Life Sciences Commons^™

Lake Mead Prefertilization Study: Preliminary Nutrient Enhancement Studies In Lake Mead, Richard P. Axler, Larry J. Paulson, Patrick J. Sollberger, Donald H. Baepler, U.S. Bureau Of Reclamation

Publications (WR)

Studies conducted by the University of Nevada-Las Vegas (UNLV), the Nevada Department of Wildlife (NDOW), the Arizona Game and Fish Department (AGFD), The Nevada Division of Environmental Protection (NDEP), and the United States Bureau of Reclamation (USBR) have identified decreased algal production as a major factor involved in the decline of the Lake Mead sport fishery. Phosphorus-laden silt particles in the Colorado River have been sedimenting out in Lake Powell since the completion of Glen Canyon Dam 286 miles upstream in 1963. This sharp decrease in phosphorus loading to Lake Mead (>5000 tons per year) has resulted in decreased …

Effects Of A Dispersed And Undispersed Crude Oil On Mangroves, Seagrasses And Corals, T. G. Ballou, Richard E. Dodge, S. C. Hess, A. H. Knap, Thomas D. Sleeter

Marine & Environmental Sciences Faculty Reports

The primary objective of this study was to evaluate the application of dispersant to spilled oil as a means of reducing adverse environmental effects of oil spills in nearshore, tropical waters. The results of numerous laboratory and field studies have suggested that dispersants may play a useful role in reducing adverse impacts on sensitive and valued environments such as mangroves, seagrasses, and corals. However, the use of dispersants has not been allowed thus far in most situations because of a lack of direct experimental data on the various effects of dispersants and the environmental trade-offs presumed to occur as a …

Thermal Tolerances And Preferences Of Fishes Of The Virgin River System (Utah, Arizona, Nevada), James E. Deacon, Paul B. Schumann, Edward L. Stuenkel

Publications (WR)

Critical thermal maxima (CTM) and thermal preferenda of the common fishes of the Virgin River were examined. Differences in final temperature preferenda and CTM for species with low thermal lability (speckled dace, spinedace, roundtail chub) correspond well with differences in their distribution and abundance in the river. These species shifted their acute thermal preferences relatively little as acclimation temperature increased. For thermally labile species (woundfin, red shiner, desert sucker, and fiannehnouth sucker), the final preferendum is a less precise indicator of probable distribution. The woundfin, an endangered fish, has a high CTM (39.5 C at 25 C acclimation) and a …

Phytoplankton Dynamics In The Very Low Salinity Region Of The James River Estuary, Virginia, U.S.A., Changho Moon

OES Theses and Dissertations

During summer and autumn discharge from the James River estuary, Virginia, was less than 120 _m³sec^-1. There was a peak phytoplankton biomass in the very low salinity region (defined as the location where surface salinity measured less than 0.5$ 0/00) and this peak represented five to ten times greater biomass than adjacent waters. The peak biomass occurred independent of the tidal state and the location of nutrient inputs. It disappeared during winter and spring, and nutrient limitation was not responsible for the low phytoplankton biomass, indicating there were physical, not chemical controlling factors.

The peak biomass …

Molting In The Mature Female Blue Crab, Callinectes Sapidus, Rathbun, Kirk J. Havens

OES Theses and Dissertations

The present study examines the hypothesis that mature female blue crabs, Callinectes sapidus, do not have a terminal anecdysis. Induced molting via eyestalk ablation, size frequency distributions and gonad and limb regeneration indices from field collected animals are used as indicators of potential post maturity molts.

Eyestalk ablation of mature females resulted in ecdysis approximately 51 days after ablation, indicating a physiological ability if mature females to complete ecdysis. Analysis of size frequency distributions indicates two distinct shifts from smaller to larger females, one in early spring and a second in early fall. While migration of larger females into …

Benthic Invertebrates And Crayfish Of Lake Mead, Susan K. Peck, William L. Pratt, James E. Pollard, Larry J. Paulson, Donald H. Baepler

Publications (WR)

The objectives of this study were to:

1. Establish baseline densities of benthic invertebrates and relative abundance of crayfish in Lake Mead.

2. Evaluate the distributions of benthic organisms and crayfish in relation to existing habitat conditions and 1imnological characteristics of Lake Mead.

