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There were two studies involved in the thesis research. In the first study, variation in the amount of adenohypophysis gonadotropins among 22 individual beef bulls were investigated. These bulls represented ...
Citation Citation
- Title:
- Gonadotropins in pituitaries of inbred and linecross beef bulls and effects of irradiation of mammalian pituitary glands on their ability to induce in vitro ovulation of frog ovaries
- Author:
- North, Warren Arthur
There were two studies involved in the thesis research. In the first study, variation in the amount of adenohypophysis gonadotropins among 22 individual beef bulls were investigated. These bulls represented four inbred lines, and six linecrosses. The bulls were raised in the Oregon State University purebred herd. The bulls were slaughtered at approximately 1000 pounds live weight. The pituitaries were removed, weighed, individually identified, sealed in glass vials, and frozen at -20°C. until needed for bioassay. Assay material was prepared by dissecting the anterior lobe from the other pituitary material and then crushing the adenohypophysis in a hand operated tissue grinder. Immature male and female mice were used to assay for gonadotropic potency. T-test values showed all bull pituitaries to contain a significant amont of both follicle stimulating hormone and luteinizing hormone when the pituitary-treated mice were compared with control mice. When the Hereford inbred lines of cattle were compared with one another no significant differences were found for gonadotropic potency. However, when the inbred Angus line was compared with each of the inbred Hereford lines, one of the inbred Hereford lines had significantly greater luteinizing hormone activity than the inbred Angus, and another inbred Hereford line had a significantly greater amount of follicle stimulating hormone activity than the inbred Angus. One of the linecrosses had significantly greater luteinizing hormone potency than all four inbred lines, and a different linecross had a significantly greater amount of follicle stimulating hormone potency than three of the four inbred lines. However, one inbred Hereford line had a significantly greater amount of luteinizing hormone than two of the Hereford linecrosses. A comparison of linecrosses showed many significant variations in one or the other gonadotropic potency. It was noted that wherever a significant difference existed, the greater potency for one or the other gonadotropin favored the linecross that had either a sire or dam of inbred Lionheart parentage. In the second study, effects of x-irradiation delivered at rates of 0, 1000, 2000, 3000, 4000, and 5000 r. to excised beef cattle, sheep, and rabbit pituitaries and their subsequent in vitro gonadotropic potency were investigated by use of grass frog ovarian fragments. The pituitary material was added to test tubes at levels of 150, 125, 100, 75, 50, 25, 10, 5, and 1 mg. per test tube. A modified (calcium free) Holtfreter solution was added to each test tube bringing the total volume to 10 ml. in each test tube. A grass frog ovarian fragment was placed in the incubation medium for 48 hours. Following incubation the number of released eggs were recorded. Origin of the ovarian fragments were identified as to ovary and position. Ovulation percentage was affected by the mammalian species from which the pituitaries came, the level of irradiation, and the amount of pituitary added to each culturing test tube. One hundred twenty-five mg. of non-irradiated sheep pituitary was able to induce a very slight amount of frog ovulation. However, sheep pituitary which received 2000 r. induced a much better ovulation percentage with 75 and 100 mg. pituitary material. When the beef cattle pituitary was delivered 1000 r. the ovulation rate remained slight, but ovulation occurred at the 100, 125, and 150 mg. levels. Irradiation levels greater than 2000 r. compared with the 2000 r. level had a depressing effect on ovulation rate. When comparing all rates of irradiation and all levels of rabbit pituitary, 25 mg. of rabbit pituitary which had received 3000 r. appeared best. At this point 40.3 percent ovulation occurred. An analysis of variance was run for all three mammalian species for the radiation rate, the pituitary level, ovary location of the frog, and position of the frog ovarian fragment. The analysis of variance showed that results are not influenced by either of the two ovaries nor by the position of the fragments. The results are significantly affected by the level of pituitary used and the amount of irradiation delivered to the mammalian pituitary.
