoplankton surveys in the Gulf of Alaska. We used visual methods (e.g. distributional centroids with directional ellipses), several indices (such as a Normalized Difference Index (NDI), and an Overlap Coefficient (OC), and several statistical methods: the Syrjala method, the Getis-Ord Gi* statistic, and a geostatistical method for comparing spatial indices. We assess the utility of these different methods in analyzing spatial output and comparing model output to data, and give recommendations for their appropriate use. Visual methods are useful for initial comparisons of model and data distributions. Metrics such as the NDI and OC give useful measures of co-location and overlap, but care must be taken in discretizing the fields into bins. The Getis-Ord Gi* statistic is useful to determine the patchiness of the fields. The Syrjala method is an easily implemented statistical measure of the difference between the fields, but does not give information on the details of the distributions. Finally, the geostatistical comparison of spatial indices gives good information of details of the distributions and whether they differ significantly between the model and the data. We conclude that each technique gives quite different information about the model-data distribution comparison, and that some are easy to apply and some more complex. We also give recommendations for

Diet dynamics of the juvenile piscivorous fish community in Spirit Lake, Iowa, USA, 1997-1998

USGS Publications Warehouse

Pelham, M.E.; Pierce, C.L.; Larscheid, J.G.

2001-01-01

We assessed temporal dynamics and variation among species and age-classes in the diets of age 0 and age 1 piscivorous fish species in Spirit Lake, Iowa, USA during 1997 and 1998. Species included walleye Stizostedion vitreum, yellow perch Perca flavescens, smallmouth bass Micropterus dolomieui, largemouth bass Micropterus salmoides, black crappie Pomoxis nigromaculatus and white bass Morone chrysops. Thirty taxa were identified in diets, including 12 species of fish. We found dramatic differences in diets among species, among age-classes within species and over time. Walleye, largemouth bass, smallmouth bass and white bass were piscivorous at age 0. Black crappie began piscivory at age 1. Yellow perch also began piscivory at age 1, but fish were a very small fraction of age-1 diets. The primary temporal pattern, seen in several species and age- classes, was an increase in piscivory from spring to fall. This pattern was due to the lack of small, age-0 prey fish in spring. Although some patterns were evident, the taxonomic composition of the diets of all species was highly variable over time, making generalizations difficult. A surprising result was the absence of yellow perch in the diet of age-0 walleye, despite their abundance in Spirit Lake and prominence in diets of age-1 walleye and other age 1-piscivores. Age-0 yellow perch were consistently too large to be eaten by age-0 piscivores, which preyed primarily on invertebrates and smaller fish such as johnny darters Etheostoma nigrum and age 0 bluegill Lepomis macrochirus. This finding suggests that predator-prey interactions and resulting population dynamics may be quite different in Spirit Lake than in other systems dominated by walleye and yellow perch.

U.S. Northern Command > Newsroom > Press Releases

Science.gov Websites

Skip to main content (Press Enter). Toggle navigation U.S. Northern Command Search Search USNORTHCOM: Search Search USNORTHCOM: Search U.S. Northern Command U.S. Northern Command Home Leadership , 2018 NORAD and USNORTHCOM to host change of command ceremony Nov. 30, 2017 United States, Mexico to

Effects of commonly used cooking practices on total mercury concentration in fish and their impact on exposure assessments.

PubMed

Morgan, J N; Berry, M R; Graves, R L

1997-01-01

The effects of cooking practices commonly used by Native Americans on total mercury concentrations in fish were investigated. A preparation factor relating mercury concentrations in fish as prepared for consumption to mercury concentration data as measured in typical environmental monitoring programs was calculated. Preparation factors are needed to provide risk assessors with a more accurate estimate of the actual amount of mercury ingested through consumption of contaminated fish. Data on fish preparation and consumption practices of two communities of Chippewa residing on the shores of Lake Superior in northern Wisconsin were used to select practices for study. The most commonly consumed species, walleye and lake trout, were selected. Whitefish livers were also selected for study. Commonly used cooking techniques including panfrying, deep-frying, baking, boiling, and smoking were duplicated in the laboratory. Total mercury concentrations were determined in fish portions before and after cooking and in a portion representative of that analyzed in programs to assess water quality (skin-on fillets). Total mercury was determined by microwave digestion-cold vapor atomic absorption spectroscopy. Mercury concentrations (wet weight basis) in panfried, baked, and boiled walleye fillets and deep-fried and baked whitefish livers ranged from 1.1 to 1.5 times higher than in corresponding raw portions. In lake trout, mercury concentrations were 1.5 to 2.0 times higher in cooked portions than in the raw portion. However, total mercury levels were constant before and after cooking, indicating the concentration effect is caused by weight (moisture and fat) loss. The addition of lemon juice to potentially release mercury from its bound state and promote volatilization did not exert any measurable influence on mercury concentrations in cooked walleye. In some cases mercury concentrations were increased with increased cooking times due to further loss of moisture and fat

Journal of Naval Science. Volume 1, Number 3, July 1975

DTIC Science & Technology

1975-07-01

includes the Maverick, Walleye, and HOBOS, homes on the video contrast of a target. Both Maverick, which is rocket powered, and Walleye, a glide...television system could give a clear-night capability. The sensor output must be transmitted to the control station, and a one-way video com...systems are already available or under development in the U.S.A. which would serve these pur- poses, including a video transmitter weighing only 3 lb𔃻

History of Red Lakes fishery, 1917-38, with observations on population status

USGS Publications Warehouse

Van Oosten, John; Deason, Hilary J.

1957-01-01

A historical account traces the development of the commercial fisheries of the Red Lakes, Minnesota, from its inception in 1917 as a war measure through 1938. The trends of production and catch per unit of effort were followed for the principal species with notes on statistics of the minor fishes. Life history data were recorded for the walleye and yellow perch. A historical account was presented of the artificial propagation of the walleye and whitefish from 1918 through 1938.

Rodent neurotoxicity bioassays for screening contaminated Great Lakes fish

DOE Office of Scientific and Technical Information (OSTI.GOV)

Beattie, M.K.; Hoffman, R.; Gerstenberger, S.

1996-03-01

Standard laboratory rat neurotoxicity protocols were used to study the consequences resulting from the consumption of walleye (Stizostedion vitreum), whitefish (Coregonus clupeaformis), and lake trout (Salvelinus namaycush) from Lake Superior (LS) and the consumption of carp (Cyprinus carpio) from Little Lake Butte des Morte (LLBM) near Oshkosh, Wisconsin, USA. Two 90-d subchronic studies are described, including a 45-d exposure to fish diets using male Sprague-Dawley hooded rats, and a 90-d exposure to fish diets using female rats of the same species. Behavioral alterations were tested using a battery of behavioral tests. In addition, pharmacologic challenges using apomorphine and D-amphetamine weremore » administered to the rats to reveal latent neurotoxic effects. Cumulative fish consumption data were recorded daily, weight gain recorded weekly, and behavior data collected prior to exposure, and on days 7, 14, 55 {+-} 2, 85 {+-} 2. Motor activity data were collected on days 30 {+-} 2, 60 {+-} 2, and 90 {+-} 2 of the feeding protocols. Brain tissue from rodents fed these fish were subsequently analyzed for either mercury (Hg) or polychlorinated biphenyls (PCB). Mercury concentrations were increased in the brains of the walleye-fed rats, and PCB concentrations ranged from 0.5 nl/L to 10 nl/L in the brains of rats fed carp from LLBM, a Lake Michigan tributary. Adult male rats fed LLBM carp for 45 d exhibited the greatest behavior responses to the dopaminergic agonist apomorphine on the accelerating rotarod, although these differences were not significant. The 90-d exposure of LS walleye or Hg-spiked LS walleye resulted in behavior alterations on tactile startle response and second footsplay. D-Amphetamine challenge caused changes in tactile startle response, second footsplay, and accelerating rotarod performance after consuming walleye diets. Rats fed LLBM carp had altered behavioral responses to apomorphine on the accelerating rotarod.« less

Confirmation of the Northern Delta Aquariids (NDA, IAU #26) and the Northern June Aquilids (NZC, IAU #164)

NASA Astrophysics Data System (ADS)

Holman, David; Jenniskens, Peter

2012-10-01

This paper resolves confusion surrounding the Northern delta-Aquariids (NDA, IAU #26). Low-light level video observations with the Cameras for All-sky Meteor Surveillance project in California show distinct showers in the months of July and August. The July shower is identified as the Northern June Aquilids (NZC, IAU #164), while the August shower matches most closely prior data on the Northern delta-Aquariids. This paper validates the existence of both showers, which can now be moved to the list of established showers. The August beta-Piscids (BPI, #342) is not a separate stream, but identical to the Northern delta-Aquariids, and should be discarded from the IAU Working List. We detected the Northern June Aquilids beginning on June 14, through its peak on July 11, and to the shower's end on August 2. The meteors move in a short-period sun grazing comet orbit. Our mean orbital elements are: q = 0.124 ± 0.002 AU, 1/a = 0.512 ± 0.014 AU^{-1}, i = 37°63 ± 0°35, omega = 324°90 ± 0°27, and Omega = 107°93 ± 0°91 (N = 131). This orbit is similar to that of sungrazer comet C/2009 U10.

Reconciling catch differences from multiple fishery independent gill net surveys

USGS Publications Warehouse

Kraus, Richard T.; Vandergoot, Christopher; Kocovsky, Patrick M.; Rogers, Mark W.; Cook, H. Andrew; Brenden, Travis O.

2017-01-01

Fishery independent gill net surveys provide valuable demographic information for population assessment and resource management, but relative to net construction, the effects of ancillary species, and environmental variables on focal species catch rates are poorly understood. In response, we conducted comparative deployments with three unique, inter-agency, survey gill nets used to assess walleye Sander vitreus in Lake Erie. We used an information-theoretic approach with Akaike’s second-order information criterion (AICc) to evaluate linear mixed models of walleye catch as a function of net type (multifilament and two types of monofilament netting), mesh size (categorical), Secchi depth, temperature, water depth, catch of ancillary species, and interactions among selected variables. The model with the greatest weight of evidence showed that walleye catches were positively associated with potential prey and intra-guild predators and negatively associated with water depth and temperature. In addition, the multifilament net had higher average walleye catches than either of the two monofilament nets. Results from this study both help inform decisions about proposed gear changes to stock assessment surveys in Lake Erie, and advance our understanding of how multispecies associations explain variation in gill net catches. Of broader interest to fishery-independent gill net studies, effects of abiotic variables and ancillary species on focal specie’s catch rates were small in comparison with net characteristics of mesh size or twine type.

Dispersal, mortality, and predation on recently-stocked rainbow trout in Dale Hollow Lake, Tennessee

USGS Publications Warehouse

Ivasauskas, Tomas J.; Bettoli, Phillip William

2011-01-01

Forty-four hatchery-raised rainbow trout (Oncorhynchus mykiss) were implanted with ultrasonic tags and stocked into Dale Hollow Lake, Tennessee, and tracked at least once per week for eight weeks to describe post-stocking dispersal rates, movements, and habitat use. Dispersal followed a three-stage pattern characterized by rapid movement away from each stocking site during the first week, relatively little dispersal during the next three weeks, and further dispersion during the final four weeks that fish were tracked. Rainbow trout exhibited a strong affinity for coves and were rarely encountered in the main channel. Tagged fish stocked in March exhibited lower mortality (Zweekly = 0.027) than those stocked in January (Zweekly = 0.062) during the first eight weeks post-stocking. Diets of potential predators in Dale Hollow Lake were examined. Walleye (Sander vitreus), smallmouth bass (Micropterus dolomieu), largemouth bass (M. salmoides), and holdover rainbow trout all preyed on recently stocked trout. Larger walleye were more likely to prey on stocked rainbow trout, and walleye of all sizes tended to prey on the smaller trout in each stocked cohort. Walleye were more likely to feed on rainbow trout during January than March. Effective stocking strategies should focus on reducing predation by stocking larger rainbow trout or by stocking when predation risk is minimized (i.e., March).

AmeriFlux CA-Man Manitoba - Northern Old Black Spruce (former BOREAS Northern Study Area)

DOE Data Explorer

Amiro, Brian [University of Manitoba

2016-01-01

This is the AmeriFlux version of the carbon flux data for the site CA-Man Manitoba - Northern Old Black Spruce (former BOREAS Northern Study Area). Site Description - 55.880° N, 98.481° W, elevation of 259 m, Boreal coniferous: Black spruce; occasional larch present in poorly-drained areas. Groundcover is moss (feathermosses and Sphagnum), Labrador Tea, Vaccinium, and willows are a main component of the understory. It was established in 1993 as a BOREAS site.

7 CFR 457.143 - Northern potato crop insurance-quality endorsement.

Code of Federal Regulations, 2013 CFR

2013-01-01

... 7 Agriculture 6 2013-01-01 2013-01-01 false Northern potato crop insurance-quality endorsement... Northern potato crop insurance—quality endorsement. The Northern Potato Crop Insurance Quality Endorsement...) Both FCIC and reinsured policies: Northern Potato Crop Insurance Quality Endorsement 1. Definitions...

7 CFR 457.143 - Northern potato crop insurance-quality endorsement.

Code of Federal Regulations, 2014 CFR

2014-01-01

... 7 Agriculture 6 2014-01-01 2014-01-01 false Northern potato crop insurance-quality endorsement... Northern potato crop insurance—quality endorsement. The Northern Potato Crop Insurance Quality Endorsement...) Both FCIC and reinsured policies: Northern Potato Crop Insurance Quality Endorsement 1. Definitions...

7 CFR 457.143 - Northern potato crop insurance-quality endorsement.

Code of Federal Regulations, 2012 CFR

2012-01-01

... 7 Agriculture 6 2012-01-01 2012-01-01 false Northern potato crop insurance-quality endorsement... Northern potato crop insurance—quality endorsement. The Northern Potato Crop Insurance Quality Endorsement...) Both FCIC and reinsured policies: Northern Potato Crop Insurance Quality Endorsement 1. Definitions...

7 CFR 457.143 - Northern potato crop insurance-quality endorsement.

Code of Federal Regulations, 2011 CFR

2011-01-01

... 7 Agriculture 6 2011-01-01 2011-01-01 false Northern potato crop insurance-quality endorsement... Northern potato crop insurance—quality endorsement. The Northern Potato Crop Insurance Quality Endorsement...) Both FCIC and reinsured policies: Northern Potato Crop Insurance Quality Endorsement 1. Definitions...

Executive Summary: Forests of the Northern United States

Treesearch

Stephen R. Shifley; Francisco X. Aguilar; Nianfu Song; Susan I. Stewart; David J. Nowak; Dale D. Gormanson; W. Keith Moser; Sherri Wormstead; Eric J. Greenfield

2012-01-01

This executive summary provides an overview of the 200-page report, Forests of the Northern United States, which covers in detail current forest conditions, recent trends, issues, threats and opportunities in the forests in the 20 Northern States. It provides a context for subsequent Northern Forest Futures Project analyses that will forecast alternative future...

Phototaxis of larval and juvenile northern pike

USGS Publications Warehouse

Zigler, S.J.; Dewey, M.R.

1995-01-01

Age- Phi northern pike Esox lucius prefer vegetated habitats that are difficult to sample with standard towed gears. Light traps can be effective for sampling larval fishes in dense vegetation, given positive phototaxis of fish. We evaluated the phototactic response of young northern pike by comparing the catches of larvae and juveniles obtained with plexiglass traps deployed with a chemical light stick versus traps deployed without a light source (controls) in a laboratory raceway and in a vegetated pond. In the laboratory tests, catches of protolarvae and mesolarvae in lighted traps were 11-35 times greater than catches in control traps. The catches of juvenile northern pike in field and laboratory experiments were 3-15 times greater in lighted traps than in control traps, even though the maximum body width of the larger juveniles was similar to the width of the entrance slots of the traps (5 mm). Larval and juvenile northern pike were photopositive; thus, light traps should effectively sample age-0 northern pike for at least 6 weeks after hatching.

Northern Nutrition.

ERIC Educational Resources Information Center

Northwest Territories Dept. of Education, Yellowknife.

This guide contains nutrition information and nutrition education strategies aimed at residents of the Canadian Arctic. Section I: (1) defines nutrition terms; (2) describes the sources and functions of essential nutrients; (3) explains Canada's food guide and special considerations for the traditional northern Native diet and for lactose…

Sowing pregerminated northern red oak acorns

Treesearch

Richard M. Godman; Gilbert A. Mattson

1992-01-01

Northern red oak is extremely difficult to regenerate, although it has produced good acorn crops nearly half of the last 32 years in northern Wisconsin. Field trials have shown that for successful seeding, you must protect acorns from predation by wildlife and sow them when temperatures are most favorable for germination.

Success of Underplanting Northern Red Oaks

Treesearch

Martin A. Spetich; Daniel C. Dey; Paul S. Johnson; David L. Graney

2004-01-01

We summarize results of the growth and survival of northern red oak (Quercus rubra L.) seedlings 11 years after planting in shelterwoods in the Boston Mountains of Arkansas. Shelterwood overstories were harvested 3 years after underplanting > 4,000 northern red oak seedlings. Woody vegetation that was competing with planted seedlings received two...

Northern Australia

Atmospheric Science Data Center

2013-04-16

article title:  Tropical Northern Australia   ... view. Water appears in blue shades in the right image, for example, because glitter makes the water look brighter at the aft camera's view ... MD. The MISR data were obtained from the NASA Langley Research Center Atmospheric Science Data Center in Hampton, VA. Image ...

Holocene climate and climate variability of the northern Gulf of Mexico and adjacent northern Gulf Coast: A review

USGS Publications Warehouse

Poore, Richard Z.

2008-01-01

Marine records from the northern Gulf of Mexico indicate that significant multidecadal- and century-scale variability was common during the Holocene. Mean annual sea-surface temperature (SST) during the last 1,400 years may have varied by 3°C, and excursions to cold SST coincide with reductions in solar output. Broad trends in Holocene terrestrial climate and environmental change along the eastern portion of the northern Gulf Coast are evident from existing pollen records, but the high-frequency details of climate variability are not well known. Continuous and well-dated records of climate change and climate variability in the western portion of the northern Gulf Coast are essentially lacking.Information on Holocene floods, droughts, and storm frequency along the northern Gulf Coast is limited. Records of floods may be preserved in continental shelf sediments, but establishing continuity and chronologies for sedimentary sequences on the shelf presents challenges due to sediment remobilization and redeposition during storms. Studies of past storm deposits in coastal lakes and marshes show promise for constructing records of past storm frequency. A recent summary of sea-level history of the northern Gulf Coast indicates sea level was higher than modern sea level several times during the last few thousand years.

27 CFR 9.70 - Northern Sonoma.

Code of Federal Regulations, 2011 CFR

2011-04-01

... 27 Alcohol, Tobacco Products and Firearms 1 2011-04-01 2011-04-01 false Northern Sonoma. 9.70 Section 9.70 Alcohol, Tobacco Products and Firearms ALCOHOL AND TOBACCO TAX AND TRADE BUREAU, DEPARTMENT OF THE TREASURY LIQUORS AMERICAN VITICULTURAL AREAS Approved American Viticultural Areas § 9.70 Northern Sonoma. (a) Name. The name of the...

27 CFR 9.70 - Northern Sonoma.

Code of Federal Regulations, 2012 CFR

2012-04-01

... 27 Alcohol, Tobacco Products and Firearms 1 2012-04-01 2012-04-01 false Northern Sonoma. 9.70 Section 9.70 Alcohol, Tobacco Products and Firearms ALCOHOL AND TOBACCO TAX AND TRADE BUREAU, DEPARTMENT OF THE TREASURY LIQUORS AMERICAN VITICULTURAL AREAS Approved American Viticultural Areas § 9.70 Northern Sonoma. (a) Name. The name of the...

27 CFR 9.70 - Northern Sonoma.

Code of Federal Regulations, 2013 CFR

2013-04-01

... 27 Alcohol, Tobacco Products and Firearms 1 2013-04-01 2013-04-01 false Northern Sonoma. 9.70 Section 9.70 Alcohol, Tobacco Products and Firearms ALCOHOL AND TOBACCO TAX AND TRADE BUREAU, DEPARTMENT OF THE TREASURY ALCOHOL AMERICAN VITICULTURAL AREAS Approved American Viticultural Areas § 9.70 Northern Sonoma. (a) Name. The name of the...

27 CFR 9.70 - Northern Sonoma.

Code of Federal Regulations, 2010 CFR

2010-04-01

... 27 Alcohol, Tobacco Products and Firearms 1 2010-04-01 2010-04-01 false Northern Sonoma. 9.70 Section 9.70 Alcohol, Tobacco Products and Firearms ALCOHOL AND TOBACCO TAX AND TRADE BUREAU, DEPARTMENT OF THE TREASURY LIQUORS AMERICAN VITICULTURAL AREAS Approved American Viticultural Areas § 9.70 Northern Sonoma. (a) Name. The name of the...

27 CFR 9.70 - Northern Sonoma.

Code of Federal Regulations, 2014 CFR

2014-04-01

... 27 Alcohol, Tobacco Products and Firearms 1 2014-04-01 2014-04-01 false Northern Sonoma. 9.70 Section 9.70 Alcohol, Tobacco Products and Firearms ALCOHOL AND TOBACCO TAX AND TRADE BUREAU, DEPARTMENT OF THE TREASURY ALCOHOL AMERICAN VITICULTURAL AREAS Approved American Viticultural Areas § 9.70 Northern Sonoma. (a) Name. The name of the...

Base of fresh ground water, northern Louisiana Salt-Dome Basin and vicinity, northern Louisiana and southern Arkansas

USGS Publications Warehouse

Ryals, G.N.

1980-01-01

The National Waste Terminal Storage Program is an effort by the U.S. Department of Energy to locate and develop sites for disposal or storage of commercially produced radioactive wastes. As part of this program, salt domes in the northern Louisiana salt-dome basin are being studied to determine their suitability as repositories. Part of the U.S. Geological Survey 's participation in the program has been to describe the regional geohydrology of the northern Louisiana salt-dome basin. A map based on a compilation of published data and the interpretation of electrical logs shows the altitude of the base of freshwater in aquifers in the northern Louisiana salt-dome basin. (USGS)

U.S. Northern Command > Newsroom > Fact Sheets

Science.gov Websites

Operations Command, North U.S. Marine Forces Northern Command U.S. Fleet Forces Command Air Forces Northern U.S. Army North Joint Task Force North Joint Task Force Civil Support Joint Task Force Alaska Joint

Imaging Lithospheric-scale Structure Beneath Northern Altiplano in Southern Peru and Northern Bolivia

NASA Astrophysics Data System (ADS)

Kumar, A.; Wagner, L. S.; Beck, S. L.; Zandt, G.; Long, M. D.

2014-12-01

The northern Altiplano plateau of southern Peru and northern Bolivia is one of the highest topographic features on the Earth, flanked by Western and Eastern Cordillera along its margin. It has strongly influenced the local and far field lithospheric deformation since the early Miocene (Masek et al., 1994). Previous studies have emphasized the importance of both the crust and upper mantle in the evolution of Altiplano plateau (McQuarrie et al., 2005). Early tomographic and receiver function studies, south of 16° S, show significant variations in the crust and upper mantle properties in both perpendicular and along strike direction of the Altiplano plateau (Dorbath et. al., 1993; Myers et al., 1998; Beck and Zandt, 2002). In order to investigate the nature of subsurface lithospheric structure below the northern Altiplano, between 15-18° S, we have determined three-dimensional seismic tomography models for Vp and Vs using P and S-wave travel time data from two recently deployed local seismic networks of CAUGHT and PULSE. We also used data from 8 stations from the PERUSE network (PERU Subduction Experiment). Our preliminary tomographic models show a complex variation in the upper mantle velocity structure with depth, northwest and southeast of lake Titicaca. We see the following trend, at ~85 km depth, northwest of lake Titicaca: low Vp and Vs beneath the Western Cordillera, high Vs beneath the Altiplano and low Vp and Vs beneath the Eastern Cordillera. This low velocity anomaly, beneath Eastern Cordillera, seems to coincide with Kimsachata, a Holocene volcano in southern Peru. At depth greater than ~85 km: we find high velocity anomaly beneath the Western Cordillera and low Vs beneath the Altiplano. This high velocity anomaly, beneath Western Cordillera, coincides with the well-located Wadati-Benioff zone seismicity and perhaps represents the subducting Nazca slab. On the southeast of lake Titicaca, in northern Bolivia, we see a consistently high velocity anomaly

7 CFR 457.146 - Northern potato crop insurance-storage coverage endorsement.

Code of Federal Regulations, 2014 CFR

2014-01-01

... 7 Agriculture 6 2014-01-01 2014-01-01 false Northern potato crop insurance-storage coverage... Northern potato crop insurance—storage coverage endorsement. The Northern Potato Crop Insurance Storage... for insurance provider) Both FCIC and reinsured policies: Northern Potato Crop Insurance Storage...

7 CFR 457.146 - Northern potato crop insurance-storage coverage endorsement.

Code of Federal Regulations, 2012 CFR

2012-01-01

... 7 Agriculture 6 2012-01-01 2012-01-01 false Northern potato crop insurance-storage coverage... Northern potato crop insurance—storage coverage endorsement. The Northern Potato Crop Insurance Storage... for insurance provider) Both FCIC and reinsured policies: Northern Potato Crop Insurance Storage...

7 CFR 457.146 - Northern potato crop insurance-storage coverage endorsement.

Code of Federal Regulations, 2011 CFR

2011-01-01

... 7 Agriculture 6 2011-01-01 2011-01-01 false Northern potato crop insurance-storage coverage... Northern potato crop insurance—storage coverage endorsement. The Northern Potato Crop Insurance Storage... for insurance provider) Both FCIC and reinsured policies: Northern Potato Crop Insurance Storage...

7 CFR 457.146 - Northern potato crop insurance-storage coverage endorsement.

Code of Federal Regulations, 2013 CFR

2013-01-01

... 7 Agriculture 6 2013-01-01 2013-01-01 false Northern potato crop insurance-storage coverage... Northern potato crop insurance—storage coverage endorsement. The Northern Potato Crop Insurance Storage... for insurance provider) Both FCIC and reinsured policies: Northern Potato Crop Insurance Storage...

Laboratory studies on the vulnerability of young white sturgeon to predation

USGS Publications Warehouse

Gadomski, D.M.; Parsley, M.J.

2005-01-01

Despite evidence of annual spawning by white sturgeon Acipenser transmontanus in rivers of the northwestern United States and Canada, in some years and locations little or no recruitment of age-0 white sturgeon has been observed. We examined the vulnerability of white sturgeon larvae and juveniles to predation to further understand possible causes of mortality. We were particularly interested in the vulnerability of older larvae and juveniles because at about 25 mm total length (TL) white sturgeon develop sharp dorsal and lateral scutes that may act as a morphological defense. In the laboratory, white sturgeon ranging from newly hatched larvae to about 170-mm TL juveniles were exposed to predatory fishes they might encounter in the natural environment. We found that channel catfish Ictalurus punctatus (mean TL = 464 mm) and northern pikeminnow Ptychocheilus oregonensis (mean TL = 472 mm) ate white sturgeon up to mean sizes of 121 and 134 mm TL, respectively. Conversely, similarly sized walleyes Sander vitreus ingested almost no white sturgeon, although juvenile walleyes (mean TL = 184 mm) ate white sturgeon up to 59 mm TL. The smallest predator we tested, prickly sculpins Cottus asper (mean TL = 126 mm), ate white sturgeon up to a mean TL of 50 mm. Our study demonstrated that predation is a likely cause of mortality of age-0 white sturgeon and may be contributing to the year-class failures that have been observed. In addition, the results from this study could be used to reduce the predation risk of artificially propagated white sturgeon released to augment declining populations since fish could be reared to sizes where their vulnerability is low.

From the Northern Eurasia Earth Science Partnership Initiative (NEESPI) towards the Northern Eurasia Future Initiative (NEFI)

NASA Astrophysics Data System (ADS)

Groisman, Pavel; Gutman, Garik; Gulev, Sergey; Maksyutov, Shamil

2015-04-01

Northern Eurasia Earth Science Partnership Initiative (NEESPI, http://neespi.org) was launched in 2004. With its multidisciplinary focus, the internationally funded NEESPI (more than 170 individual international projects during the past decade) has challenged participants to research climate-ecosystem interactions, societal impacts from extreme events in Northern Eurasia, and the feedbacks of these interactions and impacts to the global Earth system. NEESPI was endorsed by major ESSP Programs and Projects and the cornerstone support for the NEESPI studies was provided by the NASA Land Cover and Land Use Change Program and the Russian Academy of Sciences. Now it is the time to synthesis the main achievements of the NEESPI researchers and to re-assess its Science Questions and Objectives of the regional research within the new Future Earth Program paradigm with the focus on interdisciplinary solution-oriented approach that will allow effective policy-making in environment management and control. At the sequence of Workshops (the last of them will be in Prague one week prior to this Assembly) we formulated a major Science Question of the new Northern Eurasia Future Initiative (NEFI): "What will the changes in the regional ecosystems dynamics and interactions mean for the societal well-being, activities, health, and strategic planning in Northern Eurasia?" The major NEFI challenge will be the services aimed on providing in Northern Eurasia a sustainable societal development in changing climate, ecosystems, and societies. At this presentation we shall brief the audience about the main results of the NEESPI researchers, and lay down the plans for the future NEFI studies. At the side event of the Meeting, we shall initiate preparation of the book which will synthesize major NEESPI achievements.

Predation on Northern krill (Meganyctiphanes norvegica Sars).

PubMed

Simard, Yvan; Harvey, Michel

2010-01-01

We consider predation as a function of prey concentration with a focus on how this interaction is influenced by biological-physical interactions, and wider oceanographic processes. In particular, we examine how the anti-predation behaviour of Northern krill interacts with ocean-circulation process to influence its vulnerability to predation. We describe how three-dimensional (3D) circulation interacts with in situ light levels to modulate predator-prey interactions from small to large scales, and illustrate how the stability of the predator-prey system is sometimes perturbed as a consequence. Northern krill predators include a wide range of species from the pelagic and benthic strata, as well as birds. Many exhibit adaptations in their feeding strategy to take advantage of the dynamic physical-biological processes that determine the distribution, concentration and vulnerability of Northern krill. Among them, baleen whales appear to have developed particularly efficient predation strategies. A literature search indicates that Northern krill are a major contributor to ecosystem function throughout its distributional range, and a key species with respect to the flow of energy to upper trophic levels. A list of future research needed to fill gaps in our understanding of Northern krill predator-prey interaction is provided. Copyright © 2010 Elsevier Ltd. All rights reserved.

Hazard assessment of inorganics to three endangered fish in the Green River, Utah

USGS Publications Warehouse

Hamilton, S.J.

1995-01-01

Acute toxicity tests were conducted with three life stages of Colorado squawfish (Ptychocheilus lucius), razorback sucker (Xyrauchen texanus), and bonytail (Gila elegans) in a reconstituted water quality simulating the middle part of the Green River of Utah. Tests were conducted with boron, lithium, selenate, selenite, uranium, vanadium, and zinc. The overall rank order of toxicity to all species and life stages combined from most to least toxic was vanadium = zinc > selenite > lithium = uranium > selenate > boron. There was no difference between the three species in their sensitivity to the seven inorganics based on a rank-order evaluation at the species level. Colorado squawfish were 2-5 times more sensitive to selenate and selenite at the swimup life stage than older stages, whereas razorback suckers displayed equal sensitivity among life stages. Bonytail exhibited equal sensitivity to selenite, but were five times more sensitive to selenate at the swimup life stage than the older stages. Comparison of 96-hr LC50 values with a limited number of environmental water concentrations in Ashley Creek, Utah, which receives irrigation drainwater, revealed moderate hazard ratios for boron, selenate, selenite, and zinc, low hazard ratios for uranium and vanadium, but unknown ratios for lithium. These inorganic contaminants in drainwaters may adversely affect endangered fish in the Green River.

