Fish abundance and population stability in a reservoir tailwater and an unregulated headwater stream
K.E. Jacobs, W.D. Swink
1983, North American Journal of Fisheries Management (3) 395-402
Fish abundance and population stability were compared in the tailwater and in an unregulated tributary of Barren River Lake, a flood control reservoir in south central Kentucky. Fish abundance was greater in the tailwater near the dam and was dominated by three species common in the reservoir: gizzard shad (Dorosoma...
Some observations on the use of discriminant analysis in ecology
Byron K. Williams
1983, Ecology (64) 1283-1291
The application of discriminant analysis in ecological investigations is discussed. The appropriate statistical assumptions for discriminant are illustrated, and both classification and group separation approaches are outlined. Three assumptions that are crucial in ecological studies are discussed at length, and the consequences of their violation are developed. These assumptions are:...
Predicting eruptions at Mount St. Helens, June 1980 through December 1982
D. A. Swanson, T. J. Casadevall, D. Dzurisin, S. D. Malone, C. G. Newhall, C.S. Weaver
1983, Science (221) 1369-1376
Thirteen eruptions of Mount St. Helens between June 1980 and December 1982 were predicted tens of minutes to, more generally, a few hours in advance. The last seven of these eruptions, starting with that of mid-April 1981, were predicted between 3 days and 3 weeks in advance. Precursory seismicity, deformation...
Deformation monitoring at Mount St. Helens in 1981 and 1982
W.W. Chadwick Jr., D. A. Swanson, E.Y. Iwatsubo, C. C. Heliker, T.A. Leighley
1983, Science (221) 1378-1380
For several weeks before each eruption of Mount St. Helens in 1981 and 1982, viscous magma rising in the feeder conduit inflated the lava dome and shoved the crater floor laterally against the immobile crater walls, producing ground cracks and thrust faults. The rates of deformation accelerated before eruptions, and...
Eruption prediction aided by electronic tiltmeter data at Mount St. Helens
D. Dzurisin, J.A. Westphal, Daniel J. Johnson
1983, Science (221) 1381-1383
Telemetry from electronic tiltmeters in the crater at Mount St. Helens contributed to accurate predictions of all six effusive eruptions from June 1981 to August 1982. Tilting of the crater floor began several weeks before each eruption, accelerated sharply for several days, and then abruptly changed direction a few minutes...
Seismic precursors to the Mount St. Helens eruptions in 1981 and 1982
S. D. Malone, C. Boyko, C.S. Weaver
1983, Science (221) 1376-1378
Six categories of seismic events are recognized on the seismograms from stations in the vicinity of Mount St. Helens. Two types of high-frequency earthquakes occur near the volcano and under the volcano at depths of more than 4 kilometers. Medium- and low-frequency earthquakes occur at shallow depths (less than 3...
Petrologic monitoring of 1981 and 1982 eruptive products from Mount St. Helens
K. V. Cashman, J. E. Taggart
1983, Science (221) 1385-1387
New material from the dacite lava dome of Mount St. Helens, collected soon after the start of each successive extrusion, is subjected to rapid chemical and petrologic analysis. The crystallinity of the dacite lava produced in 1981 and 1982 is 38 to 42 percent, about 10 percent higher than for...
Gas emissions and the eruptions of Mount St. Helens through 1982
T. Casadevall, W. Rose, T. Gerlach, L. P. Greenland, J. Ewert, R. Wunderman, R. Symonds
1983, Science (221) 1383-1385
The monitoring of gas emissions from Mount St. Helens includes daily airborne measurements of sulfur dioxide in the volcanic plume and monthly sampling of gases from crater fumaroles. The composition of the fumarolic gases has changed slightly since 1980: the water content increased from 90 to 98 percent, and the...
Eruption-triggered avalanche, flood, and lahar at Mount St. Helens - Effects of winter snowpack
R. B. Waitt Jr., T.C. Pierson, N. S. MacLeod, R. J. Janda, B. Voight, R. T. Holcomb
1983, Science (221) 1394-1397
An explosive eruption of Mount St. Helens on 19 March 1982 had substantial impact beyond the vent because hot eruption products interacted with a thick snowpack. A blast of hot pumice, dome rocks, and gas dislodged crater-wall snow that avalanched through the crater and down the north flank. Snow in...