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3072. [Article] Synchronization of estrus and subsequent conception rates in dairy heifers and rats following treatment with melengestrol acetate
Two experiments were conducted to study the effects of melengestrol acetate (MGA) on inhibition of estrus, post-treatment conception rates in heifers and rats, and MGA given during gestation on the reproductive ...Citation Citation
- Title:
- Synchronization of estrus and subsequent conception rates in dairy heifers and rats following treatment with melengestrol acetate
- Author:
- Chakraborty, Prabir Kumar, 1936-
Two experiments were conducted to study the effects of melengestrol acetate (MGA) on inhibition of estrus, post-treatment conception rates in heifers and rats, and MGA given during gestation on the reproductive performance in rats. MGA was administered orally to Holstein heifers and by subcutaneous injection to Sprague- Dawley rats. Twenty-four Holstein heifers (Experiment 1) were used in the study and each animal in the treatment group (12 heifers) received 1.0 mg. of MGA daily for 14 consecutive days. The treatment was initiated irrespective of the stage of the estrous cycle. Following withdrawal of treatment, one-half of the animals from each of the control and treatment groups were inseminated twice at the first post-treatment estrus at approximately 12-hour intervals, the other half received single inseminations. Conception rates were based on pregnancy diagnosis at 45 or more days following the last service. Estrus was inhibited during the period of treatment in all animals in the treatment group. Withdrawal of treatment resulted in an effective synchronization of estrus and ovulation,and 83.3% of the treated animals were in heat within a 48-hour period. The difference between the number of MGA treated animals showing estrus within 3-6 days following treatment withdrawal and the number of control animals in heat during the corresponding period of time, was highly significant (P < 0.005). Treatment resulted in a significantly (P < 0.05) lower conception at the first post-treatment insemination for the treatment group compared to that of the controls (8.33 vs. 58.33 %). No significant difference in conception rates was observed between single and double inseminations at the first estrus following treatment withdrawal. Conception rate for the treatment group at the second estrus following treatment (54.54%) was similar to that of the control animals at the first estrus following cessation of treatment (58.33%). Although an equal number of animals from each group conceived following two or more services, the average number of services per conception for the treatment group (2.64) was significantly higher (P < 0.05) than that for the control group (1.54). Forty-eight sexually mature Sprague-Dawley female rats with body weights ranging from 225 to 260 gm. were used in the rat study (Experiment 2). The animals were assigned at random to three treatment groups. Two of the groups received an initial daily treatment of 0.01 mg. and 0.10 mg. of MGA (in 0.1 ml. of propylene glycol) for seven days, respectively. The control group received 0.10 ml. of propylene glycol only, for the same duration. Following withdrawal of treatment, the animals were placed in breeding cages and allowed to mate during a breeding period of ten days, each cage contained four female and two male rats. Starting on day 7 of pregnancy, one-half of the animals from each group were injected daily with 0.10 mg. of MGA for 14 consecutive days. Cyclic changes in the vaginal cytology was not inhibited in control animals and the group of animals receiving 0.01 mg. of MGA daily during the treatment period. Inhibition of cyclic changes during the period of treatment in all animals receiving daily injections of 0.10 mg. of MGA were observed. The animals in this group showed estrus on an average of 4.46 days following withdrawal of treatment. No significant differences in conception rates among the groups were detected following a breeding period of ten days. Analysis of data on growth response in the dams and their reproductive performance did not indicate any significant interaction between initial and post-breeding treatments. Post-breeding treatment resulted in significant (P < 0.01) depressing effects in mean weight gains during experimentation and an increase in mean gestation length as compared to controls. Animals receiving treatment during gestation also had a significantly lower (P < 0.05) number of pups per litter and a significantly lower (P < 0.01) mean litter weight. Pups from mothers receiving treatment during gestation had significantly lower (P < 0.01) birth weights and also registered a significantly higher (P < 0.01) percent mortality compared to controls.
