Daily variation in feed consumption by channel catfish
Dewey L. Tackett, Ray R. Carter, K.O. Allen
1988, Progressive Fish-Culturist (50) 107-110
Daily feed consumption by 0.09‐lb channel catfish (Ictalurus punctatus) stocked at 50 and 75 lb offish per 0.25‐acre pond, and by 0.57‐lb channel catfish stocked at 100 and 200 lb offish per 0.25‐acre pond, was measured for 157 d. Demand feeders were used to determine feed consumption. Feed consumption routinely...
A note on the recent natural gradient tracer test at the Borden Site
R.L. Naff, T.-C. Jim Yeh, M.W. Kemblowski
1988, Water Resources Research (24) 2099-2103
The variance in particle position, a measure of dispersion, is reviewed in the context of certain models of flow in random porous media. Asymptotic results for a highly stratified medium and an isotropic medium are particularly highlighted. Results of the natural gradient tracer test at the Borden site are reviewed...
Semianalytical computation of path lines for finite-difference models
D.W. Pollock
1988, Ground Water (26) 743-750
A semianalytical particle tracking method was developed for use with velocities generated from block centered finite-difference ground-water flow models. The method is based on the assumption that each directional velocity component varies linearly within a grid cell in its own coordinate directions. This assumption allows...
Fractional-step method for two-dimensional estuarine transport
Jerad D. Bales, Edward R. Holley
1988, Conference Paper
The fractional-step method was used in this study to split the longitudinal advective transport term from the other terms in the two-dimensional, laterally-averaged equation for estuarine mass transport. The method of characteristics with spline interpolations was used to approximate the longitudinal advective transport. A general discussion of the fractional-step method,...
Manganese inhibition of microbial iron reduction in anaerobic sediments
Derek R. Lovley, Elizabeth J.P. Phillips
1988, Geomicrobiology Journal (6) 145-155
Potential mechanisms for the lack of Fe(II) accumulation in Mn(IV)‐con‐taining anaerobic sediments were investigated. The addition of Mn(IV) to sediments in which Fe(III) reduction was the terminal electron‐accepting process removed all the pore‐water Fe(II), completely inhibited net Fe(III) reduction, and stimulated Mn(IV) reduction. In a solution buffered at pH 7,...
Overview of the structure and geothermal potential of Newberry Volcano, Oregon
D.V. Fitterman
1988, Journal of Geophysical Research Solid Earth (93) 10059-10066
Evidence from a broad range of geological and geophysical investigations of Newberry Volcano in central Oregon suggests the presence of a small magma body beneath the summit caldera. Drilling has encountered temperatures indicative of a hydrothermal system above the hypothesized magma body. On the basis of hydrothermal mineralogy the temperature...
Riverine C, N, Si and P transport to the coastal ocean: An overview
David H. Peterson, Stephen W. Hager, Laurence E. Schemel, Daniel R. Cayan
1988, Book chapter, Coastal-offshore ecosystem interactions, Volume 22 of the series Lecture notes on coastal and estuarine studies
Terrestrial ecosystems cycle and recyle inorganic nutrients including a feedback to atmospheric dry deposition and precipitation (cf. Lewis et al., 1985). Each year, however, a small fraction per unit area of the atmosphere/plant/soil flux leaks from these land-based cycles via precipitation/runoff (Meybeck, 1982). These losses are, in general, unpreventable. Moreover,...
Control of nuisance populations of crayfish with traps and toxicants
T.D. Bills, L. L. Marking
1988, Progressive Fish-Culturist (50) 103-106
Crayfish have long been a nuisance in fishrearing ponds at fish hatcheries. The rusty crayfish (Orconectes rusticus) has displaced endemic species and caused serious declines of aquatic plants in some ponds and lakes in the midwestern USA. We attempted to evaluate the effect of intensive trapping on a crayfish population...
Causes of varied sediment gravity flow types on the Alsek Prodelta, northeast Gulf of Alaska
William C. Schwab, Homa J. Lee, Bruce F. Molnia
1988, Marine Geotechnology (7) 317-342
Slope failures and subsequent mass movements have been identified in Holocene glaciomarine sediment on declivities less than 1.3° on the Alsek prodelta, Gulf of Alaska. Isolated collapse features cover less than 10 percent of a nearshore sand deposit, in water depths less than 40 m. In contrast, sediment gravity flow...
Air encapsulation during infiltration
Jim Constantz, W.N. Herkelrath, F. Murphy
1988, Soil Science Society of America Journal (52) 10-16
A series of field and laboratory experiments were performed to measure the effects of air encapsulation within the soil's transmission zone upon several infiltration properties. In the field, infiltration rates were measured using a double-cap infiltrometer (DCI), and soil-water contents were measured using time-domain reflectometry (TDR). Before half of the...
Habitat islands and the equilibrium theory of island biogeography: testing some predictions
M. Brown, J.J. Dinsmore
1988, Oecologia (75) 426-429
Species-area data from a study of marsh birds are used to test five predictions generated by the equilibrium theory of island biogeography. Three predictions are supported: we found a significant species-area relationship, a non-zero level of turnover, and a variance-mean ratio of 0.5. One prediction is rejected: the extinction rates...
Environmental impacts and regulatory policy. Implications of spray disposal of dredged material in Louisiana wetlands
Donald R. Cahoon, J.H. Cowan Jr.
1988, Coastal Management (16) 341-362
The capabilities of a new wetland dredging technology were assessed along with associated newly developed state and federal regulatory policies to determine if policy expectations realistically match the technological achievement. Current regulatory practices require amelioration of spoil bank impacts upon abandonment of an oil/gas well, but this may not occur...
