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Articles 961 - 990 of 1349

Full-Text Articles in Aquaculture and Fisheries

Idealwise Algebraic Independence For Elements Of The Completion Of A Local Domain, William Heinzer, Christel Rotthaus, Sylvia Wiegand Jul 1997

Idealwise Algebraic Independence For Elements Of The Completion Of A Local Domain, William Heinzer, Christel Rotthaus, Sylvia Wiegand

Nebraska Cooperative Fish and Wildlife Research Unit: Staff Publications

Over the past forty years many examples in commutative algebra have been constructed using the following principle: Let k be a field, let S k[xl Xn]x,xn) be a localized polynomial ring over k, and let a be an ideal in the completion S of S such that the associated prims of a are in the generic formal fiber of S; that is, p N S (0) for each p Ass(S/a):. Then S embeds in S/a, the fraction field Q(S) of S embeds in the fraction ring of S/a, and for certain choices of a, the intersection D Q(S) f3 (S/a) …


State Of The Fisheries Report 1995/1996, Jim W. Penn Apr 1997

State Of The Fisheries Report 1995/1996, Jim W. Penn

Status Reports of the Fisheries and Aquatic Resources

The State of the Fisheries document is designed as an essential supplement to the Annual Report to Parliament. By summarising data such as landings, effort, catch rates, stock assessment and breeding stock levels, this document provides a valuable reference point for all Western Australian fisheries of major importance to the commercial, recreational and aquaculture sectors. The report indicates that overall the major fish stocks which support fisheries in Western Australia are in a reasonably healthy condition. Those species which are being harvested at levels above their optimum, such as the shark stocks, are subject to increasing fishing controls designed to …


Western Australian Fisheries - At A Glance (1997), Fisheries Department Of Western Australia Jan 1997

Western Australian Fisheries - At A Glance (1997), Fisheries Department Of Western Australia

Fisheries Published Reports

Western Australia's fisheries are the envy of the world. The calibre of our research and management, and the skills of our fishermen, are recognised as second to none. We have pristine oceans and waterways from which we draw fish and fish products of the very best quality.

But while WA ranks as Australia's leading producer and exporter of fish and aquaculture products, we are not resting on our laurels. A major review of fisheries administration has cemented environmental and economic sustainability as the key management objectives, and industry now has greater scope for improving its competitiveness by pursuing new marketing …


Finfish Aquaculture In Western Australia, David Berry Jan 1997

Finfish Aquaculture In Western Australia, David Berry

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

David Berry surveys fish farming from Broome to Williams, on off shore reefs and in farm dams, for barramundi, silver perch and black bream, trout and tuna.


Fertilization Of An Oligotrophic Lake With A Deep Chlorophyll Maximum: Predicting The Effect On Primary Productivity, H. P. Gross, Wayne A. Wurtsbaugh, Phaedra E. Budy, Chris Luecke Jan 1997

Fertilization Of An Oligotrophic Lake With A Deep Chlorophyll Maximum: Predicting The Effect On Primary Productivity, H. P. Gross, Wayne A. Wurtsbaugh, Phaedra E. Budy, Chris Luecke

Watershed Sciences Faculty Publications

We investigated how epilimnetic fertilization would affect chlorophyll levels and light penetration of oligotrophic sockeye salmon (Oncorhynchus nerka) lakes and how the resulting self-shading would affect primary production of the prominent deep chlorophyll maxima (DCM) of the lakes. Epilimnetic nutrient additions to large mesocosms (330 m3) in Redfish Lake, Idaho, increased levels of primary productivity and chlorophyll a but decreased Secchi depths and light available in the metalimnion and hypolimnion. Redfish Lake and other Sawtooth Valley (Idaho) lakes had DCM in which the mean chlorophyll a peaks were 240-1000% of mean epilimnetic chlorophyll a concentrations. The DCM existed at low …


