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Articles 2641 - 2670 of 3170

Full-Text Articles in Animal Sciences

Red Kangaroos Can Set Back Range Regeneration, Andrew Mclaughlin Jan 1992

Red Kangaroos Can Set Back Range Regeneration, Andrew Mclaughlin

Journal of the Department of Agriculture, Western Australia, Series 4

After years of severe drought, stocking rates in Western Australia s arid rangelands have been kept low since the 1970s to allow native pastures to regenerate. As well, extensive re-seeding programs have started and sheep and cattle grazing on these areas has been restricted or eliminated. However, pasture regeneration in the rangelands can only succeed when grazing by all animals - sheep, cattle, kangaroos, goo.ts, camels, brumbies and donkeys - is controlled Many more red kangaroos roam throughout Western Australia's pastoral areas today than 20 years ago. The installation of windmills and troughs to water domestic livestock has allowed kangaroo …


Visual Feeding By Juvenile Bear Lake Sculpin, D. Neverman, Wayne A. Wurtsbaugh Jan 1992

Visual Feeding By Juvenile Bear Lake Sculpin, D. Neverman, Wayne A. Wurtsbaugh

Watershed Sciences Faculty Publications

Young-of-the-year Bear Lake sculpin Cottus extensus feed throughout the day on benthic invertebrates and cease feeding at night when they migrate to the metalimnion. We investigated their reliance on vision by conducting feeding trials at different light levels in the laboratory. Feeding rate reached a maximum at intermediate light levels (near 10^16 photons sm^–2 ss^–1; approximately 1 lux) but decreased as light intensity increased beyond this range. At this maximum rate, the fish fed nine times faster than they were able to feed in the dark, showing that young Bear Lake sculpin rely heavily upon vision to feed. The light …


Snake River Sockeye Salmon (Oncorhynchus Nerka) Habitat/Limnologic Research, Scott Spaulding, Wayne A. Wurtsbaugh, Shoshone-Bannock Tribe Jan 1992

Snake River Sockeye Salmon (Oncorhynchus Nerka) Habitat/Limnologic Research, Scott Spaulding, Wayne A. Wurtsbaugh, Shoshone-Bannock Tribe

Watershed Sciences Faculty Publications

This report outlines long-term planning and monitoring activities that occurred in 1991 and 1992 in the Stanley Basin Lakes of the upper Salmon River, Idaho for the purpose of sockeye salmon (Oncorhynchus nerka) recovery. Limnological monitoring and experimental sampling protocol, designed to establish a limnological baseline and to evaluate sockeye salmon production capability of the lakes, are present:ed. Also presented are recommended passage improvements for current fish passage barriers/impediments on migratory routes to the lakes. We initiated O. Nerka population evaluations for Redfish and Alturas lakes; this included population estimates of emerging kokanee fry entering each lake in the spring …


A Trophic Gradient Analysis Of Lake Powell During Spring Runnoff 1992, Wayne A. Wurtsbaugh, Clyde Lay, Darren Carlise, Corey Huxol, Craig Schaugaard, Beau Clements, David Beauchamp Jan 1992

A Trophic Gradient Analysis Of Lake Powell During Spring Runnoff 1992, Wayne A. Wurtsbaugh, Clyde Lay, Darren Carlise, Corey Huxol, Craig Schaugaard, Beau Clements, David Beauchamp

Watershed Sciences Faculty Publications

Between 26 April and 2 May 1992, students in a utah state university aquatic ecology class visited Lake Powell to do a study of trophic gradients of the reservoir. The main axis of the reservoir was surveyed, as well as less detailed analyses of Moki and Escalante Canyons. The work was conducted in collaboration with personnel from the u.s. Bureau of Reclamation headed by Bill Vernieu, and from the u.s. Geological Survey (Dick Marzolf). Some of their data appear in the physical-chemical section of this report.