Survival and growth of northern white-cedar and balsam fir seedlings in riparian management zones in northern Minnesota, USA

Treesearch

Brian J. Palik; Brooke K. Haworth; Andrew J. David; Randall K. Kolka

2015-01-01

Northern white-cedar (Thuja occidentalis) and balsam fir (Abies balsamea.) are co-occurring species in riparian forests of the western Great Lakes region. Throughout much of the region, northern white-cedar has been experiencing population declines due to herbivory by white-tailed deer (Odocoileus virginianus)....

Evidence for an east-west regional gravity trend in northern Tunisia: Insight into the structural evolution of northern Tunisian Atlas

NASA Astrophysics Data System (ADS)

Jallouli, Chokri; Mogren, Saad; Mickus, Kevin; Turki, Mohamed Moncef

2013-11-01

The Atlas orogeny in northern Algeria and Tunisia led to the destruction of Tethys oceanic lithosphere and cumulated in a collision of microplates rifted off the European margin with the North African continental margin. The location of the boundary between African plate and Kabylian microplate is expressed in northern Algeria by a crustal wedge with double vergence of thrust sheets, whereas in northern Tunisia the geologic environment is more complex and the location of the plate boundary is ambiguous. In this study, we analyzed gravity data to constrain the crustal structure along the northern margin of Tunisia. The analysis includes a separation of regional and residual gravity anomalies and the application of gradient operators to locate density contrast boundaries. The horizontal gradient magnitude and directional gradient highlight a prominent regional E-W gravity gradient in the northern Tunisian Atlas interpreted as a deep fault (active since at least the Early Mesozoic) having a variable kinematic activity depending on the tectonic regime in the region. The main E-W gravity gradient separates two blocks having different gravitational and seismic responses. The southern block has numerous gravity lineaments trending in different directions implying several density variations within the crust, whereas the northern block shows a long-wavelength negative gravity anomaly with a few lineaments. Taking into account the geologic context of the Western Mediterranean region, we consider the E-W prominent feature as the boundary between African plate and Kabylian microplate in northern Tunisia that rifted off Europe. This hypothesis fits most previous geological and geophysical studies and has an important impact on the petroleum and mineral resource prospection as these two blocks were separated by an ocean and they did not belong to the same margin.

A comparison of spring larval fish assemblages in the Strait of Georgia (British Columbia, Canada) between the early 1980s and late 2000s

NASA Astrophysics Data System (ADS)

Guan, Lu; Dower, John F.; McKinnell, Skip M.; Pepin, Pierre; Pakhomov, Evgeny A.; Hunt, Brian P. V.

2015-11-01

The concentration and composition of the larval fish assemblage in the Strait of Georgia (British Columbia, Canada) has changed between the early 1980s (1980 and 1981) and the late 2000s (2007, 2009 and 2010). During both periods, the spring larval fish assemblages were dominated by pelagic species: Clupea pallasi (Pacific herring), Merluccius productus (Pacific hake), Leuroglossus schmidti (northern smoothtongue) and Theragra chalcogramma (walleye Pollock). The average concentration of Merluccius productus, Theragra chalcogramma, Leuroglossus schmidti, and Sebastes spp. declined between the early 1980s and the late 2000s; in contrast, the absolute concentration and proportion of Pleuronectidae and several demersal fish taxa increased in the spring larval assemblage. Examination of the associations between larval fish assemblages and environmental fluctuations suggests that large-scale climate processes are potential contributors to variations in overall larval concentrations of the dominant taxa and assemblage composition in the Strait of Georgia.

Dermatophytosis in northern Africa.

PubMed

Nweze, E I; Eke, I

2016-03-01

Infections caused by dermatophytes are a global problem and a major public health burden in the world today. In Africa, especially in the northern geographical zone, dermatophytic infections are being reported at an alarming rate. This is mostly because of some local but unique cultural practices, socioeconomic and environmental conditions, lack of reliable diagnostic personnel and facilities and ineffective treatment. Interestingly, the pathogen spectrum and the clinical manifestation are most times different from what is seen in other continents. Several epidemiological studies have been performed on the incidence and aetiology of dermatophytoses in northern Africa. However, there is currently no review article with up-to-date information on the relevant findings reported so far in this region. This information is necessary for clinicians who treat dermatophytic infections all over the world since agents of dermatophytes are no longer restricted because of the rapid mobility of humans from one part of the world to another. Moreover, the epidemiology of dermatophytoses is known to change over time, thus requiring the update of information from time to time. A review of relevant studies published on dermatophytoses in northern Africa is presented. This covers all of old Sudan, Algeria, Egypt, Libya, Tunisia and Morocco. © 2015 Blackwell Verlag GmbH.

Harvesting systems for the northern forest hardwoods

Treesearch

Chris B. LeDoux

2011-01-01

This monograph is a summary of research results and environmental compliance measures for timber harvesting operations. Data are presented from the Northern Research Station's forest inventory and analysis of 20 states in the northern forest hardwoods. Harvesting systems available in the region today are summarized. Equations for estimating harvesting costs are...

The Alcoholism Situation in a Northern City

ERIC Educational Resources Information Center

Martynov, M. Iu.; Martynova, D. Iu.

2012-01-01

Alcohol abuse in Russia has been increasing in recent years, especially in northern regions, as has the incidence of alcohol-related disease rates. A survey was conducted in Surgut (the Khanty-Mansi autonomous okrug) that determined the factors lending to the prevalence of alcohol abuse among the population of the northern city and assessed the…

Seasonal prevailing surface winds in Northern Serbia

NASA Astrophysics Data System (ADS)

Tošić, Ivana; Gavrilov, Milivoj B.; Marković, Slobodan B.; Ruman, Albert; Putniković, Suzana

2018-02-01

Seasonal prevailing surface winds are analyzed in the territory of Northern Serbia, using observational data from 12 meteorological stations over several decades. In accordance with the general definition of prevailing wind, two special definitions of this term are used. The seasonal wind roses in 16 directions at each station are analyzed. This study shows that the prevailing winds in Northern Serbia have northwestern and southeastern directions. Circulation weather types over Serbia are presented in order to determine the connections between the synoptic circulations and prevailing surface winds. Three controlling pressure centers, i.e., the Mediterranean cyclone, Siberian high, and the Azores anticyclone, appear as the most important large-scale factors that influence the creation of the prevailing winds over Northern Serbia. Beside the synoptic cause of the prevailing winds, it is noted that the orography of the eastern Balkans has a major influence on the winds from the second quadrant. It was found that the frequencies of circulation weather types are in agreement with those of the prevailing winds over Northern Serbia.

Seasonally asymmetric enhancement of northern vegetation productivity

NASA Astrophysics Data System (ADS)

Park, T.; Myneni, R.

2017-12-01

Multiple evidences of widespread greening and increasing terrestrial carbon uptake have been documented. In particular, enhanced gross productivity of northern vegetation has been a critical role leading to observed carbon uptake trend. However, seasonal photosynthetic activity and its contribution to observed annual carbon uptake trend and interannual variability are not well understood. Here, we introduce a multiple-source of datasets including ground, atmospheric and satellite observations, and multiple process-based global vegetation models to understand how seasonal variation of land surface vegetation controls a large-scale carbon exchange. Our analysis clearly shows a seasonally asymmetric enhancement of northern vegetation productivity in growing season during last decades. Particularly, increasing gross productivity in late spring and early summer is obvious and dominant driver explaining observed trend and variability. We observe more asymmetric productivity enhancement in warmer region and this spatially varying asymmetricity in northern vegetation are likely explained by canopy development rate, thermal and light availability. These results imply that continued warming may facilitate amplifying asymmetric vegetation activity and cause these trends to become more pervasive, in turn warming induced regime shift in northern land.

Accessing northern California earthquake data via Internet

NASA Astrophysics Data System (ADS)

Romanowicz, Barbara; Neuhauser, Douglas; Bogaert, Barbara; Oppenheimer, David

The Northern California Earthquake Data Center (NCEDC) provides easy access to central and northern California digital earthquake data. It is located at the University of California, Berkeley, and is operated jointly with the U.S. Geological Survey (USGS) in Menlo Park, Calif., and funded by the University of California and the National Earthquake Hazard Reduction Program. It has been accessible to users in the scientific community through Internet since mid-1992.The data center provides an on-line archive for parametric and waveform data from two regional networks: the Northern California Seismic Network (NCSN) operated by the USGS and the Berkeley Digital Seismic Network (BDSN) operated by the Seismographic Station at the University of California, Berkeley.

Northern Exports of softwood products, 1980-85

Treesearch

James E. Granskog

1988-01-01

Assessment of export opportunities for softwood products from the North has been hampered by a lack of information describing foreign sales from the region. This article describes the value and volume of softwood products exported from the northern United States for 1980 through 1985. Roundwood productsmostly spruce logs from Maine and Vermont- are the largest northern...

Logging truck noise near nesting northern goshawks

Treesearch

Teryl G. Grubb; Larry L. Pater; David K. Delaney

1998-01-01

We measured noise levels of four logging trucks as the trucks passed within approximately 500 m of two active northern goshawk (Accipiter gentilis) nests on the Kaibab Plateau in northern Arizona in 1997. Neither a brooding adult female nor a lone juvenile exhibited any discernable behavioral response to logging truck noise, which peaked at 53.4 and...

Northern Parkway PTA Makes Health a Habit

ERIC Educational Resources Information Center

Ferdinand, Marilyn

2011-01-01

Health and fitness have been on the agenda of Northern Parkway Elementary School for quite some time, thanks to the concerted efforts of its involved and active PTA officers and members. For the past five years, the Northern Parkway PTA has held a popular and well-attended Family Fun and Fitness Night and has complemented the activities and…

Soil organic carbon pools in the northern circumpolar permafrost region

Treesearch

C. Tarnocai; J.G. Canadell; E.A.G. Schuur; P. Kuhry; G. Mazhitova; S. Zimov

2009-01-01

The Northern Circumpolar Soil Carbon Database was developed to determine carbon pools in soils of the northern circumpolar permafrost region. Here we report a new estimate of the carbon pools in soils of the northern permafrost region, including deeper layers and pools not accounted for in previous analyses.

Adapting online learning for Canada's Northern public health workforce.

PubMed

Bell, Marnie; MacDougall, Karen

2013-01-01

Canada's North is a diverse, sparsely populated land, where inequalities and public health issues are evident, particularly for Aboriginal people. The Northern public health workforce is a unique mix of professional and paraprofessional workers. Few have formal public health education. From 2009 to 2012, the Public Health Agency of Canada (PHAC) collaborated with a Northern Advisory Group to develop and implement a strategy to strengthen public health capacity in Canada's 3 northern territories. Access to relevant, effective continuing education was identified as a key issue. Challenges include diverse educational and cultural backgrounds of public health workers, geographical isolation and variable technological infrastructure across the north. PHAC's Skills Online program offers Internet-based continuing education modules for public health professionals. In partnership with the Northern Advisory Group, PHAC conducted 3 pilots between 2008 and 2012 to assess the appropriateness of the Skills Online program for Northern/Aboriginal public health workers. Module content and delivery modalities were adapted for the pilots. Adaptations included adding Inuit and Northern public health examples and using video and teleconference discussions to augment the online self-study component. Findings from the pilots were informative and similar to those from previous Skills Online pilots with learners in developing countries. Online learning is effective in bridging the geographical barriers in remote locations. Incorporating content on Northern and Aboriginal health issues facilitates engagement in learning. Employer support facilitates the recruitment and retention of learners in an online program. Facilitator assets included experience as a public health professional from the north, and flexibility to use modified approaches to support and measure knowledge acquisition and application, especially for First Nations, Inuit and Metis learners. Results demonstrate that

Geologic map of the northern plains of Mars

USGS Publications Warehouse

Tanaka, Kenneth L.; Skinner, James A.; Hare, Trent M.

2005-01-01

The northern plains of Mars cover nearly a third of the planet and constitute the planet's broadest region of lowlands. Apparently formed early in Mars' history, the northern lowlands served as a repository both for sediments shed from the adjacent ancient highlands and for volcanic flows and deposits from sources within and near the lowlands. Geomorphic evidence for extensive tectonic deformation and reworking of surface materials through release of volatiles occurs throughout the northern plains. In the polar region, Planum Boreum contains evidence for the accumulation of ice and dust, and surrounding dune fields suggest widespread aeolian transport and erosion. The most recent regional- and global-scale maps describing the geology of the northern plains are largely based on Viking Orbiter image data (Dial, 1984; Witbeck and Underwood, 1984; Scott and Tanaka, 1986; Greeley and Guest, 1987; Tanaka and Scott, 1987; Tanaka and others, 1992a; Rotto and Tanaka, 1995; Crumpler and others, 2001; McGill, 2002). These maps reveal highland, plains, volcanic, and polar units based on morphologic character, albedo, and relative ages using local stratigraphic relations and crater counts. This geologic map of the northern plains is the first published map that covers a significant part of Mars using topography and image data from both the Mars Global Surveyor and Mars Odyssey missions. The new data provide a fresh perspective on the geology of the region that reveals many previously unrecognizable units, features, and temporal relations. In addition, we adapted and instituted terrestrial mapping methods and stratigraphic conventions that we think result in a clearer and more objective map. We focus on mapping with the intent of reconstructing the history of geologic activity within the northern plains, including deposition, volcanism, erosion, tectonism, impact cratering, and other processes with the aid of comprehensive crater-density determinations. Mapped areas include all

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

USGS Publications Warehouse

Prichard, Carson G.; Craig, Jaquelyn M.; Roseman, Edward F.; Fischer, Jason L.; Manny, Bruce A.; Kennedy, Gregory W.

2017-03-14

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.

HUBBLE SPOTS NORTHERN HEMISPHERIC CLOUDS ON URANUS

NASA Technical Reports Server (NTRS)

2002-01-01

Using visible light, astronomers for the first time this century have detected clouds in the northern hemisphere of Uranus. The newest images, taken July 31 and Aug. 1, 1997 with NASA Hubble Space Telescope's Wide Field and Planetary Camera 2, show banded structure and multiple clouds. Using these images, Dr. Heidi Hammel (Massachusetts Institute of Technology) and colleagues Wes Lockwood (Lowell Observatory) and Kathy Rages (NASA Ames Research Center) plan to measure the wind speeds in the northern hemisphere for the first time. Uranus is sometimes called the 'sideways' planet, because its rotation axis is tipped more than 90 degrees from the planet's orbit around the Sun. The 'year' on Uranus lasts 84 Earth years, which creates extremely long seasons - winter in the northern hemisphere has lasted for nearly 20 years. Uranus has also been called bland and boring, because no clouds have been detectable in ground-based images of the planet. Even to the cameras of the Voyager spacecraft in 1986, Uranus presented a nearly uniform blank disk, and discrete clouds were detectable only in the southern hemisphere. Voyager flew over the planet's cloud tops near the dead of northern winter (when the northern hemisphere was completely shrouded in darkness). Spring has finally come to the northern hemisphere of Uranus. The newest images, both the visible-wavelength ones described here and those taken a few days earlier with the Near Infrared and Multi-Object Spectrometer (NICMOS) by Erich Karkoschka (University of Arizona), show a planet with banded structure and detectable clouds. Two images are shown here. The 'aqua' image (on the left) is taken at 5,470 Angstroms, which is near the human eye's peak response to wavelength. Color has been added to the image to show what a person on a spacecraft near Uranus might see. Little structure is evident at this wavelength, though with image-processing techniques, a small cloud can be seen near the planet's northern limb (rightmost

All Christians? Experiences of science educators in Northern Ireland

NASA Astrophysics Data System (ADS)

Murphy, Colette; Hickey, Ivor; Beggs, Jim

2010-03-01

In this paper we respond to Staver's article (this issue) on an attempt to resolve the discord between science and religion. Most specifically, we comment on Staver's downplaying of difference between Catholics and Protestants in order to focus on the religion-science question. It is our experience that to be born into one or other of these traditions in some parts of the world (especially Northern Ireland) resulted in starkly contrasting opportunities, identities and practices in becoming and being science educators. The paper starts with a short contextual background to the impact of religion on schooling and higher education in Northern Ireland. We then explore the lives and careers of three science/religious educators in Northern Ireland: Catholic (Jim) and Protestant (Ivor) males who are contemporaries and whose experience spans pre-Troubles to post-conflict and a Catholic female (Colette) who moved to Northern Ireland during the Troubles as a teenager. Finally, we discuss the situation regarding the teaching of creationism and evolution in Northern Ireland—an issue has recently generated high public interest. The Chair of the Education Committee of the Northern Ireland Assembly recently stated that "creationism is not for the RE class because I believe that it can stand scientific scrutiny and that is a debate which I am quite happy to encourage and be part of…" (News Letter 2008). It could be the case that the evolution debate is being fuelled as a deliberate attempt to undermine some of the post-conflict collaboration projects between schools and communities in Northern Ireland.

Carbon Cycling in Northern Peatlands

NASA Astrophysics Data System (ADS)

Schultz, Colin

2010-11-01

Northern peatlands span only 3 million square kilometers, about 3% of the terrestrial area of the globe, yet they represent a significant terrestrial sink for carbon dioxide. They are also important emitters of methane, an even more potent greenhouse gas. Despite their substantial role in the global carbon cycle, peatlands are not typically incorporated into global climate models. The AGU Monograph Carbon Cycling in Northern Peatlands, edited by Andrew J. Baird, Lisa R. Belyea, Xavier Comas, A. S. Reeve, and Lee D. Slater, looks at the disproportionate role peatlands play in the global carbon budget. In this interview, Eos talks with Andy Baird, University of Leeds, Leeds, United Kingdom.

Comparison of survival patterns of northern and southern genotypes of the North American tick Ixodes scapularis (Acari: Ixodidae) under northern and southern conditions

USGS Publications Warehouse

Ginsberg, Howard S.; Rulison, Eric L.; Azevedo, Alexandra; Pang, Genevieve C.; Kuczaj, Isis M.; Tsao, Jean I.; LeBrun, Roger A.

2014-01-01

BackgroundSeveral investigators have reported genetic differences between northern and southern populations of Ixodes scapularis in North America, as well as differences in patterns of disease transmission. Ecological and behavioral correlates of these genetic differences, which might have implications for disease transmission, have not been reported. We compared survival of northern with that of southern genotypes under both northern and southern environmental conditions in laboratory trials.MethodsSubadult I. scapularis from laboratory colonies that originated from adults collected from deer from several sites in the northeastern, north central, and southern U.S. were exposed to controlled conditions in environmental chambers. Northern and southern genotypes were exposed to light:dark and temperature conditions of northern and southern sites with controlled relative humidities, and mortality through time was recorded.ResultsTicks from different geographical locations differed in survival patterns, with larvae from Wisconsin surviving longer than larvae from Massachusetts, South Carolina or Georgia, when held under the same conditions. In another experiment, larvae from Florida survived longer than larvae from Michigan. Therefore, survival patterns of regional genotypes did not follow a simple north–south gradient. The most consistent result was that larvae from all locations generally survived longer under northern conditions than under southern conditions.ConclusionsOur results suggest that conditions in southern North America are less hospitable than in the north to populations of I. scapularis. Southern conditions might have resulted in ecological or behavioral adaptations that contribute to the relative rarity of I. scapularis borne diseases, such as Lyme borreliosis, in the southern compared to the northern United States.

Stratigraphy of the Martian northern plains

NASA Technical Reports Server (NTRS)

Tanaka, K. L.

1993-01-01

The northern plains of Mars are roughly defined as the large continuous region of lowlands that lies below Martian datum, plus higher areas within the region that were built up by volcanism, sedimentation, tectonism, and impacts. These northern lowlands span about 50 x 10(exp 6) km(sup 2) or 35 percent of the planet's surface. The age and origin of the lowlands continue to be debated by proponents of impact and tectonic explanations. Geologic mapping and topical studies indicate that volcanic, fluvial, and eolian deposition have played major roles in the infilling of this vast depression. Periglacial, glacial, fluvial, eolian, tectonic, and impact processes have locally modified the surface. Because of the northern plains' complex history of sedimentation and modification, much of their stratigraphy was obscured. Thus the stratigraphy developed is necessarily vague and provisional: it is based on various clues from within the lowlands as well as from highland areas within and bordering the plains. The results are summarized.

Climate impacts on northern Canada: regional background.

PubMed

Prowse, Terry D; Furgal, Chris; Bonsal, Barrie R; Peters, Daniel L

2009-07-01

Understanding the implications of climate change on northern Canada requires a background about the size and diversity of its human and biogeophysical systems. Occupying an area of almost 40% of Canada, with one-third of this contained in Arctic islands, Canada's northern territories consist of a diversity of physical environments unrivaled around the circumpolar north. Major ecozones composed of a range of landforms, climate, vegetation, and wildlife include: Arctic, boreal and taiga cordillera; boreal and taiga plains; taiga shield; and northern and southern Arctic. Although generally characterized by a cold climate, there is an enormous range in air temperature with mean annual values being as high as -5 degrees C in the south to as low as -20 degrees C in the high Arctic islands. A similar contrast characterizes precipitation, which can be > 700 mm y(-1) in some southern alpine regions to as low as 50 mm y(-1) over islands of the high Arctic. Major freshwater resources are found within most northern ecozones, varying from large glaciers or ice caps and lakes to extensive wetlands and peat lands. Most of the North's renewable water, however, is found within its major river networks and originates in more southerly headwaters. Ice covers characterize the freshwater systems for multiple months of the year while permafrost prevails in various forms, dominating the terrestrial landscape. The marine environment, which envelops the Canadian Arctic Archipelago, is dominated by seasonal to multiyear sea ice often several meters thick that plays a key role in the regional climate. Almost two-thirds of northern Canadian communities are located along coastlines with the entire population being just over 100 000. Most recent population growth has been dominated by an expansion of nonaboriginals, primarily the result of resource development and the growth of public administration. The economies of northern communities, however, remain quite mixed with traditional land

Assessing fish predation on migrating juvenile steelhead and a retrospective comparison to steelhead survival through the Priest Rapids Hydroelectric Project, Columbia River, Washington, 2009-11

USGS Publications Warehouse

Hardiman, Jill M.; Counihan, Timothy D.; Burgess, Dave S.; Simmons, Katrina E.; Holmberg, Glen S.; Rogala, Josh; Polacek, Rochelle

2012-01-01

The U.S. Geological Survey (USGS) and the Washington Department of Fish and Wildlife (WDFW) have been working with the Public Utility District No. 2 of Grant County, Washington (Grant PUD), to increase their understanding of predator-prey interactions in the Priest Rapids Hydroelectric Project (PRP), Columbia River, Washington. For this study, the PRP is defined as the area approximately 6 kilometers upstream of Wanapum Dam to the Priest Rapids Dam tailrace, 397.1 miles from the mouth of the Columbia River. Past year’s low survival numbers of juvenile steelhead (Oncorhynchus mykiss) through Wanapum and Priest Rapids Dams has prompted Grant PUD, on behalf of the Priest Rapids Coordinating Committee, to focus research efforts on steelhead migration and potential causal mechanisms for low survival. Steelhead passage survival in 2009 was estimated at 0.944 through the Wanapum Development (dam and reservoir) and 0.881 through the Priest Rapids Development and for 2010, steelhead survival was 0.855 for Wanapum Development and 0.904 for Priest Rapids Development. The USGS and WDFW implemented field collection efforts in 2011 for northern pikeminnow (Ptychocheilus oregonensis), smallmouth bass (Micropterus dolomieu), and walleye (Sander vitreus, formerly Stizostedion vitreum) and their diets in the PRP. For predator indexing, we collected 948 northern pikeminnow, 237 smallmouth bass, 18 walleye, and two largemouth bass (Micropterus salmoides). The intent of this study was to provide standardized predation indices within individual reaches of the PRP to discern spatial variability in predation patterns. Furthermore, the results of the 2011 study were compared to results of a concurrent steelhead survival study. Our results do not indicate excessively high predation of Oncorhynchus spp. occurring by northern pikeminnow or smallmouth bass in any particular reach throughout the study area. Although we found Oncorhynchus spp. in the predator diets, the relative

Northern red oak volume growth on four northern Wisconsin habitat types

Treesearch

Michael Demchik; Kevin M. Schwartz; Rory Braun; Eric Scharenbrock

2014-01-01

Northern red oak (Quercus rubra) grows across much of Wisconsin. Using site factors to aid in prediction of volume and basal area increment facilitates management of red oak and other species of interest. Currently, habitat type (Wisconsin Habitat Type Classification System) is often determined when stands are inventoried. If habitat type were...

Building the New Northern Ontario Rural Medical School.

ERIC Educational Resources Information Center

Rourke, James T. B.

2002-01-01

Opening in 2004, the new Northern Ontario Rural Medical School will address the rural doctor shortage in Canada. Supported by Laurentian University and Lakehead University, learning sites will be in hospitals, community clinics, and physicians' offices throughout northern Ontario. The curriculum will be patient-centered and clinical problem-based…

Northern forest lands: resident attitudes and resource use

Treesearch

Herbert E. Echelberger; Albert E. Luloff; Frederick E. Schmidt; Frederick E. Schmidt

1991-01-01

Describes socioeconomic characteristics of residents of northern New Hampshire and northeastern Vermont; their level of participation in outdoor recreational activities; perceptions of community problems; and attitudes concerning local versus regional planning, public ownership of northern forest lands, and other pertinent issues with respect to changes in patterns of...

7 CFR 457.144 - Northern potato crop insurance-processing quality endorsement.

Code of Federal Regulations, 2011 CFR

2011-01-01

... 7 Agriculture 6 2011-01-01 2011-01-01 false Northern potato crop insurance-processing quality... Northern potato crop insurance—processing quality endorsement. The Northern Potato Crop Insurance.... Definitions Broker. Any business enterprise regularly engaged in the buying and selling of processing potatoes...

7 CFR 457.144 - Northern potato crop insurance-processing quality endorsement.

Code of Federal Regulations, 2014 CFR

2014-01-01

... 7 Agriculture 6 2014-01-01 2014-01-01 false Northern potato crop insurance-processing quality... Northern potato crop insurance—processing quality endorsement. The Northern Potato Crop Insurance.... Definitions Broker. Any business enterprise regularly engaged in the buying and selling of processing potatoes...

7 CFR 457.144 - Northern potato crop insurance-processing quality endorsement.

Code of Federal Regulations, 2013 CFR

2013-01-01

... 7 Agriculture 6 2013-01-01 2013-01-01 false Northern potato crop insurance-processing quality... Northern potato crop insurance—processing quality endorsement. The Northern Potato Crop Insurance.... Definitions Broker. Any business enterprise regularly engaged in the buying and selling of processing potatoes...

7 CFR 457.144 - Northern potato crop insurance-processing quality endorsement.

Code of Federal Regulations, 2012 CFR

2012-01-01

... 7 Agriculture 6 2012-01-01 2012-01-01 false Northern potato crop insurance-processing quality... Northern potato crop insurance—processing quality endorsement. The Northern Potato Crop Insurance.... Definitions Broker. Any business enterprise regularly engaged in the buying and selling of processing potatoes...

Site index comparisons among northern hardwoods in northern Wisconsin and Upper Michigan.

Treesearch

Willard H. Carmean

1979-01-01

Compares site index for 13 species found in even-aged northern hardwood stands. Shows that these species differ greatly in site index when growing together, but can be grouped into four general site index classes. Site relations between several species differed with soil drainage.

A Grammar of Northern Mao (Mawes Aas'e)

ERIC Educational Resources Information Center

Ahland, Michael Bryan

2012-01-01

Northern Mao is an endangered Afroasiatic-Omotic language of western Ethiopia with fewer than 5,000 speakers. This study is a comprehensive grammar of the language, written from a functional/typological perspective which embraces historical change as an explanation for synchronic structure. The grammar introduces the Northern Mao people, aspects…

NPDES Permit for Northern Border Pipeline Company in Montana

EPA Pesticide Factsheets

Under NPDES permit MT-0030791, the Northern Border Pipeline Company is authorized to discharge from locations along the Northern Border Gas Transmission Pipeline located within the exterior boundaries of the Fort Peck Indian Reservation, Montana.

Long-term changes in fish mercury levels in the historically impacted English-Wabigoon River system (Canada).

PubMed

Neff, Margaret R; Bhavsar, Satyendra P; Arhonditsis, George B; Fletcher, Rachael; Jackson, Donald A

2012-09-01

The English-Wabigoon River system in Northwestern Ontario, Canada, was one of the most heavily mercury-contaminated waterways in the world due to historical discharges in the 1960s from a chlor-alkali plant. This study examines long-term (1970-2010) monitoring data to assess temporal trends in mercury contamination in Walleye, Northern Pike and Lake Whitefish, three species important for sport and subsistence fishing in this region, using dynamic linear modeling and piecewise regression. For all lakes and species, there is a significant decline (36-94%) in mercury concentrations through time; however, there is evidence that this decline is either slowing down or levelling off. Concentrations in the English-Wabigoon fish are elevated, and may still present a potential health risk to humans consuming fish from this system. Various biotic and abiotic factors are examined as possible explanations to slowing rates of decline in mercury concentrations observed in the mid-1980s.

Response of northern hardwood forests to nutrient perturbation

Treesearch

Christopher Eagar; Scott Bailey; Amey Bailey

1999-01-01

Substantial amounts of calcium have been depleted from the soils of northern hardwood forests in northern New Engtand over the past 50 years. Portions of this depleted calcium have been incorporated into the biomass of the aggrading forests; however, significant amounts have been leached into drainage waters and lost from the ecosystem.

Northern Forest DroughtNet: A New Framework to Understand Impacts of Precipitation Change on the Northern Forest Ecosystem

NASA Astrophysics Data System (ADS)

Asbjornsen, H.; Rustad, L.; Templer, P. H.; Jennings, K.; Phillips, R.; Smith, M.

