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At least 1,315 records · Page 73Linked to original sources
USGS2003

Population genetic structure of Santa Ynez rainbow trout – 2001 based on microsatellite and mtDNA analyses

Microsatellite allelic and mitochondrial DNA (mtDNA) haplotype diversity are analyzed in eight rainbow trout ( Oncorhynchus mykiss ) collections: two from tributaries flowing into the upper Santa Ynez River watershed at Gibraltar Reservoir (Camuesa and Gidney creeks); three from tributaries between Gibraltar and Jameson reservoirs (Fox, Blue Canyon, and Alder creeks); one from a tributary above Jameson Reservoir (Juncal Creek); Jameson Reservoir; and one from the mainstem Santa Ynez River above the Jameson Reservoir. Both analyses reveal a high degree of population structure. Thirteen microsatellite loci are amplified from 376 fish. Population pairwise comparisons show significant differences in allelic frequency among all populations with the exception of Juncal Creek and Jameson Reservoir (p = 0.4). Pairwise F st values range from 0.001 (Juncal Creek and Jameson Reservoir) to 0.17 (Camuesa and Juncal creeks) with an overall value of 0.021. Regression analyses (Slatkin 1993) supports an isolation-bydistance model in the five populations below Jameson Reservoir (intercept = 1.187, slope = -0.41, r2 = 0.67). A neighbor-joining bootstrap value of 100% (based on 2000 replicate trees) separates the populations sampled above and below Juncal Dam. Composite haplotypes from 321 fish generated using mtDNA sequence data (Dloop) reveal four previously described haplotypes (MYS1, MYS3, MYS5 and MYS8; Nielsen et al. 1994a), and one (MYS5) was found in all populations. Mean haplotype diversity is 0.48. Pairwise F st values from mtDNA range from -0.019 to 0.530 (0.177 over all populations) and are larger than those for microsatellites in 26 of 28 pairwise comparisons. In addition, the mtDNA and microsatellites provide contrasting evidence of the relationship of Fox and Alder creeks to the other six populations. Discrepancies between the two markers are likely due to the unique properties of the two marker types and their value in revealing historic (mtDNA) versus contemporary (microsatellites) genetic relationships. The contrasting results may indicate how relationships among the upper Santa Ynez River populations have changed since the installation of Juncal Dam. Comparisons of mtDNA haplotype frequencies from fish collected for this study with samples analyzed previously in JLN’s laboratory (1993) reveal significant differences in mtDNA haplotypes for Fox and Alder creeks. In the 2001 samples from this study, there is a loss of three haplotypes despite larger sample sizes. AMOVA analysis of what we term “upper” (Alder, Fox, Blue Canyon, Camuesa, Gidney creeks and the upper Santa Ynez mainstem) and “lower” (Hilton, Salsipuedes and the lower mainstem Santa Ynez River) Santa Ynez River populations (1993-2001) reveal that 11% of the variance in haplotypes is found between the upper and lower drainage. A comparison of the mtDNA data from this study with those available for southern California coastal and California hatchery O. mykiss populations yields F st values of 0.15 and 0.47, respectively. Differentiation of mtDNA haplotypes for population pairs of Santa Ynez River and hatchery fish show no significant differentiation between wild and at least one hatchery strain in Cachuma Reservoir, Hilton Creek, and the Lower Santa Ynez River.

California↗
USGS2020

Global status of trout and char: Conservation challenges in the twenty-first century

Freshwater ecosystems are among the most threatened ecosystems in the world (Richter et al. 1997; Strayer and Dudgeon 2010), and freshwater fishes may now be the most threatened group of vertebrates (Ricciardi and Rasmussen 1999; Vorosmarty et al. 2010; Darwall and Freyhof 2016). Of the 7,300 freshwater fish species globally assessed by the International Union for Conservation of Nature (IUCN, www.iucnredlist.org) in 2013, nearly one of every three species was threatened with extinction (Darwall and Freyhof 2016). Growing pressures from a multitude of direct and indirect human stressors (e.g., habitat loss and degradation, pollution, invasive species, overexploitation, diversion or alteration of biological flows, climate change, and others) threaten the persistence of many freshwater fish species and entire aquatic communities around the globe (Limburg et al. 2011). This pattern is particularly true for salmonid fishes (family Salmonidae, subfamily Salmoninae, belonging to the genera Oncorhynchus, Salvelinus, Salmo, Hucho, Parahucho, Brachymystax, and Salvethymus). Salmonids are globally-distributed, coldwater taxa with life-cycles restricted entirely to freshwater ecosystems (typically referred to as trout and char), but also Atlantic and Pacific salmon with more complex anadromous life-histories.