Each student was responsible for compiling a report on one of the following specific …


Lake Trout Spawning In Lake Tahoe: Egg Incubation In Deepwater Macrophyte Beds, D. A. Beauchamp, B. C. Allen, R. C. Richards, Wayne A. Wurtsbaugh, C. R. Goldman Jan 1992

Lake Trout Spawning In Lake Tahoe: Egg Incubation In Deepwater Macrophyte Beds, D. A. Beauchamp, B. C. Allen, R. C. Richards, Wayne A. Wurtsbaugh, C. R. Goldman

Watershed Sciences Faculty Publications

Although most populations of lake trout Salvelinus namaycush spawn over rocky shoals, use of these substrates by lake trout has not yet been found in Lake Tahoe. Large cobble substrate exists at depths less than 20 m, and steep, fractured, rocky substrate can be found in isolated areas from the surface down to at least 100 m, but no evidence of spawning activity in these areas has been found. Instead, at least a portion of the population spawns on deepwater mounds (40–60 m deep) over beds of the macrophyte Chara delicatula. This is the first known report of lake trout …


Population Status And Characteristics Of Macrhybopsis Gelida, Platygobio Gracilis And Rhinichthys Cataractae In The Missouri River Basin, Selena J. Werdon Jan 1992

Population Status And Characteristics Of Macrhybopsis Gelida, Platygobio Gracilis And Rhinichthys Cataractae In The Missouri River Basin, Selena J. Werdon

Electronic Theses and Dissertations

Few sturgeon chub (Macrhybopsis gelida: Cyprinidae) have been collected in the last decade, therefore their status, habitat selection and morphology were investigated at 172 previous collection sites. Data on two ecologically similar species, Platygobio gracilis and Rhinichthys cataractae, were also collected. Macrhvbopsis gelida were collected at 28 sites on the Powder River (n = 158) in Wyoming and Montana, and at one site on the Yellowstone River (n = 1) in Montana. Age-I, Age-II and Age-III M. gelida were collected. Specimens were 37 to 95 mm in total length. Macrhvbopsis gelida were ripe in mid-June, at water temperatures of 18.3-22. …


A Study Of The Summer Steelhead, Oncorhynchus Mykiss In Several Intermittent Tributaries Of The Satus Creek Basin, Washington, Joel Denney Hubble Jan 1992

A Study Of The Summer Steelhead, Oncorhynchus Mykiss In Several Intermittent Tributaries Of The Satus Creek Basin, Washington, Joel Denney Hubble

All Master's Theses

The summer steelhead, Oncorhynchus mykiss population was studied in three intermittent tributaries in the Satus Creek Basin. There was a strong tendency for post emergent fry, resulting from redds located in intermittent reaches to move downstream. However, survival to perennial flow conditions was very low. Steelhead production in Dry Creek appears to be lower than in Logy Creek, because of elevated water temperatures and minimal spring and summer stream flow.


Sea-Surface Temperature Related Fisheries And Resource Markets, Jeffrey Michael Rasinski Jan 1992

Sea-Surface Temperature Related Fisheries And Resource Markets, Jeffrey Michael Rasinski

Marine Affairs Theses and Major Papers

This thesis addresses the potential application of sea-surface temperature (SST) data to economic resource markets. It considers the revolution in technology and the accessibility of timely, accurate SST observations for resource markets. Specifically, it addresses issues related to pelagic fisheries and the fish meal industry. The thesis presents a discussion and overview of the upwelling ecosystem of Peru and the Peruvian anchovy (Engraulis ringens) including quantitative analysis and forecasts for the fishery and fish meal prices. This analysis is used to demonstrate the commercial application and relationship between SST and related resource markets. The thesis establishes a bioeconomic statistical model …


State Of The Fisheries Report 1991, Fisheries Department Of Western Australia Dec 1991

State Of The Fisheries Report 1991, Fisheries Department Of Western Australia

Status Reports of the Fisheries and Aquatic Resources

The State of the Fisheries is published annually by the Fisheries Department as part of the statutory reporting process required under the Fisheries Act. This report covers developments and production in the State's fisheries up to the end of December 1991. Full details of the department's operations for this period are published separately in the department's annual reports for the financial years ending June 1991 and 1992. Figures provided in the tables are derived from catch returns completed by fishermen which are processed by the Australian Bureau of Statistics up to June 1991. Other information provided in the text comes …


A Review Of Plant Introductions To The Kimberley 1955 To 1987, R Mccartney Nov 1991

A Review Of Plant Introductions To The Kimberley 1955 To 1987, R Mccartney

Grain and other field crops published reports

This report summarizes the work done by the Department of Agriculture, Western Australia, in the west and north Kimberley in introducing plant species during 1955-1987.