A double survey estimate for sighting probability of sea otters in California
James A. Estes, Ronald J. Jameson
1988, Journal of Wildlife Management (52) 70-76
We developed an estimator for the probability of sighting sea otters (Enhydra lutris) by shore- based counters, based on simultaneous double-surveys. We then estimated probability of sighting sea otters in California and evaluated the estimator's principal assumptions. The overall probability of sighting sea otters on 5 replicated double-surveys at each...
Post-epizootic surveys of waterfowl for duck plague (duck virus enteritis)
C. J. Brand, D. E. Docherty
1988, Avian Diseases (32) 722-730
Surviving birds from nine duck plague outbreaks in urban and confined waterfowl were sampled for duck plague (DP) virus and DP antibody during 1979-86. Duck plague virus was found in combined oral and cloacal swabs of birds from three outbreaks, and DP-neutralizing antibody was demonstrated in some birds from all...
Areal variation in recharge to and discharge from the Floridan aquifer system in Florida
Walter R. Aucott
1988, Water-Resources Investigations Report 88-4057
This report is a revision and update of existing recharge maps of the Floridan aquifer system to include quantitative information derived from Regional Aquifer Systems Analysis models as well as other recent information and also includes information on discharge from the system. The report represents predevelopment conditions with inset map...
Chemical characteristics of prairie lakes in south-central North Dakota--their potential for influencing use by fish and wildlife
G.A. Swanson, T. C. Winter, V. A. Adomaitis, James W. LaBaugh
1988, Technical Report 18
No abstract available....
Experimental oxygen isotope fractionation between siderite-water and phosphoric acid liberated CO2-siderite
W.W. Carothers, L.H. Adami, R.J. Rosenbauer
1988, Geochimica et Cosmochimica Acta (52) 2445-2450
The equilibrium fractionation of O isotopes between synthetic siderite and water has been measured at temperatures ranging from 33° to 197°C. The fractionation between siderite and water over this temperature range can be represented by the equation: 103 ln α = 3.13 × 106T−2 −...
High-resolution 40Ar 39Ar chronology of Oligocene volcanic rocks, San Juan Mountains, Colorado
M. A. Lanphere
1988, Geochimica et Cosmochimica Acta (52) 1425-1434
The central San Juan caldera complex consists of seven calderas from which eight major ash-flow tuffs were erupted during a period of intense volcanic activity that lasted for approximately 2 m.y. about 26–28 Ma. The analytical precision of conventional K-Ar dating in this time interval is not sufficient to unambiguously...
Statistical methods for investigating quiescence and other temporal seismicity patterns
M.V. Matthews, P.A. Reasenberg
1988, Pure and Applied Geophysics PAGEOPH (126) 357-372
We propose a statistical model and a technique for objective recognition of one of the most commonly cited seismicity patterns:microearthquake quiescence. We use a Poisson process model for seismicity and define a process with quiescence as one with a particular type of piece-wise constant intensity function. From this model, we...
The metal oxide fraction of pelagic sediment in the equatorial North Pacific Ocean: A source of metals in ferromanganese nodules
D.Z. Piper
1988, Geochimica et Cosmochimica Acta (52) 2127-2145
Pelagic sediment recovered at DOMES Site A in the equatorial North Pacific (151°W, 9° 15′N) consists of a surface homogeneous layer, approximately 10 cm thick, overlying a strongly mottled layer that is lighter in color. The radiolarian composition of both units is Quaternary. In areas where this sediment was only...
Isotopic evidence for organic matter oxidation by manganese reduction in the formation of stratiform manganese carbonate ore
P.M. Okita, J.B. Maynard, E.C. Spiker, E. R. Force
1988, Geochimica et Cosmochimica Acta (52) 2679-2685
Unlike other marine-sedimentary manganese ore deposits, which are largely composed of manganese oxides, the primary ore at Molango (Hidalgo State, Mexico) is exclusively manganese carbonate (rhodochrosite, Mn-calcite, kutnahorite). Stable isotope studies of the carbonates from Molango provide critical new information relevant to the controversy over syngenetic and diagenetic models of...
Integrated aeration systems
V. K. Dawson, L. L. Marking
1988, Progressive Fish-Culturist (50) 62-63
Abstract has not been submitted...
Foraging by northern fulmars (Fulmarus glacialis) at a nearshore, anticyclonic tidal eddy in the northern Bering Sea, Alaska
J. Christopher Haney
1988, Colonial Waterbirds (11) 318-321
Northern Fulmars (Fulmar glacialis) fed on ice-associated macrofauna (probably gammarid amphipods) and pinniped offal concentrated by convergent flow at an eddy boundary near Northwest Cape on St. Lawrence Island, Alaska. The eddy was anticyclonic, measured approximately 1.5 by 2.25 km, and was generated by nearshore streaming induced by the cape’s...
Use of muscovy duck embryo fibroblasts for the isolation of viruses from wild birds
D. E. Docherty, Paul G. Slota
1988, Journal of Tissue Culture Methods (11) 165-170
Techniques are described for the preparation, cryopreservation, and inoculation of Muscovy duck embryo cell cultures. The procedure yields a susceptible reproducible cell culture system for the isolation and cultivation of viruses from wild birds....
Feeding ecology of canvasbacks staging on Pool 7 of the Upper Mississippi River
C. E. Korschgen, L. S. George, W. L. Green
M.W. Weller, editor(s)
1988, Book chapter, Waterfowl in winter
Foods consumed by canvasback ducks (Aythya valisineria), food availability, and energetic relationships were studied on Navigation Pool 7 of the upper Mississippi River in 1978, 1979, and 1980. Canvasbacks fed primarily upon winter buds of American wildcelery (Vallisneria americana) and tubers of stiff arrowhead (Sagittaria rigida). In 1980, waterfowl consumed...