3. Measure seasonal changes in abundances of benthic organisms and crayfish in Lake Mead.

4. Compare observations of Procambarus clarkii life history in Lake Mead to reports from other aquatic systems.

5. Evaluate the importance of benthic organisms and crayfish as food sources for game fish in Lake Mead.

Estimation Of Food Limitation In Daphnia Pulex From Boulder Basin, Lake Mead, Thomas Mark Bartanen

Publications (WR)

In February, 1982 I began a year-long study to determine if growth and reproduction in Daphnia Pulex were limited by the amount of food available in Boulder Basin, Lake Mead. To determine this, I made monthly collections of Daphnia Pulex and natural lake seston from an already established station in Boulder Basin. I cultured the Daphnia Pulex under simulated field conditions in a flow-through feeding apparatus using four different food regimes; 1-natural lake seston filtered through 80 um mesh to remove other zooplankton, 2-lake seston (as above) with an enrichment of 10³ cells-ml^-1 of Chlamydomonas reinhardti, 3-lake …

Lake Mead Cover Enhancement Project, Jennifer Stevens Haley, Suzanne Leavitt, Larry Paulson, Donald H. Baepler

Publications (WR)

Ninety-three wildlife agencies were surveyed for information on their attempts to improve fish habitat. In addition, an annotated bibliography including over 100 summaries was completed on:

1. largemouth bass cover requirements and preferences,

2. use and effectiveness of artificial cover,

3. aquatic plant introduction and species requirements for germination and establishment,

4. terrestrial plant introduction and species requirements for germination and establishment, and

5. nutrient exchange between sediment, aquatic plants, and water.

A reconnaissance of existing terrestrial and aquatic vegetation was completed in June 1986 including the production of a video tape of the Nevada shoreline of Lake Mead.

Cover …

An Annual Study Of Phytoplankton Composition And Associated Environmental Conditions Of Lake Trashmore, Virginia Beach, Virginia, Seba B. Sheavly

Biological Sciences Theses & Dissertations

A 12 month study of Lake Trashmore was conducted on phytoplankton composition, inorganic nutrients and their seasonal associations. The dominant phytoplankton groups observed were diatoms, chlorophyceans and cyanobacteria. Phytoplankton assemblage patterns were coupled with pH, temperature, dissolved oxygen, nitrites and silicates. Diatoms dominated during periods of high nutrient concentrations, cooler temperatures and an unstable water column. Cyanobacteria forms dominated during periods of warmer temperatures, higher pH and decreased nitrogen and dissolved oxygen concentrations. A seasonal community shift occurred from cyanobacterial dominance to chlorophycean dominance when pH levels decreased. The lake is eutrophic based on indices of chlorophyll a concentrations, transparency …

Growth Potential Of Young Black Sea Bass, Centropristis Striata, In Artificial Environments, Joung Won Kim

OES Theses and Dissertations

The growth potential of the commercially important marine finfish, black sea bass (Centropristis striata), was examined for aquaculture under controlled conditions. The effect of food and body weight on growth was evaluated using juveniles and young black sea bass cultured with a natural diet and a commercial diet at various feeding levels.

Growth was affected by type of food, food consumption rate, and fish body weight. For fish having positive weight gain, absolute growth rate (gram/day) increased exponentially as food consumption rate (percent of body weight per day) and/or body weight increased. Instantaneous growth rate (percent of body weight per …

A Comparison Of Potential Fishing Methods Associated With Fish Aggregating Devices Off The Northeast Coast Of Puerto Rico, Alan M. Friedlander

OES Theses and Dissertations

Six fish aggregating devices (FADs) were deployed in June and monitored through December 1986. Emphasis was placed on trolling, live-bait handlining and longlining.