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3073. [Article] Variation in the timing of coho salmon (Oncorhynchus kisutch) migration and spawning relative to river discharge and temperature
Coho salmon (Oncorhynchus kisutch) migration and spawning are unique components of the salmon life cycle because they require synchrony of behavior with other individuals as well as with acceptable fluvial ...Citation Citation
- Title:
- Variation in the timing of coho salmon (Oncorhynchus kisutch) migration and spawning relative to river discharge and temperature
- Author:
- LovellFord, Rachel
Coho salmon (Oncorhynchus kisutch) migration and spawning are unique components of the salmon life cycle because they require synchrony of behavior with other individuals as well as with acceptable fluvial conditions. As with other organisms that exhibit group mating behavior, it is likely that environmental cues trigger coho salmon movement to spawning grounds. These cues may also provide usable habitat for migration and spawning. River discharge, temperature, and length of day have long been assumed to be the environmental cues which trigger migration and spawning of coho salmon as coho return within the same season each year to spawn. Hatchery studies have also shown that the timing of reproductive behavior is heritable. If this heritability is determined by the fluvial conditions of the spawning grounds, then a predictable relationship should exist between reproductive behavior and the hydrologic and thermal regimes. Surprisingly, no defensible correlations between discharge thresholds and spawning or migrating activity have been identified for naturally reproducing coho salmon. Thermal, velocity, and depth limitations have been identified for coho salmon, but these values have not been examined in combination or within the context of a hydrologic and thermal regime. This study compares interannual patterns in the timing of coho mid-river migration in the North Umqua (180 km up river from the estuary) and the initiation of spawn timing in the Smith River basins (Oregon) with river discharge and water temperature data to ascertain whether these behaviors are driven by fluvial conditions. Additionally, we used this data to identify the window over which most migration and spawning takes place in our test systems. On the North Umpqua, coho salmon mid-river migration initiated (first 5% of migrants) after summer peak temperatures and following a threshold average daily temperature of 18 C°, but before fall storm events occurred. In most years, approximately 75% of the migrating coho salmon have moved past the Winchester Dam before fall storms initiated and when discharge remained less than the 11 year average for the month of November, more similar to summer than winter flow levels. Additionally, characteristic lengths and numbers of peaks within the distribution of annual migrations were attributable to the generational cohort that the migration belonged to despite the similarity in population size across all years. These patterns in the distribution of generational cohorts suggest an inherited timing response as well as highlight cohorts which may contain diminished sub-populations. The initiation of coho salmon spawning appears limited both by a thermal threshold of 12 C° in all basins, as well as by a minimal discharge threshold, which is unique to each stream. Continued spawning activity occurs as discharge remains elevated from fall levels. It is also notable that there was no statistical difference in the date of the initiation of spawning within each basin in a given year or across years at a given site. Together, these studies highlight the important role that the coho salmon genome plays in reproductive timing as well as the ways that fluvial thresholds limit reproductive behavior in time. Coho have survived because of their genome has been resilient when faced with environmental change. Future work should consider variability in fluvial conditions relative to coho salmon phenotypic plasticity over time. Coho salmon phenotypic plasticity will determine whether the rate of change of the hydrologic and thermal regimes important to coho salmon survival outpaces the coho’s ability to adapt. This study contributed to this future work by establishing baseline relationships between the behavior of a threatened species and measurable environmental thresholds.
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3074. [Article] Estimates of combining abilities, heterotic effects and phenotypic correlations among in-bred lines of beef cattle and their line-crosses
The investigations were based on a complete diallel cross among three inbred lines of Hereford cattle. Records of Angus calves born during the same period were used to obtain more accurate estimates of ...Citation Citation
- Title:
- Estimates of combining abilities, heterotic effects and phenotypic correlations among in-bred lines of beef cattle and their line-crosses
- Author:
- Humes, Paul Edwin
The investigations were based on a complete diallel cross among three inbred lines of Hereford cattle. Records of Angus calves born during the same period were used to obtain more accurate estimates of environmental effects and to determine breed differences among the various traits included in the study. Estimates of general combining ability, specific combining ability and reciprocal effects were obtained. In addition, heterotic estimates of the linecross calves were determined as well as phenotypic correlations among all the performance traits, blood constituents, carcass traits, organoleptic measurements and endocrine gland weights. General and specific combining ability effects were either small or nonexistent for all of the preweaning traits of the males except conformation score at 227 kg. Among the females, significant general combining ability effects were detected for preweaning ADG, age at 227 kg. and condition score at 227 kg. Specific combining ability effects were nonsignificant among both sexes except for birth weights of the 2 X 3 and 3 X 2 cross females. Angus calves were smaller at birth, had higher preweaning gains, were younger at 227 kg. and had higher conformation and condition scores at weaning than the Hereford calves. A significant heterotic effect was detected for percent stillbirths with the linecross calves showing more vigor and fewer dead at birth. The Angus exceeded the Herefords in percent calves born and weaned (P < .01). All other preweaning and weaning traits did not exhibit overall linecross superiority likely as a result of the low milk production of the inbred dams. Angus calves were lower in postweaning rate and efficiency of gain, higher in conformation and condition scores and younger at the end of the feed test than the Herefords. General combining ability effects were