2014-12-01

Recent trends and projections for future change for the U.S. northern forests suggest that the region's climate is becoming warmer, wetter, and, ironically, drier, with more precipitation occurring as large events, separated by longer periods with no precipitation. However, to date, precipitation manipulation experiments conducted in forest ecosystems represent only ~5% of all such experiments worldwide, and our understanding of how the mesic-adapted northern forest will respond to greater frequency and intensity of drought in the future is especially poor. Several important challenges have hampered previous research efforts to conduct forest drought experiments and draw robust conclusions, including difficulties in reducing water uptake by deep and lateral tree roots, logistical and financial constraints to establishing and maintaining large-scale field experiments, and the lack of standardized approaches for determining the appropriate precipitation manipulation treatment (e.g., amount and timing of throughfall displacement), designing and constructing the throughfall displacement infrastructure, identifying key response variables, and collecting and analyzing the field data. The overarching goal of this project is to establish a regional research coordination network - Northern Forest DroughtNet - to investigate the impacts of changes in the amount and distribution of precipitation on the hydrology, biogeochemistry, and carbon (C) cycling dynamics of northern temperate forests. Specific objectives include the development of a standard prototype for conducting precipitation manipulation studies in forest ecosystems (in collaboration with the international DroughtNet-RCN) and the implementation of this prototype drought experiment at the Hubbard Brook Experimental Forest. Here, we present the advances made thus far towards achieving the objectives of Northern Forest DroughtNet, plans for future work, and an invitation to the larger scientific community interested

Survey of northern informal and formal mental health practitioners

PubMed Central

O'Neill, Linda; George, Serena; Sebok, Stefanie

2013-01-01

Background This survey is part of a multi-year research study on informal and formal mental health support in northern Canada involving the use of qualitative and quantitative data collection and analysis methods in an effort to better understand mental health in a northern context. Objective The main objective of the 3-year study was to document the situation of formal and informal helpers in providing mental health support in isolated northern communities in northern British Columbia, northern Alberta, Yukon, Northwest Territories and Nunavut. The intent of developing a survey was to include more participants in the research and access those working in small communities who would be concerned regarding confidentiality and anonymity due to their high profile within smaller populations. Design Based on the in-depth interviews from the qualitative phase of the project, the research team developed a survey that reflected the main themes found in the initial qualitative analysis. The on-line survey consisted of 26 questions, looking at basic demographic information and presenting lists of possible challenges, supports and client mental health issues for participants to prioritise. Results Thirty-two participants identified various challenges, supports and client issues relevant to their mental health support work. A vast majority of the respondents felt prepared for northern practice and had some level of formal education. Supports for longevity included team collaboration, knowledgeable supervisors, managers, leaders and more opportunities for formal education, specific training and continuity of care to support clients. Conclusion For northern-based research in small communities, the development of a survey allowed more participants to join the larger study in a way that protected their identity and confidentiality. The results from the survey emphasise the need for team collaboration, interdisciplinary practice and working with community strengths as a way to

Evaluating the power to detect temporal trends in fishery independent surveys: A case study based on Gillnets Set in the Ohio waters of Lake Erie for walleye

USGS Publications Warehouse

Wagner, Tyler; Vandergoot, Christopher S.; Tyson, Jeff

2009-01-01

Fishery-independent (FI) surveys provide critical information used for the sustainable management and conservation of fish populations. Because fisheries management often requires the effects of management actions to be evaluated and detected within a relatively short time frame, it is important that research be directed toward FI survey evaluation, especially with respect to the ability to detect temporal trends. Using annual FI gill-net survey data for Lake Erie walleyes Sander vitreus collected from 1978 to 2006 as a case study, our goals were to (1) highlight the usefulness of hierarchical models for estimating spatial and temporal sources of variation in catch per effort (CPE); (2) demonstrate how the resulting variance estimates can be used to examine the statistical power to detect temporal trends in CPE in relation to sample size, duration of sampling, and decisions regarding what data are most appropriate for analysis; and (3) discuss recommendations for evaluating FI surveys and analyzing the resulting data to support fisheries management. This case study illustrated that the statistical power to detect temporal trends was low over relatively short sampling periods (e.g., 5–10 years) unless the annual decline in CPE reached 10–20%. For example, if 50 sites were sampled each year, a 10% annual decline in CPE would not be detected with more than 0.80 power until 15 years of sampling, and a 5% annual decline would not be detected with more than 0.8 power for approximately 22 years. Because the evaluation of FI surveys is essential for ensuring that trends in fish populations can be detected over management-relevant time periods, we suggest using a meta-analysis–type approach across systems to quantify sources of spatial and temporal variation. This approach can be used to evaluate and identify sampling designs that increase the ability of managers to make inferences about trends in fish stocks.

Silvicultural guide for northern hardwoods in the northeast

Treesearch

William B. Leak; Mariko Yamasaki; Robbo. Holleran

2014-01-01

This revision of the 1987 silvicultural guide includes updated and expanded silvicultural information on northern hardwoods as well as additional information on wildlife habitat and the management of mixed-wood and northern hardwood-oak stands. The prescription methodology is simpler and more field-oriented. This guide also includes an appendix of familiar tables and...

Reappraisal of the relationship between the northern Nevada rift and Miocene extension in the northern Basin and Range Province

USGS Publications Warehouse

Colgan, Joseph P.

2013-01-01

The northern Nevada rift is a prominent mafic dike swarm and magnetic anomaly in north-central Nevada inferred to record the Middle Miocene (16.5-15.0 Ma) extension direction in the northern Basin and Range province in the western United States. From the 245°-250° rift direction, Basin and Range extension is inferred to have shifted 45° clockwise to a modern direction of 290°-300° during the late Miocene. The region surrounding the northern Nevada rift was actively extending while the rift formed, and these domains are all characterized by extension oriented 280°-300°. This direction is distinctly different from the rift direction and nearly identical to the modern Basin and Range direction. Although the rate, structural style, and distribution of Basin and Range extension appear to have undergone a significant change in the late Miocene (ca. 10 Ma), the overall spreading direction does not. Middle Miocene extension was directed perpendicular to the axis of the thickest crust formed during Mesozoic shortening and this orientation may reflect gravitational collapse of this thick crust. Orientation of northern Nevada rift dikes may reflect a short-lived regional stress field related to the onset of Yellowstone hotspot volcanism.

Hubble Spots Northern Hemispheric Clouds on Uranus

NASA Technical Reports Server (NTRS)

1997-01-01

Using visible light, astronomers for the first time this century have detected clouds in the northern hemisphere of Uranus. The newest images, taken July 31 and Aug. 1, 1997 with NASA Hubble Space Telescope's Wide Field and Planetary Camera 2, show banded structure and multiple clouds. Using these images, Dr. Heidi Hammel (Massachusetts Institute of Technology) and colleagues Wes Lockwood (Lowell Observatory) and Kathy Rages (NASA Ames Research Center) plan to measure the wind speeds in the northern hemisphere for the first time.

Uranus is sometimes called the 'sideways' planet, because its rotation axis tipped more than 90 degrees from the planet's orbit around the Sun. The 'year' on Uranus lasts 84 Earth years, which creates extremely long seasons - winter in the northern hemisphere has lasted for nearly 20 years. Uranus has also been called bland and boring, because no clouds have been detectable in ground-based images of the planet. Even to the cameras of the Voyager spacecraft in 1986, Uranus presented a nearly uniform blank disk, and discrete clouds were detectable only in the southern hemisphere. Voyager flew over the planet's cloud tops near the dead of northern winter (when the northern hemisphere was completely shrouded in darkness).

Spring has finally come to the northern hemisphere of Uranus. The newest images, both the visible-wavelength ones described here and those taken a few days earlier with the Near Infrared and Multi-Object Spectrometer (NICMOS) by Erich Karkoschka (University of Arizona), show a planet with banded structure and detectable clouds.

Two images are shown here. The 'aqua' image (on the left) is taken at 5,470 Angstroms, which is near the human eye's peak response to wavelength. Color has been added to the image to show what a person on a spacecraft near Uranus might see. Little structure is evident at this wavelength, though with image-processing techniques, a small cloud can be seen near the planet's northern limb

Northern tropical Atlantic climate since late Medieval times from Northern Caribbean coral geochemistry

NASA Astrophysics Data System (ADS)

Kilbourne, K. H.; Xu, Y.

2015-12-01

Paleoclimate reconstructions of different global climate modes over the last 1000 years provide the basis for testing the relative roles of forced and unforced variability climate system, which can help us improve projections of future climate change. The Medieval Climate Anomaly (MCA) has been characterized by a combination of persistent La Niña-like conditions, a positive North Atlantic Oscillation (+NAO), and increased Atlantic Meridional Overturning Circulation (AMOC). The northern tropical Atlantic is sensitive to each of these climate patterns, but not all of them have the same regional fingerprint in the modern northern tropical Atlantic. The relative influence of different processes related to these climate patterns can help us better understand regional responses to climate change. The regional response of the northern tropical Atlantic is important because the tropical Atlantic Ocean is a large source of heat and moisture to the global climate system that can feedback onto global climate patterns. This study presents new coral Sr/Ca and δ18O data from the northern tropical Atlantic (Anegada, British Virgin Islands). Comparison of the sub-fossil corals that grew during the 13th and 14th Centuries with modern coral geochemical data from this site indicates relatively cooler mean conditions with a decrease in the oxygen isotopic composition of the water consistent with lower salinities. Similar average annual cycles between modern and sub-fossil Sr/Ca indicate no change in seasonal temperature range, but a difference in the relative phasing of the δ18O seasonal cycles indicates that the fresher mean conditions may be due to a more northerly position of the regional salinity front. This localized response is consistent with some, but not all of the expected regional responses to a La Niña-like state, a +NAO state, and increased AMOC. Understanding these differences can provide insight into the relative importance of advection versus surface fluxes for

Impacts of Northern Pike on stocked Rainbow Trout in Pactola Reservoir, South Dakota

USGS Publications Warehouse

Scheibel, Natalie C.; Dembkowski, Daniel J.; Davis, Jacob L.; Chipps, Steven R.

2016-01-01

Establishment of nonnative Northern Pike Esox lucius in Pactola Reservoir, South Dakota, has prompted concern among biologists about the influence of this species on the lake’s intensively managed salmonid fisheries. Ancedotal information suggests that catch rates of Rainbow Trout Oncorhynchus mykiss have declined while mean size and abundance of Northern Pike has increased, although quantitative information on diet and growth of the Northern Pike population is lacking. To address potential interactions between Northern Pike and Rainbow Trout, we assessed size-dependent predation by Northern Pike on Rainbow Trout and determined the relative energetic contribution of stocked Rainbow Trout to Northern Pike growth using bioenergetics modeling. Stable isotopes combined with traditional diet analyses revealed that smaller Northern Pike (<600 mm TL) consumed primarily centrarchids and Rainbow Smelt Osmerus mordax, and Rainbow Trout contributed less than 10% to their annual energy consumption. In contrast, larger Northern Pike (≥600 mm TL) consumed primarily Rainbow Trout, which accounted for 56% of their annual energy consumption. Combining estimates of Northern Pike predation with production costs of catchable-size Rainbow Trout revealed that annual economic losses ranged from US$15,259 to $24,801 per year. Over its lifespan, an age-10 Northern Pike was estimated to consume ~117 Rainbow Trout worth approximately $340. Thus, Northern Pike predation substantially influences salmonid management initiatives and is likely a primary factor contributing to reduced Rainbow Trout abundance and return to anglers in Pactola Reservoir. Strategies for reducing Northern Pike predation on Rainbow Trout include increasing the size of stocked fish or altering the timing and spatial distribution of stocking events.

Blinded by the light? Nearshore energy pathway coupling and relative predator biomass increase with reduced water transparency across lakes.

PubMed

Tunney, Tyler D; McCann, Kevin S; Jarvis, Lauren; Lester, Nigel P; Shuter, Brian J

2018-04-01

Habitat coupling is a concept that refers to consumer integration of resources derived from different habitats. This coupling unites fundamental food web pathways (e.g., cross-habitat trophic linkages) that mediate key ecological processes such as biomass flows, nutrient cycling, and stability. We consider the influence of water transparency, an important environmental driver in aquatic ecosystems, on habitat coupling by a light-sensitive predator, walleye (Sander vitreus), and its prey in 33 Canadian lakes. Our large-scale, across-lake study shows that the contribution of nearshore carbon (δ 13 C) relative to offshore carbon (δ 13 C) to walleye is higher in less transparent lakes. To a lesser degree, the contribution of nearshore carbon increased with a greater proportion of prey in nearshore compared to offshore habitats. Interestingly, water transparency and habitat coupling predict among-lake variation in walleye relative biomass. These findings support the idea that predator responses to changing conditions (e.g., water transparency) can fundamentally alter carbon pathways, and predator biomass, in aquatic ecosystems. Identifying environmental factors that influence habitat coupling is an important step toward understanding spatial food web structure in a changing world.

The influence of external subsidies on diet, growth and Hg concentrations of freshwater sport fish: implications for management and fish consumption advisories.

PubMed

Lepak, Jesse M; Hooten, Mevin B; Johnson, Brett M

2012-10-01

Mercury (Hg) contamination in sport fish is a global problem. In freshwater systems, food web structure, sport fish sex, size, diet and growth rates influence Hg bioaccumulation. Fish stocking is a common management practice worldwide that can introduce external energy and contaminants into freshwater systems. Thus, stocking can alter many of the factors that influence Hg concentrations in sport fish. Here we evaluated the influence of external subsidies, in the form of hatchery-raised rainbow trout Oncorhynchus mykiss on walleye Sander vitreus diet, growth and Hg concentrations in two freshwater systems. Stocking differentially influenced male and female walleye diets and growth, producing a counterintuitive size-contamination relationship. Modeling indicated that walleye growth rate and diet were important explanatory variables when predicting Hg concentrations. Thus, hatchery contributions to freshwater systems in the form of energy and contaminants can influence diet, growth and Hg concentrations in sport fish. Given the extensive scale of fish stocking, and the known health risks associated with Hg contamination, this represents a significant issue for managers monitoring and manipulating freshwater food web structures, and policy makers attempting to develop fish consumption advisories to protect human health in stocked systems.

The influence of external subsidies on diet, growth and Hg concentrations of freshwater sport fish: implications for management and fish consumption advisories

USGS Publications Warehouse

Lepak, J.M.; Hooten, M.B.; Johnson, B.M.

2012-01-01

Mercury (Hg) contamination in sport fish is a global problem. In freshwater systems, food web structure, sport fish sex, size, diet and growth rates influence Hg bioaccumulation. Fish stocking is a common management practice worldwide that can introduce external energy and contaminants into freshwater systems. Thus, stocking can alter many of the factors that influence Hg concentrations in sport fish. Here we evaluated the influence of external subsidies, in the form of hatchery-raised rainbow trout Oncorhynchus mykiss on walleye Sander vitreus diet, growth and Hg concentrations in two freshwater systems. Stocking differentially influenced male and female walleye diets and growth, producing a counterintuitive size-contamination relationship. Modeling indicated that walleye growth rate and diet were important explanatory variables when predicting Hg concentrations. Thus, hatchery contributions to freshwater systems in the form of energy and contaminants can influence diet, growth and Hg concentrations in sport fish. Given the extensive scale of fish stocking, and the known health risks associated with Hg contamination, this represents a significant issue for managers monitoring and manipulating freshwater food web structures, and policy makers attempting to develop fish consumption advisories to protect human health in stocked systems.

Northern Conference Film and Video Guide on Native and Northern Justice Issues.

ERIC Educational Resources Information Center

Simon Fraser Univ., Burnaby (British Columbia).

Intended for teachers and practitioners, this film and video guide contains 235 entries pertaining to the administration of justice, culture and lifestyle, and education and services in northern Canada. It is divided into eight sections: Native lifestyle (97 items); economic development (28), rights and self-government (20); education and training…

68. Photocopy of drawing (from print, Burlington Northern Engineering Office) ...

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

68. Photocopy of drawing (from print, Burlington Northern Engineering Office) STRESS DIAGRAM - Burlington Northern Railroad Bridge, Spanning Willamette River at River Mile 6.9, Portland, Multnomah County, OR

Paludification and forest retreat in northern oceanic environments.

PubMed

Crawford, R M M; Jeffree, C E; Rees, W G

2003-01-01

Examination of temperature variations over the past century for Europe and the Arctic from northern Norway to Siberia suggests that variations in the North Atlantic Oscillation are associated with an increase in oceanicity in certain maritime regions. A southward depression of the tree line in favour of wet heaths, bogs and wetland tundra communities is also observed in northern oceanic environments. The physiological basis for this change in ecological succession from forest to bog is discussed in relation to the long-term effects of flooding on tree survival. The heightened values currently detected in the North Atlantic Oscillation Index, together with rising winter temperatures, and increased rainfall in many areas in northern Europe, presents an increasing risk of paludification with adverse consequences for forest regeneration, particularly in areas with oceanic climates. Climatic warming in oceanic areas may increase the area covered by bogs and, contrary to general expectations, lead to a retreat rather than an advance in the northern limit of the boreal forest. High water-table levels are not automatically detrimental to forest survival as can be seen in swamp, bottom land and mangrove forests. Consequently, the inhibitory effects of flooding on tree survival and regeneration in northern regions should not be uncritically accepted as merely due to high water levels. Evidence is discussed which suggests that physiological and ecological factors may interact to inhibit forest regeneration in habitats where there is a risk of prolonged winter-flooding combined with warmer winters and cool moist summers.

Paludification and Forest Retreat in Northern Oceanic Environments

PubMed Central

CRAWFORD, R. M. M.; JEFFREE, C. E.; REES, W. G.

2003-01-01

Examination of temperature variations over the past century for Europe and the Arctic from northern Norway to Siberia suggests that variations in the North Atlantic Oscillation are associated with an increase in oceanicity in certain maritime regions. A southward depression of the treeline in favour of wet heaths, bogs and wetland tundra communities is also observed in northern oceanic environments. The physiological basis for this change in ecological succession from forest to bog is discussed in relation to the long‐term effects of flooding on tree survival. The heightened values currently detected in the North Atlantic Oscillation Index, together with rising winter temperatures, and increased rainfall in many areas in northern Europe, presents an increasing risk of paludification with adverse consequences for forest regeneration, particularly in areas with oceanic climates. Climatic warming in oceanic areas may increase the area covered by bogs and, contrary to general expectations, lead to a retreat rather than an advance in the northern limit of the boreal forest. High water‐table levels are not automatically detrimental to forest survival as can be seen in swamp, bottomland and mangrove forests. Consequently, the inhibitory effects of flooding on tree survival and regeneration in northern regions should not be uncritically accepted as merely due to high water levels. Evidence is discussed which suggests that physiological and ecological factors may interact to inhibit forest regeneration in habitats where there is a risk of prolonged winter‐flooding combined with warmer winters and cool moist summers. PMID:12509342

76 FR 55345 - Northern New Mexico Resource Advisory Committee

Federal Register 2010, 2011, 2012, 2013, 2014

2011-09-07

... DEPARTMENT OF AGRICULTURE Forest Service Northern New Mexico Resource Advisory Committee AGENCY: Forest Service, USDA. ACTION: Notice of meeting. SUMMARY: The Northern New Mexico Resource Advisory Committee (NNM RAC) will meet in Albuquerque, New Mexico. The committee is authorized under the Secure Rural...

76 FR 29722 - Northern New Mexico Resource Advisory Committee

Federal Register 2010, 2011, 2012, 2013, 2014

2011-05-23

... DEPARTMENT OF AGRICULTURE Forest Service Northern New Mexico Resource Advisory Committee AGENCY: Forest Service, USDA. ACTION: Notice of meeting. SUMMARY: The Northern New Mexico Resource Advisory Committee (NNMRAC) will meet in Albuquerque, New Mexico. The committee is authorized under the Secure Rural...

77 FR 48949 - Northern New Mexico Resource Advisory Committee

Federal Register 2010, 2011, 2012, 2013, 2014

2012-08-15

... DEPARTMENT OF AGRICULTURE Forest Service Northern New Mexico Resource Advisory Committee AGENCY: Forest Service, USDA. ACTION: Notice of meeting. SUMMARY: The Northern New Mexico Resource Advisory Committee (NNM RAC) will meet in Albuquerque, New Mexico. The committee is authorized under the Secure Rural...

Developing a topographic model to predict the northern hardwood forest type within Carolina northern flying squirrel (Glaucomys sabrinus coloratus) recovery areas of the southern Appalachians

USGS Publications Warehouse

Evans, Andrew; Odom, Richard H.; Resler, Lynn M.; Ford, W. Mark; Prisley, Stephen

2014-01-01

The northern hardwood forest type is an important habitat component for the endangered Carolina northern flying squirrel (CNFS; Glaucomys sabrinus coloratus) for den sites and corridor habitats between boreo-montane conifer patches foraging areas. Our study related terrain data to presence of northern hardwood forest type in the recovery areas of CNFS in the southern Appalachian Mountains of western North Carolina, eastern Tennessee, and southwestern Virginia. We recorded overstory species composition and terrain variables at 338 points, to construct a robust, spatially predictive model. Terrain variables analyzed included elevation, aspect, slope gradient, site curvature, and topographic exposure. We used an information-theoretic approach to assess seven models based on associations noted in existing literature as well as an inclusive global model. Our results indicate that, on a regional scale, elevation, aspect, and topographic exposure index (TEI) are significant predictors of the presence of the northern hardwood forest type in the southern Appalachians. Our elevation + TEI model was the best approximating model (the lowest AICc score) for predicting northern hardwood forest type correctly classifying approximately 78% of our sample points. We then used these data to create region-wide predictive maps of the distribution of the northern hardwood forest type within CNFS recovery areas.

64. Photocopy of drawing (from print, Burlington Northern Engineering Office, ...

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

64. Photocopy of drawing (from print, Burlington Northern Engineering Office, Seattle) STRESS SHEET - Burlington Northern Railroad Bridge, Spanning Willamette River at River Mile 6.9, Portland, Multnomah County, OR

The Maritime Cultural Landscape of Northern Patagonia

NASA Astrophysics Data System (ADS)

Lira, Nicolás

2017-12-01

This article is a contribution to the study of the indigenous navigation and its boats in the region of northern Patagonia. This article also aims to contribute to the understanding of indigenous navigation practices and technologies and their origins from prehistoric times to the mid-twentieth century. It presents and discusses the concept of Westerdahl's Maritime Cultural Landscape in relation to other landscape concepts. This model is applied to northern Patagonia in order to discuss if it is possible to speak of a true maritime culture in the region. For this purpose, archaeological, historical and ethnographic data are presented in an integrative and innovative methodology for the discipline. Finally, the Maritime Cultural Landscape model will allow the integration of aquatic and terrestrial landscapes as routes traveled by native inhabitants of northern Patagonia and southern Chile, and propose an important and diversified maritime, river and lake tradition.

75 FR 61786 - Northern Lights Fund Trust, et al.; Notice of Application

Federal Register 2010, 2011, 2012, 2013, 2014

2010-10-06

...] Northern Lights Fund Trust, et al.; Notice of Application September 30, 2010. AGENCY: Securities and... certain financial instruments. Applicants: Northern Lights Fund Trust (``NLFT''), Arrow Investment Advisors, LLC (``AIA''), and Northern Lights Distributors, LLC (``NLD''). Filing Dates: The application was...

77 FR 76475 - Environmental Management Site-Specific Advisory Board, Northern New Mexico

Federal Register 2010, 2011, 2012, 2013, 2014

2012-12-28

... DEPARTMENT OF ENERGY Environmental Management Site-Specific Advisory Board, Northern New Mexico... the Environmental Management Site-Specific Advisory Board (EM SSAB), Northern New Mexico. The Federal... INFORMATION CONTACT: Menice Santistevan, Northern New Mexico Citizens' Advisory Board (NNMCAB), 94 Cities of...

7 CFR 457.142 - Northern potato crop insurance provisions.

Code of Federal Regulations, 2010 CFR

2010-01-01

... 7 Agriculture 6 2010-01-01 2010-01-01 false Northern potato crop insurance provisions. 457.142 Section 457.142 Agriculture Regulations of the Department of Agriculture (Continued) FEDERAL CROP INSURANCE CORPORATION, DEPARTMENT OF AGRICULTURE COMMON CROP INSURANCE REGULATIONS § 457.142 Northern potato...

Vegetative substrates used by larval northern pike in Rainy and Kabetogama Lakes, Minnesota

Treesearch

Anne L. Timm; Rodney B. Pierce

2015-01-01

Our objective was to identify characteristics of aquatic vegetative communities used as larval northern pike nursery habitat in Rainy and Kabetogama lakes, glacial shield reservoirs in northern Minnesota. Quatrefoil light traps fished at night were used to sample larval northern pike in 11 potential nursery areas. Larval northern pike were most commonly sampled among...

Marine reptiles from the Late Cretaceous of northern Patagonia

NASA Astrophysics Data System (ADS)

Gasparini, Z.; Casadio, S.; Fernández, M.; Salgado, L.

2001-04-01

During the Campanian-Maastrichtian, Patagonia was flooded by the Atlantic and reduced to an archipelago. Several localities of northern Patagonia have yielded marine reptiles. Analysis of several assemblages suggests that the diversity and abundance of pelagic marine reptiles in northern Patagonia was higher by the end of the Cretaceous than previously thought. Several plesiosaurids, including Aristonectes parvidens and the polycotylid Sulcusuchus, and the first remains of mosasaurinae have been found. The Cretaceous marine reptile record from South America is scanty. Nevertheless, materials described here suggest that Tethyan and Weddelian forms converged in northern Patagonia, as seen with invertebrates.

Auger planting of oak seedlings in northern Arkansas

Treesearch

Eric Heitzman; Adrian Grell

2003-01-01

Planting oak seedlings to regenerate upland oak forests is a promising but untested silvicultural practice in the Ozark Mountains of northern Arkansas. The stony (cherty) soils of the region make it difficult to dig deep planting holes using conventional hand planting tools. In 2001, we planted 1-0 northern red oak and white oak seedlings in 0.5 to 1 acre group...

The northern hardwood forests of the Anthracite Region

Treesearch

C. F. Burnham; M. J. Ferree; F. E. Cunningham

1947-01-01

The northern hardwood type forest is found only in the northern counties of the Anthracite Region. It dominates the highlands from Sullivan County on the west, to Monroe County on the east. The early lumbermen back in the 1860's, according to Illick and Frontz, "found (some) valleys, hillsides and mountains covered with a dense growth of enormous white pine...

A test of point-sampling in northern hardwoods

Treesearch

Dale S. Solomon

1975-01-01

Plot- and point-sampling were compared with a complete inventory of two different stands of northern hardwoods. Prisms with basal-area factors of 5, 10, 20, 30, and 40 and a ¼-acre plot were used. Only the 5-factor prism gave a significantly different estimate. Therefore, a prism factor of 10 or greater is suggested for use in northern hardwoods.

Expansive Northern Volcanic Plains

NASA Image and Video Library

2015-04-16

Mercury northern region is dominated by expansive smooth plains, created by huge amounts of volcanic material flooding across Mercury surface in the past, as seen by NASA MESSENGER spacecraft. The volcanic lava flows buried craters, leaving only traces of their rims visible. Such craters are called ghost craters, and there are many visible in this image, including a large one near the center. Wrinkle ridges cross this scene and small troughs are visible regionally within ghost craters, formed as a result of the lava cooling. The northern plains are often described as smooth since their surface has fewer impact craters and thus has been less battered by such events. This indicates that these volcanic plains are younger than Mercury's rougher surfaces. Instrument: Mercury Dual Imaging System (MDIS) Center Latitude: 60.31° N Center Longitude: 36.87° E Scale: The large ghost crater at the center of the image is approximately 103 kilometers (64 miles) in diameter http://photojournal.jpl.nasa.gov/catalog/PIA19415

Aerial view of reroofing of northern LTA ship hangar, circa ...

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

Aerial view of re-roofing of northern LTA ship hangar, circa 1957. - Marine Corps Air Station Tustin, Northern Lighter Than Air Ship Hangar, Meffett Avenue & Maxfield Street, Tustin, Orange County, CA

Dens of northern flying squirrels in the Pacific Northwest.

Treesearch

A.B. Carey; T.M. Wilson; C.C. Maguire; B.L. Biswell

1997-01-01

Silvicultural prescriptions to enhance northern flying squirrel (Glaucoinys sabrinus) habitat have been suggested as an aid for recovery of the threatened northern spotted owl (Strix occidentalis caurina). Flying squirrels are hypothesized to be limited by den sites (cavities in trees) and by food (truffles). However, no...

Associations between omega-3 fatty acids, selenium content, and mercury levels in wild-harvested fish from the Dehcho Region, Northwest Territories, Canada.

PubMed

Reyes, Ellen S; Aristizabal Henao, Juan J; Kornobis, Katherine M; Hanning, Rhona M; Majowicz, Shannon E; Liber, Karsten; Stark, Ken D; Low, George; Swanson, Heidi K; Laird, Brian D

2017-01-01

To better understand the risks and benefits of eating wild-harvested fish from the Northwest Territories, Canada, levels of total mercury (HgT) and selenium (Se) and composition of omega-3 fatty acid (n-3 FA) were measured in muscle tissue of fish harvested from lakes in the Dehcho Region, Northwest Territories, Canada. Average HgT levels ranged from 0.057 mg/kg (cisco) to 0.551 mg/kg (northern pike), while average n-3 FA concentrations ranged from 101 mg/100 g (burbot) to 1,689 mg/100 g (lake trout). In contrast to HgT and n-3 FA, mean Se concentrations were relatively similar among species. Consequently, species such as lake whitefish, cisco, and longnose sucker displayed the highest nutrient levels relative to HgT content. Levels of HgT tended to increase with fish size, while Se and n-3 FA levels were typically not associated with fork length or fish weight. Interestingly, HgT concentration was occasionally inversely related to tissue nutrient content. Significant negative correlations were observed between Hg and n-3 FA for lake trout, northern pike, and walleye. There were also significant negative correlations between Hg and Se noted for lake whitefish, cisco, and northern pike. Samples with the highest nutritional content displayed, on occasion, lower levels of HgT. This study provides valuable information for the design of probabilistic models capable of refining public health messaging related to minimizing Hg risks and maximizing nutrient levels in wild-harvested fish in the Canadian subarctic.

Aspartylglucosaminuria in northern Norway: a molecular and genealogical study.

PubMed Central

Tollersrud, O K; Nilssen, O; Tranebjaerg, L; Borud, O

1994-01-01

Aspartylglucosaminuria (AGU, McKusick 208400) is an autosomal recessive lysosomal storage disorder. Ninety percent of all patients are from Finland and only sporadic cases have been reported from elsewhere. In northern Norway, however, nine patients from seven families have been diagnosed with AGU. All these Norwegian patients were homozygous for the most prevalent Finnish AGU mutation (AGUFin) and show the polymorphism uniquely associated with AGUFin in Finland. Genealogical investigation of nine parents proved Finnish ancestry in all pedigrees. Therefore, AGU in Norway most likely resulted from immigration of Finnish carriers. These Finnish immigrants originated mostly from the Tornio valley area in northern Finland in a continuous immigration movement from 1700 to 1900. The majority settled in the western part of northern Norway, leading to a "cluster" of AGU in that particular area. The Finnish immigrants intermixed considerably with Lapps and these two ethnic origins should thus be considered as high risk groups for AGUFin in northern Norway. PMID:8064811

Effects of fire in the Northern Great Plains

USGS Publications Warehouse

Higgins, Kenneth F.; Kruse, Arnold D.; Piehl, James L.

1989-01-01

This publication is a review of selected literature about prescribed burning in the Northern Great Plains (NGP) for management of wildlife. It also will be useful to other resource managers and researchers and to persons interested in the NGP. It is more 'descriptive' than 'interpretative.'The publication is a joint effort of the South Dakota State Cooperative Fish and Wildlife Research Unit (SDCFWRU), South Dakota State University, Brookings; the Northern Prairie Wildlife Research Center (NPWRC), Jamestown, N.D.; and the U.S. Fish and Wildlife Service (USFWS), Fergus Falls, Minn. Manuscript typing and library services were shared between SDCFWRU and NPWRC.This publication (EC 761) is the second of three SDSU Extension circulars on grassland fires. EC 760 is Prescribed burning guidelines in the Northern Great Plains; EC 762 is Annotated bibliography of fire literature relative to northern grasslands in South-Central Canada and North-Central United States and contains many more citations than presented in this publication. All three circulars may be obtained from either the Wildlife and Fisheries Sciences Department; SDSU Box 2206; ph (605) 688-6121; or from the Ag Communications Bulletin Room; SDSU Box 2231; ph (605) 688-5628; both in Brookings, S.D. 57007.

Vulnerability to predation and physiological stress responses of experimentally descaled juvenile Chinook salmon, Oncorhynchus tshawytscha

USGS Publications Warehouse

Gadomski, Dena M.; Mesa, Matthew G.; Olson, Todd M.

1994-01-01

Juvenile salmonids,Oncorhynchus spp., commonly encounter conditions (e.g., during hatchery release and dam passage) that result in damage to the skin, scale, and slime complex. We conducted laboratory experiments to determine if descaling of juvenile chinook salmon,O. tshawytscha, increased their vulnerability to predation, and to assess the physiological stress responses elicited by descaling. Salmon were experimentally descaled on either 10% or 20% of their total body area. When offered equal numbers of control and descaled juvenile chinook salmon, northern squawfish,Ptychocheilus oregonensis, did not consume significantly more of either prey type (48–60% of consumed prey were descaled). Juvenile chinook salmon descaled on 10% of their body area did show significant physiological stress responses, however. Mean concentrations of plasma cortisol peaked 1 h after descaling, and returned to control levels by 12 h. Plasma glucose peaked 3 h post-treatment and remained elevated for 24 h. Plasma lactate increased immediately following treatment and returned to undisturbed control levels by 3 h. The osmoregulatory response of plasma potassium was highly variable, but plasma sodium decreased immediately and remained low for 24 h. The observed physiological responses suggest that descaling of juvenile chinook salmon could result in decreased resistance to disease and other stressors encountered in the field, possibly leading to reduced performance capacity and lowered survival.