There was a significant difference (x2 = 7.815, pCoryphaena hippurus) which made up 64.2% of the catch.

Handlining at night around inshore buoys for one boat yielded 82.7 kg per trip. Pelagic fish comprised 83.9% of the catch, with the majority (81.4%) being kingfish (Scomberomorous cavalla). Catch rates were 50% higher and the species diversity much greater on the FADs versus control during experimental nightfishing, but the difference was not significant.

Longlining resulted in 3.4 …

Growth Rate Of Stony Corals Of Broward County, Florida: Effects From Past Beach Renourishment Projects, Richard E. Dodge, Broward County Erosion Prevention District Environmental Quality Control Board

Marine & Environmental Sciences Faculty Reports

The skeletal growth of hermatypic (reef-building) corals is a sensitive indicator of environmental conditions and perturbations. In particular, excessive sedimentation and turbidity act to depress coral growth because energy expenditure is required to remove sediment and because turbidity reduces light energy necessary for coral health and nutrition.

Normalized annual growth (linear skeletal extension) rates of Broward County, Florida reef-building corals were over 16 years (1985-1970). Star corals (Montastrea annularis) and brain corals (Diploria labyrinthiformis) were collected from each of four reef sites at two depths (9m and 18m). Collection areas were located in the vicinity of …

Las Vegas Wash And Lake Mead Proposed Water Quality Standards: Revisions And Rationale, State Of Nevada: Division Of Environmental Protection

Publications (WR)

Rationale of review and for proposed changes to the Nevada Pollution Control Regulations (NAC 445.1354, 445.1355, 445.1356, 455.1367, 445.1352, 445.1353, 445.1350, 445.1351) before the State Environmental Commission on June 23 and 24, 1987.

Raw Nutrient Data, Leanna Gail

Publications (WR)

Data collected at various stations around Lake Mead. Includes information about substances present in various water samples.

Comparison Of Littoral And Limnetic Zooplankton Communities Of Lake Mead, Patrick Joseph Sollberger

Publications (WR)

Microfaunal communities were studied in littoral (inshore) and limnetic (offshore) areas of the lower basin in Lake Mead to compare species composition and abundance between the two zones. Planktonic forms (zooplankton) dominated inshore and offshore habitats and the occurrence of littoral species was low. Therefore, high similarity in zooplankton species composition was found among all sampling stations. This was perhaps due to two main factors: (i) the physical and chemical environment among the stations were very similar and (ii) the lack of aquatic vegetation in the littoral zone reduced the occurrence of littoral species.

Although species composition did not vary …

Depth-Controlled Modified Combine For Direct Drilling And Lupin Row Spacing., R. Belford, G Reithmuller

Experimental Summaries - Plant Research

Trial 87WH52, (86M56)

Depth-controlled modified combine for direct drilling.

To compare soil penetration resistance, crop growth, water use, nutrient uptake and root development of wheat 1) sown after scarifying; 2) direct drilled with a combine; 3) direct drilled with the depth-controlled modified combine with loosening ties at 5, 9 or 13 cm; or 4) sown after deep ripping with an Agrowplow to 13 or 30 cm.

Trial 87M82

Location: Merredin Research Station paddock T6 south.

Lupin row spacing

Rapeseed, Tillage., J. D. Warren, Brenda Shackley

Experimental Summaries - Plant Research

1. Rapeseed. Assessment of Early Maturing Brassica napus Lines 87KA74, 87LG42, Assessment of Early Flowering Brassica juncea Lines 87KA44, 87E41, 87LG38, 87KA44, 87LG38, Yield Performance of Traizine Resistant Rapeseed 87AL25, 87E40, 87KA42, 87KA42, 87LG37, 87MA32, Assessment of Short Statured B. napus lines 87AL26, 87KA43, 87MA33, Rapeseed Extension: Demonstration Trials 87ERS39, 87JE29, 87KA41, 87NA78. 2. Tillage. The effect of Gypsum, tillage and nitrogen on cereal yields in a continuous crop system 84KA28 The effect of Gypsum, tillage and nitrogen on cereal yields farm system with a medic component 87KA47 Pasture regeneration counts for tillage trials 77MT51, 77M56, 77WH88, 82M35, 85M67A, 86M56.