significant or highly significant for conformation and condition scores at the end of the feed test for both sexes. A significant general combining ability effect was detected for feed efficiency of the males. Specific combining ability effects were significant for postweaning ADG of males and females. Heterotic effects were significant for postweaning rate of gain and feed per unit gain among the females and for age at 363 kg. among the males. Heterosis for conformation and condition scores were not found for either sex. Angus calves had higher blood levels of amino acids and urea than Herefords. Amino acids and urea were higher in females than in males and increased with increasing age in both sexes. Creatinine levels in the blood were quite consistent between sexes and breeds. Differences in general combining ability, specific combining ability and heterosis were nonsignificant for all blood constituents at all weights. The Angus excelled the Herefords in components of carcass grade, thyroid gland weight and testicle weight, but Herefords excelled in loin-eye area and percent lean in the 12th rib. General combining ability effects were significant or highly significant for components of carcass grade, percent drip, tenderness, juiciness and thyroid gland weight. No specific combining ability differences were detected. Heterotic effects were important only for testicle weight of the 1 X 2 and 2 X1 cross males. For the entire study, line 1 excelled the other lines in general combining ability for most of the traits. Correlation coefficients indicated that compensatory effects for poor suckling gains occurred during the early part of the post-weaning period. Birth weight was highly associated with preweaning growth rates in Hereford females but was not associated with pre-weaning growth rates in the Angus females. The relationship between suckling gain and conformation and condition scores at all weights were important, but no relationship between postweaning rate of gain and conformation and condition scores were found. Less efficient animals had higher blood levels of amino acids and larger amounts of fat in the carcasses. Conformation scores of the live animals were positively associated with carcass conformation, marbling, carcass grade and loin-eye area. This would indicate that muscling and carcass grade can be determined in the live animal.
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3075. [Article] Effect of certain blood enzymes and cellular constituents on growth in different genetic groups of sheep
In the present study, five breeds of ewes and their lambs were utilized. The breeds used were: Border Cheviot, Dorset Horn, Columbia, Suffolk and Willamette. In all, 31 ewes and 42 lambs were involved. The ...Citation Citation
- Title:
- Effect of certain blood enzymes and cellular constituents on growth in different genetic groups of sheep
- Author:
- Hutto, Daniel C.
In the present study, five breeds of ewes and their lambs were utilized. The breeds used were: Border Cheviot, Dorset Horn, Columbia, Suffolk and Willamette. In all, 31 ewes and 42 lambs were involved. The blood constituents which were determined for the ewes and lambs were: acid and alkaline phosphatase, hematocrit, hemoglobin and red and white blood cell numbers. Blood samples were taken and analyzed for each ewe and lamb, at two-week intervals, from the ninth or tenth day of lactation until approximately 94 days subsequent to lambing. At 100 days of age the lambs were scored for conformation and condition. Then the lambs were slaughtered and a sample of each carcass was cooked and submitted to a taste panel to obtain scores for tenderness and preference. Acid phosphatase levels of activity were approximately three times higher for lambs than for ewes at 10 days following lambing, and two times higher than the level for ewes for the entire testing period. Highly significant breed and period differences were observed for acid phosphatase levels in lambs. No breed differences for this enzyme were noted in ewes. Alkaline phosphatase levels of activity were higher in lambs than in ewes throughout the testing period. The average alkaline phosphatase value for lambs was 8.07 units compared to 2.96 units for the ewes. The average alkaline phosphatase value of lambs was highest at 10 days (11.00 units) and lowest at 80 days (6.36 units). Alkaline phosphatase levels were affected statistically (P<.01) by breed, sex and period, and ewe values were affected (P<.01) by breed, period and type of birth. Hematocrit values were only slightly higher in lambs than in ewes. At the first testing period the ewe values slightly exceeded the lamb values, but from the second period until the end of the test the lamb values were higher than the ewe values. Highly significant (P<.01) differences were found in ewes according to breed and period, whereas, lamb hematocrit values differed according to age of dam and period (P<.01). Hemoglobin levels followed a pattern similar to that found for hematocrit in lambs and ewes. Hemoglobin values for lambs and ewes reached the highest level at 24 days subsequent to lambing. Hemoglobin levels differed significantly (P<.01) in ewes according to breed and period, and in lambs according to period (P<.01) and sex (P<.05). Average red blood cell counts were higher for ewes (9,690,000) than for lambs (8,920,000) at 10 days subsequent to lambing, but by 94 days the average ewe red blood count was 8,440,000 compared to 10,680,000 for lambs. No breed differences could be found in red blood cell numbers for ewes or lambs. However, period and birth type differences were observed in lambs. White blood cell numbers were slightly more than one thousand lower for lambs than for ewes at 10 days following lambing. The lamb values were still lower than the ewe values at 24 days, but by 38 days the lamb values exceeded the ewe values. White blood cell numbers differed significantly (P<.01) for ewes according to breed and according to breed, birth type and period for lambs. A slight sex difference in white blood cell numbers was observed in lambs. The Columbia lambs had the lowest conformation and condition scores of any of the breeds. The Border Cheviots and the Willamettes had the highest scores for conformation and condition, respectively. However, the Columbias had the highest preference and tenderness scores of any of the breeds, while the Border Cheviots had the lowest preference and tenderness scores of any of the breeds. The breeds ranked in the following order for average weight gains of lambs: Willamettes, Suffolks, Columbias, Dorest Horns and Border Cheviots. Body weight of lambs differed significantly (P<.01) according to breed, birth type and period and (P<.05) according to sex. None of the variables studied seemed to be highly related to growth rate in lambs.