Bereavement Counselling in Uganda and Northern Ireland: A Comparison

ERIC Educational Resources Information Center

Montgomery, Lorna; Owen-Pugh, Valerie

2018-01-01

Therapeutic interventions for bereavement in Northern Ireland and in the Sub-Saharan African country of Uganda are compared. Semi-structured interviews were conducted with Ugandan (n = 18) and Northern Irish (n = 20) therapists. These were thematically analysed. The findings focused on: the counselling context, the characteristics of counsellors,…

The Quaternary thrust system of the northern Alaska Range

USGS Publications Warehouse

Bemis, Sean P.; Carver, Gary A.; Koehler, Richard D.

2012-01-01

The framework of Quaternary faults in Alaska remains poorly constrained. Recent studies in the Alaska Range north of the Denali fault add significantly to the recognition of Quaternary deformation in this active orogen. Faults and folds active during the Quaternary occur over a length of ∼500 km along the northern flank of the Alaska Range, extending from Mount McKinley (Denali) eastward to the Tok River valley. These faults exist as a continuous system of active structures, but we divide the system into four regions based on east-west changes in structural style. At the western end, the Kantishna Hills have only two known faults but the highest rate of shallow crustal seismicity. The western northern foothills fold-thrust belt consists of a 50-km-wide zone of subparallel thrust and reverse faults. This broad zone of deformation narrows to the east in a transition zone where the range-bounding fault of the western northern foothills fold-thrust belt terminates and displacement occurs on thrust and/or reverse faults closer to the Denali fault. The eastern northern foothills fold-thrust belt is characterized by ∼40-km-long thrust fault segments separated across left-steps by NNE-trending left-lateral faults. Altogether, these faults accommodate much of the topographic growth of the northern flank of the Alaska Range.Recognition of this thrust fault system represents a significant concern in addition to the Denali fault for infrastructure adjacent to and transecting the Alaska Range. Although additional work is required to characterize these faults sufficiently for seismic hazard analysis, the regional extent and structural character should require the consideration of the northern Alaska Range thrust system in regional tectonic models.

Challenges in assessing food environments in northern and remote communities in Canada.

PubMed

Skinner, Kelly; Burnett, Kristin; Williams, Patricia; Martin, Debbie; Stothart, Christopher; LeBlanc, Joseph; Veeraraghavan, Gigi; Sheedy, Amanda

2016-06-09

Effective tools for retail food environments in northern and remote communities are lacking. This paper examines the challenges of conducting food environment assessments in northern and remote communities in Canada encountered during our experience with a food costing project. One of the goals of the Paying for Nutrition in the North project is to develop guidelines to improve current food costing tools for northern Canada. Paying for Nutrition illustrates the complex context of measuring food environments in northern and remote communities. Through the development of a food costing methodology guide to assess northern food environments, several contextual issues emerged, including retail store oligopolies in communities; the importance of assessing food quality; informal social food economies; and the challenge of costing the acquisition and consumption of land- and water-based foods. Food environment measures designed for northern and remote communities need to reflect the geographic context in which they are being employed and must include input from local residents.

Northern goshawk (Accipiter gentilis)

Treesearch

John R. Squires; Richard T. Reynolds

1997-01-01

The Northern Goshawk (hereafter referred to as Goshawk) is a large forest raptor, occupying boreal and temperate forests throughout the Holarctic. In North America, it breeds from Alaska to Newfoundland and south (Fig. 1). This partial migrant winters throughout its breeding range including occasionally the Great Plains and southeastern states; some...

Movements of northern flying squirrels in different-aged forest stands of western Oregon

USGS Publications Warehouse

Martin, K.J.; Anthony, R.G.

1999-01-01

In western Oregon, northern flying squirrels (Glaucomys sabrinus) are the primary prey species for northern spotted owls (Strix occidentalis caurina), an old-growth associated species. To assess differences between old-growth and second-growth habitat, we livetrapped and radiotagged 39 northern flying squirrels to estimate their home range sizes and describe movements in 2 old-growth and 2 second-growth conifer forest stands in the Cascade Mountains of central Oregon. Sampling periods were summer and fall of 1991-92. Home range sizes averaged 4.9 ha and did not differ (P > 0.30) between the 2 stand types. Male northern flying squirrels had larger (P ??? 0.03) mean home ranges (5.9 ?? 0.8 ha; ?? ?? SE; n = 20) than females (3.9 ?? 0.4 ha; n = 19). Northern flying squirrel movement distances between successive, noncorrelated telemetry locations averaged 71 m (n = 1,090). No correlation was found between distances moved and stand type or sex. Northern flying squirrel's home range sizes, movements, and densities were similar between the 2 stand types. We suggest abundance and movements of northern flying squirrels are not influencing the preferential selection of oldgrowth forests by northern spotted owls.

Detecting the limits of northern and southern lineages of tanoak in northern California

Treesearch

Eduardo Sandoval-Castro; Richard S. Dodd

2015-01-01

Two chloroplast lineages of tanoak (Notholithocarpus densiflorus) meet between Korbel and Hoopa in the North Coast of California. Our earlier work suggests these lineages arose from southern and northern glacial refugia and this region represents their colonizing fronts. Earlier, we detected only one population of mixed lineages, suggesting that...

Phylogeography of the antilopine wallaroo (Macropus antilopinus) across tropical northern Australia.

PubMed

Wadley, Jessica J; Fordham, Damien A; Thomson, Vicki A; Ritchie, Euan G; Austin, Jeremy J

2016-11-01

The distribution of antilopine wallaroo, Macropus antilopinus , is marked by a break in the species' range between Queensland and the Northern Territory, coinciding with the Carpentarian barrier. Previous work on M. antilopinus revealed limited genetic differentiation between the Northern Territory and Queensland M. antilopinus populations across this barrier. The study also identified a number of divergent lineages in the Northern Territory, but was unable to elucidate any geographic structure. Here, we re-examine these results to (1) determine phylogeographic patterns across the range of M. antilopinus and (2) infer the biogeographic barriers associated with these patterns. The tropical savannahs of northern Australia: from the Cape York Peninsula in the east, to the Kimberley in the west. We examined phylogeographic patterns in M. antilopinus using a larger number of samples and three mtDNA genes: NADH dehydrogenase subunit 2, cytochrome b, and the control region. Two datasets were generated and analyzed: (1) a subset of samples with all three mtDNA regions concatenated together and (2) all samples for just control region sequences that included samples from the previous study. Analysis included generating phylogenetic trees based on Bayesian analysis and intraspecific median-joining networks. The contemporary spatial structure of M. antilopinus mtDNA lineages revealed five shallow clades and a sixth, divergent lineage. The genetic differences that we found between Queensland and Northern Territory M. antilopinus samples confirmed the split in the geographic distribution of the species. We also found weak genetic differentiation between Northern Territory samples and those from the Kimberley region of Western Australia, possibly due to the Kimberley Plateau-Arnhem Land barrier. Within the Northern Territory, two clades appear to be parapatric in the west, while another two clades are broadly sympatric across the Northern Territory. MtDNA diversity of M

Implementing E-Learning in Northern Ireland: Prospects and Challenges

ERIC Educational Resources Information Center

Uhomoibhi, James O.

2006-01-01

Purpose: Aims to examine trends in the development of e-learning in Northern Ireland, report on existing policies, practices and issues affecting its implementation across the sectors. Design/methodology/approach: The present study draws on e-learning policies and strategies that have been developed for Northern Ireland. Examples were drawn from…

Geomorphology and landscape organization of a northern peatland complex

NASA Astrophysics Data System (ADS)

Richardson, M. C.

2012-12-01

The geomorphic evolution of northern peatlands is governed by complex ecohydrological feedback mechanisms and associated hydro-climatic drivers. For example, prevailing models of bog development (i.e. Ingram's groundwater mounding hypothesis and variants) attempt to explicitly link bog dome characteristics to the regional climate based on analytical and numerical models of lateral groundwater flow and the first-order control of water table position on rates of peat accumulation. In this talk I will present new results from quantitative geomorphic analyses of a northern peatland complex at the De Beers Victor diamond mine site in the Hudson Bay Lowlands of northern Ontario. This work capitalizes on spatially-extensive, high-resolution topographic (LiDAR) data to rigorously test analytical and numerical models of bog dome development in this landscape. The analysis and discussion are then expanded beyond individual bog formations to more broadly consider ecohydrological drivers of landscape organization, with implications for understanding and modeling catchment-scale runoff response. Results show that in this landscape, drainage patterns exhibit relatively well-organized characteristics consistent with observed runoff responses in six gauged research catchments. Interpreted together, the results of these geomorphic and hydrologic analyses help refine our understanding of water balance partitioning among different landcover types within northern peatland complexes. These findings can be used to help guide the development of appropriate numerical model structures for hydrologic prediction in ungauged peatland basins of northern Canada.

Climate change vulnerability and adaptation in the Northern Rocky Mountains [Part 2

Treesearch

Jessica E. Halofsky; David L. Peterson; S. Karen Dante-Wood; Linh Hoang; Joanne J. Ho; Linda A. Joyce

2018-01-01

The Northern Rockies Adaptation Partnership (NRAP) identified climate change issues relevant to resource management in the Northern Rockies (USA) region, and developed solutions intended to minimize negative effects of climate change and facilitate transition of diverse ecosystems to a warmer climate. The NRAP region covers 183 million acres, spanning northern Idaho,...

Climate change vulnerability and adaptation in the Northern Rocky Mountains [Part 1

Treesearch

Jessica E. Halofsky; David L. Peterson; S. Karen Dante-Wood; Linh Hoang; Joanne J. Ho; Linda A. Joyce

2018-01-01

The Northern Rockies Adaptation Partnership (NRAP) identified climate change issues relevant to resource management in the Northern Rockies (USA) region, and developed solutions intended to minimize negative effects of climate change and facilitate transition of diverse ecosystems to a warmer climate. The NRAP region covers 183 million acres, spanning northern Idaho,...

Effects of multiple acute stressors on the predator avoidance ability and physiology of juvenile Chinook salmon

USGS Publications Warehouse

Mesa, Matthew G.

1994-01-01

Northern squaw fish Ptychocheilus oregonensis are the predominant predators of juvenile Pacific salmonids Oncorhynchus spp. in the Columbia River, and their predation rates are greatest just below dams. Because juvenile salmonids are commonly subjected to multiple stressors at dams in the course of their seaward migration, high predation rates below dams may be due in part to an increase in the vulnerability of stressed fish. I conducted laboratory experiments to examine the predator avoidance ability and physiological stress responses of juvenile chinook salmon O. tshawytscha subjected to treatments (stressors) designed to simulate routine hatchery practices (multiple handlings) or dam passage (multiple agitations). Both stressors resulted in lethargic behavior in the fish, and agitation also caused disorieniation and occasional injury. When equal numbers of stressed and unstressed fish were exposed to northern squawfish for up to 1 h, significantly more stressed fish were eaten, but this effect was not evident during longer exposures. The lack of differential predation in trials lasting up to 24 h can be explained by the rapid development of schooling behavior in the prey, but other possibilities exist, such as changing ratios of stressed and unstressed prey over time. Concentrations of plasma cortisol, glucose, and lactate in fish subjected to multiple stressors were similar and sometimes cumulative, returned to prestress levels within 6-24 h, and correlated poorly with predator avoidance ability. My results suggest that juvenile salmonids are capable of avoiding predators within 1 h after being subjected to multiple acute stressors even though physiological homeostasis may be altered for up to 24 h. Therefore, because juvenile salmonids typically reside in lailrace areas for only a short time after dam passage, measures aimed at reducing physical stress or protecting them as they migrate through dam tailraces may help alleviate the relatively intense predation

Biological Correlates of Northern-Southern Italy Differences in IQ

ERIC Educational Resources Information Center

Templer, Donald I.

2012-01-01

The present study was intended to provide perspective, albeit less than unequivocal, on the research of Lynn (2010) who reported higher IQs in the northern than southern Italian regions. He attributes this to northern Italians having a greater genetic similarity to middle Europeans and southern Italians to Mediterranean people. Higher regional IQ…

Petroleum resource potential GIS of northern Afghanistan

USGS Publications Warehouse

Steinshouer, Douglas W.; Klett, Timothy R.; Ulmishek, Gregory F.; Wandrey, Craig J.; Wahl, Ronald R.; Hill, Ronald J.; Pribil, Michael J.; Pawlewicz, Mark J.; King, J. David; Agena, Warren F.; Taylor, David J.; Amirzada, Abdulla; Selab, Amir Mohammad; Mutteh, Abdul-Salam; Haidari, Ghulam Naqshband; Wardak, Moeengul Gullabudeen

2006-01-01

The CD-ROM contains an ESRI ArcReader format GIS project presenting the results of a petroleum resource assessment of Northern Afghanistan, and other data used in the petroleum assessment. Geologic, structural, field, well, political, and other GIS layers covering Afghanistan, Northern Afghanistan and adjacent areas, along with associated geochemical and other data tables pertinent to a petroleum assessment are included. The purpose of this GIS is to provide the basic data layers and tables required to support the petroleum assessment, data for further exploration and development, and an index of known data.

Evidence for recent populations bottlenecks in northern spotted owls (Strix occidentalis Caurina)

Treesearch

W.Chris Funk; Eric D. Forsman; Matthew Johnson; Thomas D. Mullins; Susan M. Haig

2009-01-01

The northern spotted owl (Strix occidentalis caurina) is one of the most controversial threatened subspecies ever listed under the US Endangered Species Act. Despite protection of its remaining forest habitat, recent field studies show continued declines of northern spotted owls. One potential threat to northern spotted owls which has not yet been...

Timing of the Northern Prince Gustav Ice Stream retreat and the deglaciation of northern James Ross Island, Antarctic Peninsula during the last glacial-interglacial transition

NASA Astrophysics Data System (ADS)

Nývlt, Daniel; Braucher, Régis; Engel, Zbyněk; Mlčoch, Bedřich

2014-09-01

The Northern Prince Gustav Ice Stream located in Prince Gustav Channel, drained the northeastern portion of the Antarctic Peninsula Ice Sheet during the last glacial maximum. Here we present a chronology of its retreat based on in situ produced cosmogenic 10Be from erratic boulders at Cape Lachman, northern James Ross Island. Schmidt hammer testing was adopted to assess the weathering state of erratic boulders in order to better interpret excess cosmogenic 10Be from cumulative periods of pre-exposure or earlier release from the glacier. The weighted mean exposure age of five boulders based on Schmidt hammer data is 12.9 ± 1.2 ka representing the beginning of the deglaciation of lower-lying areas (< 60 m a.s.l.) of the northern James Ross Island, when Northern Prince Gustav Ice Stream split from the remaining James Ross Island ice cover. This age represents the minimum age of the transition from grounded ice stream to floating ice shelf in the middle continental shelf areas of the northern Prince Gustav Channel. The remaining ice cover located at higher elevations of northern James Ross Island retreated during the early Holocene due to gradual decay of terrestrial ice and increase of equilibrium line altitude. Schmidt hammer R-values are inversely correlated with 10Be exposure ages and could be used as a proxy for exposure history of individual granite boulders in this region and favour the hypothesis of earlier release of boulders with excessive 10Be concentrations from glacier directly at this site. These data provide evidences for an earlier deglaciation of northern James Ross Island when compared with other recently presented cosmogenic nuclide based deglaciation chronologies, but this timing coincides with rapid increase of atmospheric temperature in this marginal part of Antarctica.

Management of percids in Lake Erie, North America

USGS Publications Warehouse

Hatch, Richard W.; Nepszy, Stephen J.; Rawson, Michael R.; van Densen, W.L.T.; Steinmetz, B.; Hughes, R.H.

1990-01-01

Lake Erie's fish populations and their habitats have undergone very substantial changes since 1945. Of the four percid forms originally present, the blue pike (Stizostedion vitreum glaucum) is presumed extinct, and the sauger (S. canadense) was commercially extinct by the 1950's. The walleye (S. v. vitreum) has remained stable in eastern Lake Erie but the highly productive stock of the western basin collapsed in the 1960's. Closure of the walleye fishery from 1970 to 1973, necessitated by mercury contamination, provided an opportunity for the development of an international management plan for restoration of the stock. An inter-agency Scientific Protocol Committee evaluated walleye dynamics and recommended management by quota beginning in 1976. Although quotas have been exceeded several times, the walleye stock responded well to limited exploitation, steadily increased, and expanded its range. Landings of the yellow perch (Perca flavescens) increased during the 1950's, but a steady decline in abundance, beginning in the early 1970's led to the formation in 1980 of another international inter-agency task group to recommend a basis for quota management. The short-term management recommendation, reported and accepted in 1986, was to reduce fishing effort by 20% by 1990. Both management schemes evolved when the resource agencies of the five jurisdictions (New York, Pennsylvania, Ohio, Michigan, and Ontario), in the two nations surrounding Lake Erie, perceived a need for the increased and improved management of a shared resource. They sought an international forum in which to develop strategies, appointed inter-agency scientific task groups to develop a basis for management recommendations, and adopted a quota management scheme. Each jurisdiction is responsible for the enforcement and allocation of its portion of the quota between user groups. Reports of catch, effort, and biological observations on stock performance are submitted annually to a standing technical

Winter prey caching by northern hawk owls in Minnesota

Treesearch

Richard R. Schaefer; D. Craig Rudolph; Jesse F. Fagan

2007-01-01

Northern Hawk Owls (Surnia ulula) have been reported to cache prey during the breeding season for later consumption, but detailed reports of prey caching during the non-breeding season are comparatively rare. We provided prey to four individual Northern Hawk Owls in wintering areas in northeastern Minnesota during 2001 and 2005 and observed their...

Site index curves for northern hardwoods in northern Wisconsin and Upper Michigan.

Treesearch

Willard H. Carmean

1978-01-01

Site index curves based on stem analyses were computed for 13 species found in even-aged, second growth northern hardwood stands. These curves showed that most species had similarly-shaped height growth curves in early years, but after 40 years differences in both rate and pattern of growth between species was evident for trees growing on medium and good sites. Most...

75 FR 80788 - Northern New Mexico Resource Advisory Committee Meeting

Federal Register 2010, 2011, 2012, 2013, 2014

2010-12-23

... DEPARTMENT OF AGRICULTURE Forest Service Northern New Mexico Resource Advisory Committee Meeting AGENCY: Forest Service, USDA. ACTION: Notice of meeting. SUMMARY: The Northern New Mexico Resource Advisory Committee (NNMRAC) will meet in Albuquerque, New Mexico. The committee is meeting as authorized...

Saturn, Approaching Northern Summer

NASA Image and Video Library

2016-09-15

Since NASA's Cassini spacecraft arrived at Saturn in mid-2004, the planet's appearance has changed greatly. The shifting angle of sunlight as the seasons march forward has illuminated the giant hexagon-shaped jet stream around the north polar region, and the subtle bluish hues seen earlier in the mission have continued to fade. Earlier views obtained in 2004 and 2009 (see PIA06077 and PIA11667) demonstrate how drastically the illumination has changed. This view shows Saturn's northern hemisphere in 2016, as that part of the planet nears its northern hemisphere summer solstice in May 2017. Saturn's year is nearly 30 Earth years long, and during its long time there, Cassini has observed winter and spring in the north, and summer and fall in the south. The spacecraft will complete its mission just after northern summer solstice, having observed long-term changes in the planet's winds, temperatures, clouds and chemistry. Cassini scanned across the planet and its rings on April 25, 2016, capturing three sets of red, green and blue images to cover this entire scene showing the planet and the main rings. The images were obtained using Cassini's wide-angle camera at a distance of approximately 1.9 million miles (3 million kilometers) from Saturn and at an elevation of about 30 degrees above the ring plane. The view looks toward the sunlit side of the rings from a sun-Saturn-spacecraft angle, or phase angle, of 55 degrees. Image scale on Saturn is about 111 miles (178 kilometers) per pixel. The exposures used to make this mosaic were obtained just prior to the beginning of a 44-hour movie sequence. http://photojournal.jpl.nasa.gov/catalog/PIA21046

Estimating cull in northern hardwoods

Treesearch

W.M. Zillgitt; S.R. Gevorkiantz

1946-01-01

Cull in northern hardwood stands is often very heavy and is difficult to estimate. To help clarify this situation and aid the average cruiser to become more accurate in his estimates, the study reported here should prove very helpful.

Trends in Northern Hemisphere surface cyclone frequency and intensity

USGS Publications Warehouse

McCabe, G.J.; Clark, M.P.; Serreze, Mark C.

2001-01-01

One of the hypothesized effects of global warming from increasing concentrations of greenhouse gases is a change in the frequency and/or intensity of extratropical cyclones. In this study, winter frequencies and intensities of extratropical cyclones in the Northern Hemisphere for the period 1959-97 are examined to determine if identifiable trends are occurring. Results indicate a statistically significant decrease in midlatitude cyclone frequency and a significant increase in high-latitude cyclone frequency. In addition, storm intensity has increased in both the high and midlatitudes. The changes in storm frequency correlate with changes in winter Northern Hemisphere temperature and support hypotheses that global warming may result in a northward shift of storm tracks in the Northern Hemisphere.

Regional Crustal Velocity Models for Northern Arabian Platform and Turkish-Iranian Plateau

NASA Astrophysics Data System (ADS)

Aleqabi, G.; Wysession, M.; Ghalib, H.

2008-12-01

The geological structure of the Northern Arabian platform and surrounding mountains is dominated by the collision and suturing of the Arabian plate with the Eurasian plate and the formation of the Turkish-Iranian plateau. The structure of the Northern Arabian platform and surrounding region is poorly constrained. A recent deployment of 10 broadband seismometers in northern and central Iraq provides an opportunity to refine velocity models of the region. We have applied the Niching Genetic Algorithm waveform inversion technique to Rayleigh and Love waves traversing the Northern Arabian platform, the Zagros fold belt, the southern Turkish Plateau, the Iranian Plateau. Results show variations in crustal thickness and shear wave velocity between the Northern Arabian platform and the Turkish-Iranian plateau. In general the shear wave velocities are higher in the Northern Arabian platform than in the Plateaus. Variation of shear velocities within each of the provinces reflects the diversity in tectonic environment across the Zagros fold belt and the complex tectonic history of the region. Crustal thickness results show little crustal thickening has occurred due to collision.

Relationship of epithermal gold deposits to large-scale fractures in northern Nevada

USGS Publications Warehouse

Ponce, D.A.; Glen, J.M.G.

2002-01-01

Geophysical maps of northern Nevada reveal at least three and possibly six large-scale arcuate features, one of which corresponds to the northern Nevada rift that possibly extends more than 1,000 km from the Oregon- Idaho border to southern Nevada. These features may reflect deep discontinuities within the earth's crust, possibly related to the impact of the Yellowstone hot spot. Because mid-Miocene epithermal gold deposits have been shown to correlate with the northern Nevada rift, we investigate the association of other epithermal gold deposits to other similar arcuate features in northern Nevada. Mid-Miocene and younger epithermal gold- silver deposits also occur along two prominent aeromagnetic anomalies west of the northern Nevada rift. Here, we speculate that mid-Miocene deposits formed along deep fractures in association with mid-Miocene rift- related magmatism and that younger deposits preferentially followed these preexisting features. Statistical analysis of the proximity of epithermal gold deposits to these features suggests that epithermal gold deposits in northern Nevada are spatially associated with large-scale crustal features interpreted from geophysical data.

Master Agreement between Northern Michigan University Board of Control and American Association of University Professors, Northern Michigan Chapter, June 30, 1987-June 30 1990.

ERIC Educational Resources Information Center

American Association of Univ. Professors, Washington, DC.

The collective bargaining agreement between Northern Michigan University Board of Control and Northern Michigan University chapter of the American Association of University Professors covering the period June 30, 1987-June 30, 1990 is presented. Items covered in the agreement include: chapter recognition, nondiscrimination, access to information,…

Marking guides for northern hardwoods under the selection system

Treesearch

Carl, Jr. Arbogast

1957-01-01

The preparation of these guides has been a joint undertaking of research and national forest administration. Reviews and suggestions of other members of the Station who are active in northern hardwood research were helpful, especially those from men working at the Upper Peninsula Research Center in Marquette, Mich., and the Northern Lakes Research Center in Wausau, Wis...

Northern Helping Practitioners and the Phenomenon of Secondary Trauma

ERIC Educational Resources Information Center

O'Neill, Linda K.

2010-01-01

This article highlights a narrative inquiry study that considered the experience of and the effects on 8 northern helping practitioners (5 women, 3 men, ages 30-60) who have 7 to 40 years of experience in providing trauma support in isolated communities in northern BC and the Yukon. Using a three-phase narrative analysis, 10 categories provided a…

Northern nursing practice in a primary health care setting.

PubMed

Vukic, Adele; Keddy, Barbara

2002-12-01

This paper explicates the nature of outpost nursing work, and/or the day-to-day realities of northern nursing practice in a primary health care setting in Canada. The study was carried out to systematically explore the work of nurses in an indigenous setting. Institutional ethnography, pioneered by Dorothy Smith was the methodology used to guide this research. The theoretical perspective of this methodology does not seek causes or links but intends to explicate visible practices. It is intended to explicate the social organization of specific discourses that inform work processes of nurses working in remote indigenous communities. The data originated from various sources including spending 2 weeks in a northern remote community shadowing experienced nurses, taking field notes and audio taping interviews with these nurses. One of the two researchers was a northern practice nurse for many years and has had taught in an outpost nursing programme. As part of the process, texts were obtained from the site as data to be incorporated in the analysis. The lived experiences have added to the analytical understanding of the work of nurses in remote areas. Data uncovered documentary practices inherent to the work setting which were then analysed along with the transcribed interviews and field notes derived from the on-site visit. Identifying disjuncture in the discourse of northern nursing and the lived experience of the nurses in this study was central to the research process. The results indicated that the social organization of northern community nursing work required a broad generalist knowledge base for decision making to work effectively within this primary health care setting. The nurse as 'other' and the invisibility of nurses' work of building a trusting relationship with the community is not reflected in the discourse of northern nursing. Trust cannot be quantified or measured yet it is fundamental to working effectively with the community. The nurses in this study

Vesta Partly Shadowed Northern Regions

NASA Image and Video Library

2012-06-01

This image from NASA Dawn spacecraft shows a part of asteroid Vesta surface reasonably far north into the northern hemisphere which appears washed out because it has been stretched to make features visible that would otherwise be too dark to see.

75 FR 47259 - Northern New Mexico Resource Advisory Committee Meeting

Federal Register 2010, 2011, 2012, 2013, 2014

2010-08-05

... DEPARTMENT OF AGRICULTURE Forest Service Northern New Mexico Resource Advisory Committee Meeting AGENCY: Forest Service, USDA. ACTION: Notice of meeting. SUMMARY: The Northern New Mexico Resource Advisory Committee will meet in Albuquerque, New Mexico. The committee is meeting as authorized under the...

75 FR 29717 - Northern New Mexico Resource Advisory Committee Meeting

Federal Register 2010, 2011, 2012, 2013, 2014

2010-05-27

... DEPARTMENT OF AGRICULTURE Forest Service Northern New Mexico Resource Advisory Committee Meeting AGENCY: Forest Service, USDA. ACTION: Notice of meeting. SUMMARY: The Northern New Mexico Resource Advisory Committee will meet in Albuquerque, New Mexico. The committee is meeting as authorized under the...

Northern perspectives on medical elective tourism: a qualitative study.

PubMed

Coke, Sarah; Kuper, Ayelet; Richardson, Lisa; Cameron, Anita

2016-01-01

The Royal College of Physicians and Surgeons of Canada recognizes education to be necessary for doctors to provide culturally safe care. Communities in northern Canada have large populations of Aboriginal people and other marginalized groups. Our goal was to identify the elements of appropriate predeparture curricula for these medical trainees. We conducted our study in Kenora, Ontario. With the help of a core collaborative group and the support of the local Aboriginal Health Access Centre, we interviewed a purposive sample of community members about their interactions with trainees from southern Canada. Aboriginal and non-Aboriginal researchers with roots in northern and southern Canada brought perspectives to the inductive analysis. We conducted 17 semistructured interviews between February and March 2014. Participants felt that southern trainees were inadequately educated in northern politics, society and history. They identified 2 more themes: determinants of health affecting the local Aboriginal population, and provider and patient factors affecting delivery of culturally competent care. Participants also shared ideas on how best to implement this content into curricula. Providing culturally competent care to northern communities is a complex process requiring education. Using a collaborative method, we were able to delineate the experiences of members of a northern community and identify knowledge gaps of southern trainees travelling there. Our results provide a foundation for the content and structure of formal predeparture curricula to enable such trainees to provide culturally safe care.

Northern perspectives on medical elective tourism: a qualitative study

PubMed Central

Coke, Sarah; Kuper, Ayelet; Richardson, Lisa; Cameron, Anita

2016-01-01

Background: The Royal College of Physicians and Surgeons of Canada recognizes education to be necessary for doctors to provide culturally safe care. Communities in northern Canada have large populations of Aboriginal people and other marginalized groups. Our goal was to identify the elements of appropriate predeparture curricula for these medical trainees. Methods: We conducted our study in Kenora, Ontario. With the help of a core collaborative group and the support of the local Aboriginal Health Access Centre, we interviewed a purposive sample of community members about their interactions with trainees from southern Canada. Aboriginal and non-Aboriginal researchers with roots in northern and southern Canada brought perspectives to the inductive analysis. Results: We conducted 17 semistructured interviews between February and March 2014. Participants felt that southern trainees were inadequately educated in northern politics, society and history. They identified 2 more themes: determinants of health affecting the local Aboriginal population, and provider and patient factors affecting delivery of culturally competent care. Participants also shared ideas on how best to implement this content into curricula. Interpretation: Providing culturally competent care to northern communities is a complex process requiring education. Using a collaborative method, we were able to delineate the experiences of members of a northern community and identify knowledge gaps of southern trainees travelling there. Our results provide a foundation for the content and structure of formal predeparture curricula to enable such trainees to provide culturally safe care. PMID:27398374

Phylogeographic analysis of mitochondrial DNA in northern Asian populations.

PubMed

Derenko, Miroslava; Malyarchuk, Boris; Grzybowski, Tomasz; Denisova, Galina; Dambueva, Irina; Perkova, Maria; Dorzhu, Choduraa; Luzina, Faina; Lee, Hong Kyu; Vanecek, Tomas; Villems, Richard; Zakharov, Ilia

2007-11-01

To elucidate the human colonization process of northern Asia and human dispersals to the Americas, a diverse subset of 71 mitochondrial DNA (mtDNA) lineages was chosen for complete genome sequencing from the collection of 1,432 control-region sequences sampled from 18 autochthonous populations of northern, central, eastern, and southwestern Asia. On the basis of complete mtDNA sequencing, we have revised the classification of haplogroups A, D2, G1, M7, and I; identified six new subhaplogroups (I4, N1e, G1c, M7d, M7e, and J1b2a); and fully characterized haplogroups N1a and G1b, which were previously described only by the first hypervariable segment (HVS1) sequencing and coding-region restriction-fragment-length polymorphism analysis. Our findings indicate that the southern Siberian mtDNA pool harbors several lineages associated with the Late Upper Paleolithic and/or early Neolithic dispersals from both eastern Asia and southwestern Asia/southern Caucasus. Moreover, the phylogeography of the D2 lineages suggests that southern Siberia is likely to be a geographical source for the last postglacial maximum spread of this subhaplogroup to northern Siberia and that the expansion of the D2b branch occurred in Beringia ~7,000 years ago. In general, a detailed analysis of mtDNA gene pools of northern Asians provides the additional evidence to rule out the existence of a northern Asian route for the initial human colonization of Asia.

Agreement between Board of Control, Northern Michigan University, and American Association of University Professors, Northern Michigan University Chapter, July 1, 1984-June 30, 1987.

ERIC Educational Resources Information Center

American Association of Univ. Professors, Washington, DC.

The collective bargaining agreement between Northern Michigan University Board of Control and Northern Michigan University Chapter (280 members) of the American Association of University Professors (AAUP) covering the period July 1, 1984-June 30, 1987 is presented. Items covered in the agreement include: definitions and recognition of AAUP;…

Comparative ability of northern pintails, gadwalls, and northern shovelers to metabolize foods

USGS Publications Warehouse

Miller, M.R.