Book chapter↗
USGS2021

Understanding genetics for successful conservation and restoration of resilient Chesapeake Bay brook trout populations

Traditionally, fisheries management has focused on the abundance, distribution, and size structure of populations. Although these factors remain key aspects of management, a large and growing body of evidence highlights the importance of genetics in conserving wild populations, especially when populations are small and isolated (Frankham et al. 2017). Local adaptations are very common among fishes and help populations cope with specific conditions in their local environment (Fraser et al. 2011). The field of conservation genetics and genomics is highly technical and has advanced rapidly in recent years, offering a wealth of information to support brook trout conservation and restoration. A major impediment to successfully incorporating these advances into conservation outcomes is that most fisheries managers have only a basic understanding of fish genetics and its relevance to their management decisions.

Maryland, Virginia↗
USGS1990

Mass-marking of otoliths of lake trout sac fry by temperature manipulation

The otoliths of 676,000 sac fry of lake trout Salvelinus namaycush in 1986, and of 1,100,000 in 1987, were marked by daily manipulation of water temperature. The fish were stocked into Lake Huron in the spring. Otolith marks consisted of groups of daily growth rings accentuated into recognizable patterns by steadily raising and lowering the temperature about IOA?C (from a base of 1-4A?C) over 14h. In 1987, groups of marked and control fish were held for 6 months. The otoliths were removed from samples of the fish, embedded in epoxy, thin-sectioned by grinding in the sagittal plane, etched, and viewed by using a combination of a compound microscope (400-1000x) and a video enhancement system. One or more readable otolith sections were obtained from 39 of a sample of 40 fish. Three independent readers examined 41 otoliths for marks and correctly classified the otoliths, with accuracies of 85, 98,and 100%, as being from marked or unmarked fish. The exact number of rings in a recognizable pattern sometimes differed from the number of temperature cycles to which the fish were exposed. Counts of daily rings within groups of six rings varied less than counts within groups of three rings.

Book chapter↗
USGS1982

Habitat suitability index models: Cutthroat trout

Cutthroat trout, Salmo clarki, are a polytypic species consisting of several geographically distinct forms with a broad distribution and a great amount of genetic diversity (Hickman 1978; Behnke 1979). Behnke (1979) recognized 13 extant subspecies: Coastal cutthroat (S. c. clarki) in coastal streams from Prince William Sound, Alaska to the Eel Rlver in California; mountain cutthroat (~. ~. alpestris) in upper Columbia and F~Dser River drainages of British Columbia; west slope cutthroat (S. c. lewisi) in the upper Columbia, Salmon, Clearwater, South Saskatchewan and upper Missouri drainages of Montana and Idaho; an undescribed subspecies in the Alvord basin, Oregon; Lahonton cutthroat (S. c ..henshawi), Pauite cutthroat (S. c. seleniris), and an undescribed- subspecies in the Humboldt River drafnage of the Lahontan basin of Nevada and California; Yellowstone cutthroat (S. c. bouvieri) in the Yellowstone drainage of Wyoming and Montana and the Snake River drainage of Wyoming, Idaho, and Nevada; an undescribed subspecies (fine spotted) in the upper Snake River, Wyoming; Bonneville cutthroat (S. c. utah) in the Bonneville basin in Utah, Nevada, Idaho, and Wyoming; Colorado River cutthroat (~. ~. pleuriticus) in the Colorado River drainage in Wyoming, Utah, New Mexico, and Colorado; greenback cutthroat (S. c. stomias) in the South Platte and Arkansas River systems; and Rio Grande cutthroat (~. ~. virginalis) in the Rio Grande River drainage of Colorado and New Mexico. Many of these 13 subspecies are included on Federal or State endangered or threatened species lists. Temperature and chemical preferences, migration, and other ecological and life history attributes vary among cutthroat subspecies (Behnke 1979). Differences in growth rate (Carlander 1969; Scott and Crossman 1973; Behnke 1979) and food preferences have also been reported (Trojnar and Behnke 1974) between some subspecies.