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The average size and age of chinook salmon (Oncorhynchus tshawytscha) caught in commercial fisheries along the Pacific Coast of North America have decreased substantially in this century. These declines ...
Citation Citation
- Title:
- Changes in size and age at maturity of Columbia River upriver bright fall chinook salmon (Oncorhynchus tshawytscha) : implications for stock fitness, commercial value, and management
- Author:
- Beaty, Roy E.
The average size and age of chinook salmon (Oncorhynchus tshawytscha) caught in commercial fisheries along the Pacific Coast of North America have decreased substantially in this century. These declines might be caused in part by changes in size and age at maturity within the stocks contributing to those fisheries. Upriver Brights (Brights), a stock of fall chinook salmon in the Columbia River, are one of those stocks. The purposes of this study were to (1) determine if average size and age at maturity of Brights have declined, (2) gain a better understanding of the factors that may contribute to such declines, and (3) describe potential consequences of these changes. Data from in-river fisheries suggest that the average weight of mature Brights returning to the Columbia River has decreased approximately 2.7 kg since the 1910s, an average rate of about 0.1 lb·yr⁻¹ (45 g·yr⁻¹ ). Most of the potential biases in these data tend to make this estimate conservative. Insufficient data were available to describe changes in average age at maturity. There are many potential causes for the decline in average size of mature Brights, including factors that affect very early life stages. Other researchers have determined that size at maturity appears to be highly influenced by inheritance, gender, and growth rate. I describe how maternal size can influence -- through time of spawning, choice of spawning site, and egg size -- the viability of the young, which carry the dam's genes for size. The size-related ability to produce viable offspring may have been changed by modifications in the environment. Very little is known about how changes in the natural environment for spawning, incubation, and rearing may have contributed to a decline in average size at maturity. Artificial propagation and rearing, such as at Priest Rapids Hatchery, seems to produce adult Brights that are smaller, younger, and more likely to be male than their natural counterparts. The net result is that the average hatchery fish may have only about 0.80 of the reproductive potential of the average natural fish. Changes in growth conditions in the ocean probably did not contribute to the change in size, although the ocean fisheries of Southeast Alaska and British Columbia appear to select, in the genetic sense, against large size and old age in Brights. Since 1978, in-river commercial fisheries have caught larger Brights and a higher proportion of females than are found in the escapement of the Priest Rapids Hatchery component of the stock, but the fisheries impact the two sexes differently by taking the larger males and the smaller females. The effect on the natural component may differ because of their apparently larger average size. I found no evidence that larger fish or more females were caught when 8-in. minimum restrictions were in effect on gillnet mesh size relative to periods when mesh size was not restricted. Impounding the mainstem during the last 50+ yr may have removed obstacles to migration (e.g., Celilo Falls) that selected for large size in Brights, but that hypothesis could not be tested. The perserverance of larger and older phenotypes in the Bright stock suggests that countervailing selection -- perhaps during spawning, incubation, and/or early rearing -- may have resisted the effects of a century of size- and age-selective fisheries. That resistance, however, may reduce the productivity of the stock. Declines in average size and age at maturity can have undesireable consequences. Lower average size means less biomass landed and lower commercial value. Lower average fecundity and a diminished ability to reproduce in some environments are also expected. Loss of size and age classes may reduce the ability of the stock to adapt to environmental variations. These results are relevant to several management practices. A holistic approach to fishery management issues is necessary to avoid erroneous conclusions based on narrow perspectives. Measuring reproductive potential of the catch and escapement would be superior to the conventional practice of simply counting numbers of fish. Many aspects of artificial propagation can be improved, including broodstock aquisition, mating regimes, and rearing practices. Stock abundance is a major factor in determining the effect of many management practices on the stock. In general, fisheries managers must be mindful that they manage very complex natural systems.