1984-01-01

Feeding trials were used to compare the ability of northern pintails (Anas acuta), gadwalls (A. strepera), and northern shovelers (A. clypeata) to metabolize energy from a turkey starter ration, alfalfa pellets, and common barnyardgrass (Echinochloa crusgalli) seeds. No differences (P > 0.05) were detected among the three species for any of the three foods (kg body weight/day basis), for dry matter intake (DMI), body weight gain (BWG), apparent metabolizable energy (AME), or metabolized energy (MEE) on any given diet consumed in quantities large enough to promote body weight gain. The AME content of alfalfa was 57% less than the value for turkey starter and 50% less than for barnyardgrass seeds. All three species metabolized more energy and gained weight faster when fed turkey starter. Energy modeling may be facilitated if additional research verifies that all species of dabbling ducks have equal ability to obtain energy from foods available to them in the wild. Behavioral and morphological factors may be more important in defining feeding niches than digestive physiology, at least for the three duck species tested, at the time of year of the experiments, and within the limits of the quality of foods used.

Evaluating the power to detect temporal trends in fishery-independent time surveys: A case study based on gill nets set in the Ohio waters of Lake Erie for walleyes

USGS Publications Warehouse

Wagner, Tyler; Vandergoot, Christopher S.; Tyson, Jeff

2011-01-01

Fishery-independent (FI) surveys provide critical information used for the sustainable management and conservation of fish populations. Because fisheries management often requires the effects of management actions to be evaluated and detected within a relatively short time frame, it is important that research be directed toward FI survey evaluation, especially with respect to the ability to detect temporal trends. Using annual FI gill-net survey data for Lake Erie walleyes Sander vitreus collected from 1978 to 2006 as a case study, our goals were to (1) highlight the usefulness of hierarchical models for estimating spatial and temporal sources of variation in catch per effort (CPE); (2) demonstrate how the resulting variance estimates can be used to examine the statistical power to detect temporal trends in CPE in relation to sample size, duration of sampling, and decisions regarding what data are most appropriate for analysis; and (3) discuss recommendations for evaluating FI surveys and analyzing the resulting data to support fisheries management. This case study illustrated that the statistical power to detect temporal trends was low over relatively short sampling periods (e.g., 5–10 years) unless the annual decline in CPE reached 10–20%. For example, if 50 sites were sampled each year, a 10% annual decline in CPE would not be detected with more than 0.80 power until 15 years of sampling, and a 5% annual decline would not be detected with more than 0.8 power for approximately 22 years. Because the evaluation of FI surveys is essential for ensuring that trends in fish populations can be detected over management-relevant time periods, we suggest using a meta-analysis–type approach across systems to quantify sources of spatial and temporal variation. This approach can be used to evaluate and identify sampling designs that increase the ability of managers to make inferences about trends in fish stocks.

Calculating competition in thinned northern hardwoods.

Treesearch

Sharon A. Winsauer; James A. Mattson

1992-01-01

Describes four methods of calculating competition to individual trees and compares their effectiveness in explaining the 3-year growth response of northern hardwoods after various mechanized thinning practices.

77 FR 61595 - Northern Illinois Municipal Power; Notice of Filing

Federal Register 2010, 2011, 2012, 2013, 2014

2012-10-10

... DEPARTMENT OF ENERGY Federal Energy Regulatory Commission [Docket No. EL13-5-000] Northern Illinois Municipal Power; Notice of Filing October 2, 2012. Take notice that on October 1, 2012, Northern Illinois Municipal Power filed its Revised and Superseding Proposed Revenue Requirement for reactive supply...

Two new species of Chiropterotriton (Caudata: Plethodontidae) from northern Mexico.

PubMed

Rovito, Sean M; Parra-Olea, Gabriela

2015-11-24

Species of the genus Chiropterotriton are distributed through much of northern and eastern Mexico. The genus has presented taxonomic difficulties, with a number of species waiting to be described. We describe two new species, Chiropterotriton cieloensis sp. nov. and Chiropterotriton infernalis sp. nov., from the Mexican state of Tamaulipas based on both molecular and morphological data. We present a phylogenetic hypothesis for the group, with emphasis on the taxa from northern Mexico, based on mitochondrial DNA, and discuss the other species of northern Mexico, especially the wider-ranging C. multidentatus, to which the new species were formerly assigned.

Flow characteristics of rivers in northern Australia: Implications for development

NASA Astrophysics Data System (ADS)

Petheram, Cuan; McMahon, Thomas A.; Peel, Murray C.

2008-07-01

SummaryAnnual, monthly and daily streamflows from 99 unregulated rivers across northern Australia were analysed to assess the general surface water resources of the region and their implications for development. The potential for carry-over storages was assessed using the Gould-Dincer Gamma method, which utilises the mean, standard deviation, skewness and lag-one serial correlation coefficient of annual flows. Runs Analysis was used to describe the characteristics of drought in northern Australia and the potential for 'active' water harvesting was evaluated by Base Flow Separation, Flow Duration Curves and Spells Analysis. These parameters for northern Australia were compared with data from southern Australia and data for similar Köppen class from around the world. Notably, the variability and seasonality of annual streamflow across northern Australia were observed to be high compared with that of similar Köppen classes from the rest of the world (RoW). The high inter-annual variability of runoff means that carry-over storages in northern Australia will need to be considerably larger than for rivers from the RoW (assuming similar mean annual runoff, yield and reliability). For example, in the three major Köppen zones across the North, it was possible (theoretically) to only exploit approximately 33% (Köppen Aw; n = 6), 25% (Köppen BSh; n = 12) and 13% (Köppen BWh; n = 11) of mean annual streamflow (assuming a hypothetical storage size equal to the mean annual flow). Over 90% of north Australian rivers had a Base Flow Index of less than 0.4, 72% had negative annual lag-one autocorrelation values and in half the rivers sampled greater than 80% of the total flow occurred during the 3-month peak period. These data confirm that flow in the rivers of northern Australia is largely event driven and that the north Australian environment has limited natural storage capacity. Hence, there is relatively little opportunity in many northern rivers to actively harvest water

Cultivating Uncultured Bacteria from Northern Wetlands: Knowledge Gained and Remaining Gaps

PubMed Central

Dedysh, Svetlana N.

2011-01-01

Northern wetlands play a key role in the global carbon budget, particularly in the budgets of the greenhouse gas methane. These ecosystems also determine the hydrology of northern rivers and represent one of the largest reservoirs of fresh water in the Northern Hemisphere. Sphagnum-dominated peat bogs and fens are the most extensive types of northern wetlands. In comparison to many other terrestrial ecosystems, the bacterial diversity in Sphagnum-dominated wetlands remains largely unexplored. As demonstrated by cultivation-independent studies, a large proportion of the indigenous microbial communities in these acidic, cold, nutrient-poor, and water-saturated environments is composed of as-yet-uncultivated bacteria with unknown physiologies. Most of them are slow-growing, oligotrophic microorganisms that are difficult to isolate and to manipulate in the laboratory. Yet, significant breakthroughs in cultivation of these elusive organisms have been made during the last decade. This article describes the major prerequisites for successful cultivation of peat-inhabiting microbes, gives an overview of the currently captured bacterial diversity from northern wetlands and discusses the unique characteristics of the newly discovered organisms. PMID:21954394

Visual impairment in Northern Ireland.

PubMed Central

Canavan, Y. M.; Jackson, A. J.; Stewart, A.

1997-01-01

Statistics on the registration of blind and partially-sighted patients in Northern Ireland underestimate the true extent of visual impairment within our community. In comparison to other UK regions, where between 0.53% and 0.59% of the population avail of blind or partial sight registration, only 0.35% of residents in Northern Ireland appear on the respective registers. Most patients on the combined registers are in the older age groups and many also suffer from other disabilities. Regional discrepancies may be attributed to a combination of factors including: patient attitudes to the registration process, medical attitudes to registration and local anomalies in the way in which social services departments both record and present annual registration returns. Better liaison is necessary between the community, hospital and voluntary sector providers to improve identification and support services for the visually impaired in the future. PMID:9414937

The Impact of Insects in the Northern Hardwoods Type

Treesearch

H. J. Macaloney

1966-01-01

The northern hardwoods type occupies about 16 percent -- 8.2 million acres -- of the commercial forest land in the Lake States. The timber has high unit values and represents about 42 percent of the total value of all the commercial forest in the region. Increasing values and markets for northern hardwoods in recent years have stressed the need for better quality in...

Suicide and Young People: The Case of Northern Ireland

ERIC Educational Resources Information Center

Tomlinson, Mike

2007-01-01

Suicides in Northern Ireland are examined in the context of what is known about global and regional trends with respect to gender and age, and change over time. For Northern Ireland, suicide numbers and rates are plotted for 10-24 year olds from 1967 to 2005. Questions are raised about the validity of officially registered suicides in the light of…

Is the northern Saw-whet Owl (Aegolius acadicus) nomadic?

Treesearch

Jeffery S. Marks

1997-01-01

The first recorded nesting of a Northern Saw-whet Owl (Aegolius acadicus) in the Snake River Birds of Prey Area in southwestern Idaho occurred in a nest box in 1986. Occupancy of nest boxes by Northern Saw-whet Owls varied considerably (0 to 8 nests per year) over the next 10 years. Numbers of rodents fluctuated during this same period, and the...

Rural telemedicine project in northern New Mexico

DOE Office of Scientific and Technical Information (OSTI.GOV)

Zink, S.; Hahn, H.; Rudnick, J.

A virtual electronic medical record system is being deployed over the Internet with security in northern New Mexico using TeleMed, a multimedia medical records management system that uses CORBA-based client-server technology and distributed database architecture. The goal of the NNM Rural Telemedicine Project is to implement TeleMed into fifteen rural clinics and two hospitals within a 25,000 square mile area of northern New Mexico. Evaluation of the project consists of three components: job task analysis, audit of immunized children, and time motion studies. Preliminary results of the evaluation components are presented.

Coastal geomorphology of the Martian northern plains

NASA Technical Reports Server (NTRS)

Parker, Timothy J.; Gorsline, Donn S.; Saunders, Stephen R.; Pieri, David C.; Schneeberger, Dale M.

1993-01-01

The paper considers the question of the formation of the outflow channels and valley networks discovered on the Martian northern plains during the Mariner 9 mission. Parker and Saunders (1987) and Parker et al. (1987, 1989) data are used to describe key features common both in the lower reaches of the outflow channels and within and along the margins of the entire northern plains. It is suggested, that of the geological processes capable of producing similar morphologies on earth, lacustrine or marine deposition and subsequent periglacial modification offer the simplest and most consistent explanation for the suit of features found on Mars.

Comparative reproductive and physiological responses of northern bobwhite and scaled quail to water deprivation

USGS Publications Warehouse

Giuliano, W.M.; Patino, R.; Lutz, R.S.

1998-01-01

We compared reproductive and physiological responses of captive female northern bobwhite (Colinus virginianus) and scaled quail (Callipepla squamata) under control and water deprivation conditions. Scaled quail required less food and water to reproduce successfully under control conditions than northern bobwhite. Additionally, in scaled quail, serum osmolality levels and kidney mass were unaffected by water deprivation, whereas in northern bobwhite, serum osmolality levels increased and kidney mass declined. This finding indicates that scaled quail may have osmoregulatory abilities superior to those of northern bobwhite. Under control conditions, northern bobwhite gained more body mass and produced more but smaller eggs than scaled quail. Under water deprivation conditions, northern bobwhite lost more body mass but had more laying hens with a higher rate of egg production than scaled quail. Our data suggest that northern bobwhite allocated more resources to reproduction than to body maintenance, while scaled quail apparently forego reproduction in favor of body maintenance during water deprivation conditions.

40 CFR 81.100 - Eastern Washington-Northern Idaho Interstate Air Quality Control Region.

Code of Federal Regulations, 2010 CFR

2010-07-01

... 40 Protection of Environment 17 2010-07-01 2010-07-01 false Eastern Washington-Northern Idaho... Designation of Air Quality Control Regions § 81.100 Eastern Washington-Northern Idaho Interstate Air Quality Control Region. The Eastern Washington-Northern Idaho Interstate Air Quality Control Region consists of...

Fishing for Northern Pike in Minnesota: A comparison of anglers and dark house spearers

USGS Publications Warehouse

Schroeder, Susan A.; Fulton, David C.

2014-01-01

In order to project fishing effort and demand of individuals targeting Northern Pike Esox lucius in Minnesota, it is important to understand the catch orientations, management preferences, and site choice preferences of those individuals. Northern Pike are specifically targeted by about 35% of the approximately 1.5 million licensed anglers in Minnesota and by approximately 14,000–15,000 dark house spearers. Dark house spearing is a traditional method of harvesting fish through the ice in winter. Mail surveys were distributed to three research strata: anglers targeting Northern Pike, dark house spearing license holders spearing Northern Pike, and dark house spearing license holders angling for Northern Pike. Dark house spearers, whether spearing or angling, reported a stronger orientation toward keeping Northern Pike than did anglers. Anglers reported a stronger orientation toward catching large Northern Pike than did dark house spearers when spearing or angling. Northern Pike regulations were the most important attribute affecting site choice for respondents in all three strata. Models for all strata indicated a preference for lakes without protected slot limits. However, protected slot limits had a stronger negative influence on lake preference for dark house spearing licensees (whether spearing or angling) than for anglers.

The Northern Manitoba Mining Academy

NASA Astrophysics Data System (ADS)

Alexandre, Paul

2017-04-01

The Northern Manitoba Mining Academy (NMMA, miningacademy.ca) is a new educational institution located in Flin Flon, Manitoba. It is associated with the University College of the North and is specifically intended to serve the needs of the Northern Manitoban communities with regards to job creation by providing training in a variety of mining, construction, and exploration related areas. NMMA's mission is to provide innovative and responsible solutions for the creation of a knowledgeable, skilled, and sustainable workforce within a vibrant, mineral-rich resource industry. It facilitates strategic training initiatives and research activities in order to strengthen the social, economic, and environmental benefits of a robust mining and resources sector. In terms of education, NMMA offers its own programs, mostly short courses in health and safety, courses organized by the University College of the North (wilderness safety, prospecting, and exploration), and courses organized in association with provincial Industries-Based Safety Programs and Associations (a variety of construction-related trades). However, the programming is not limited to those courses already on the syllabus: the Academy operates on open-doors policy and welcomes people with their unique and diverse needs; it prides itself in its ability to tailor or create specific on-demand courses and deliver them locally in the North. The Northern Manitoba Mining Academy also provides access to its world-class facilities for field-based undergraduate courses, as well as graduate students and researchers doing field work. Full sample preparation facilities are offered to students and scientists in all natural and environmental sciences.

Workshop on the Martian Northern Plains: Sedimentological, Periglacial, and Paleoclimatic Evolution

NASA Technical Reports Server (NTRS)

Kargel, Jeffrey S. (Editor); Moore, Jeffrey (Editor); Parker, Timothy (Editor)

1993-01-01

Papers that have been accepted for presentation at the Workshop on the Martian Northern Plains: Sedimentological, Periglacial, and Paleoclimatic Evolution, on 12-14 Aug. 1993 in Fairbanks, Alaska are included. Topics covered include: hydrological consequences of ponded water on Mars; morphological and morphometric studies of impact craters in the Northern Plains of Mars; a wet-geology and cold-climate Mars model: punctuation of a slow dynamics approach to equilibrium; the distribution of ground ice on Mars; and stratigraphy of the Martian Northern Plains.

78 FR 51716 - Northern Natural Gas Company; Notice of Application

Federal Register 2010, 2011, 2012, 2013, 2014

2013-08-21

... DEPARTMENT OF ENERGY Federal Energy Regulatory Commission [Docket No. CP13-528-000] Northern Natural Gas Company; Notice of Application Take notice that on August 1, 2013, Northern Natural Gas... section 7(c) of the Natural Gas Act and part 157 of the Commission's regulations to construct and operate...

Education Policy Reforms of Secondary Education in the Northern Territory

ERIC Educational Resources Information Center

Palmer, Bill

2004-01-01

An original study of the Ramsay Committee report entitled "Future Directions for Secondary Education in the Northern Territory" (the "Secondary Review") was presented in December 2004 at the ANZCIES National Conference in Melbourne. This was prior to the Northern Territory Government deciding how many of the recommendations of…

Phylogeographic Analysis of Mitochondrial DNA in Northern Asian Populations

PubMed Central

Derenko, Miroslava ; Malyarchuk, Boris ; Grzybowski, Tomasz ; Denisova, Galina ; Dambueva, Irina ; Perkova, Maria ; Dorzhu, Choduraa ; Luzina, Faina ; Lee, Hong Kyu ; Vanecek, Tomas ; Villems, Richard ; Zakharov, Ilia 

2007-01-01

To elucidate the human colonization process of northern Asia and human dispersals to the Americas, a diverse subset of 71 mitochondrial DNA (mtDNA) lineages was chosen for complete genome sequencing from the collection of 1,432 control-region sequences sampled from 18 autochthonous populations of northern, central, eastern, and southwestern Asia. On the basis of complete mtDNA sequencing, we have revised the classification of haplogroups A, D2, G1, M7, and I; identified six new subhaplogroups (I4, N1e, G1c, M7d, M7e, and J1b2a); and fully characterized haplogroups N1a and G1b, which were previously described only by the first hypervariable segment (HVS1) sequencing and coding-region restriction-fragment–length polymorphism analysis. Our findings indicate that the southern Siberian mtDNA pool harbors several lineages associated with the Late Upper Paleolithic and/or early Neolithic dispersals from both eastern Asia and southwestern Asia/southern Caucasus. Moreover, the phylogeography of the D2 lineages suggests that southern Siberia is likely to be a geographical source for the last postglacial maximum spread of this subhaplogroup to northern Siberia and that the expansion of the D2b branch occurred in Beringia ∼7,000 years ago. In general, a detailed analysis of mtDNA gene pools of northern Asians provides the additional evidence to rule out the existence of a northern Asian route for the initial human colonization of Asia. PMID:17924343

77 FR 35958 - Northern Natural Gas Company; Notice of Application

Federal Register 2010, 2011, 2012, 2013, 2014

2012-06-15

... Natural Gas Company; Notice of Application Take notice that on May 30, 2012, Northern Natural Gas Company... authority, pursuant to Part 157 of the Commission's regulations and section 7(b) of the Natural Gas Act, to... public inspection. Specifically, Northern Natural Proposes to sell to DKM approximately 126 miles of 24...

75 FR 35779 - Northern Natural Gas Company; Notice of Application

Federal Register 2010, 2011, 2012, 2013, 2014

2010-06-23

... Natural Gas Company; Notice of Application June 16, 2010. Take notice that on June 2, 2010, Northern Natural Gas Company (Northern), 1111 South 103rd Street, Omaha, Nebraska 68124, filed with the Federal Energy Regulatory Commission an application under section 7 of the Natural Gas Act, for a certificate of...

ACHP | Heritage Tourism and the Federal Government: Northern New Mexico

Science.gov Websites

Publications Search skip specific nav links Home arrow Publications arrow Intro: Heritage Tourism and the Federal Government: Northern New Mexico Perspectives Heritage Tourism and the Federal Government: Northern information Heritage tourism offers a triple benefit to communities—it promotes the preservation of their

Food habits of Northern Goshawks nesting in south central Wyoming

Treesearch

John R. Squires

2000-01-01

Northern Goshawks (Accipiter gentiles) nesting in south central Wyoming consumed at least 33 species of prey; 14 were mammals and 19 were birds. Based on percent occurrence in regurgitated pellets, dominant (>10% frequency) prey species included: red squirrel (Tamiasciurus hudsonicus; present in 50% of pellets), Northern Flicker (Colaptes auratus; 34...

50 CFR 226.203 - Critical habitat for northern right whales.

Code of Federal Regulations, 2014 CFR

2014-10-01

... 50 Wildlife and Fisheries 10 2014-10-01 2014-10-01 false Critical habitat for northern right whales. 226.203 Section 226.203 Wildlife and Fisheries NATIONAL MARINE FISHERIES SERVICE, NATIONAL... § 226.203 Critical habitat for northern right whales. (a) Great South Channel. The area bounded by 41°40...

50 CFR 226.203 - Critical habitat for northern right whales.

Code of Federal Regulations, 2012 CFR

2012-10-01

... 50 Wildlife and Fisheries 10 2012-10-01 2012-10-01 false Critical habitat for northern right whales. 226.203 Section 226.203 Wildlife and Fisheries NATIONAL MARINE FISHERIES SERVICE, NATIONAL... § 226.203 Critical habitat for northern right whales. (a) Great South Channel. The area bounded by 41°40...

50 CFR 226.203 - Critical habitat for northern right whales.

Code of Federal Regulations, 2013 CFR

2013-10-01

... 50 Wildlife and Fisheries 10 2013-10-01 2013-10-01 false Critical habitat for northern right whales. 226.203 Section 226.203 Wildlife and Fisheries NATIONAL MARINE FISHERIES SERVICE, NATIONAL... § 226.203 Critical habitat for northern right whales. (a) Great South Channel. The area bounded by 41°40...

Northern hemisphere dust storms on Mars

NASA Technical Reports Server (NTRS)

James, P. B.

1993-01-01

Dust storms in the northern hemisphere of Mars appear to be less common than the more familiar southern hemisphere storms, and essentially, no activity north of about 30 latittude has been documented. The data are, however, subject to an observational bias because Mars is near aphelion during oppositions, which occur during the most likely seasons for dust activity in the north. The amount of dust activity in the northern hemisphere is clearly very relevant to the role of atmospheric transport in the dust cycle. The classic global storms that occur during spring in the southern hemisphere are observed to transport dust from sources in the southern hemisphere to sinks or temporary depositories in the north. The question of whether atmospheric transport can close the dust cycle, i.e., return the dust to the southern hemisphere sources on some timescale, is clearly relevant to the solution of the puzzle of how the dust storm cycle is modulated, i.e., why storms occur in some years but not in others. There are data that suggest that the spring/early summer season in the northern hemisphere of Mars during the year following the major 1977 storms observed by Viking was very dusty. A number of observations of the vicinity of the receding north polar cap showed clear evidence of substantial dust activity in the sub-Arctic region.

Pace slows in northern Rockies

DOE Office of Scientific and Technical Information (OSTI.GOV)

Stremel, K.

1984-03-01

This paper deals with recent natural gas development and production in the northern Rocky Mountain region. Because of restricted gas markets, the pace has slowed construction of gas processing and gathering facilities. The gas and oil companies which are planning or building new projects are discussed.

Transferring climate research results to stakeholder needs in Northern Germany

NASA Astrophysics Data System (ADS)

Meinke, Insa

2013-04-01

The North German Climate Office was established in 2006 at the Institute for Coastal Research at the Helmholtz-Zentrum Geesthacht, Germany as consequence of an increased public information need regarding coastal climate change and its impacts in Northern Germany. The service is characterized by an intensive dialogue between regional climate research and stakeholders in Northern Germany. About once a week scientists of the North German climate office are invited to contribute to public dialogue events. Also, numerous direct inquiries are answered and expert interviews are conducted. From this dialogue process specific stakeholder information needs are localized and analysed to develop tailored information products. To provide easy and user specific access to research results interactive web tools are developed. One example is the North German climate atlas, an interactive web tool on possible future climate change in Northern Germany. Another interactive web tool is informing on present and future coastal protection needs in Northern Germany. Another aim of our information products is to assess and summarize the existing scientific knowledge on climate, climate change and impacts in Northern Germany. A mini IPCC-like regional assessment report has been published in 2010, which is summarizing, discussing and assessing the scientific knowledge on regional climate, climate change and impacts as well as possible adaptation strategies in the metropolitan region of Hamburg.

Structure and deformation history of the northern range of Trinidad and adjacent areas

NASA Astrophysics Data System (ADS)

Algar, S. T.; Pindell, J. L.

1993-08-01

Conflicting models have been proposed for both the evolution of northern South America and the neotectonics of the south Caribbean plate boundary zone. The Trinidadian portion of the margin is particularly controversial, but surprisingly it has been little studied. We present a structural analysis of Trinidad's Northern Range, pertinent updates of the island's stratigraphy and sedimentology, and new zircon fission track age determinations, and use them to constrain Trinidad's geologic history, and to better understand the controlling tectonic processes. In our interpretation Trinidad's three E-ENE striking ranges, which are separated by late Neogene-Recent depocenters, expose (1) the Northern Range Group, generally greenschist-metamorphosed Upper Jurassic to Cretaceous north facing continental slope sediments of the Northern Range, deposited on the northern South American passive margin 200-400 km to the WNW, and (2) the Trinidad Group, Cretaceous-Paleogene shelf slope sediments of the central and southern Trinidad deposited less than 100 km WNW of their present location. A small allochthon composing the Sans Souci Group Cretaceous tholeiitic volcaniclastic, basaltic, and gabbroic rocks (Sans Souci Formation) and sediments (Toco Formation) now in the northeastern Northern Range, has been transported hundreds of kilometers from the west with the Caribbean Plate. Despite earlier references to Cretaceous orogenesis, all deformation in Trinidad is of Cenozoic age. The first deformation in the Northern Range (D1) formed north vergent nappes and induced greenschist metamorphism, probably in the Late Eocene or Oligocene. The nappes developed either by the underthrusting of the Proto-Caribbean crust beneath South America due to convergence between North and South America, or as gravity slides caused by oversteepening induced by this convergence and/or the passage of the Caribbean Plate's peripheral bulge and arrival of its foredeep. Northern Range D2 deformation is south

Wildfires in Northern Siberian Larch Dominated Communities

NASA Technical Reports Server (NTRS)

Khaurk, Viacheslav I.; Ranson, Kenneth J.; Dvinskaya, Maria L.; Im, Sergey T.

2011-01-01

The fire history of the northern larch forests within the permafrost zone in a portion of northern Siberia (approx 66 deg N, 100 deg E) was studied. Since there is little to no human activities in this area fires within the study area were mostly caused by lightning. Fire return intervals (FRI) were estimated based on burn marks on tree stems and dates of tree natality. FRI values varied from 130 yr to 350 yr with 200 +/- 50 yr mean. In southerly larch dominated communities FRI was found to be shorter (77 +/- 20 yr at approx 61 deg. N, and 82 +/- 7 at 64 deg N), and longer at the northern boundary (approx 71 deg) of larch stands (320 +/- 50 yr). During the Little Ice Age period in the 16th to 18th centuries FRI was approximately twice as long as recorded in this study. Fire caused changes in the soil including increases in soil drainage and permafrost thawing depth and a radial growth increase of about 2 times (with more than 6 times observed). This effect may simulate the predicted warming impact on the larch growth in the permafrost zone.

Mechanical suppression of northern pike (Esox lucius) populations in small Arizona reservoirs

USGS Publications Warehouse

Kuzmenko, Yuliya; Spesiviy, Timofy; Bonar, Scott A.

2010-01-01

Introduced populations of northern pike Esox lucius have provided angling opportunities in the western United States (McMahon and Bennett 1996). However, the northern pike is a voracious piscivore and its large size, high fecundity, and broad physiological tolerance make it capable of drastically altering ecosystems it invades (Marchetti et al. 2004). Indeed, predation by northern pike has been shown to significantly alter fish community structure and put native fishes at a higher extinction risk (He and Kitchell 1990, Findlay et al. 2000). Predation by northern pike is viewed as a significant threat to native stocks of salmonids in Washington, British Columbia, and California (McMahon and Bennett 1996, California Department of Fish and Game [CDFG] 2003).

Hypolactasia in the indigenous populations of northern Russia.

PubMed

Kozlov, A I

1998-01-01

The distribution of hypolactasia (PH) in the indigenous populations of the polar and related territories of the Russian Federation was investigated by an oral lactose tolerance. The frequency of hypolactasia in Kildin Saami population is 48%, Komi-Izhem-63%, Northern Mansi-71%, Northern Khanty-72%, West Siberia Nenets-78%. Generally hypolactasia frequencies in indigenous groups of Arctic and Sub-Arctic territories of Russia are higher than in the "reference" samples of Slav (Russian, 40-49%) and Permian Finn (Komi-Permiak and Udmurtian, 50-59%) groups.

Juvenile movement and natal dispersal on northern goshawks in Arizona

Treesearch

J. David Wiens; Richard T. Reynolds; Barry R. Noon

2006-01-01

We investigated the departure, transient movement, and local settlement stages of natal dispersal in a population of Northern Goshawks (Accipiter gentilis) on the Kaibab Plateau of northern Arizona. The study included 614 color-banded juveniles produced at 555 nests during 1991-2003, 89 of which were radio-marked during 1998-2001. Radio-marked...

Drinking and Smoking Habits of Students at Northern Territory University.

ERIC Educational Resources Information Center

Roberts, Kathryn L.; Jackson, Adrian S.

Persons in the Northern Territory who drink have the highest per capita daily consumption of alcohol and the highest rate of tobacco smoking in Australia. This study identifies the drinking patterns and demographic and personal variables that might predict risk levels for Northern Territory University (NTU) students and therefore give direction to…

76 FR 12721 - Northern Natural Gas Company; Notice of Application

Federal Register 2010, 2011, 2012, 2013, 2014

2011-03-08

... Natural Gas Company; Notice of Application Take notice that on February 18, 2011, Northern Natural Gas... application pursuant to section 7(b) of the Natural Gas Act (NGA) and Part 157 of the Commission's regulations..., Northern Natural Gas Company, P.O. Box 3330, Omaha, Nebraska 68103-0330, or by calling (402) 398-7103...

Northern goshawk habitat: an intersection of science, management, and conservation

Treesearch

Richard T. Reynolds; Russell T. Graham; Douglas A. Boyce

2008-01-01

We responded to the claim by Greenwald et al. (2005) that the management recommendations for the northern goshawk in the Southwestern United States (MRNG; Reynolds et al. 1992), a food web-based conservation plan that incorporated both northern goshawk (Accipiter gentilis) and multiple prey habitats, may be inadequate to protect goshawks. Greenwald...

Ecology and social system of northern gibbons living in cold seasonal forests.

PubMed

Guan, Zhen-Hua; Ma, Chang-Yong; Fei, Han-Lan; Huang, Bei; Ning, Wen-He; Ni, Qing-Yong; Jiang, Xue-Long; Fan, Peng-Fei

2018-07-18

Gibbons in China represent the northernmost margin of present day gibbon species distribution (around N25°). Compared to tropical habitats, northern gibbon habitats are characterized by low temperatures and remarkable seasonal variation in fruit abundance. How gibbons adapt to their cold and seasonal habitats and what ecological factors affect their sociality are key questions for understanding their ecology and social system evolution, the elucidation of which will contribute to the conservation of these special populations/species. According to preliminary short-term studies, northern gibbons consume more leaves and use larger home ranges than tropical gibbons. Interestingly, some Nomascus groups consist of more than one adult female. However, these preliminary results are not well understood or incorporated into current socio-ecological theories regarding gibbon species. To better understand northern gibbons, our team has systematically studied three habituated groups of Nomascus concolor, three groups of N. nasutus, and two habituated groups of Hoolock tianxing since 2002. In this paper, we stress the challenges facing gibbons living in northern habitats and summarize their behavioral adaptations to their harsh environments. We also describe the northern gibbon social system and discuss the potential relationships between their ecology and sociality. Finally, we highlight future research questions related to northern gibbons in China.

Multiple Landslide-Hazard Scenarios Modeled for the Oakland-Berkeley Area, Northern California

USGS Publications Warehouse

Pike, Richard J.; Graymer, Russell W.