Deep earthquakes beneath Mount St. Helens: Evidence for magmatic gas transport?
C.S. Weaver, J.E. Zollweg, S. D. Malone
1983, Science (221) 1391-1394
Small-magnitude earthquakes began beneath Mount St. Helens 40 days before the eruption of 20 March 1982. Unlike earlier preeruption seismicity for this volcano, which had been limited to shallow events (less than 3 kilometers), many of these earthquakes were deep (between 5 and 11 kilometers). The location of these preeruptive...
Reproduction by the endangered cui-ui in the lower Truckee River
G.G. Scoppettone, Gary Wedemeyer, M. Coleman, H. Burge
1983, Transactions of the American Fisheries Society (112) 788-793
Adult spawning behavior and emigration of larvae of the endangered cui-ui Chasmistes cujus were studied in a natural side channel of the lower Truckee River. External radio-tags placed on eight apparently did not affect spawning behavior. Cui-uis spawned in clusters of two to seven fish; usually a single female was...
Results of an adaptive environmental assessment modeling workshop concerning potential impacts of drilling muds and cuttings on the marine environment
Gregor T. Auble, Austin K. Andrews, Richard A. Ellison, David B. Hamilton, Richard A. Johnson, James E. Roelle, David R. Marmorek
1983, Report
Drilling fluids or "muds" are essential components of modern drilling operations. They provide integrity for the well bore, a medium for removal of formation cuttings, and lubrication and cooling of the drill bit and pipe. The modeling workshop described in this report was conducted September 14-18, 1981 in Gulf Breeze,...
Opening of the Red Sea: Constraints from a palaeomagnetic study of the As Sarat volcanic field, south‐western Saudi Arabia
Karl S. Kellogg, R. L. Reynolds
1983, Geophysical Journal of the Royal Astronomical Society (74) 649-665
Four stratigraphic sections through alkali basalt flows of Oligocene to Miocene age (29‐24 Ma) in the As Sarat volcanic field, south‐western Saudi Arabia, were sampled for palaeomagnetic study. After systematic alternating‐field demagnetization, 42 magnetically acceptable flows (139 samples) yield a mean direction of magnetization of =355.3°, =15.2° (α=4.3°), which defines...
Vegetation characteristics important to common songbirds in east Texas
Richard N. Conner, James G. Dickson, Brian A. Locke, Charles A. Segelquist
1983, The Wilson Bulletin (95) 349-361
Multivariate studies of breeding bird communities have used principal component analysis (PCA) or several-group (three or more groups) discriminant function analysis (DFA) to ordinate bird species on vegetational continua (Cody 1968, James 1971, Whitmore 1975). In community studies, high resolution of habitat requirements for individual species is not always...
Rapid method for measuring rotenone in water at piscicidal concentrations
V. K. Dawson, P.D. Harman, D.P. Schultz, J. L. Allen
1983, Transactions of the American Fisheries Society (112) 725-727
A high‐performance liquid chromatography (HPLC) procedure that is rapid, specific, and sensitive (limit of detection <0.005 mg/liter) was developed for monitoring application and degradation rates of rotenone. For analysis, a water sample is buffered to pH 5 and injected through a Sep Pak(R) C18 disposable cartridge. The cartridge adsorbs and retains...
Feminization of channel catfish by oral administration of steroid sex hormones
C. A. Goudie, B.D. Redner, B.A. Simco, K. B. Davis
1983, Transactions of the American Fisheries Society (112) 670-672
Oral administration of 17‐β‐estradiol or 17‐α‐ethynyltestosterone to sexually undifferentiated channel catfish Ictaturus punctatus during the first 21 days after yolk‐sac absorption resulted in the production of 100% females. The androgen was effective at doses of 6 to 600 μg/g of feed, but not at 0.6 μg/g....