For the purposes of this repor1the following areas are defined thus:

• West Kimberley- lies between latitude 17°5 and 19°5 and longitude 121°E and 127°E, with an extension to the north of 1° between 121°E and I 24°20'E. The area is 118,000 km".

• North Kimberley - lies north of latitude 17°5 and between longitude 124°20'E and 127°30'E. The area is 85,000 km'.

• East Kimberley-lies north of latitude 19°5 and between longitude 127°30'E and …


The Identification, Distribution, And Status Of The Threatened Dismal Swamp Shrew (Sorex Longirostris Fisheri), Thomas M. Padgett Oct 1991

The Identification, Distribution, And Status Of The Threatened Dismal Swamp Shrew (Sorex Longirostris Fisheri), Thomas M. Padgett

Biological Sciences Theses & Dissertations

Southeastern shrews (Sorex longirostris) were trapped throughout southeastern Virginia and northeastern North Carolina to determine if any morphological characters could

be identified that would aid in the identification and distribution of the threatened subspecies Sorex l._ fisheri, endemic to the Great Dismal Swamp, the more upland nominate subspecies Sorex l. longirostris, and possible intergrades between the two subspecies. Animals were classified a priori into three groups, based on their location of capture. Animals collected from the Great Dismal Swamp National Wildlife Refuge (GDSNWR) and associated bottomland habitats were designated as "fisheri", animals collected farthest from the Swamp as "longirostris", and …


Selecting And Developing Reliable Bore Sites In The Eastern Wheatbelt, Richard George Jun 1991

Selecting And Developing Reliable Bore Sites In The Eastern Wheatbelt, Richard George

Bulletins 4000 -

In the Western Australian wheatbelt, groundwater supplies contribute about 40 per cent of the on-farm livestock requirements and occasionally domestic water supply systems. The first part of this Bulletin comments on sites suitable for both high yielding bores and also those which yield water suitable for livestock. The second part outlines techniques for constructing and developing a bore. Throughout this Bulletin livestock quality water, for adult sheep, is defined as groundwater of less than 12,000 mg/L (or 850 grains per gallon) which has not been subject to localized pollution. For other livestock, the maximum salinities range from 2,600 mg/L for …


Appendix To The Final Report Of The Rfac. Statistical Summary Of Public Responses To Key Issues., Recreational Fishing Advisory Committee Western Australia. May 1991

Appendix To The Final Report Of The Rfac. Statistical Summary Of Public Responses To Key Issues., Recreational Fishing Advisory Committee Western Australia.

Fisheries Management Papers

This paper has been published as a separate appendix to the final report of the Recreational Fishing Advisory Committee, and should be read in conjunction with it, and the Committee's discussion paper ("Final report of the Recreational Fishing Advisory Committee - Fisheries Management Paper No. 41 1991). The key issues that were identified in the discussion paper came up under the following headings: 5.1 Environment 5.2 Resource Sharing 5.3 Access for Fishing 5.4 Research 5.5 Management rules 5.6 Enforcement 5.7 Charter fishing 5.8 Funding and licensing 5.9 Community consultation 5.10 Public awareness and community education.


The Ecology Of Franklin's Ground Squirrel In Indiana, Peter M. Benjamin May 1991

The Ecology Of Franklin's Ground Squirrel In Indiana, Peter M. Benjamin

All-Inclusive List of Electronic Theses and Dissertations

A reduction in the distribution of the Franklin's ground squirrel in the eastern portion of its range has led to its classification as a threatened species in Indiana. Information is lacking on this species' habitat requirements and population characteristics in Indiana, which limits management capabilities. The purpose of this study was to identify preferred habitat and population characteristics of the Franklin's ground squirrel in Indiana. Radio telemetry was conducted from April 1987 to September 1988 at 3 sites along a railroad right-of-way (ROW} in Benton County, Indiana. Land use and habitat types were mapped; species composition, density, percent cover, percent …


Is Rainbow Trout Condition Influenced By Invertebrate-Drift Density?, Randall B. Filbert May 1991