Evaluation Of New Pasture Legume Species In Terms Of Summer Feeding Value And Effects On Wool Production., S E. Flecker, C W. Thorn, J. B. Rowe, Tess Casson

Experimental Summaries - Plant Research

86KA71, Pasture legumes improve the feeding value of summer pastures in a mediterranean-type environment by maintaining the protein intake of grazing animals over the dry summer period, much of which comes from the ingestion of legume burr (A.D. Wilson and N.L. Hindley, 1968). Some of the most important species of pasture legumes to have been released commercially are Trifolium subterraneum (sub.clover), Medicago truncatula (barrel medic) and Medicago polymorpha (burr medic) (D.B. Purser, G.B. Taylor and W.J. Collins, 1987). What little information is available on the feeding value of these species suggests that barrel medic pod (H. Brownlee, 1973) and dry …

Trial 65sg5, I Rowland., W Hawkins

Experimental Summaries - Plant Research

Trial 65SG5. Location - Paddock H5 on Salmon Gum Research Station

Cleared in 1962, then cropped until the start of the trial in 1968. Two of the four blocks were sown to Cyprus Barrel medic which is topdressed with superphosphate. The other two blocks regenerate volunteer pasture which is not topdressed. In 1984 all pasture plots were sown to SERENA medic. This grew exceptionally well in 1984 and set a lot of seed. In 1987 field peas were introduced into 4 reps of an existing medic: crop rotation.

Trial 80na6, I Rowland., W Hawkins

Experimental Summaries - Plant Research

Trial 80NA6. Location - B. Harrington, 6 km west of Darkin.

Cleared 1962, cropped 1977 (oats), 1978 (oats and Lupins), pasture in 1979. Continuously cropped to cereals up to 1986, then changed to wheat after wheat, lupins or clover.

Agronomy Of Wheat Cultivars., W. K. Anderson, M. Seymour

Experimental Summaries - Plant Research

Location: Northam, Wongan Hills, East Beverley, Corrigin and Merredin.

Time of sowing x wheat cultivars, 87N07, 87N011, 87WH7, 87NA4, 87M11. Time of sowing x wheat cultivars.

Nitrogen rates x wheat cultivars, 87N05, 87N09, 87WH5, 87NA2, 87M9.

Seed rates x wheat cultivars, 87N06, 87N010, 87WH6, 8JNA3, 87M10.

Wheat cultivar factorial, 87N04, 87N08, 87WH4, 87NA1.

Tillage Investigations., R. J. Jarvis, L. G. Butcher, L. D.J. Smith

Experimental Summaries - Plant Research

77A16, red/brown sandy loam - York gum. 77WH17, yellow clayey-sand (Wongan loamy sand). 77M13, red sandy clay loam (Salmon Gum, Gimlet). 77Mt15, gravelly loamy sand/sandy loam - forest soil. 77A43 brown loamy sand/sandy loam - jam country. 77WH88, grey loamy sand over gravel at 50 cm - Elphin soil series – Mallee. 77M56, red sandy clay loam - salmon gum, Gimlet. 82M35, Loamy sand/sandy loam – Mallee. 77E52, fine white sand over gravel at 40 cm. 85SG28, grey-brown calcareous Earth - Kumarl – SGRS. 84M064, heavy land management systems - medium rainfall area. 84M063, heavy land management systems - ne …

Harvest Index Of Lupins, Low Tillering Cereals And Maturity By Sowing Date In Cereals., R. J. Delane, J. C. Mathews, J. A. Bright

Experimental Summaries - Plant Research

Trial 87GE21

Effect of plant density on branching, pod setting and yield development of lupins.