Bathyal ostracodes from the Florida-Hatteras slope, the Straits of Florida, and the Blake Plateau
Thomas M. Cronin
1983, Marine Micropaleontology (8) 89-119
Epibathyal ostracodes from the Florida-Hatteras slope, the Blake Plateau and the Straits of Florida were studied to determine the relationship of numerous genera and species to bottom-water environmental conditions such as dissolved oxygen and bottom-water temperatures. From a total of 100 samples, 44 samples evenly distributed between 200 and 1100...
Seedling establishment on a landslide site
Cliff R. Hupp
1983, Castanea (48) 89-98
Two landslide scars (slide tracks) were plot sampled one and two years after landsliding to determine plant species involved in ecesis. The study site is located in a blockfield cove on Massanutten Mountain, northern Virginia. Old growth forest, adjacent to the slide tracks, is composed primarily of hemlock (Tsuga canadensis)...
Density estimation of small-mammal populations using a trapping web and distance sampling methods
David R. Anderson, Kenneth P. Burnham, Gary C. White, David L. Otis
1983, Ecology (64) 674-680
Distance sampling methodology is adapted to enable animal density (number per unit of area) to be estimated from capture-recapture and removal data. A trapping web design provides the link between capture data and distance sampling theory. The estimator of density is D = Mt+1f(0), where Mt+1 is the...
Ages estimated from a diffusion equation model for scarp degradation
Steven M. Colman, Ken Watson
1983, Science (221) 263-265
The diffusion equation derived from the continuity equation for hillslopes is applied to scarp erosion in unconsolidated materials. Solutions to this equation allow direct calculation of the product of the rate coefficient and the age of the scarp from measurements of scarp morphology. Where the rate coefficient can be estimated...
Sulfur diagenesis in Everglades peat and origin of pyrite in coal
Z. S. Altschuler, M. M. Schnepfe, C.C. Silber, F.O. Simon
1983, Science (221) 221-227
The pattern of sulfur transformation in peat across the Everglades basin indicates that pyrite formation in organic-rich swamps depends on the use of organic oxysulfur compounds in dissimilatory respiration by sulfur-reducing bacteria. This paragenesis explains the primary distribution of sulfur compounds in low-sulfur coals and possibly in most coals and...
Multiple microtektite horizons in upper Eocene marine sediments: No evidence for mass extinctions
G. Keller, Steven L. D’Hondt, T.L. Vallier
1983, Science (221) 150-152
Microtektites have been recovered from three horizons in eight middle Eocene to middle Oligocene marine sediment sequences. Five of these occurrences are coeval and of latest Eocene age (37.5 to 38.0 million years ago); three are coeval and of early late Eocene age (38.5 to 39.5 million...
Cholinesterase inhibition of birds inhabiting wheat fields treated with methyl parathion and toxaphene
K. R. Niethammer, Thomas S. Baskett
1983, Archives of Environmental Contamination and Toxicology (12) 471-475
Red-winged blackbirds (Agelaius phoeniceus) and dickcissels (Spiza americana) inhabiting wheat fields treated with 0.67 kg AI/ha methyl parathion and 1.35 kg AI/ha toxaphene showed brain cholinesterase (ChE) inhibition compared with birds inhabiting untreated fields. Maximum inhibition occurred about five days after insecticide application. ChE activities again approached “normal” 10 days...
Effective record length for the T-year event
Gary D. Tasker
1983, Journal of Hydrology (64) 39-47
The effect of serial dependence on the reliability of an estimate of the T-yr. event is of importance in hydrology because design decisions are based upon the estimate. In this paper the reliability of estimates of the T-yr. event from two common distributions is given as a function of number of observations...
Concentrated nesting of mallards and gadwalls on Miller Lake Island, North Dakota
Harold F. Duebbert, John T. Lokemoen, David E. Sharp
1983, Journal of Wildlife Management (47) 729-740
Island-nesting mallards (Anas platyrhynchos) and gadwalls (A. strepera) were studied on a 4.5-ha island in 385-ha Miller Lake in northwestern North Dakota during 1976-80. During the 5-year study, 2,561 duck nests of 9 species were found on Island A located 180 m offshore; 59% were mallard and 34% were gadwall....