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3077. [Article] Geochemistry of Plutonic Rocks of the Western Cascades, Washington & Oregon : Relationship to Crustal Segmentation and Ore Genesis
The volcanic (~45-10 Ma) and plutonic rocks (~37-12 Ma) comprising the Western Cascades extend from northernmost California to southern British Columbia and are ancestral to modern arc magmatism. The ancestral ...Citation Citation
- Title:
- Geochemistry of Plutonic Rocks of the Western Cascades, Washington & Oregon : Relationship to Crustal Segmentation and Ore Genesis
- Author:
- Utevsky, Elinor S.
The volcanic (~45-10 Ma) and plutonic rocks (~37-12 Ma) comprising the Western Cascades extend from northernmost California to southern British Columbia and are ancestral to modern arc magmatism. The ancestral arc hosts a series of small plutons that are locally associated with porphyry (Cu-Mo) and epithermal (Au) ore deposits. Three crustal segments identified by Schmidt et al. (2008, 2013) in the modern arc are potentially reflected in the geochemistry of the ancestral Cascades as well: Paleozoic-Mesozoic accreted terranes, metamorphic rocks, and granites to the north; thin Paleocene Siletzia oceanic crust of the Columbia Embayment in the center; and Paleozoic-Mesozoic ultramafic sheets and marine arc-related volcanic and sedimentary rocks of the Klamath Terrane to the south. Therefore, the Western Cascades of Washington and Oregon provide a field laboratory to examine the chemical compositions and ages of granitoid intrusions associated with a variety of magmatic-hydrothermal ore deposits, and to compare the compositions with the along-arc variation of the age, composition and thickness of the underlying crust. The majority of the 15 new zircon U-Pb ages reported in this study are 27 to 12 Ma with the exception of the ~37 Ma Snoqualmie North Fork intrusions of central WA. A total of 610 zircons were analyzed, of which 118 have ages older than the main population and are considered to be xenocrystic or inherited. The north segment contains the oldest (up to 67 Ma) and most continuous inherited population. The absence of inherited grains older than 67 Ma suggests that neither the North Fork nor White River districts overlie old crystalline crust, but instead overlie Paleocene-Eocene volcanics that are the likely source of inherited zircons. Districts of the Columbia segment have sparse inherited zircon populations (n = 38 of 350 total), ranging from 54 to 20 Ma. The dearth of inherited zircons in the center of the arc suggests limited contamination by a source no older than 55 Ma, likely the dominant Eocene sources of detrital zircon found within the Tyee Formation. Districts overlying the Klamath Terrane have slightly more substantial inherited zircon populations than districts overlying Siletzia but still decidedly few inherited grains (a total of 25 out of 85 grains analyzed, ranging from 44 to 19 Ma); these grains are likely sourced from similar contaminants to those underlying the central segment of the arc, instead of from accreted Mesozoic rocks of the Klamath Terrane. The hypabyssal plutonic rocks represent a small area (~1%) of exposures in the Western Cascades, and range in composition from diorites to granodiorites and minor granite. Fe-Ti oxides, where preserved, include magnetite and ilmenite in proportion of ~2:1, and together with presence of hornblende and biotite are suggestive of modest oxidation states of ~ ΔNNO of 0 to 1 (Carmichael & Nicholls, 1967). Abundant hornblende is observed in 31 of 36 available petrographic sections. Ba/Nb values are not obviously correlated with SiO₂ content from any given district, but tend to increase at any given SiO₂ content from north to south. Th/Ta ratios notably increase with SiO₂, and are lowest in the mid-latitude districts (North Santiam, Detroit Dam, Quartzville, and Blue River). While increased slab fluid could increase Ba relative to Nb, the greater abundance of Ba, Th, and Th/Ta southward at given SiO₂ are more consistent with an increased role of crustal contamination. Dy/Yb ratios decrease with increasing SiO₂ contents with the exception of the North Fork District. V/Sc ratios decrease with increasing SiO₂ with the exception of samples of the Spirit Lake Pluton, and slightly increase from south to north at any given SiO₂ content. Zircons in the Western Cascades plutonic rocks have characteristically large negative Eu anomalies (Eu/Eu* < 0.5) and small positive Ce anomalies, correlated with relatively reduced oxidation states and low water contents, even when directly associated with moderately economic porphyry Cu deposits. Although these magmas are sufficiently water-rich to abundantly crystallize and fractionate amphibole (at least 3 wt. % H₂O), it is evident that plagioclase likely crystallized early and was not suppressed by high water contents (> 3 wt. % H₂O). There is no evidence that Western Cascade magmas were strongly oxidized (> NNO +1). Although crustal thickness is poorly constrained in the north and south segments, it is evidently variable along-arc (and may thicken slightly to the south), but is likely relatively thin. I therefore suggest that crustal thickness and lithology substantially control ore potential within the Western Cascade Arc.