FWS/OBS↗
USGS1984

Habitat Suitability Index Models: Rainbow trout

A review and synthesis of existing information were used to develop riverine and lacustrine habitat models for rainbow trout (Salmo gairdneri), a freshwater species. The models are scaled to produce an index of habitat suitability between 0 (unsuitable habitat) to 1 (optimally suitable habitat) for freshwater areas of the continental United States. Other habitat suitability models found in the literature are also included. Habitat suitability indexes (HSI's) are designed for use with the habitat evaluation procedures developed by the U.S. Fish and Wildlife Service. Also included are discussions of Suitability Index (SI) curves as used in the Instream Flow Incremental Methodology (IFIM) and SI curves available for an IFIM analysis of Fallfish habitat.

FWS/OBS↗
USGS1956

Biology of young lake trout (Salvelinus namaycush) in Lake Michigan

Experimental fishing with gill nets of 5 mesh sizes (2 3/8 to 3 inches) in Lake Michigan in 1930-32 yielded more than 16,000 young lake trout. Data are presented here on age, growth, length-weight relationship, abundance, geographical and bathymetric distribution, and other details of their biology.

Research Report↗
USGS1993

Chronic toxicity of Pydraul 50E to lake trout

Industrial phosphate esters, both triaryl and alkyl aryl phosphate esters, are used as fire resistant hydraulic fluids and as fire retardant plasticizers (Lapp 1976). Hydraulic fluids probably represent the largest contribution of phosphate ester compounds released into the environment. Lapp (1976) estimated that 65 to 70 percent of all phosphate ester hydraulic fluids were utilized in automotive and steel industries. He also estimated that 80 percent of the annual consumption of hydraulic fluids in 1976 was the result of leaks in industrial hydraulic systems. These data suggest phosphate esters are likely to be constituents of industrial effluents and, consequently, could be in point source discharges.

Bulletin of Environmental Contamination and Toxico↗
USGS2001

Behavioral dysfunctions correlate to altered physiology in rainbow trout (Oncorynchus mykiss) exposed to cholinesterase-inhibiting chemicals

We selected four metrics of swimming behavior (distance swam, speed, rate of turning, and tortuosity of path) and the commonly used biochemical marker, brain cholinesterase (ChE) activity, to assess (1) the sensitivity and reliability of behavior as a potential biomarker in monitoring work, (2) the potential for these endpoints to be used in automated monitoring, and (3) the linkage between behavior and its underlying biochemistry. Malathion-exposed fish exhibited large decreases in distance and speed and swam in a more linear path than control fish after 24 h exposure. By 96 h exposure, fish still swam slower and traveled less distance; fish fully recovered after 48 h in clean water. Diazinon-exposed fish exhibited decreases in distance, speed, and turning rate compared to controls. After 48 h recovery in clean water, fish exposed to diazinon had not recovered to control levels. The behavioral responses provided measures of neurotoxicity that were easily quantifiable by automated means, implying that the inclusion of behavior in monitoring programs can be successful. Furthermore, correlations between behavior and biochemical endpoints, such as ChE inhibition, suggest that this approach can provide a meaningful link between biochemistry and behavior and can provide useful information on toxicant impacts.

Archives of Environmental Contamination and Toxico↗
USGS2013

The impact of small irrigation diversion dams on the recent migration rates of steelhead and redband trout ( Oncorhynchus mykiss )

Barriers to migration are numerous in stream environments and can occur from anthropogenic activities (such as dams and culverts) or natural processes (such as log jams or dams constructed by beaver ( Castor canadensis )). Identification of barriers can be difficult when obstructions are temporary or incomplete providing passage periodically. We examine the effect of several small irrigation diversion dams on the recent migration rates of steelhead ( Oncorhynchus mykiss ) in three tributaries to the Methow River, Washington. The three basins had different recent migration patterns: Beaver Creek did not have any recent migration between sites, Libby Creek had two-way migration between sites and Gold Creek had downstream migration between sites. Sites with migration were significantly different from sites without migration in distance, number of obstructions, obstruction height to depth ratio and maximum stream gradient. When comparing the sites without migration in Beaver Creek to the sites with migration in Libby and Gold creeks, the number of obstructions was the only significant variable. Multinomial logistic regression identified obstruction height to depth ratio and maximum stream gradient as the best fitting model to predict the level of migration among sites. Small irrigation diversion dams were limiting population interactions in Beaver Creek and collectively blocking steelhead migration into the stream. Variables related to stream resistance (gradient, obstruction number and obstruction height to depth ratio) were better predictors of recent migration rates than distance, and can provide important insight into migration and population demographic processes in lotic species.

Washington↗