2008-01-01

With the exception of Los Angeles, perhaps no urban area in the United States is more at risk from landsliding, triggered by either precipitation or earthquake, than the San Francisco Bay region of northern California. By January each year, seasonal winter storms usually bring moisture levels of San Francisco Bay region hillsides to the point of saturation, after which additional heavy rainfall may induce landslides of various types and levels of severity. In addition, movement at any time along one of several active faults in the area may generate an earthquake large enough to trigger landslides. The danger to life and property rises each year as local populations continue to expand and more hillsides are graded for development of residential housing and its supporting infrastructure. The chapters in the text consist of: *Introduction by Russell W. Graymer *Chapter 1 Rainfall Thresholds for Landslide Activity, San Francisco Bay Region, Northern California by Raymond C. Wilson *Chapter 2 Susceptibility to Deep-Seated Landsliding Modeled for the Oakland-Berkeley Area, Northern California by Richard J. Pike and Steven Sobieszczyk *Chapter 3 Susceptibility to Shallow Landsliding Modeled for the Oakland-Berkeley Area, Northern California by Kevin M. Schmidt and Steven Sobieszczyk *Chapter 4 Landslide Hazard Modeled for the Cities of Oakland, Piedmont, and Berkeley, Northern California, from a M=7.1 Scenario Earthquake on the Hayward Fault Zone by Scott B. Miles and David K. Keefer *Chapter 5 Synthesis of Landslide-Hazard Scenarios Modeled for the Oakland-Berkeley Area, Northern California by Richard J. Pike The plates consist of: *Plate 1 Susceptibility to Deep-Seated Landsliding Modeled for the Oakland-Berkeley Area, Northern California by Richard J. Pike, Russell W. Graymer, Sebastian Roberts, Naomi B. Kalman, and Steven Sobieszczyk *Plate 2 Susceptibility to Shallow Landsliding Modeled for the Oakland-Berkeley Area, Northern California by Kevin M. Schmidt and Steven

Habitat use and movement patterns of Northern Pintails during spring in northern Japan: the importance of agricultural lands

USGS Publications Warehouse

Yamaguchi, Noriyuki M.; Hupp, Jerry W.; Flint, Paul L.; Pearce, John M.; Shigeta, Yusuke; Shimada, Tetsuo; Hiraoka, Emiko N.; Higuchi, Hiroyoshi

2012-01-01

From 2006 to 2009, we marked 198 Northern Pintails (Anas acuta) with satellite transmitters on their wintering areas in Japan to study their migration routes and habitat use in spring staging areas. We hypothesized that the distribution of pintails during spring staging was influenced by patterns of land use and expected that the most frequently used areas would have more agricultural habitat than lesser-used areas. We obtained 3031 daily locations from 163 migrant pintails marked with satellite transmitters and identified 524 stopover sites. Based on a fixed kernel home range analysis of stopover utilization distribution (UD), core staging areas (areas within the 50% UD) were identified in northern Honshu and western Hokkaido, and were used by 71% of marked pintails. Core staging areas had a greater proportion of rice fields than peripheral (51–95% UD) and rarely used (outside the 95% UD) staging areas. Stopover sites also contained more rice fields and other agricultural land than were available at regional scales, indicating that pintails selected rice and other agricultural habitats at regional and local scales. Pintails remained at spring staging areas an average of 51 d. Prolonged staging in agricultural habitats of northern Japan was likely necessary for pintails to prepare for transoceanic migration to Arctic nesting areas in eastern Russia.

GIA induced intraplate seismicity in northern Central Europe

NASA Astrophysics Data System (ADS)

Brandes, Christian; Steffen, Holger; Steffen, Rebekka; Wu, Patrick

2015-04-01

Though northern Central Europe is regarded as a low seismicity area (Leydecker and Kopera, 1999), several historic earthquakes with intensities of up to VII affected the area in the last 1200 years (Leydecker, 2011). The trigger for these seismic events is not sufficiently investigated yet. Based on the combination of historic earthquake epicentres with the most recent fault maps we show that the historic seismicity concentrated at major reverse faults. There is no evidence for significant historic earthquakes along normal faults in northern Central Europe. The spatial and temporal distribution of earthquakes (clusters that shift from time to time) implies that northern Central Europe behaves like a typical intraplate tectonic region as demonstrated for other intraplate settings (Liu et al., 2000) We utilized Finite Element models that describe the process of glacial isostatic adjustment to analyse the fault behaviour. We use the change in Coulomb Failure Stress (dCFS) to represent the minimum stress required to reach faulting. A negative dCFS value indicates that the fault is stable, while a positive value means that GIA stress is potentially available to induce faulting or cause fault instability or failure unless released temporarily by an earthquake. The results imply that many faults in Central Europe are postglacial faults, though they developed outside the glaciated area. This is supported by the characteristics of the dCFS graphs, which indicate the likelihood that an earthquake is related to GIA. Almost all graphs show a change from negative to positive values during the deglaciation phase. This observation sheds new light on the distribution of post-glacial faults in general. Based on field data and the numerical simulations we developed the first consistent model that can explain the occurrence of deglaciation seismicity and more recent historic earthquakes in northern Central Europe. Based on our model, the historic seismicity in northern Central Europe

Jupiter's Northern Lights

NASA Image and Video Library

2017-09-06

This is a reconstructed view of Jupiter's northern lights through the filters of Juno's Ultraviolet Imaging Spectrometer (UVS) instrument on Dec. 11, 2016, as the Juno spacecraft approached Jupiter, passed over its poles, and plunged towards the equator. Such measurements present a real challenge for the spacecraft's science instruments: Juno flies over Jupiter's poles at 30 miles (50 kilometers) per second -- more than 100,000 miles per hour -- speeding past auroral forms in a matter of seconds. https://photojournal.jpl.nasa.gov/catalog/PIA21938

Generic names of northern and southern fur seals (Mammalia: Otariidae)

USGS Publications Warehouse

Gardner, A.L.; Robbins, C.B.

1998-01-01

We have resolved a nomenclatural problem discovered during research on the northern fur seal that concerns the correct generic name for this taxon and for fur seals of the Southern Hemisphere. The unfortunate practice by some 19th century authors to use names in their Latinized form, but to date them from their first appearance as French common names led to the use of Arctocephalus for southern fur seals when the name correctly applies to the northern fur seal, known today as Callorhinus ursinus. However, Arctocephalus and Callorhinus are antedated by Otoes G. Fischer, 1817, which is the earliest available generic for the fur seal of the northern Pacific. The earliest available generic name for southern fur seals is Halarctus Gill, 1866. To avoid the confusion that would result from replacing the currently used generic names with those required by strict adherence to the Principle of Priority, we have petitioned the International Commission on Zoological nomenclature to preserve Arctocephalus and Callorhinus for the southern and northern fur seals, respectively.

MGS Mars Orbiter Laser (MOLA) Surface Topography of Northern Hemisphere

NASA Technical Reports Server (NTRS)

1997-01-01

A 'picket fence' rendition of surface topography in the northern hemisphere of Mars from the Mars Orbiter Laser Altimeter (MOLA). The profile was obtained during the Mars Global Surveyor Capture Orbit Calibration Pass on September 15, 1997. The profile runs from 73oN to 10oS latitude and passes through the topographically subdued northern plains, the western part of the Elysium volcanic province, which shows 3 miles (5 kilometers) of relief, and the chaotic 'dichotomy' boundary between the northern plains and ancient southern highlands. The MOLA profile is approximately 3000 miles (5000 kilometers) long and has a resolution on the surface of 1000 feet (330 meters) and a vertical resolution of approximately 3 feet (1 meter).

The outlook for northern forests

Treesearch

Stephen R. Shifley; W. Keith Moser; Sherri Wormstead; Francisco X. Aguilar

2016-01-01

The forests of the Northern United States have been remarkably resilient to nearly four centuries of immigration and settlement with associated anthropogenic disturbances caused by farming, logging, burning, urbanization, trade, and many other factors. Although resilient, forests conditions have been significantly impacted by humans as is illustrated by the extent of...

Sampling considerations for demographic and habitat studies of Northern Goshawks

Treesearch

Richard T. Reynolds; J. David Wiens; Suzanne M. Joy; Susan R. Salafsky

2005-01-01

We used mark-recapture methods to monitor Northern Goshawks (Accipiter gentilis) and their nests over 12 yr in an increasing sample of breeding territories (37 in 1991 to 121 in 2002) in northern Arizona. As many as 8 yr of repeated nest searching were required to identify the population of breeders, as individuals skipped egg-laying on territories...

50 CFR 226.203 - Critical habitat for northern right whales.

Code of Federal Regulations, 2011 CFR

2011-10-01

... 50 Wildlife and Fisheries 9 2011-10-01 2011-10-01 false Critical habitat for northern right whales. 226.203 Section 226.203 Wildlife and Fisheries NATIONAL MARINE FISHERIES SERVICE, NATIONAL OCEANIC AND... Critical habitat for northern right whales. (a) Great South Channel. The area bounded by 41°40′ N/69°45′ W...

LEECHES (ANNELIDA: EUHIRUDINEA) OF NORTHERN ARKANSAS

EPA Science Inventory

Twenty-one lotic and lentic environments throughout central and northern Arkansas were surveyed for the presence of leeches during June 2004, and April, July - October, 2005. Fourteen species of leeches (Desserobdella cryptobranchii, Desserobdella phalera, Desserobdella picta, H...

40 CFR 81.116 - Northern Missouri Intrastate Air Quality Control Region.

Code of Federal Regulations, 2011 CFR

2011-07-01

... Quality Control Region. 81.116 Section 81.116 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY... Air Quality Control Regions § 81.116 Northern Missouri Intrastate Air Quality Control Region. The Northern Missouri Intrastate Air Quality Control Region consists of the territorial area encompassed by the...

40 CFR 81.116 - Northern Missouri Intrastate Air Quality Control Region.

Code of Federal Regulations, 2010 CFR

2010-07-01

... Quality Control Region. 81.116 Section 81.116 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY... Air Quality Control Regions § 81.116 Northern Missouri Intrastate Air Quality Control Region. The Northern Missouri Intrastate Air Quality Control Region consists of the territorial area encompassed by the...

Genetics Show Current Decline and Pleistocene Expansion in Northern Spotted Owls

USGS Publications Warehouse

Funk, W. Chris; Forsman, Eric D.; Mullins, Thomas D.; Haig, Susan M.

2008-01-01

The northern spotted owl (Strix occidentalis caurina) is one of the most controversial threatened subspecies ever listed under the U.S. Endangered Species Act. Because of concern for persistence of the subspecies, logging on Federal lands in the U.S. Pacific Northwest was dramatically reduced under the Northwest Forest Plan in 1994. Despite protection of its remaining forest habitat, recent field studies show continued demographic declines of northern spotted owls. One potential threat to northern spotted owls that has not yet been shown is loss of genetic variation from population bottlenecks that can increase inbreeding depression and decrease adaptive potential. Here, we show recent genetic bottlenecks in northern spotted owls using a large genetic dataset (352 individuals from across the subspecies' range and 11 microsatellite loci). The signature of bottlenecks was strongest in Washington State, in agreement with field data. Interestingly, we also found a genetic signature of Pleistocene expansion in the same study areas where recent bottlenecks were shown. Our results provide independent evidence that northern spotted owls have recently declined, and suggest that loss of genetic variation is an emerging threat to the subspecies' persistence. Reduced effective population size (Ne), shown here in addition to field evidence for demographic decline, highlights the increasing vulnerability of this bird to extinction.

The timing and extent of Quaternary glaciation of Stok, northern Zanskar Range, Transhimalaya, of northern India

NASA Astrophysics Data System (ADS)

Orr, Elizabeth N.; Owen, Lewis A.; Murari, Madhav K.; Saha, Sourav; Caffee, Marc W.

2017-05-01

The glacial history of three tributary valleys (Namlung, Gopal Kangri and Stok Kangri) of the Stok valley, south of the Indus valley in the northern sector of the Zanskar Range, northern India is characterized using geomorphic mapping and cosmogenic 10Be surface exposure dating. The new glacial chronostratigraphy for the Stok valley is the first for the northern Zanskar Range and provides insights into the spatial variability of glaciation in the Himalayan-Tibetan orogen. This framework facilitates the understanding of the nature and the timing of landscape evolution and paleoenvironmental change in the Himalayan-Tibetan orogen. At least four glacial stages are evident within each of the tributary valleys of Gopal Kangri (MG1-MG4, youngest to oldest) and Stok Kangri (MS1-MS4) that feed into the Stok valley. With the exception of the MG4 glacial advance ( 124 ka) in Gopal Kangri, the Stok valley has preserved evidence of glaciations from 50 ka to the present. Equilibrium-line altitudes and glacier reconstructions for the Stok valley and its tributaries demonstrate that glaciations have become progressively less extensive through time. Former glacier extents of the Stok region are comparable in length with glacial advances during the last glacial cycle in eastern Zanskar and in the southern Ladakh Range to the south and north of the Indus valley, respectively. Landscape evolution in the study area has occurred across numerous glacial-interglacial cycles by a combination of glacial and fluvial processes and is similar to that of the Ladakh Range.

Anisotropic Rayleigh-wave phase velocities beneath northern Vietnam

NASA Astrophysics Data System (ADS)

Legendre, Cédric P.; Zhao, Li; Huang, Win-Gee; Huang, Bor-Shouh

2015-02-01

We explore the Rayleigh-wave phase-velocity structure beneath northern Vietnam over a broad period range of 5 to 250 s. We use the two-stations technique to derive the dispersion curves from the waveforms of 798 teleseismic events recoded by a set of 23 broadband seismic stations deployed in northern Vietnam. These dispersion curves are then inverted for both isotropic and azimuthally anisotropic Rayleigh-wave phase-velocity maps in the frequency range of 10 to 50 s. Main findings include a crustal expression of the Red River Shear Zone and the Song Ma Fault. Northern Vietnam displays a northeast/southwest dichotomy in the lithosphere with fast velocities beneath the South China Block and slow velocities beneath the Simao Block and between the Red River Fault and the Song Da Fault. The anisotropy in the region is relatively simple, with a high amplitude and fast directions parallel to the Red River Shear Zone in the western part. In the eastern part, the amplitudes are generally smaller and the fast axis displays more variations with periods.

February 2003 marine atmospheric conditions and the bora over the northern Adriatic

USGS Publications Warehouse

Dorman, C.E.; Carniel, S.; Cavaleri, L.; Sclavo, M.; Chiggiato, J.; Doyle, J.; Haack, T.; Pullen, J.; Grbec, B.; Vilibic, I.; Janekovic, I.; Lee, C.; Malacic, V.; Orlic, M.; Paschini, E.; Russo, A.; Signell, R.P.

2007-01-01

A winter oceanographic field experiment provided an opportunity to examine the atmospheric marine conditions over the northern Adriatic. Mean February winds are from a northeasterly direction over most of the Adriatic and a more northerly direction along the western coast. Wind speeds are fastest in jets over the NE coast during bora events and weakest in the mid-northwestern Adriatic. Diurnal air temperature cycles are smallest on the NE coast and largest in the midwestern Adriatic. The maximum sea-air difference is +10??C on the eastern coast and near zero on the midwestern Adriatic. Boras are northeasterly (from) wind events that sweep off Croatia and Slovenia, bringing slightly colder and drier air over the northern Adriatic. The main bora season is December to March. Winter 2002-2003 was normal for bora events. Synoptic-scale temporal variations are correlated over the northern Adriatic. Fastest Bora winds and highest wind stress over the northern Adriatic is concentrated in four topographically controlled jets. The strongest is the Senj Jet, while the Trieste Jet extends across the entire northern Adriatic. Between each two jets is a weak wind zone. The greatest mean net heat loss is in bora jets in the NE Adriatic, where it was -438 W m-2 and is weakest in the midwestern northern Adriatic, where it was near zero. Wind stress is concentrated over the NE half of Adriatic in four bora jets, while wind stress is weak in the NW Adriatic. There is significant variation in wind stress mean and standard deviation structure over the northern Adriatic with each bora event. Copyright 2006 by the American Geophysical Union.

High Rates of Staphylococcus aureus USA400 Infection, Northern Canada

PubMed Central

Golding, George R.; Levett, Paul N.; McDonald, Ryan R.; Irvine, James; Quinn, Brian; Nsungu, Mandiangu; Woods, Shirley; Khan, Mohammad; Ofner-Agostini, Marianna

2011-01-01

Surveillance of Staphylococcus aureus infections in 3 northern remote communities of Saskatchewan was undertaken. Rates of methicillin-resistant infections were extremely high (146–482/10,000 population), and most (98.2%) were caused by USA400 strains. Although USA400 prevalence has diminished in the United States, this strain is continuing to predominate throughout many northern communities in Canada. PMID:21470471

Sea-floor gouges caused by migrating gray whales off northern California

USGS Publications Warehouse

Cacchione, D.A.; Drake, D.E.; Field, M.E.; Tate, G.B.

1987-01-01

Side-scan sonar records collected during March and April 1981 and 1982 off northern California contain elongate depressions whose sizes and shapes are similar to sea-floor gouges made by feeding gray whales (Eschrichtius robustus) in the northern Bering Sea and in shallow embayments off British Columbia. The discovery of the whale gouges in the sonar records was unexpected, and supports some of the previous speculation that gray whales feed opportunistically during migration. Gouges occupy about 0.032% of the 7.6 km2 of sea floor that was surveyed, which represents about 575 metric tons of excavated material. Although seemingly minor in amount, the total amount of bottom sediment removed from the central and northern California continental shelf by gray whale activities year after year represents macroscale biologically induced erosion and could have significant geological implications in shelf erosion and depositional schemes. This is the only published evidence of benthic feeding by gray whales along their migration route off northern California. ?? 1987.

Possible mechanism linking ocean conditions to low body weight and poor recruitment of age-0 walleye pollock (Gadus chalcogrammus) in the southeast Bering Sea during 2007

NASA Astrophysics Data System (ADS)

Gann, Jeanette C.; Eisner, Lisa B.; Porter, Steve; Watson, Jordan T.; Cieciel, Kristin D.; Mordy, Calvin W.; Yasumiishi, Ellen M.; Stabeno, Phyllis J.; Ladd, Carol; Heintz, Ron A.; Farley, Edward V.

2016-12-01

Changes to physical and chemical oceanographic structure can lead to changes in phytoplankton biomass and growth, which, in-turn, lead to variability in the amount of energy available for transfer to higher trophic levels (e.g., forage fish). In general, age-0 (juvenile) walleye pollock (Gadus chalcogrammus) have been shown to have low fitness (determined by energy density and size), in warm years compared to average or cold years in the southeastern Bering Sea. Contrary to these findings, the year 2007 was a cold year with low fitness of age-0 pollock compared to the transition year of 2006 (transitioning from warm to cold conditions) and cold years, 2008-2011. In late summer/early fall (mid-August through September), significantly lower surface silicic acid concentrations coupled with low phytoplankton production and chlorophyll a (Chl a) biomass were observed in 2007 among 2006-2012 (P<0.05). We postulate that the low silicic acid concentrations may be an indication of reduced surface nutrient flux during summer, leading to low primary productivity (PP). The nutrient replenishing shelf/slope water exchange that occurred during late October-February (2006-2007) indicates that deep-water nutrient/salinity reserves for the start of the 2007 growing season were plentiful and had similar concentrations to other years (2006-2012). The spring bloom magnitude appeared to be slightly below average, and surface silicic acid concentrations at the end of the spring bloom period in 2007 appeared similar to other years in the middle domain of the southeastern Bering Sea. However, during summer (June-August) 2007, high stratification and the low number of storm events resulted in low flux of nutrients to surface waters, indicated by the low surface silicic acid concentrations at the end of summer (mid-August through September). Surface silicic acid may be useful as an indicator of surface nutrient enrichment (and subsequent PP) during summer since other macronutrients (e

An alternative method for processing northern blots after capillary transfer.

PubMed

Nilsen, Timothy W

2015-03-02

Different laboratories use different methods for the prehybridization, hybridization, and washing steps of the northern blotting procedure. In this protocol, a northern blot is pretreated with Church and Gilbert hybridization buffer to block nonspecific probe-binding sites. The immobilized RNA is then hybridized to a DNA probe specific for the RNA of interest. Finally, the membrane is washed and subjected to autoradiography or phosphorimaging. The solutions and conditions described here may be ideal for those who prefer to use fewer ingredients in their solutions. This protocol is designed to achieve the same goals as other northern blotting approaches. It minimizes background (nonspecific adherence of probe to membrane and nonspecific hybridization) and maximizes specific hybridization to RNAs immobilized on a membrane. © 2015 Cold Spring Harbor Laboratory Press.

Flood of April and May 2008 in Northern Maine

USGS Publications Warehouse

Lombard, Pamela J.

2010-01-01

Severe flooding occurred in Aroostook and Penobscot Counties in northern Maine between April 28 and May 1, 2008, and was most extreme in the town of Fort Kent. Peak streamflows in northern Aroostook County were the result of a persistent heavy snowpack that caused high streamflows when it quickly melted during the third week of April 2008. Snowmelt was followed by from two to four inches of rainfall over a 2-day period in northern Maine. Peak water-surface elevations resulting from the flood were obtained from 13 continuous-record streamgages and 63 surveyed high-water marks in Aroostook and Penobscot Counties. Peak streamflows were obtained from 20 sites on 15 streams through stage/discharge rating curves or hydraulic flow models. Peak water-surface elevations and streamflows were the highest ever recorded at seven continuous-record streamgages, which had between 25 and 84 years of record in northern Aroostook County. The annual exceedance probability (the percent chance of exceeding the streamflow recorded during the April/May 2008 flood during any given year) at six streamgages in northern Maine was equal to or less than 1 percent. Data from flood-insurance studies published by the Federal Emergency Management Agency were available for five of the locations analyzed for the April/May 2008 flood and were compared to streamflows and observed peak water-surface elevations from the 2008 flood. Water-surface elevations that would be expected given the observed flow as applied to the effective flood insurance studies ranged from between 1 and 4 feet from the water-surface elevations observed during the 2008 flood. Differences were likely the result of up to 30 years of additional data for the calculation of recurrence intervals and the fact that hydraulic models used for the models had not previously been calibrated to a flood of this magnitude.

Strip cutting in northern hardwoods

Treesearch

Richard M. Godman

1992-01-01

Interest in clearcutting young northern hardwood stands in strips is running high, especially now that mechanical fellers and skidders have been developed to harvest these stands. Strip cutting has several advantages-no overstory to worry about when treating the site, no overstory to remove later, and the economic advantage of cutting the strip only once.

Development of northern red oak rooted cutting and enrichment planting systems

Treesearch

Matthew H. Gocke; Jamie Schuler; Daniel J. Robison; Barry Goldfarb

2005-01-01

Enrichment planting may provide an efficient means to establish elite northern red oak (Quercus rubra L.) genotypes in recently harvested natural forests. However, planting northern red oak (NRO) seedlings into natural stands has proven difficult in the past, especially when competition and other stress factors are not controlled.

Visual Grading and Quality of 1-0 Northern Red Oak Seedlings

Treesearch

S.L. Clark; S.E. Scblarbaum; Paul P. Kormanik

2000-01-01

Past research has used detailed measurements of various growth characteristics to determine seedling grades and quality of northern red oak nursery stock This study evaluates the effectiveness ofa visual grading process. similar to thosefound in commercial nursery operations, to distinguish high quality seedlings. Northern red oak (Quercus rubra...

Groundwater management in northern Iraq

NASA Astrophysics Data System (ADS)

Stevanovic, Zoran; Iurkiewicz, Adrian

2009-03-01

Groundwater is vital and the sole resource in most of the studied region of northern Iraq. It has a significant role in agriculture, water supply and health, and the elimination of poverty in rural areas. Although Iraq is currently dramatically disturbed by complex political and socio-economic problems, in its northern part, i.e. the Kurdish-inhabited region, fast urbanization and economic expansion are visible everywhere. Monitoring and water management schemes are necessary to prevent aquifer over-exploitation in the region. Artificial recharge with temporary runoff water, construction of subsurface dams and several other aquifer management and regulation measures have been designed, and some implemented, in order to improve the water situation. Recommendations, presented to the local professionals and decision-makers in water management, include creation of Water Master Plans and Water User Associations, synchronization of drilling programmes, rehabilitation of the existing well fields, opening of new well fields, and the incorporation of new spring intakes in some areas with large groundwater reserves, as well as construction of numerous small-scale schemes for initial in situ water treatment where saline groundwater is present.

Mercury distribution and lipid oxidation in fish muscle: Effects of washing and isoelectric protein precipitation

USGS Publications Warehouse

Gong, Y.; Krabbenhoft, D.P.; Ren, L.; Egelandsdal, B.; Richards, M.P.

2011-01-01

Nearly all the mercury (Hg) in whole muscle from whitefish (Coregonus clupeaformis) and walleye (Sander vitreus) was present as methyl mercury (MeHg). The Hg content in whole muscle from whitefish and walleye was 0.04-0.09 and 0.14-0.81 ppm, respectively. The myofibril fraction contained approximately three-fourths of the Hg in whitefish and walleye whole muscle. The sarcoplasmic protein fraction (e.g., press juice) was the next most abundant source of Hg. Isolated myosin, triacylglycerols, and cellular membranes contained the least Hg. Protein isolates prepared by pH shifting in the presence of citric acid did not decrease Hg levels. Addition of cysteine during washing decreased the Hg content in washed muscle probably through the interaction of the sulfhydryl group in cysteine with MeHg. Primary and secondary lipid oxidation products were lower during 2 ??C storage in isolates prepared by pH shifting compared to those of washed or unwashed mince from whole muscle. This was attributed to removing some of the cellular membranes by pH shifting. Washing the mince accelerated lipid peroxide formation but decreased secondary lipid oxidation products compared to that of the unwashed mince. This suggested that there was a lipid hydroperoxide generating system that was active upon dilution of aqueous antioxidants and pro-oxidants. ?? 2011 American Chemical Society.

Diet of the double-crested cormorant in western Lake Erie

USGS Publications Warehouse

Bur, Michael T.; Tinnirello, Sandra L.; Lovell, Charles D.; Tyson, Jeff T.

1999-01-01

Sport and commercial fishing interest groups are concerned about potential impacts double-crested cormorants (Phalacrocorax auritus) may have on fish species. Our objectives for this study were to determine the diet of the cormorant in western Lake Erie and the diet overlap and competition for resources with piscivorous fish, such as walleye (Stizostedion vitreum). The stomach contents of 302 double-crested cormorants collected in western Lake Erie consisted primarily of young-of-the-year gizzard shad (Dorosoma cepedianum), emerald shiner (Notropis atherinoides), and freshwater drum (Aplodinotus grunniens). In the spring, freshwater drum were the most frequently occurring food in the stomachs and constituted the greatest portion of the diet by weight. Young gizzard shad became the most abundant prey and made up the largest percentage of the diet by weight in the stomachs from the end of July through October. Emerald shiners were abundant in the diet during June, September, and October. The fish species that cormorants ate resembled, by proportion, the species mix found in trawl catches. The diets of cormorants and walleyes were similar from July to October with significant overlap. Results from this study suggest impacts of cormorants at current population levels in Lake Erie are not detrimental to sport and commercial fishing. Therefore, control for the purpose of reducing competition for prey fish with walleye is not warranted at this time.

Y chromosomal evidence on the origin of northern Thai people.

PubMed

Brunelli, Andrea; Kampuansai, Jatupol; Seielstad, Mark; Lomthaisong, Khemika; Kangwanpong, Daoroong; Ghirotto, Silvia; Kutanan, Wibhu

2017-01-01

The Khon Mueang represent the major group of people present in today's northern Thailand. While linguistic and genetic data seem to support a shared ancestry between Khon Mueang and other Tai-Kadai speaking people, the possibility of an admixed origin with contribution from local Mon-Khmer population could not be ruled out. Previous studies conducted on northern Thai people did not provide a definitive answer and, in addition, have largely overlooked the distribution of paternal lineages in the area. In this work we aim to provide a comprehensive analysis of Y paternal lineages in northern Thailand and to explicitly model the origin of the Khon Mueang population. We obtained and analysed new Y chromosomal haplogroup data from more than 500 northern Thai individuals including Khon Mueang, Mon-Khmer and Tai-Kadai. We also explicitly simulated different demographic scenarios, developed to explain the Khon Mueang origin, employing an ABC simulation framework on both mitochondrial and Y microsatellites data. Our results highlighted a similar haplogroup composition of Khon Mueang and Tai-Kadai populations in northern Thailand, with shared high frequencies of haplogroups O-PK4, O-M117 and O-M111. Our ABC simulations also favoured a model in which the ancestors of modern Khon Mueang originated recently after a split from the other Tai-Kadai populations. Our different analyses concluded that the ancestors of Khon Mueang are likely to have originated from the same source of the other Tai-Kadai groups in southern China, with subsequent admixture events involving native Mon-Khmer speakers restricted to some specific populations.

The Evolution of Northern Hemisphere Glaciation

NASA Astrophysics Data System (ADS)

Wright, J. D.

2001-05-01

For much of the last 50 million years, high-latitude regions remained too warm to allow snow to accumulate and form ice sheets. Shackleton et al. (1984) published a landmark paper correlating the first occurrence of ice-rafted detritus (IRD) observed at Rockall Plateau with a prominent increase in benthic foraminiferal d18O values during the late Pliocene. These late Pliocene to Pleistocene ice sheets were modulated on an orbital frequency and have characterized the global climate over the past 2.6 myr (Shackleton and Opdyke, 1973; Shackleton et al., 1984; Ruddiman, et al., 1986). During the early Pliocene, northern hemisphere glaciation (NHG) variations were less significant (Jansen et al., 1993). Our understanding of the Plio-Pleistocene ice sheet cycles can be viewed from two different perspectives. When viewed from the late Pleistocene, the fundamental question is what changed near the early/late Pliocene boundary to produce the large-scale, glacial-interglacial cycles of the past 2.6 Ma. In contrast, the view from the middle to late Miocene is quite different. Since the pioneering work of Shackleton et al. (1984), the record of NHG has been extended further back in time with drilling in the Norwegian Sea (ODP Leg 104). At Sites 642 and 644, IRD was found throughout the late Miocene and back to ~12 Ma. More recent drilling in the high northern latitudes occurred on ODP Leg 151. Site 909 recovered a middle Miocene section from the Fram Straits with rounded quartz grains that were interpreted as IRD (Wolf-Welling et al., 1996). Age estimates for those sediments place the first northern hemisphere ice sheets at least as old as 14 Ma. The occurrence of sand-sized particles (>1000 μm) and coal below this level indicates the possibility of glacial activity in the Northern Hemisphere as early as 16 Ma. Thus, the late Pliocene to Pleistocene cycles appear to be the resumption of the glacial-interglacial pattern that began during the Miocene. While the Miocene ice

Ten Years after Patten: Young People and Policing in Northern Ireland

ERIC Educational Resources Information Center

Byrne, Jonny; Jarman, Neil

2011-01-01

Through a comprehensive review of existing literature, this article documents young people's experiences of policing during the period of political transition and extensive reform of the structures of policing in Northern Ireland since the publication of the Independent Commission on Policing for Northern Ireland (The Patten Report) in 1999. The…

75 FR 44789 - Northern Natural Gas Company; Notice of Technical Conference

Federal Register 2010, 2011, 2012, 2013, 2014

2010-07-29

... DEPARTMENT OF ENERGY Federal Energy Regulatory Commission [Docket No. RP10-841-000] Northern Natural Gas Company; Notice of Technical Conference July 20, 2010. By order dated July 9, 2010 \\1\\ the... discussed in the July 9, 2010 Order. \\1\\ Northern Natural Gas Company, 132 FERC ] 61,021 (2010). FERC...

Lightning and forest fires in the northern Rocky Mountain region

Treesearch

H. T. Gisborne

1926-01-01

During the past 18 years lightning has caused 39 per cent of the forest fires in the northern Rocky Mountain district, which includes Montana, northern Idaho, and a small portion of northeastern Washington. For the seasons of 1924 and 1925 the figures are 51 per cent and 80 per cent, respectively. As long as such conditions prevail it should be of decided value to know...

The Enigma of Mercury's Northern Rise

NASA Astrophysics Data System (ADS)

James, P. B.

2018-05-01

Various aspects of the "northern rise" make it hard to explain: Its composition and chronology don't stand out from its surroundings, it seems to have uplifted late, and it has a huge gravity anomaly. We'll discuss the possible formation mechanisms.