Hydroacoustic Assessment Of Abundance And Diel Distribution Of Sockeye Salmon And Kokanee In The Sawtooth Valley Lakes, Idaho, D. Beauchamp, Chris Luecke, Wayne A. Wurtsbaugh, H. G. Gross, Phaedra E. Budy, S. Spaulding, R. Dilenger, C. P. Gubala Jan 1997

Hydroacoustic Assessment Of Abundance And Diel Distribution Of Sockeye Salmon And Kokanee In The Sawtooth Valley Lakes, Idaho, D. Beauchamp, Chris Luecke, Wayne A. Wurtsbaugh, H. G. Gross, Phaedra E. Budy, S. Spaulding, R. Dilenger, C. P. Gubala

Watershed Sciences Faculty Publications

We used dual-beam hydroacoustics and echo integration techniques, combined with midwater trawling and gillnetting, to assess the abundance and distribution of the endangered Snake River juvenile sockeye salmon and resident kokanee (both Oncorhynchus nerka) in Sawtooth Valley lakes of Idaho during September 1991 and 1992. Abundance of O. nerka varied among the four lakes containing this species (12,500–257,000) and varied between years in Redfish Lake (86,400 in 1994 and 241,000 in 1992) and Alturas Lake (230,000 in 1991 and 257,000 in 1992). In Alturas Lake, where piscivore densities were high and zooplankton densities were low, small acoustic targets (≤18 cm …


Nutrient Limitation Of Oligotrophic Sockeye Salmon Lakes Of Idaho (Usa), Wayne A. Wurtsbaugh, H. P. Gross, Chris Luecke, Phaedra E. Budy Jan 1997

Nutrient Limitation Of Oligotrophic Sockeye Salmon Lakes Of Idaho (Usa), Wayne A. Wurtsbaugh, H. P. Gross, Chris Luecke, Phaedra E. Budy

Watershed Sciences Faculty Publications

"Phytoplankton production in lake ecosystems is frequently controlled by amounts of nitrogen and phosphorus (Smith 1982, Elser et al. 1990), as well as minor- and micro-nutrients (Wurtsbaugh & Horne 1983, Wurtsbaugh 1988, Lovstad & Bjorndalen 1990). Nutrient limitation is often studied to determine which nutrient(s) should be reduced to control lake eutrophication (Schindler 1974(. Conversely, nutrients have been used for decades to stimulate plankton and, subsequently, fish production in aquaculture (Bardach et al. 1972). More recently, lake fertilization has been used to augment salmon runs for commercial exploitation (Hyatt & Stockner 1985, lye et al. 1988), and it has been …


Comparison Of The Aquatic Ecology Of Side-Canyons And The Main Channel Of Lake Powell 1997, Wayne A. Wurtsbaugh, Kirsten L. Gallo Jan 1997

Comparison Of The Aquatic Ecology Of Side-Canyons And The Main Channel Of Lake Powell 1997, Wayne A. Wurtsbaugh, Kirsten L. Gallo

Watershed Sciences Faculty Publications

Physical characteristics of lakes are highly interrelated with biological characteristics. We measured and analyzed the physical characteristics of two side canyons in order to better understand differences in productivity between side canyons and the main channel and to provide general information on the characteristics of the lake.


1997 Rapid Ecological Assessment Northern Great Plains Steppe Ecoregion: Western And Central South Dakota, Northwestern Nebraska, Eastern Wyoming, A Final Report, Terri Hildebrand Jan 1997

1997 Rapid Ecological Assessment Northern Great Plains Steppe Ecoregion: Western And Central South Dakota, Northwestern Nebraska, Eastern Wyoming, A Final Report, Terri Hildebrand

Nebraska Game and Parks Commission: White Papers, Conference Presentations, and Manuscripts

In an effort to gain a more complete understanding of existing vegetative communities of the Northern Great Plains Steppe Ecoregion, rapid ecological assessment was undertaken throughout the ecoregion during the field season of 1997. Field office personnel of The Nature Conservancy and private contractors evaluated previously delineated regions in accordance with methodology determined in May of 1997. The following document presents results of the rapid ecological assessments performed by Hildebrand Contracting. The purpose of this document is to provide The Nature Conservancy with information to help determine the vegetative features of regions sampled. The specific areas and boundaries for evaluation …