Is Rainbow Trout Condition Influenced By Invertebrate-Drift Density?, Randall B. Filbert

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Users of the Instream Flow Incremental Methodology CTFIM) commonly assume that there is a positive linear relationship between available habitat (WUA) and stream fish biomass. However, several studies have shown a lack cf correlation between WUA and biomass. Such poor relationships may occur if other factors limit fish abundance. Food availability is a potentially important factor limiting abundance of stream fishes and can affect blomass by influencing fish condition (individual weight). I collected rainbow trout (Oncorhynchus mykiss) exposed to different levels of invertebrate-drift density to determine if condition was greater where food was more abundant. I also examined …


Fisheries Research Report No 91 - A Synopsis Of The Biology And The Exploitation Of The Australasian Pilchard, Sardinops Neopilchardus (Steindachner) Part Ii: History Of Stock Assessment And Exploitation, W. J. Fletcher Mar 1991

Fisheries Research Report No 91 - A Synopsis Of The Biology And The Exploitation Of The Australasian Pilchard, Sardinops Neopilchardus (Steindachner) Part Ii: History Of Stock Assessment And Exploitation, W. J. Fletcher

Fisheries Research Reports

This report summarises the studies which have provided information on the population characteristics and exploitation of the pilchard, Sardinops neopilchardus in Australia and New Zealand. This review was undertaken to determine whether existing data could be used to assess the status of Western Australian or other stocks or, alternatively, what additional information was required.

The mean size of pilchards caught varies among locations but, in general, fish are between 140 and 160 mm LCF, corresponding to ages 2 - 5 years. The length-weight relationship also varies between locations

Attempts to initiate pilchard fisheries have been hampered by the lack of …


Predation Risk And The Importance Of Cover For Juvenile Rainbow Trout In Lentic Systems, R. A. Tabor, Wayne A. Wurtsbaugh Jan 1991

Predation Risk And The Importance Of Cover For Juvenile Rainbow Trout In Lentic Systems, R. A. Tabor, Wayne A. Wurtsbaugh

Watershed Sciences Faculty Publications

Juvenile rainbow trout Oncorhynchus mykiss stocked in midelevation reservoirs in Utah inhabit shallow nearshore areas and are vulnerable to predation from piscivorous fish and birds. We determined the use and importance of nearshore habitats by (1) measuring habitat selection by, prey availability to, and feeding of juvenile rainbow trout in two reservoirs with populations of predators, and (2) measuring survival and growth rates in the presence and absence of cover in a pond experiment where adult brown trout Salmo trutta were predators. In the reservoirs juvenile rainbow trout (60–120 mm standard length) were abundant in complex inshore habitats but avoided …


Survey Of The Damage Caused To Trees By Goats, Steve Gherardi, Dick Mills, Tim Johnson Jan 1991

Survey Of The Damage Caused To Trees By Goats, Steve Gherardi, Dick Mills, Tim Johnson

Journal of the Department of Agriculture, Western Australia, Series 4

The damage that goats can cause to trees is one of the major problems associated with their farming in the agricultural areas of Australia. It is also considered one of the main hindrances to the development of the goat industry. The Department of Agriculture s Goat Industry Development Unit surveyed mohair and cashmere producers to determine the prevalence of tree damage and its extent and severity; why producers believed goats damaged trees; and how producers minimised or prevented this damage.


Trees And Livestock : A Productive Co-Existence, Richard Moore Jan 1991

Trees And Livestock : A Productive Co-Existence, Richard Moore

Journal of the Department of Agriculture, Western Australia, Series 4

Trees, as part of farming can help to combat land degradation problems and produce a good economic return from timber at the same time. For example, there is now clear evidence that planting trees can help combat salinity by lowering water-table levels. Trees can also substantially improve overall farm productivity by providing shelter for pastures and livestock. The challenge is to find practical and economical methods of integrating trees and farming. A combination of widely-spaced trees and livestock is one promising method. This article describes the benefits of this type of agroforestry to farmers, suitable locations and how to practice …


Mariculture Management For Pohnpei State, Federated States Of Micronesia, Kevin Brooks Foster Jan 1991