Plate tectonics of the northern part of the Pacific Ocean

NASA Astrophysics Data System (ADS)

Verzhbitsky, E. V.; Kononov, M. V.; Kotelkin, V. D.

2007-10-01

Geophysical data on the northern part of the Pacific Ocean were systematized to compile a map of geomagnetic and geothermal studies of the Bering Sea. The absence of reliable data about the formation time of the Bering Sea structures of oceanic and continental origins is noted; this hampered the assessment of the geodynamical processes in the North Pacific. Based on the geophysical data, we estimated the age of the structures of the Bering Sea floor such as the Commander Basin (21 My), the Shirshov Ridge (95 and 33 My in the northern and southern parts, respectively), the Aleutian Basin (70 My), the Vitus Arch (44 My), the Bowers Ridge (30 My), and the Bowers Basin (40 My). These values are confirmed by the geological, geophysical, and kinematic data. A numerical modeling of the formation of extensive regional structures (Emperor Fracture Zone, Chinook Trough, and others) in the Northern Pacific is carried out. A conclusion was made on the basis of the geological and geothermal analysis that the northern and southern parts of the Shirshov Ridge have different geological ages and different tectonic structures. The northern part of the ridge is characterized by an upthrust-nappe terrain origin, while the southern part has originated from a torn-away island arc similar to the origin of the Bowers Ridge. The sea floor of the Aleutian Basin represents a detached part of the Upper Cretaceous Kula plate, on which spreading processes took place in the Vitus Arch area in the Eocene. The final activity phase in the Bering Sea began 21 My B.P. by spreading of the ancient oceanic floor of the Commander Basin. Based on the age estimations of the structures of the Bering Sea floor, the results of the modeling of the process of formation of regional fracture zones and of the geomagnetic, geothermal, tectonic, geological, and structural data, we calculated and compiled a kinematic model (with respect to a hot spot reference system) of the northern part of the Pacific Ocean for 21

Reproduction and microhabitat selection in a sharply declining Northern Bobwhite population

USGS Publications Warehouse

Collins, B.M.; Williams, C.K.; Castelli, Paul M.

2009-01-01

Northern Bobwhite (Colinus virginianus) populations have been declining throughout their range, but some of the sharpest declines have been documented in the Mid-Atlantic states. We conducted a 2 year (2006-2007) breeding season (1 May-30 Sep) telemetry study in southern New Jersey to collect baseline data on Northern Bobwhite reproductive rates, and nest and brood microhabitat selection. We located 23 Northern Bobwhite nests, of which 21 were usable for survival analyses. Incubation-period nest survival rate was 0.454 ?? 0.010 (95 CI =0.2800.727). Mean clutch size was 14.2 ?? 0.58 (range 10-19, n = 20) and hatching success was 96.1 ?? 2.0 (range 86-100%, n = 10). The estimated probability that an individual that entered the breeding season would initiate incubation of ???1 nest was 0.687 for females and 0.202 for males. Nest microhabitat selection was positively related to visual obstruction and percentage of litter. Brood microhabitat selection was positively related to visual obstruction, vegetation height, and percentage of forbs but negatively related to percentage of cool season grass and litter. Fecundity metrics for Northern Bobwhites in southern New Jersey appear similar to those reported elsewhere in the species' range. Conservation efforts to increase Northern Bobwhite reproductive success in southern New Jersey should focus on increasing the quantity of available breeding habitat. ?? 2009 by the Wilson Ornithological Society.

Regional Climate Service in Northern Germany -The North German Climate Office

NASA Astrophysics Data System (ADS)

Meinke, I.; Von Storch, H.

2012-12-01

The North German Climate Office was established in 2006 at the Institute for Coastal Research at the Helmholtz-Zentrum Geesthacht, Germany as consequence of an increased public information need regarding coastal climate change and its impacts in Northern Germany. The service is characterized by an intensive dialogue between regional climate research and stakeholders in Northern Germany. About once a week scientists of the North German climate office are invited to contribute to public dialogue events. Also numerous direct inquiries are answered and expert interviews are conducted. From this dialogue process specific stakeholder information needs are localized and analysed to develop tailored information products. To provide easy and user specific access to research results interactive web tools are developed. One example is the North German climate atlas, an interactive web tool on possible future climate change in Northern Germany. Another interactive web tool is informing on present and future coastal protection needs in Northern Germany. Another aim of our information products is to assess and summarize the existing scientific knowledge on climate, climate change and impacts in Northern Germany. A mini IPCC-like regional assessment report has been published in 2010, which is summarizing, discussing and assessing the scientific knowledge on regional climate, climate change and impacts as well as possible adaptation strategies in the metropolitan region of Hamburg.

Long-term variability in Northern Hemisphere snow cover and associations with warmer winters

USGS Publications Warehouse

McCabe, Gregory J.; Wolock, David M.

2010-01-01

A monthly snow accumulation and melt model is used with gridded monthly temperature and precipitation data for the Northern Hemisphere to generate time series of March snow-covered area (SCA) for the period 1905 through 2002. The time series of estimated SCA for March is verified by comparison with previously published time series of SCA for the Northern Hemisphere. The time series of estimated Northern Hemisphere March SCA shows a substantial decrease since about 1970, and this decrease corresponds to an increase in mean winter Northern Hemisphere temperature. The increase in winter temperature has caused a decrease in the fraction of precipitation that occurs as snow and an increase in snowmelt for some parts of the Northern Hemisphere, particularly the mid-latitudes, thus reducing snow packs and March SCA. In addition, the increase in winter temperature and the decreases in SCA appear to be associated with a contraction of the circumpolar vortex and a poleward movement of storm tracks, resulting in decreased precipitation (and snow) in the low- to mid-latitudes and an increase in precipitation (and snow) in high latitudes. If Northern Hemisphere winter temperatures continue to warm as they have since the 1970s, then March SCA will likely continue to decrease.

Long-term variability in Northern Hemisphere snow cover and associations with warmer winters

USGS Publications Warehouse

McCabe, G.J.; Wolock, D.M.

2010-01-01

A monthly snow accumulation and melt model is used with gridded monthly temperature and precipitation data for the Northern Hemisphere to generate time series of March snow-covered area (SCA) for the period 1905 through 2002. The time series of estimated SCA for March is verified by comparison with previously published time series of SCA for the Northern Hemisphere. The time series of estimated Northern Hemisphere March SCA shows a substantial decrease since about 1970, and this decrease corresponds to an increase in mean winter Northern Hemisphere temperature. The increase in winter temperature has caused a decrease in the fraction of precipitation that occurs as snow and an increase in snowmelt for some parts of the Northern Hemisphere, particularly the mid-latitudes, thus reducing snow packs and March SCA. In addition, the increase in winter temperature and the decreases in SCA appear to be associated with a contraction of the circumpolar vortex and a poleward movement of storm tracks, resulting in decreased precipitation (and snow) in the low- to mid-latitudes and an increase in precipitation (and snow) in high latitudes. If Northern Hemisphere winter temperatures continue to warm as they have since the 1970s, then March SCA will likely continue to decrease. ?? 2009 Springer Science+Business Media B.V.

78 FR 26064 - Endangered and Threatened Wildlife and Plants; Draft Conservation Strategy for the Northern...

Federal Register 2010, 2011, 2012, 2013, 2014

2013-05-03

...] Endangered and Threatened Wildlife and Plants; Draft Conservation Strategy for the Northern Continental... availability of a draft Conservation Strategy for the Northern Continental Divide Ecosystem grizzly bear (Ursus.... ADDRESSES: An electronic copy of the draft Conservation Strategy for the Northern Continental Divide grizzly...

Maturation and reproduction of northern flying squirrels in Pacific Northwest forests.

Treesearch

Lisa J. Villa; Andrew B. Carey; Todd M. Wilson; Karma E. Glos

1999-01-01

Northern flying squirrels are the primary prey of northern spotted owls and are important dispersers of fungal spores in Pacific Northwest forests. Despite the importance of these squirrels in forest ecosystems, information is lacking on life history and methods for determining age and reproductive condition. In the laboratory, we measured epiphyseal notch, femur...

Northern Eurasian Heat Waves and Droughts

NASA Technical Reports Server (NTRS)

Schubert, Siegfried; Wang, Hailan; Koster, Randal; Suarez, Max; Groisman, Pavel

2013-01-01

This article reviews our understanding of the characteristics and causes of northern Eurasian summertime heat waves and droughts. Additional insights into the nature of temperature and precipitation variability in Eurasia on monthly to decadal time scales and into the causes and predictability of the most extreme events are gained from the latest generation of reanalyses and from supplemental simulations with the NASA GEOS-5 AGCM. Key new results are: 1) the identification of the important role of summertime stationary Rossby waves in the development of the leading patterns of monthly Eurasian surface temperature and precipitation variability (including the development of extreme events such as the 2010 Russian heat wave), 2) an assessment of the mean temperature and precipitation changes that have occurred over northern Eurasia in the last three decades and their connections to decadal variability and global trends in SST, and 3) the quantification (via a case study) of the predictability of the most extreme simulated heat wave/drought events, with some focus on the role of soil moisture in the development and maintenance of such events. A literature survey indicates a general consensus that the future holds an enhanced probability of heat waves across northern Eurasia, while there is less agreement regarding future drought, reflecting a greater uncertainty in soil moisture and precipitation projections. Substantial uncertainties remain in our understanding of heat waves and drought, including the nature of the interactions between the short-term atmospheric variability associated with such extremes and the longer-term variability and trends associated with soil moisture feedbacks, SST anomalies, and an overall warming world.

Growth, condition, diet, and consumption rates of northern pike in three Arizona reservoirs

USGS Publications Warehouse

Flinders, J.M.; Bonar, Scott A.

2008-01-01

Northern pike (Esox lucius L.) introductions are controversial in the western United States due to suspected impacts they might have on established sport fisheries and potential illegal introductions. Tbree Arizona reservoirs, Parker Canyon Lake, Upper Lake Mary and Long Lake were sampled to examine the diet, consumption dynamics, and growth of northern pike. Northern pike diets varied by season and reservoir. In Parker Canyon Lake, diets were dominated by rainbow trout in winter and spring and bluegill and green sunfish in the fall. In Long Lake the northern pike ate crayfish in spring and early summer and switched to young of the year common carp in summer and fall. Black crappie, golden shiners, and crayfish were the major prey in Upper Lake Mary during spring, but they switched to stocked rainbow trout in the fall. Northern pike growth was in the high range of growth reported throughout the United States. Estimated northern pike specific consumption rate (scr) of rainbow trout (g/g/d ?? 10-6) was greatest in Upper Lake Mary (scr = 329.1 ?? 23.7 g/g/d ?? 10-6) where stocked fingerling (280 mm TL) rainbow trout stocked in Long Lake (scr = 1.4 ?? 0.1 g/g/d ?? 10-6) and Parker Canyon Lake (scr = 287.2 ?? 15.1 g/g/d ?? 10-6) where catchable-sized rainbow trout were stocked. Managers should consider the cost-benefits of stocking fish >200 mm TL in lakes containing northern pike. ?? Copyright by the North American Lake Management Society 2008.

75 FR 21048 - Northern Lights Fund Trust, et al.; Notice of Application

Federal Register 2010, 2011, 2012, 2013, 2014

2010-04-22

... SECURITIES AND EXCHANGE COMMISSION [Investment Company Act Release No. 29208; 812-13651] Northern Lights Fund Trust, et al.; Notice of Application April 16, 2010. AGENCY: Securities and Exchange... shareholder approval and would grant relief from certain disclosure requirements. Applicants: Northern Lights...

76 FR 11773 - Environmental Management Site-Specific Advisory Board, Northern New Mexico

Federal Register 2010, 2011, 2012, 2013, 2014

2011-03-03

... DEPARTMENT OF ENERGY Environmental Management Site-Specific Advisory Board, Northern New Mexico... the Environmental Management Site-Specific Advisory Board (EM SSAB), Northern New Mexico. The Federal... Courtyard by Marriott, 3347 Cerrillos Road, Santa Fe, New Mexico 87507. FOR FURTHER INFORMATION CONTACT...

Strip clearcutting to regenerate northern hardwoods.

Treesearch

Frederick T. Metzger

1980-01-01

Describes results of strip clearcutting trials in mature northern hardwood and hemlock-hardwood stands in the Lake States. Two strip width and orientations were tested, with and without herbicide treatment of the advance regeneration. Establishment, growth, and species composition of the regeneration were assessed.

An introduction to the biology of Northern krill (Meganyctiphanes norvegica Sars).

PubMed

Tarling, Geraint A; Ensor, Natalie S; Fregin, Torsten; Goodall-Copestake, William P; Fretwell, Peter

2010-01-01

This chapter provides a background to research on Northern krill biology, starting with a description of its morphology and identifying features, and the historical path to its eventual position as a single-species genus. There is a lack of any euphausiid fossil material, so phylogenetic analysis has relied on comparative morphology and ontogeny and, more recently, genetic methods. Although details differ, the consensus of these approaches is that Meganyctiphanes is most closely related to the genus Thysanoessa. The light organs (or photophores) are well developed in Northern krill and the control of luminescence in these organs is described. A consideration of the distribution of the species shows that it principally occupies shelf and slope waters of both the western and eastern coasts of the North Atlantic, with a southern limit at the boundary with sub-tropical waters (plus parts of the Mediterranean) and a northern limit at the boundary with Arctic water masses. Recent evidence of a northward expansion of these distributional limits is considered further. There have been a variety of techniques used to sample and survey Northern krill populations for a variety of purposes, which this chapter collates and assesses in terms of their effectiveness. Northern krill play an important ecological role, both as a contributor to the carbon pump through the transport of faecal material to the deeper layers, and as a key prey item for groundfish, squid, baleen whales, and seabirds. The commercial exploitation of Northern krill has been slow to emerge since its potential was considered by Mauchline [Mauchline, J (1980). The biology of mysids and euphausiids. Adv. Mar. Biol. 18, 1-681]. However, new uses for products derived from krill are currently being found, which may lead to a new wave of exploitation. Copyright © 2010 Elsevier Ltd. All rights reserved.

Young Women's Positive and Negative Perceptions of Self in Northern Ireland

ERIC Educational Resources Information Center

McAlister, Siobhan; Neill, Gail

2007-01-01

This paper represents analysis of one aspect of a larger research project examining the everyday lives and experiences of young women in Northern Ireland. As an introductory exercise within focus groups, 48 young women considered and discussed the good and not so good things about being a young woman in Northern Ireland. Through these accounts…

Human and biophysical factors influencing modern fire disturbance in northern Wisconsin

Treesearch

Brian R. Sturtevant; David T. Cleland

2007-01-01

Humans cause most wildfires in northern Wisconsin, but interactions between human and biophysical variables affecting fire starts and size are not well understood. We applied classification tree analyses to a 16-year fire database from northern Wisconsin to evaluate the relative importance of human v. biophysical variables affecting fire occurrence within (1) all cover...

Is seedling grading beneficial to artificial regeneration of northern red oaks?

Treesearch

Paul P. Kormanik; Shi-Jean S. Sung; Stanley J. Zarnoch

2005-01-01

Effective and consistent success with artificial regeneration of northern red oak (Quercus rubra L.) has been achieved on many sites using 1-0 graded seedlings produced with the nursery protocol developed by the USDA Forest Service at the Institute of Tree Root Biology in cooperation with the Georgia Forestry Commission. Small northern red oak (NRO)...

Patterns of alcohol consumption in middle-aged men from France and Northern Ireland. The PRIME study.

PubMed

Marques-Vidal, P; Arveiler, D; Evans, A; Montaye, M; Bingham, A; Ruidavets, J B; McMaster, D; Haas, B; Amouyel, P; Ducimetière, P

2000-04-01

To assess the patterns of alcohol consumption in France and Northern Ireland. Four cross-sectional studies. Sample of 50-59 y old men living in France and Northern Ireland, consuming at least one unit of alcoholic beverage per week. 5363 subjects from France and 1367 from Northern Ireland. None. Consumption of wine was higher in France whereas consumption of beer and spirits was higher in Northern Ireland. Alcohol drinking was rather homogeneous throughout the week in France, whereas Fridays and Saturdays accounted for 60% of total alcohol consumption in Northern Ireland. In both countries, current smokers had a higher consumption of all types of alcoholic beverages than non-smokers. Similarly, obese and hypertensive subjects had a higher total alcohol consumption than non-obese or normotensive subjects, but the type of alcoholic beverages differed between countries. In Northern Ireland, subjects which reported some physical activity consumed significantly less alcoholic beverages than sedentary subjects, whereas no differences were found in France. Conversely, subjects with dyslipidemia consumed more alcoholic beverages than normolipidemic subjects in France, whereas no differences were found in Northern Ireland. In France, total alcohol, wine and beer consumption was negatively related to socioeconomic status and educational level. In Northern Ireland, total alcohol, beer and spirits consumption was negatively related whereas wine consumption was positively related to socioeconomic status and educational level. Alcohol drinking patterns differ between France and Northern Ireland, and also according to cardiovascular risk factors, socioeconomic and educational levels. Merck, Sharp & Dohme-Chibret (France), the NICHSA and the Department of Health and Social Service (Northern Ireland).

Perspectives on polio and immunization in Northern Nigeria.

PubMed

Renne, Elisha

2006-10-01

Through the efforts of the global campaign to eradicate poliomyelitis, polio cases have declined worldwide, from 35,251 cases in 1988, to 1449 cases as of 28 October 2005. However, confirmed cases of wild polio virus continue to be reported from Northern Nigeria. This paper examines the reasons for the difficulties in eradicating polio in Northern Nigeria from the perspective of residents of one town, Zaria, in northern Kaduna State. Research methods included participant observation, open-ended interviews and the collection of polio-related documents. While some people believed that the vaccine was contaminated by anti-fertility substances, others questioned the focus on polio when measles and malaria were considered more harmful. Some also distrusted claims about the safety of Western biomedicine. These concerns relate to questions about the appropriateness of vertical health interventions, where levels of routine immunization are low. While the Polio Eradication Initiative was considered to be cost-effective by Western donors, from the perspective of some people in Zaria it was seen as undermining primary health care, suggesting that a collaborative, community-based framework for primary health care, which includes routine immunization, would be a more acceptable approach.

75 FR 64719 - Environmental Management Site-Specific Advisory Board, Northern New Mexico

Federal Register 2010, 2011, 2012, 2013, 2014

2010-10-20

... DEPARTMENT OF ENERGY Environmental Management Site-Specific Advisory Board, Northern New Mexico... the Environmental Management Site-Specific Advisory Board (EM SSAB), Northern New Mexico. The Federal... at Santa Fe, 750 North St. Francis Drive, Santa Fe, New Mexico. FOR FURTHER INFORMATION CONTACT...

76 FR 22090 - Environmental Management Site-Specific Advisory Board, Northern New Mexico

Federal Register 2010, 2011, 2012, 2013, 2014

2011-04-20

... DEPARTMENT OF ENERGY Environmental Management Site-Specific Advisory Board, Northern New Mexico... the Environmental Management Site-Specific Advisory Board (EM SSAB), Northern New Mexico. The Federal... a.m.-5 p.m. ADDRESSES: Santa Claran Hotel, 464 North Riverside Drive, Espanola, New Mexico 87532...

75 FR 53280 - Environmental Management Site-Specific Advisory Board, Northern New Mexico

Federal Register 2010, 2011, 2012, 2013, 2014

2010-08-31

... DEPARTMENT OF ENERGY Environmental Management Site-Specific Advisory Board, Northern New Mexico... the Environmental Management Site-Specific Advisory Board (EM SSAB), Northern New Mexico. The Federal... Inn and Conference Center, 1508 Paseo Del Pueblo Sur, Taos, New Mexico 87571. FOR FURTHER INFORMATION...

Risk assessment of precipitation extremes in northern Xinjiang, China

NASA Astrophysics Data System (ADS)

Yang, Jun; Pei, Ying; Zhang, Yanwei; Ge, Quansheng

2018-05-01

This study was conducted using daily precipitation records gathered at 37 meteorological stations in northern Xinjiang, China, from 1961 to 2010. We used the extreme value theory model, generalized extreme value (GEV) and generalized Pareto distribution (GPD), statistical distribution function to fit outputs of precipitation extremes with different return periods to estimate risks of precipitation extremes and diagnose aridity-humidity environmental variation and corresponding spatial patterns in northern Xinjiang. Spatiotemporal patterns of daily maximum precipitation showed that aridity-humidity conditions of northern Xinjiang could be well represented by the return periods of the precipitation data. Indices of daily maximum precipitation were effective in the prediction of floods in the study area. By analyzing future projections of daily maximum precipitation (2, 5, 10, 30, 50, and 100 years), we conclude that the flood risk will gradually increase in northern Xinjiang. GEV extreme value modeling yielded the best results, proving to be extremely valuable. Through example analysis for extreme precipitation models, the GEV statistical model was superior in terms of favorable analog extreme precipitation. The GPD model calculation results reflect annual precipitation. For most of the estimated sites' 2 and 5-year T for precipitation levels, GPD results were slightly greater than GEV results. The study found that extreme precipitation reaching a certain limit value level will cause a flood disaster. Therefore, predicting future extreme precipitation may aid warnings of flood disaster. A suitable policy concerning effective water resource management is thus urgently required.

Forest types of the northern Rocky Mountains and their climatic controls

Treesearch

J. A. Larsen

1930-01-01

The purpose in this report is to describe the natural forest types of the northern Rocky Mountains in Montana and northern Idaho, to point out their natural distribution and chief silvical characteristics, and to show in what degree they are controlled by differences in topography and climate. Such information may be useful in laying the foundation for later, more...

Chapter 4: Northern spotted owl habitat and populations: status and threats

Treesearch

Damon B. Lesmeister; Raymond J. Davis; Peter H. Singleton; J. David. Wiens

2018-01-01

The northern spotted owl (Strix occidentalis caurina) was listed as threatened under the Endangered Species Act in 1990 (USFWS 1990). Providing adequate amounts of suitable forest cover to sustain the subspecies was a major component of the first recovery plan for northern spotted owls (USFWS 1992) and a driver in the basic reserve design and old-...

Survival and height growth of northern white-cedar from 18 provenances

Treesearch

Richard M. Jeffers

1976-01-01

Northern white-cedar from 18 provenances was evaluated for total height in the nursery and for survival and total height in two field plantings in northern Wisconsin and in western Upper Michigan. There were significant differences among provenances in survival at one location and in height at both field locations 5 years after planting; there were no differences among...

Characteristics of Swarm Seismicity in Northern California

NASA Astrophysics Data System (ADS)

Chiorini, S.; Lekic, V.

2017-12-01

Seismic swarms are characterized by an anomalously large number of earthquakes compared to the background rate of seismicity that are tightly clustered in space (typically, one to tens of kilometers) and time (typically, days to weeks). However, why and how swarms occur is poorly understood, partly because of the difficulty of identifying the range of swarm behaviors within large seismic catalogs. Previous studies have found that swarms, compared to other earthquake sequences, appear to be more common in extensional (Vidale & Shearer, 2006) and volcanic settings (Hayashi & Morita, 2003). In addition, swarms more commonly exhibit migration patterns, consistent with either fluid diffusion (Chen & Shearer, 2011; Chen et al., 2012) or aseismic creep (Lohman & McGuire, 2007), and are preferentially found in areas of enhanced heat flow (Enescu, 2009; Zaliapin & Ben Zion, 2016). While the swarm seismicity of Southern California has been studied extensively, that of Northern California has not been systematically documented and characterized. We employed two complementary methods of swarm identification: the approach of Vidale and Shearer (2006; henceforth VS2006) based on a priori threshold distances and timings of quakes, and the spatio-temporal distance metric proposed by Zaliapin et al. (2008; henceforth Z2008) in order to build a complete catalog of swarm seismicity in Northern California spanning 1984-2016 (Waldhauser & Schaff, 2008). Once filtered for aftershocks, the catalog allows us to describe the main features of swarm seismicity in Northern California, including spatial distribution, association or lack thereof with known faults and volcanic systems, and seismically quiescent regions. We then apply a robust technique to characterize the morphology of swarms, leading to subsets of swarms that are oriented either vertically or horizontally in space. When mapped, vertical swarms show a significant association with volcanic regions, and horizontal swarms with

Winter in Northern Europe (WINE) Project

NASA Technical Reports Server (NTRS)

Vonzahn, U.

1982-01-01

The scientific aims, work plan, and organization of the Middle Atmosphere Program winter in northern Europe (MAP/WINE) are described. Proposed contributions to the MAP/WINE program from various countries are enumerated. Specific atmospheric parameters to be examined are listed along with the corresponding measurement technique.

Northern Prairie Wildlife Research Center—Celebrating 50 years of science

USGS Publications Warehouse

Austin, Jane E.; Shaffer, Terry L.; Igl, Lawrence D.; Johnson, Douglas H.; Krapu, Gary L.; Larson, Diane L.; Mech, L. David; Mushet, David M.; Sovada, Marsha A.

2017-10-30

The Northern Prairie Wildlife Research Center (NPWRC) celebrated its 50-year anniversary in 2015. This report is written in support of that observance. We document why and how the NPWRC came to be and describe some of its many accomplishments and the influence the Center’s research program has had on natural resource management. The history is organized by major research themes, proceeds somewhat chronologically within each theme, and covers the Center’s first 50 years of research. During that period, Center scientists authored more than 1,700 publications and reports. More than 1,000 seasonal or temporary field personnel, and more than 100 graduate students, contributed to the Center’s success; many went on to have exemplary careers in natural resource management, conservation, and education. The mission of the Northern Prairie Wildlife Research Center today remains true to the original vision: to provide the knowledge needed to understand, conserve, and manage the Nation’s natural resources for current and future generations, with an emphasis on species and ecosystems of the northern Great Plains. The Center’s first 50 years of applied biological research provides a deep scientific foundation on which to address emerging issues for the natural resources in the northern Great Plains and beyond.

Neogene carbonate exploration play concepts for Northern New Guinea: New iteration from field work and seismic stratigraphy along the Northern New Guinea Fault Zone

DOE Office of Scientific and Technical Information (OSTI.GOV)

Pigott, J.D.; Geiger, C.

1994-07-01

Recent field reconnaissance, petrography, nanno and foraminifera age determinations, and seismic stratigraphy of the Sepik and Piore subbasins of northern New Guinea reveal the existence of an extensive, tectonically unstable, Miocene-Pliocene carbonate shelf system. These findings represent the first recorded evidence of northern Papuan limestones coeval in age to those of the hydrocarbon productive Salawati Basin of Irian Jaya. Moreover, these observations also demonstrate the significance of episodic activities of the northern New Guinea fault zone upon the changes in carbonate sedimentation and diagenesis. During the Neogene, algal biosparites to foraminiferal biomicrites defined the clean portion of a mixed clastic-carbonatemore » shelf system of the northern New Guinea basin, which began at the central New Guinea cordillera and deepened northward. This shelf was interrupted by coral-coralline algal boundstone fringing- to patch-reef buildups with associated skeletal grainstones. Clean carbonates were spatially and temporally restricted to basement blocks, which episodically underwent uplift while terrigenous dilutes carbonates were more common in adjacently subsiding basement block bathymetric lows. These tectonic expressions were caused by the spatially transient nature of constraining bends of the evolving north New Guinea faults. As shown by seismic stratigraphy, by the late Miocene to the early Pliocene the uplift of the Bewani-Torricelli Mountains sagittally divided the shelf of the northern New Guinea basin into the Ramu-Sepik and the Piore basins. Continued regional sinistral transpression between the Pacific and the New Guinea leading edge of the Indo-Australian plates led to the reverse tilting of the Piore basin, the shallowing of the former distal shelf with concomitant extensive biolithite development (e.g., on subsiding volcanic islands) eventual uplifting of the Oenake Range, and en echelon faulting of the Bewani-Torricelli Mountains.« less

Illuminating Northern California’s Active Faults

USGS Publications Warehouse

Prentice, Carol S.; Crosby, Christopher J.; Whitehill, Caroline S.; Arrowsmith, J. Ramon; Furlong, Kevin P.; Philips, David A.

2009-01-01

Newly acquired light detection and ranging (lidar) topographic data provide a powerful community resource for the study of landforms associated with the plate boundary faults of northern California (Figure 1). In the spring of 2007, GeoEarthScope, a component of the EarthScope Facility construction project funded by the U.S. National Science Foundation, acquired approximately 2000 square kilometers of airborne lidar topographic data along major active fault zones of northern California. These data are now freely available in point cloud (x, y, z coordinate data for every laser return), digital elevation model (DEM), and KMZ (zipped Keyhole Markup Language, for use in Google EarthTM and other similar software) formats through the GEON OpenTopography Portal (http://www.OpenTopography.org/data). Importantly, vegetation can be digitally removed from lidar data, producing high-resolution images (0.5- or 1.0-meter DEMs) of the ground surface beneath forested regions that reveal landforms typically obscured by vegetation canopy (Figure 2)

Frosty Gullies on the Northern Plains

NASA Image and Video Library

2015-07-15

Seasonal frost commonly forms at middle and high latitudes on Mars, much like winter snow on Earth. However, on Mars most frost is carbon dioxide dry ice rather than water ice. This image is from NASA Mars Reconnaissance Orbiter. This image shows frost in gully alcoves in a crater on the Northern plains. The frost highlights details of the alcoves, since it forms in different amounts depending on slopes and shadows as well as the type of material making up the ground. Rugged rock outcrops appear dark and shadowed, while frost highlights the upper alcove and the steepest route down the slope. Most changes associated with gullies are observed in the Southern hemisphere. However, some are seen in the Northern hemisphere, where steep slopes are less common. HiRISE is monitoring these gullies to look for changes and to understand the behavior of the frost. http://photojournal.jpl.nasa.gov/catalog/PIA19852

Normal hematology and serum chemistry of northern fur seals (Callorhinus ursinus) in captivity.

PubMed

Kohyama, Kaoru; Inoshima, Yasuo

2017-09-01

Northern fur seals (Callorhinus ursinus) are endemic to the North Pacific Ocean. They were hunted for their fur and became endangered in the late 1800s, but their populations recovered following the introduction of protection laws. Recently, populations have been decreasing again, although the reasons are unclear. For individuals that are bred and reared in captivity as part of ex situ conservation projects, details of blood characteristics are essential to ensure good health. However, the normal ranges of hematology and serum chemistry of captive northern fur seals have not been defined. This study determined the normal ranges of hematology and serum chemistry of captive fur seals. Blood samples were collected every month for 2 years from four captive northern fur seals in Japan (three born in an aquarium and one kept in the same aquarium following rescue). Fifteen blood characteristics and 29 serum chemistry properties were compared with those previously reported for wild northern fur seals in the USA. Several parameters were not within the normal ranges reported previously in wild northern fur seals. In particular, levels of alkaline phosphatase was outside of the normal ranges previously reported. The hematological and serum chemistry ranges in this study can help provide a guideline for understanding the health of northern fur seals in captivity. © 2017 Wiley Periodicals, Inc.

77 FR 25514 - Northern Trust Investments, Inc., et al.; Notice of Application

Federal Register 2010, 2011, 2012, 2013, 2014

2012-04-30

... Trust Investments, Inc., et al.; Notice of Application April 24, 2012. AGENCY: Securities and Exchange... sections 12(d)(1)(A) and (B) of the Act. Applicants: Northern Trust Investments, Inc. (``Northern Trust''), FlexShares Trust (``Trust''), and Foreside Fund Services, LLC (``Foreside''). Summary of Application...

75 FR 24686 - Environmental Management Site-Specific Advisory Board, Northern New Mexico

Federal Register 2010, 2011, 2012, 2013, 2014

2010-05-05

... DEPARTMENT OF ENERGY Environmental Management Site-Specific Advisory Board, Northern New Mexico... Mexico. The Federal Advisory Committee Act (Pub. L. 92- 463, 86 Stat. 770) requires that public notice of..., San Juan Pueblo, New Mexico 87566. FOR FURTHER INFORMATION CONTACT: Menice Santistevan, Northern New...