Location: Geraldton

To determine the influence of plant density and between-plant variability in vegetative growth on the branching, pod setting and yield development of lupins

Trial 87GE9

Chemicals to control vegetative growth and improve pod set in lupins.

Location: West Binnu

To examine the effect of a number of growth regulating chemicals on the branching, pod setting and yield of lupins under conditions favoring high biomass production.

Trial 87GE19

Chemicals to control vegetative growth and improve pod set in lupins.

Location: Nabawa

To examine the …

Crop Agronomy., S. Porritt

Experimental Summaries - Plant Research

Seeding machinery for stubble retention in lupin cereal rotations, 85LG21, and 85LG22. Dynamic Lifter (cereal mix) fertiliser evaluation, 86LG2. Cultural systems for lupin: wheat rotations on water repellent soils, 87ES2. Stubble retention and Rovral for brownspot control in lupins, 87M66. Straw length Effects on wheat growth on red-brown earths, 87M70. Row spacing and stubble retention effects on wheat growth on red-brown earths, 87M71. Nitrogen fertiliser for wheat production after volunteer pasture or sub clover-based pasture, 87ME73 and 87ME74. Effect of seeding rate and sowing depth on lupin establishment, 87ME75. Time of seeding various wheat varieties, 87WE76.

Experiments On Grain Yield In A Range Of Old And Modern Wheat Varieties., K. H.M. Siddique, D. Tennant, R. K. Belford, M. W. Perry, L. Mclaughlin, A. R. Thompson

Experimental Summaries - Plant Research

Growth, yield, water use and water use efficiency of old and modern wheat varieties in a mediterranean type environment, 87M17 and 87WH14. Ear and stem dry matter at anthesis and grain yield in a range of wheat varieties, 87M18.

Field Pea Agronomy., I. A. Pritchard, G. Cooper, D. Dodge

Experimental Summaries - Plant Research

Field peas sowing rates, 87A31. Field peas time of sowing, 87A32. Field peas factional agronomy, 87A33. Field pea sowing rates, 87N092. Field peas time of sowing, 87N093. field peas - factorial agronomy, 87N094.

Wheat Experimental Results, S. P. Loss

Experimental Summaries - Plant Research

The development of wheat relative to frost susceptibility, 87NA10. Optimum flowering times of wheat, 87NA11 and 87WH8. Grain growth and development of a historical set of wheats.

High Input Barley Production Systems In The High Rainfall Zone., G. J. Parlevliet

Experimental Summaries - Plant Research

Barley systems in the high rainfall zone effect of nitrogen fungicides and seeding rate on barley yield, 87BR2.

Long Season Wheat, W. R. Smith, K. Anderson

Experimental Summaries - Plant Research

Agronomy of long season wheats, 87AL9, 87AL10, 87ES3, 87ES4, 87JE2, 87JE3, 87MT8, 87MT9 and 87NA9. Septoria control in long season wheat, 87E4 and 87MT10. Nitrogen response by long season wheat, 87ES5 and 87JE4. Phenology of long season wheats, 87E5 and 87MT11.

Disease And Insect Resistance; Murex Medic Evaluation; Legume Species Phasic Development, D J. Gillespie

Experimental Summaries - Plant Research

A summary of the performance of the control varieties (four replications) is shown in Table 3. A summary of the root rot ratings for some varieties showing a range of root rot susceptibility to all four pathogens is given in Table 4. Plant weights were recorded for all varieties tested against the three pathogens in the Western Australian experiments. Results for 12 of the 60 varieties are shown in Table 5. Murex medic evaluation. 86MT56 (Mount Barker), Gravelly loam pH 5.2 (water). 86NA46 (Darken) Loamy sand pH 5.4 86M037 (Regans Ford) Fine red sand pH 5.8 All sites were established …