Mariculture Management For Pohnpei State, Federated States Of Micronesia, Kevin Brooks Foster

Marine Affairs Theses and Major Papers

The Marine Resources Division of Pohnpei State, Federated States of Micronesia is currently engaged in development activities that include the establishment of family scale mariculture projects for community members of remote villages and outer islands. The goal of this undertaking is to supplement subsistence and income generation ventures for community members through the wise use and exploitation of the marine environment. These aims may be jeopardized unless a management plan is devised that reflects the customary marine resource practices as embraced by islanders from each community. The intent of this thesis projects is to devise a mariculture management model that …


Prospects For Fisheries Development In West Africa, Steven K. Ireland Jan 1991

Prospects For Fisheries Development In West Africa, Steven K. Ireland

Marine Affairs Theses and Major Papers

The production of food is a primary concern for the countries of Africa. Marine fisheries can contribute toward alleviating undernutrition and provide employment opportunities in developing countries. In West Africa there are substantial marine fisheries resources but there is a need for development and improved management of these resources. Fisheries development efforts have thus far achieved limited success in the region. However, there is considerable potential for increasing the contribution of fisheries to economic development if the problems of fisheries development can be overcome.


Malaysia And The Law Of The Sea, Mohd Fadzil Shuhaimi Jan 1991

Malaysia And The Law Of The Sea, Mohd Fadzil Shuhaimi

Marine Affairs Theses and Major Papers

The new legal regime of the oceans has brought many changes in the Malacca Strait. The most recent one in the enactment of the Malaysian Exclusive Economic Zone Act 1984 as corollary to its proclamation on the Exclusive Economic Zone in 1980. A year later, the Fisheries Act 1985 was enacted by Malaysia as a result of increasing needs to address new issues in fisheries protection and management in the Malaysian fisheries waters. The conclusion of the 1982 United Nations Convention on the Law of the Sea, among other things, has improvised the concept of transit passage in the straits …


Long Term Management Measures For The Cockburn Sound Restricted Entry Fisheries., P. Millington Dec 1990

Long Term Management Measures For The Cockburn Sound Restricted Entry Fisheries., P. Millington

Fisheries Management Papers

The objective of this management plan is to introduce rules which will ensure there is a real reduction in professional fishing units and fishing effort in the medium to long term. This reduction should enable a small professional fishery to co-exist with the recreational sector, supply fresh fish to the metropolitan area, ensuring there is no proliferation of "shamateur fishing" and providing a supply of recreational angling bait.


Lake Mead Nutrient Enhancement Project, Peter D. Vaux, Larry J. Paulson, Nevada Department Of Wildlife, National Oceanic And Atmospheric Administration Dec 1990

Lake Mead Nutrient Enhancement Project, Peter D. Vaux, Larry J. Paulson, Nevada Department Of Wildlife, National Oceanic And Atmospheric Administration

Publications (WR)

The Lake Mead Fertilization Project is a research program designed to investigate the potential for using large-scale artificial fertilization to enhance the game fisheries of this reservoir through an increase in the population of threadfin shad, the system's primary forage species. A substantial decline in the population of largemouth bass, together with poor condition of adult striped bass, are the two major issues affecting the Lake Mead game fisheries. Both issues have been hypothesized to be a result of an inadequate amount of forage in the reservoir. Previous studies have in turn suggested that a major factor limiting the shad …


A Report On Black-Tailed Prairie Dogs In Nebraska, Their Biology, Behavior, Ecology, Management, And Responses To A Visual Barrier Fence, Nancy S. Foster Dec 1990

A Report On Black-Tailed Prairie Dogs In Nebraska, Their Biology, Behavior, Ecology, Management, And Responses To A Visual Barrier Fence, Nancy S. Foster

School of Natural Resources: Dissertations, Theses, and Student Research

I examined the effects of a visual barrier fence, which had a see-through visibility of 600/0, on the foraging, vigilance, and aggressive behaviors of adult female black-tailed prairie dogs from June through August 1990 in central Nebraska. I also examined changes in their home ranges and use of an area in response to this fence. Prairie dogs prefer an open view of their surroundings. Therefore, I expected animals near a visual barrier to spend more time in vigilance and aggression, and less time foraging. Adult female prairie dogs exposed to the visual barrier devoted more time to foraging and less …