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Abstract -- The species Oncorhynchus mykiss expresses a complex array of life histories across much of its range as well as considerable geographic variation. Several subspecies have been proposed (Behnke ...
Citation Citation
- Title:
- Factors that Influence Evolutionary Significant Unit Boundaries and Status Assessment in a Highly Polymorphic Species, Oncorhynchus mykiss, in the Columbia Basin
Abstract -- The species Oncorhynchus mykiss expresses a complex array of life histories across much of its range as well as considerable geographic variation. Several subspecies have been proposed (Behnke 1992), although none of them are formally recognized. Two of the proposed subspecies in North America include both trout and steelhead life histories: O.m. irideus, or Coastal rainbow/steelhead, and O.m. gairdneri, or Inland redband/steelhead. A third subspecies that includes an anadromous life history occurs in Asia, while all other North American subspecies are entirely trout. In the Pacific Northwest, the boundary between the coastal and inland subspecies occurs in the Columbia Gorge, where the Columbia River cuts through the Cascade Mountain Range. The steelhead and trout life histories within these two subspecies are genetically more similar to each other than to fish with the same life history in the other subspecies, indicating that the different life histories within a geographic area share an evolutionary origin (Allendorf 1975). Recent molecular systematic surveys suggest that this proposed taxonomic model of North American 0. mykiss subspecies may be over simplified and inaccurate (Currens 1997, Busby et al. 1996, F. Utter, U. of Washington); however, it remains the available model until final revisions to the taxonomy are adopted. The NOAA Fisheries Service (NMFS) further divided 0. mykiss into multiple "Evolutionarily Significant Units" (ESUs)(Waples 1991, 56 FR 58612, Waples 1995) for listing consideration under the federal Endangered Species Act (ESA). The ESA considers "distinct" populations of taxonmnic species to be "species" eligible for legal protection (16 U.S.C. 1532[161). NMFS adopted the concept of ESUs to serve as distinct population segments in their ESA listing decisions, along with specific criteria for defining them. Evidence for whether or not rainbow trout and steelhead are in the same ESUs is presented in this report according to the criteria provided by NMFS policy (56 FR 58612). The U.S. Fish and Wildlife Service (USFWS) likewise recognizes "Distinct Population Segments" (DPSs) that may be listed under ESA. The agencies share jurisdiction over 0. mykiss for ESA decisions, with NMFS overseeing the anadromous steelhead and USFWS overseeing the freshwater trout. NMFS has described ESUs for all Northwest steelhead, whether they have been listed or not (Busby et al. 1996); however, the USFWS has not generally described DPSs for Northwest 0. mykiss trout. During the original coast-wide status review of steelhead conducted in the 1990s, the NMFS Biological Review Team concluded that, in general, 0. mykiss trout are part of steelhead ESUs in cases where the two forms are sympatric and have an opportunity to interbreed (Busby et al. 1996). The review team was less conclusive about whether trout above artificial barriers were part of the ESUs. Trout that are sympatric with steelhead were also included in the ESUs by NMFS in the final listing determinations, but they were not listed. The steelhead in five of the ESUs in the Pacific Northwest were listed, including the Lower Columbia (63 FR 13347), Willamette, Mid-Columbia (64 FR 14517), Upper Columbia and Snake ESUs (62 FR 43937), all of which are in the Columbia Basin. As a result of two recent court cases NMFS is now reexamming the biological relationship between trout and steelhead populations in the ESUs where steelhead are listed and is reassessing the extinction risk of the whole ESUs from the perspective of both life histories. First, the Hogan decision in Oregon concluded that the Services may describe distinct population segments for ESA listing, but once ESUs or DPSs are described, the Services cannot list only part of one of one of them (Alsea Valley Alliance v. Evans [161 F.Supp. 2d 1154, D. Oreg. 2001]). So if NMFS finds trout to be part of an ESU along with steelhead, the Service cannot assess the extinction risk of only the steelhead in the ESU or list only the steelhead. Second, lawsuits in California about nonanadromous 0. mykiss upstream of man-made barriers (mostly impassible dams) made a similar argument, stating that such populations are related to the steelhead populations below the barriers and should be included in the ESUs and listed (EDC v. Evans, SACV- 00-1212-AHS (EEA), United States District Court, C.D. California). The purpose of this report is to provide more detailed information about trout and steelhead in the Columbia Basin listed ESUs. This report will address two major issues. The first section provides information that will be used to review whether trout and steelhead populations are biologically part the same ESUs, as defined by NMFS criteria. The second section provides information that will be used to review the extinction risks of entire ESUs if trout are considered along with steelhead. A similar, separate report is being prepared for California ESUs where steelhead are listed.