Northern protected areas will become important refuges for biodiversity tracking suitable climates.

PubMed

Berteaux, Dominique; Ricard, Marylène; St-Laurent, Martin-Hugues; Casajus, Nicolas; Périé, Catherine; Beauregard, Frieda; de Blois, Sylvie

2018-03-15

The Northern Biodiversity Paradox predicts that, despite its globally negative effects on biodiversity, climate change will increase biodiversity in northern regions where many species are limited by low temperatures. We assessed the potential impacts of climate change on the biodiversity of a northern network of 1,749 protected areas spread over >600,000 km 2 in Quebec, Canada. Using ecological niche modeling, we calculated potential changes in the probability of occurrence of 529 species to evaluate the potential impacts of climate change on (1) species gain, loss, turnover, and richness in protected areas, (2) representativity of protected areas, and (3) extent of species ranges located in protected areas. We predict a major species turnover over time, with 49% of total protected land area potentially experiencing a species turnover >80%. We also predict increases in regional species richness, representativity of protected areas, and species protection provided by protected areas. Although we did not model the likelihood of species colonising habitats that become suitable as a result of climate change, northern protected areas should ultimately become important refuges for species tracking climate northward. This is the first study to examine in such details the potential effects of climate change on a northern protected area network.

Evaluating recovery potential of the northern white rhinoceros from cryopreserved somatic cells

PubMed Central

Kock, Richard; Vahala, Jiri; Diekhans, Mark; Fiddes, Ian; Armstrong, Joel; Paten, Benedict; Ryder, Oliver A.; Steiner, Cynthia C.

2018-01-01

The critically endangered northern white rhinoceros is believed to be extinct in the wild, with the recent death of the last male leaving only two remaining individuals in captivity. Its extinction would appear inevitable, but the development of advanced cell and reproductive technologies such as cloning by nuclear transfer and the artificial production of gametes via stem cells differentiation offer a second chance for its survival. In this work, we analyzed genome-wide levels of genetic diversity, inbreeding, population history, and demography of the white rhinoceros sequenced from cryopreserved somatic cells, with the goal of informing how genetically valuable individuals could be used in future efforts toward the genetic rescue of the northern white rhinoceros. We present the first sequenced genomes of the northern white rhinoceros, which show relatively high levels of heterozygosity and an average genetic divergence of 0.1% compared with the southern subspecies. The two white rhinoceros subspecies appear to be closely related, with low genetic admixture and a divergent time <80,000 yr ago. Inbreeding, as measured by runs of homozygosity, appears slightly higher in the southern than the northern white rhinoceros. This work demonstrates the value of the northern white rhinoceros cryopreserved genetic material as a potential gene pool for saving this subspecies from extinction. PMID:29798851

Population structure and dynamics of northern pike and smallmouth bass in Coeur d’Alene Lake, Idaho.

USGS Publications Warehouse

Walrath, John D.; Quist, Michael C.; Firehammer, Jon A.

2015-01-01

Numerous species have been introduced to Coeur d'Alene Lake, Idaho over the last century, but minimal research has been completed to understand their population dynamics. The objective of this study was to describe the population demographics and dynamics of northern pike (Esox lucius) and smallmouth bass (Micropterus dolomieu), two important nonnative sport fishes in the system to provide information that will assist with guiding management decisions. The oldest northern pike was age 7 and the oldest smallmouth bass was age 11. Populations of both species exhibited very stable recruitment with a recruitment coefficient of determination of 0.99 for northern pike and 0.98 for smallmouth bass. Total annual mortality was estimated as 66% for northern pike and 42% for smallmouth bass. Growth of northern pike in Coeur d'Alene Lake was comparable to the 50–75th percentiles of growth exhibited by lentic northern pike populations across North America. Northern pike in Coeur d'Alene Lake were most similar to populations in the north-central and northeast United States with fast growth rates and short life spans. In contrast, smallmouth bass grew slowly and generally fell within the 5th percentile of lentic smallmouth bass populations in North America. Smallmouth bass in Coeur d'Alene Lake were similar to other populations in northern regions of the United States displaying slow growth rates with high longevity. Results of this study provide important insight on nonnative northern pike and smallmouth bass population dynamics.

Seismotectonics and crustal stress across the northern Arabian plate

NASA Astrophysics Data System (ADS)

yassminh, R.; Gomez, F. G.; Sandvol, E. A.; Ghalib, H. A.; Daoud, M.

2013-12-01

The region encompassing the collision of northern Arabia with Eurasia is a tectonically heterogeneous region of distributed deformation. The northern Arabia plate is bounded to the west by the subducting Sinai plate and the left-lateral Dead Sea transform. This complexity suggests that there are, multiple competing processes that may influence regional tectonics in northern Arabia and adjacent areas. Earthquake mechanisms provide insight into crustal kinematics and stress; however, reliable determination of earthquake source parameters can be challenging in a complex geological region, such as the continental collision zone between the Arabian and Eurasian plates. The goal of this study is to investigate spatial patterns of the crustal stress in the northern Arabian plate and surrounding area. The focal mechanisms used in this study are based on (1) first-motion polarities for earthquakes recorded by Syrian earthquake center during 2000-2011, and (2) regional moment tensors from broadband seismic data, from Turkey and Iraq. First motion focal mechanisms were assigned quality classifications based on the variation of both nodal planes. Regional moment tensor analysis can be significantly influenced by seismic velocity structure; thus, we have divided the study area into regions based on tectonic units. For each region, a specific velocity model is defined using waveform-modeling technique prior to the regional moment tensor inversion. The resulting focal mechanisms, combined with other previously published focal mechanisms for the study area, provide a basis for stress inversion analysis. The resulting deviatoric stress tensors show the spatial distribution of the maximum horizontal stress varies from NW-SE along the Dead Sea Fault to the N-S toward the east. We interpret this to reflect the eastward change from the transform to collision processes in northern Arabia. Along the Dead Sea Fault, transposition of the sigma-1 and sigma-2 to vertical and horizontal

Modeling co-occurrence of northern spotted and barred owls: accounting for detection probability differences

USGS Publications Warehouse

Bailey, Larissa L.; Reid, Janice A.; Forsman, Eric D.; Nichols, James D.

2009-01-01

Barred owls (Strix varia) have recently expanded their range and now encompass the entire range of the northern spotted owl (Strix occidentalis caurina). This expansion has led to two important issues of concern for management of northern spotted owls: (1) possible competitive interactions between the two species that could contribute to population declines of northern spotted owls, and (2) possible changes in vocalization behavior and detection probabilities of northern spotted owls induced by presence of barred owls. We used a two-species occupancy model to investigate whether there was evidence of competitive exclusion between the two species at study locations in Oregon, USA. We simultaneously estimated detection probabilities for both species and determined if the presence of one species influenced the detection of the other species. Model selection results and associated parameter estimates provided no evidence that barred owls excluded spotted owls from territories. We found strong evidence that detection probabilities differed for the two species, with higher probabilities for northern spotted owls that are the object of current surveys. Non-detection of barred owls is very common in surveys for northern spotted owls, and detection of both owl species was negatively influenced by the presence of the congeneric species. Our results suggest that analyses directed at hypotheses of barred owl effects on demographic or occupancy vital rates of northern spotted owls need to deal adequately with imperfect and variable detection probabilities for both species.

40 CFR 81.149 - Northern Coastal Plain Intrastate Air Quality Control Region.

Code of Federal Regulations, 2013 CFR

2013-07-01

... 40 Protection of Environment 18 2013-07-01 2013-07-01 false Northern Coastal Plain Intrastate Air Quality Control Region. 81.149 Section 81.149 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY... Air Quality Control Regions § 81.149 Northern Coastal Plain Intrastate Air Quality Control Region. The...

40 CFR 81.149 - Northern Coastal Plain Intrastate Air Quality Control Region.

Code of Federal Regulations, 2010 CFR

2010-07-01

... 40 Protection of Environment 17 2010-07-01 2010-07-01 false Northern Coastal Plain Intrastate Air Quality Control Region. 81.149 Section 81.149 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY... Air Quality Control Regions § 81.149 Northern Coastal Plain Intrastate Air Quality Control Region. The...

40 CFR 81.149 - Northern Coastal Plain Intrastate Air Quality Control Region.

Code of Federal Regulations, 2012 CFR

2012-07-01

... 40 Protection of Environment 18 2012-07-01 2012-07-01 false Northern Coastal Plain Intrastate Air Quality Control Region. 81.149 Section 81.149 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY... Air Quality Control Regions § 81.149 Northern Coastal Plain Intrastate Air Quality Control Region. The...

40 CFR 81.149 - Northern Coastal Plain Intrastate Air Quality Control Region.

Code of Federal Regulations, 2014 CFR

2014-07-01

... 40 Protection of Environment 18 2014-07-01 2014-07-01 false Northern Coastal Plain Intrastate Air Quality Control Region. 81.149 Section 81.149 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY... Air Quality Control Regions § 81.149 Northern Coastal Plain Intrastate Air Quality Control Region. The...

40 CFR 81.149 - Northern Coastal Plain Intrastate Air Quality Control Region.

Code of Federal Regulations, 2011 CFR

2011-07-01

... 40 Protection of Environment 17 2011-07-01 2011-07-01 false Northern Coastal Plain Intrastate Air Quality Control Region. 81.149 Section 81.149 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY... Air Quality Control Regions § 81.149 Northern Coastal Plain Intrastate Air Quality Control Region. The...

From Poetry to Music: "Northern Lullaby"

ERIC Educational Resources Information Center

Cardany, Audrey Berger

2011-01-01

Nancy White Carlstrom's children's book, "Northern Lullaby," conjures through poetry the beauty of the Alaskan landscape in the evening. The book provides an opportunity for music teachers to help their students transform text and visual images to music. The author describes connections for reading comprehension in the general music…

Nesting success of Northern Pintails on the coastal Yukon-Kuskokwim Delta, Alaska

USGS Publications Warehouse

Flint, Paul L.; Grand, James B.

1996-01-01

We studied nesting chronology and success of Northern Pintails (Anas acuta) on the coastal Yukon-Kuskokwim Delta, Alaska during the summers of 1991-1993. We found a total of 795 nests during three annual searches of a 27.4 km2 area. Minimum nest density averaged 9.67 nests per km2. Nesting success varied among years and ranged from 43.12% in 1991 to 10.74% in 1993 (average 23.95%). Most nest loss was the result of predation and tidal flooding. Daily nest survival probability declined with nest initiation date in all three years and also varied with nest age in 1992. Clutch size averaged 7.63 ± 0.067 (SE) eggs per nest and was larger than reported for other populations of Northern Pintails. Clutch size declined during the 44-47 day nesting interval at a greater rate than reported for other populations of Northern Pintails. We conclude that sub-arctic and prairie nesting Northern Pintails have similar reproductive potentials.

Evaporite karst of northern lower Michigan

USGS Publications Warehouse

Black, T.J.

1997-01-01

Michigan has three main zones of evaporite karst: collapse breccia in Late Silurian deposits of the Mackinac Straits region; breccia, collapse sinks, and mega-block collapse in Middle Devonian deposits of Northern Lower Michigan, which overlaps the preceding area; and areas of soil swallows in sinks of Mississippian deposits between Turner and Alabaster in Arenac and Iosco counties, and near Grand Rapids in Kent County. The author has focused his study on evaporite karst of the Middle Devonian deposits. The Middle Devonian depos its are the Detroit River Group: a series consisting of limestone, dolomite, shale, salt, gypsum, and anhydrite. The group occurs from subcrop, near the surface, to nearly 1400 feet deep from the northern tip of the Southern Peninsula to the south edge of the "solution front" Glacial drift is from zero to 350 feet thick. Oil and gas exploration has encountered some significant lost-circulation zones throughout the area. Drilling without fluid returns, casing-seal failures, and lost holes are strong risks in some parts of the region. Lost fluid returns near the top of the group in nearby areas indicate some karst development shortly after deposition. Large and irregular lost-circulation zones, linear and patch trends of large sink holes, and 0.25 mile wide blocks of down-dropped land in the northern Lower Peninsula of Michigan were caused by surface- and ground-water movement along faults into the Detroit River Group. Glaciation has removed some evidence of the karst area at the surface. Sinkhole development, collapse valleys, and swallows developed since retreat of the glacier reveal an active solution front in the Detroit River Group.

Boulder Strewn Plain in Northern Utopia Planitia

NASA Image and Video Library

2010-03-31

This image taken by NASA Mars Reconnaissance Orbiter in the Cydnus Rupes region, shows that the northern plains of Mars are rock and boulder strewn landscapes otherwise devoid of major features except a few impact craters.

Fukushima derived radiocesium in subsistence-consumed northern fur seal and wild celery

DOE PAGES

Ruedig, Elizabeth; Duncan, Colleen; Dickerson, Bobette; ...

2015-11-28

In July 2014, our investigative team traveled to St. Paul Island, Alaska to measure concentrations of radiocesium in wild-caught food products, primarily northern fur seal (Callorhinus ursinus). The 2011 Fukushima Daiichi Nuclear Power Plant accident released radiocesium into the atmosphere and into the western Pacific Ocean; other investigators have detected Fukushima-derived radionuclides in a variety of marine products harvested off the western coast of North America. We tested two subsistence-consumed food products from St. Paul Island, Alaska for Fukushima-derived radionuclides: 54 northern fur seal, and nine putchki (wild celery, Angelica lucida) plants. Individual northern fur seal samples were below minimummore » detectable activity concentrations of 137Cs and 134Cs, but when composited, northern fur seal tissues tested positive for trace quantities of both isotopes. Radiocesium was detected at an activity concentration of 37.2 mBq 134Cs kg -1 f.w. (95% CI: 35.9–38.5) and 141.2 mBq 137Cs kg -1f.w. (95% CI: 135.5–146.8). The measured isotopic ratio, decay-corrected to the date of harvest, was 0.26 (95% CI: 0.25–0.28). The Fukushima nuclear accident released 134Cs and 137Cs in roughly equal quantities, but by the date of harvest in July 2014, this ratio was 0.2774, indicating that this population of seals has been exposed to small quantities of Fukushima-derived radiocesium. Activity concentrations of both 134Cs and 137Cs in putchki were below detection limits, even for composited samples. Northern fur seal is known to migrate between coastal Alaska and Japan and the trace 134Cs in northern fur seal tissue suggests that the population under study had been minimally exposed Fukushima-derived radionuclides. Despite this inference, the radionuclide quantities detected are small and no impact is expected as a result of the measured radiation exposure, either in northern fur seal or human populations consuming this species.« less

Fukushima derived radiocesium in subsistence-consumed northern fur seal and wild celery

DOE Office of Scientific and Technical Information (OSTI.GOV)

Ruedig, Elizabeth; Duncan, Colleen; Dickerson, Bobette

In July 2014, our investigative team traveled to St. Paul Island, Alaska to measure concentrations of radiocesium in wild-caught food products, primarily northern fur seal (Callorhinus ursinus). The 2011 Fukushima Daiichi Nuclear Power Plant accident released radiocesium into the atmosphere and into the western Pacific Ocean; other investigators have detected Fukushima-derived radionuclides in a variety of marine products harvested off the western coast of North America. We tested two subsistence-consumed food products from St. Paul Island, Alaska for Fukushima-derived radionuclides: 54 northern fur seal, and nine putchki (wild celery, Angelica lucida) plants. Individual northern fur seal samples were below minimummore » detectable activity concentrations of 137Cs and 134Cs, but when composited, northern fur seal tissues tested positive for trace quantities of both isotopes. Radiocesium was detected at an activity concentration of 37.2 mBq 134Cs kg -1 f.w. (95% CI: 35.9–38.5) and 141.2 mBq 137Cs kg -1f.w. (95% CI: 135.5–146.8). The measured isotopic ratio, decay-corrected to the date of harvest, was 0.26 (95% CI: 0.25–0.28). The Fukushima nuclear accident released 134Cs and 137Cs in roughly equal quantities, but by the date of harvest in July 2014, this ratio was 0.2774, indicating that this population of seals has been exposed to small quantities of Fukushima-derived radiocesium. Activity concentrations of both 134Cs and 137Cs in putchki were below detection limits, even for composited samples. Northern fur seal is known to migrate between coastal Alaska and Japan and the trace 134Cs in northern fur seal tissue suggests that the population under study had been minimally exposed Fukushima-derived radionuclides. Despite this inference, the radionuclide quantities detected are small and no impact is expected as a result of the measured radiation exposure, either in northern fur seal or human populations consuming this species.« less

Active deformation processes of the Northern Caucasus deduced from the GPS observations

NASA Astrophysics Data System (ADS)

Milyukov, Vadim; Mironov, Alexey; Rogozhin, Eugeny; Steblov, Grigory; Gabsatarov, Yury

2015-04-01

The Northern Caucasus, as a part of the Alpine-Himalayan mobile belt, is a zone of complex tectonics associated with the interaction of the two major tectonic plates, Arabian and Eurasian. The first GPS study of the contemporary geodynamics of the Caucasus mountain system were launched in the early 1990s in the framework of the Russia-US joint project. Since 2005 observations of the modern tectonic motion of the Northern Caucasus are carried out using the continuous GPS network. This network encompasses the territory of three Northern Caucasian Republics of the Russian Federation: Karachay-Cherkessia, Kabardino-Balkaria, and North Ossetia. In the Ossetian part of the Northern Caucasus the network of GPS survey-mode sites has been deployed as well. The GPS velocities confirm weak general compression of the Northern Caucasus with at the rate of about 1-2 mm/year. This horizontal motion at the boundary of the Northern Caucasus with respect to the Eurasian plate causes the higher seismic and tectonic activity of this transition zone. This result confirms that the source of deformation of the Northern Caucasus is the sub-meridional drift of the Arabian plate towards the adjacent boundary of the Eastern European part of the Eurasian lithospheric plate. The concept of such convergence implies that the Caucasian segment of the Alpine-Himalayan mobile belt is under compression, the layers of sedimentary and volcanic rocks are folded, the basement blocks are subject to shifts in various directions, and the upper crust layers are ruptured by reverse faults and thrusts. Weak deviation of observed velocities from the pattern corresponding to homogeneous compression can also be revealed, and numerical modeling of deformations of major regional tectonic structures, such as the Main Caucasus Ridge, can explain this. The deformation tensor deduced from the velocity field also exhibits the sub-meridional direction of the major compressional axes which coincides with the direction of

Fukushima derived radiocesium in subsistence-consumed northern fur seal and wild celery.

PubMed

Ruedig, Elizabeth; Duncan, Colleen; Dickerson, Bobette; Williams, Michael; Gelatt, Thomas; Bell, Justin; Johnson, Thomas E

2016-02-01

In July 2014, our investigative team traveled to St. Paul Island, Alaska to measure concentrations of radiocesium in wild-caught food products, primarily northern fur seal (Callorhinus ursinus). The 2011 Fukushima Daiichi Nuclear Power Plant accident released radiocesium into the atmosphere and into the western Pacific Ocean; other investigators have detected Fukushima-derived radionuclides in a variety of marine products harvested off the western coast of North America. We tested two subsistence-consumed food products from St. Paul Island, Alaska for Fukushima-derived radionuclides: 54 northern fur seal, and nine putchki (wild celery, Angelica lucida) plants. Individual northern fur seal samples were below minimum detectable activity concentrations of (137)Cs and (134)Cs, but when composited, northern fur seal tissues tested positive for trace quantities of both isotopes. Radiocesium was detected at an activity concentration of 37.2 mBq (134)Cs kg(-1) f.w. (95% CI: 35.9-38.5) and 141.2 mBq (137)Cs kg(-1) f.w. (95% CI: 135.5-146.8). The measured isotopic ratio, decay-corrected to the date of harvest, was 0.26 (95% CI: 0.25-0.28). The Fukushima nuclear accident released (134)Cs and (137)Cs in roughly equal quantities, but by the date of harvest in July 2014, this ratio was 0.2774, indicating that this population of seals has been exposed to small quantities of Fukushima-derived radiocesium. Activity concentrations of both (134)Cs and (137)Cs in putchki were below detection limits, even for composited samples. Northern fur seal is known to migrate between coastal Alaska and Japan and the trace (134)Cs in northern fur seal tissue suggests that the population under study had been minimally exposed Fukushima-derived radionuclides. Despite this inference, the radionuclide quantities detected are small and no impact is expected as a result of the measured radiation exposure, either in northern fur seal or human populations consuming this species. Published by Elsevier

Northern goshawk and its prey in the Black Hills: Habitat assessment

Treesearch

Russell T. Graham; Shelley Bayard de Volo; Richard T. Reynolds

2015-01-01

The northern goshawk is classified as a Sensitive Species in all USDA Forest Service regions, including on the Black Hills National Forest in western South Dakota and northeastern Wyoming. An assessment was conducted of the quality of northern goshawk nesting and foraging habitat, along with the habitat quality of 22 of the goshawk’s prey species. A Delphi (expert...

Temporal Tendencies of River Discharge of Five Watersheds of Northern Mexico

Treesearch

José Návar; Humberto Hernández; Julio Ríos

2006-01-01

The watersheds of northern Mexico that encompasses the Rio San Pedro, Sinaloa, Nazas, Aguanaval, San Juan, and San Fernando-Soto La Marina are located within the main mountain ranges of northern Mexico and within the zone of large deserts of the boreal hemisphere. The hydro-climate variations, the management of forest soils and land use changes are shaping the supply...

Future human health research directions for the Canadian Northern Contaminants Program.

PubMed

Donaldson, Shawn G; Curren, Meredith S; Adlard, Bryan; Provost, Jonathan; Leech, Tara; Tikhonov, Constantine; Feeley, Mark; Tomlinson, Scott; Shearer, Russel

2013-01-01

Studies conducted in the mid-1980s and early 1990s demonstrated that persistent organic pollutants (POPs) and metals were reaching the Arctic ecosystem at unexpectedly high levels, many of which had no Arctic or Canadian sources. Epidemiological and toxicological studies in Canada and in other countries have found that these contaminants may pose a risk to human health. The objective of this paper is to provide the foundation for the discussion on future northern human health research under the Northern Contaminants Program (NCP) in Canada. This short discussion of human health priorities will help guide a path forward for future northern human health research in Canada to address on-going and new health concerns related to contaminants exposure in the Canadian Arctic.

Future human health research directions for the Canadian Northern Contaminants Program

PubMed Central

Donaldson, Shawn G.; Curren, Meredith S.; Adlard, Bryan; Provost, Jonathan; Leech, Tara; Tikhonov, Constantine; Feeley, Mark; Tomlinson, Scott; Shearer, Russel

2013-01-01

Studies conducted in the mid-1980s and early 1990s demonstrated that persistent organic pollutants (POPs) and metals were reaching the Arctic ecosystem at unexpectedly high levels, many of which had no Arctic or Canadian sources. Epidemiological and toxicological studies in Canada and in other countries have found that these contaminants may pose a risk to human health. The objective of this paper is to provide the foundation for the discussion on future northern human health research under the Northern Contaminants Program (NCP) in Canada. This short discussion of human health priorities will help guide a path forward for future northern human health research in Canada to address on-going and new health concerns related to contaminants exposure in the Canadian Arctic. PMID:24282784

Carrion use by northern goshawks

Treesearch

John R. Squires

1995-01-01

Northern goshawks (Accipiter gentilis) feed on a wide variety of birds and mammals (R. T. Reynolds, et al. 1992, USDA For. Ser. Gen. Tech. Rep. RM-217. Fort Collins, CO U.S.A.), but few accounts describe goshawks feeding on carrion. J.H. Schnell (1958, Condor 60:377-403) stated that, "It seems highly unlikely that the goshawk would forage for carrion under normal...

Neotectonic deformation model of the Northern Algeria from Paleomagnetic data

NASA Astrophysics Data System (ADS)

Derder, M. E. M.; Henry, B.; Maouche, S.; Amenna, M.; Bayou, B.; Djellit, H.; Ymel, H.; Gharbi, S.; Abtout, A.; Ayache, M.

2012-04-01

The seismic activity of the Western Mediterranean area is partly concentrated in northern Africa, particularly in northern Algeria, as it is shown by the strongest recent earthquakes of "Zemmouri" 21 May 2003 Mw=6.9 and the "El Asnam" 10 October 1980 Ms= 7.3. This seismicity is due to the tectonic activity related to the convergence between Africa and Eurasia plates since at least the Oligocene. The deformation is mostly compressional with associated folds, strike-slip faults and thrusts, and a direction of shortening between N-S and NNW-SSE. This convergence involves a tectonic transpression which is expressed by active deformation along the plate boundary. In northern Algeria, the seismicity is concentrated in a coastal E-W thin band zone (the Tell Atlas). Active structures define there NE-SW trending folds and NE-SW sinistral transpressive faults, which affect the intermountain and coastal Neogene to Quaternary sedimentary basins (e.g. " Cheliff "basin, " Mitidja "basin, …). These reverse faults are associated with NW-SE to E-W strike-slips deep faults. The active tectonics could be explained by a simple blocks rotation kinematics model. In order to test the validity of this kinematic model, three different paleomagnetic studies have been conducted. The first one concerned the "Cheliff" basin where sedimentary Neogene formations were extensively sampled (66 sites). The second study was carried out on Miocene andesite and dacite rocks cropping out along the northern coastal zone of the "Cheliff" basin ("Beni Haoua" area, 19 sites). The third study has been carried out on the Miocene magmatic rocks (rhyolites and basalts) cropping out north-eastern part of the "Mitidja" basin ("Cap Djinet" - "Boumerdes" area, 23 sites). The obtained results show existence of paleomagnetic clockwise rotations in all the studied areas and then validates the kinematics block rotation model. Accordingly, the deformation related to the convergence between the Africa and Eurasia

Trophic ecology of northern pike and their effect on conservation of westslope cutthroat trout.

USGS Publications Warehouse

Walrath, John D.; Quist, Michael C.; Firehammer, Jon A.

2015-01-01

Westslope Cutthroat Trout Oncorhynchus clarkii lewisi in Coeur d’Alene Lake, Idaho, have declined in recent years; predation by Northern Pike Esox lucius, a nonnative sport fish, is thought to be a causative mechanism. The goal of this study was to describe the seasonal food habits of Northern Pike and determine their influence on Westslope Cutthroat Trout in Coeur d’Alene Lake by using a bioenergetics modeling approach. Fish were sampled monthly from March 2012 to May 2013 using pulsed-DC electrofishing and experimental gillnetting in four bays. Northern Pike catch rates from electrofishing were generally low but increased slightly each season and were highest in the southern portion of the lake; catch rates from gillnetting were approximately 50% higher during the two spring sampling periods compared with the summer and fall. Seasonal growth and food habits of 695 Northern Pike (TL = 16.2–108.0 cm; weight = 24–9,628 g) were analyzed. Diets primarily consisted of kokanee O. nerka, Westslope Cutthroat Trout, and Yellow PerchPerca flavescens. Results of a bioenergetics model estimated that Westslope Cutthroat Trout represented approximately 2–30% of the biomass consumed by age-1–4 Northern Pike. Total Westslope Cutthroat Trout biomass consumed by Northern Pike (2008–2011 year-classes) across all seasons sampled was estimated to be 1,231 kg (95% CI = 723–2,396 kg), and the total number consumed was 5,641 (95% CI = 3,311–10,979). The highest occurrence of Westslope Cutthroat Trout in Northern Pike diets was observed during spring. Thus, reducing Northern Pike predation on Westslope Cutthroat Trout would be one tool worth considering for conserving Westslope Cutthroat Trout populations in Coeur d’Alene Lake.

Sustaining northern red oak forests: managing oak from regeneration to canopy dominance in mature stands

Treesearch

Daniel C. Dey; Gary W. Miller; John M. Kabrick

2008-01-01

Across the range of northern red oak, managers have problems sustaining current stocking of northern red oak in forests. Oak species are adapted to frequent stand disturbances that reduce the abundance of shade tolerant competitors and control fast-growing pioneer species. A widely recommended approach to regenerating northern red oak is to develop relatively large...

The Economic Impact of Ulster University on the Northern Ireland Economy. Higher Education in Focus

ERIC Educational Resources Information Center

Kelly, Ursula; McNicoll, Iain; White, James

2015-01-01

This study provides an analysis of the economic impact of Ulster University and its students on the Northern Ireland economy. With over 26,000 students, Ulster University is Northern Ireland's largest university in terms of student numbers. With its headquarters based at the Coleraine Campus, it has three more campuses in Northern Ireland: the…

50 CFR 648.62 - Northern Gulf of Maine (NGOM) scallop management area.

Code of Federal Regulations, 2011 CFR

2011-10-01

... 50 Wildlife and Fisheries 10 2011-10-01 2011-10-01 false Northern Gulf of Maine (NGOM) scallop... OCEANIC AND ATMOSPHERIC ADMINISTRATION, DEPARTMENT OF COMMERCE FISHERIES OF THE NORTHEASTERN UNITED STATES Management Measures for the Atlantic Sea Scallop Fishery § 648.62 Northern Gulf of Maine (NGOM) scallop...

Exposure to Community Violence and Political Socialization among Adolescents in Northern Ireland

ERIC Educational Resources Information Center

Shepherd, Linda

2007-01-01

This study evaluates the effects of adolescent exposure to cross-community violence, intense paramilitary operations, aggression, and intimidation in Northern Ireland. Using publicly available survey data gathered by agencies in Northern Ireland, the research examines the effects of exposure to political violence with focus upon the manner by…

78 FR 50405 - Amended Application for Presidential Permit; Northern Pass Transmission LLC

Federal Register 2010, 2011, 2012, 2013, 2014

2013-08-19

... project would adversely affect the operation of the U.S. electric power supply system under normal and... proposed project. Northern Pass is wholly owned by NU Transmission Ventures, Inc., a wholly-owned..., that would meet the needs of the Project.'' On July 1, 2013, Northern Pass submitted an amended...

40 CFR 408.110 - Applicability; description of the Northern shrimp processing in the contiguous States subcategory.

Code of Federal Regulations, 2011 CFR

2011-07-01

... Northern shrimp processing in the contiguous States subcategory. 408.110 Section 408.110 Protection of... SEAFOOD PROCESSING POINT SOURCE CATEGORY Northern Shrimp Processing in the Contiguous States Subcategory § 408.110 Applicability; description of the Northern shrimp processing in the contiguous States...

40 CFR 408.110 - Applicability; description of the Northern shrimp processing in the contiguous States subcategory.

Code of Federal Regulations, 2010 CFR

2010-07-01

... Northern shrimp processing in the contiguous States subcategory. 408.110 Section 408.110 Protection of... SEAFOOD PROCESSING POINT SOURCE CATEGORY Northern Shrimp Processing in the Contiguous States Subcategory § 408.110 Applicability; description of the Northern shrimp processing in the contiguous States...

Site classification for northern forest species

Treesearch

Willard H. Carmean

1977-01-01

Summarizes the extensive literature for northern forest species covering site index curves, site index species comparisons, growth intercepts, soil-site studies, plant indicators, physiographic site classifications, and soil survey studies. The advantages and disadvantages of each are discussed, and suggestions are made for future research using each of these methods....

Forests of the Northern United States

Treesearch

Stephen R. Shifley; Francisco X. Aguilar; Nianfu Song; Susan I. Stewart; David J. Nowak; Dale D. Gormanson; W. Keith Moser; Sherri Wormstead; Eric J. Greenfield

2012-01-01

Bounded by Maine, Maryland, Missouri, and Minnesota, the 20 Northern States have a larger population and a higher proportion of forest cover than other comparably sized U.S. regions. Forest-associated issues across the North include insect and disease pests, invasive species, forest management capacity, management standards, biodiversity, forest fragmentation, water...

Construction Services at Northern Arizona University.

ERIC Educational Resources Information Center

Van Dyke, Gary

Construction Services is an innovative response to a chronic construction-remodeling problem at Northern Arizona State University. It is an in-house facilities maintenance department designed to address a variety of needs: prevention of construction or remodeling done by individual staff or faculty members without regard for applicable codes;…