State Of The Fisheries Report 1990, Fisheries Department Of Western Australia Dec 1990

State Of The Fisheries Report 1990, Fisheries Department Of Western Australia

Status Reports of the Fisheries and Aquatic Resources

The State of the Fisheries is published annually by the Fisheries Department as part of the statutory reporting process required under the Fisheries Act. This report covers developments and production in the State's fisheries up to the end of December 1990. Full details of the department's operations for this period are published separately in the department's annual reports for the financial years ending June 1990 and 1991. Figures provided in the tables are derived from catch returns completed by fishermen which are processed by the Australian Bureau of Statistics up to June 1990. Other information provided in the text comes …


The Effects Of Two Polycyclic Aromatic Hydrocarbons Benzo[A]Pyrene And Naphthalene On Reproductive Success Embryological Development Larval Physiology And Mortality Of The Mud Crab Rhithropanopeus Harisii (Gould), Gregory V. White Oct 1990

The Effects Of Two Polycyclic Aromatic Hydrocarbons Benzo[A]Pyrene And Naphthalene On Reproductive Success Embryological Development Larval Physiology And Mortality Of The Mud Crab Rhithropanopeus Harisii (Gould), Gregory V. White

OES Theses and Dissertations

Polycyclic aromatic hydrocarbons (PAHs) such as naphthalene (Nap) and benzo[a]pyrene (B[a]P) are common in the water column and sediments of estuarine and coastal areas. The mud crab Rhithropanopeus harrisii was exposed to varying concentrations of Nap or B[a]P to determine the effects on reproductive success, embryological development, larval physiology and mortality. Nap and B[a]P decreased hatching success and prolonged embryological development. Both pollutants produced high abnormality frequencies for egg exposed larvae. Molt frequency and respiratory rates of larvae from non-exposed eggs were more chronically affected by these pollutants than were egg exposed larvae. The EC50 concentrations were determined for …


Future Policy For Charter Fishing Operations In Western Australia., P. Millington Sep 1990

Future Policy For Charter Fishing Operations In Western Australia., P. Millington

Fisheries Management Papers

About 40 boats in Western Australia gain some of their income from taking recreational fishing parties out on charter. Half of these charter boats are also licensed commercial fishing boats. There are few Fisheries Department controls over charter boat fishing at present. However, with increasing tourism and leisure time, there are sound reasons for the Minister for fisheries to tighten up the controls over charter boat fishing to prevent over-exploitation in some areas or on particular stocks.


State Of The Fisheries Report 1989, Fisheries Department Of Western Australia Jun 1990

State Of The Fisheries Report 1989, Fisheries Department Of Western Australia

Status Reports of the Fisheries and Aquatic Resources

The State of the Fisheries is published annually by the Fisheries Department as part of the statutory reporting process required under the Fisheries Act. This report covers developments and production in the State's fisheries up to the end of December 1989. Full details of the department's operations for this period are published separately in the department's annual reports for the financial years ending June 1989 and 1990. Figures provided in the tables are derived from catch returns completed by fishermen which are processed by the Australian Bureau of Statistics. Other information provided in the text comes from research programs conducted …


Fisheries Research Report No. 89 - Relationships Among Partial And Whole Lengths And Weights For Western Australian Pink Snapper Chrysophrys Auratus (Sparidae), M. J. Moran, C. Burton Jun 1990

Fisheries Research Report No. 89 - Relationships Among Partial And Whole Lengths And Weights For Western Australian Pink Snapper Chrysophrys Auratus (Sparidae), M. J. Moran, C. Burton

Fisheries Research Reports

Pink snapper, Chrysophrysauratus (Sparidae) is one of the major commercial and recreational fish in Western Australian inshore waters. This report presents a number of equations and conversion factors for management and scientific study of the species. Equations to calculate total lengths from partial lengths will facilitate enforcement of minimum legal lengths when snapper are landed in a "head-off" condition. For fisheries science purposes, there are equations to convert among total length, standard length and length to caudal fork; and to convert lengths and weights of processed fish to whole lengths and weights. Length-weight relationships are presented and compared with those …