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3079. [Article] Lower Snake River Compensation Plan; Oregon Spring Chinook Salmon Evaluation Studies - 2005 Annual Progress Report
Abstract -- This annual progress report summarizes spring Chinook salmon monitoring data for the Lower Snake River Compensation Plan (LSRCP) facilities in 2005. Also summarized are adult broodstock monitoring ...Citation Citation
- Title:
- Lower Snake River Compensation Plan; Oregon Spring Chinook Salmon Evaluation Studies - 2005 Annual Progress Report
Abstract -- This annual progress report summarizes spring Chinook salmon monitoring data for the Lower Snake River Compensation Plan (LSRCP) facilities in 2005. Also summarized are adult broodstock monitoring data collected in the Grande Ronde Basin by the Nez Perce Tribe (NPT) and the Confederated Tribes of the Umatilla Indian Reservation (CTUIR). The main objectives of this report are to document and evaluate spring Chinook salmon culture performance for hatchery programs and achievement of management objectives in the Imnaha and Grande Ronde river basins. These data are used to design culture practices to optimize egg-to-smolt survival rate, smolt quality, smolt-to-adult survival rate, and successful spawning in nature by hatcheryreared adults, as well as to provide information to adapt the programs to most effectively meet management objectives. This report provides information on rearing and release operations for the 2003 brood year of juvenile Chinook salmon smolts, the collection, spawning, and adult characteristics of adult Chinook salmon in the 2005 return year, and the collection of eggs for the 2005 brood year. Lower Snake River Compensation Plan (LSRCP) ODFW- Eastern Oregon Fish Research (EOFR)
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3080. [Article] Lower Snake River Compensation Plan; Oregon Spring Chinook Salmon Evaluation Studies - 2006 Annual Progress Report
Abstract -- This annual progress report summarizes spring Chinook salmon monitoring data for the Lower Snake River Compensation Plan (LSRCP) facilities in 2006. Also summarized are adult broodstock monitoring ...Citation Citation
- Title:
- Lower Snake River Compensation Plan; Oregon Spring Chinook Salmon Evaluation Studies - 2006 Annual Progress Report
Abstract -- This annual progress report summarizes spring Chinook salmon monitoring data for the Lower Snake River Compensation Plan (LSRCP) facilities in 2006. Also summarized are adult broodstock monitoring data collected in the Grande Ronde Basin by the Nez Perce Tribe (NPT) and the Confederated Tribes of the Umatilla Indian Reservation (CTUIR). The main objectives of this report are to document and evaluate spring Chinook salmon culture performance for hatchery programs and achievement of management objectives in the Imnaha and Grande Ronde river basins. These data are used to design culture practices to optimize egg-to-smolt survival rate, smolt quality, smolt-to-adult survival rate, and successful spawning in nature by hatcheryreared adults, as well as to provide information to adapt the programs to most effectively meet management objectives. This report provides information on rearing and release operations for the 2004 brood year of juvenile Chinook salmon smolts, the collection, spawning, and adult characteristics of adult Chinook salmon in the 2006 return year, and the collection of eggs for the 2006 brood year. Lower Snake River Compensation Plan (LSRCP) ODFW- Eastern Oregon Fish Research (EOFR)