Fisheries Research Report No 108 - Aspects Of The Biology And Stock Assessment Of The Whitebait, Hyperlophus Vittatus,In South Western Australia, D. J. Gaughan, W. J. Fletcher, R J. Tregonning, J. Goh Oct 1996

Fisheries Research Report No 108 - Aspects Of The Biology And Stock Assessment Of The Whitebait, Hyperlophus Vittatus,In South Western Australia, D. J. Gaughan, W. J. Fletcher, R J. Tregonning, J. Goh

Fisheries Research Reports

The biology, distribution and stock size of whitebait along the lower west coast of Western Australia were studied between 1991 and 1994. Age, growth and reproductive biology of whitebait were investigated using samples collected from the commercial fishery. The distribution of adult whitebait and their main spawning times were determined using data on eggs that were caught in plankton samples. Aspects of the population dynamics of whitebait were investigated by examining the relationships of historical catch data with fishing effort and some environmental parameters.

Whitebait are a small species with most growth occurring in the first year (K = I. …


Fisheries Research Report No 107 - Chemical Composition Of Yabbies (Cherax Albidus Clark 1936) From Western Australian Farm Dams, Kevin A. Francesconi, Noel M. Morrissy Oct 1996

Fisheries Research Report No 107 - Chemical Composition Of Yabbies (Cherax Albidus Clark 1936) From Western Australian Farm Dams, Kevin A. Francesconi, Noel M. Morrissy

Fisheries Research Reports

Proximate analyses, amino acid and fatty acid profiles, mineral composition and heavy metal and pesticide residues have been determined for tail muscle from Cherax albidus Clark 1936 (the yabby), sampled from Western Australian farm dams. The proximate analysis values for water, protein, ash, carbohydrate and energy content and the amino acid and fatty acid profiles of yabby tail muscle were similar to those reported for other decapods. Fat levels were low and, hence, cholesterol was very low in tail meat. Organochlorine pesticides were undetectable and heavy metal residues were well below maximum permitted concentrations for human consumption.


Fisheries Research Report No 105 - The Western Rock Lobster Fishery 1986/87 To 1990/91, C. F. Chubb, E. H. Barker, R. S. Brown Jul 1996

Fisheries Research Report No 105 - The Western Rock Lobster Fishery 1986/87 To 1990/91, C. F. Chubb, E. H. Barker, R. S. Brown

Fisheries Research Reports

This report on the western rock lobster (Panulirus cygnus, George 1962) fishery covers the five seasons 1986/87 to 1990/91 and is the latest in a series of reports on the State's largest and most valuable fishery. While more detailed data bases exist, these reports form a historical record of basic data for use by both industry and research workers, now and in the future. Catch and fishing effort in the seasons (1986/87 to 1990/91) varied between 8500 and 12300 tonnes and 11.3 and 12.8 million pot lifts respectively. This report provides detail on the distribution of catches and fishing effort; …


Reform Of The Endangered Species Act: Overview Of Administrative Reforms [Congressional Hearing Material Submitted By Bruce E. Babbitt, Secretary, Department Of Interior], Dinah Bear Jun 1996

Reform Of The Endangered Species Act: Overview Of Administrative Reforms [Congressional Hearing Material Submitted By Bruce E. Babbitt, Secretary, Department Of Interior], Dinah Bear

Biodiversity Protection: Implementation and Reform of the Endangered Species Act (Summer Conference, June 9-12)

31 pages.


A Tribal Perspective On Esa Reform, Ted Strong Jun 1996

A Tribal Perspective On Esa Reform, Ted Strong

Biodiversity Protection: Implementation and Reform of the Endangered Species Act (Summer Conference, June 9-12)

4 pages.


How The Regulated Community Views Regulation To Protect Living Resources: The Endangered Species Act, Biological Diversity, And Ecosystem Management, Steven P. Quarles Jun 1996

How The Regulated Community Views Regulation To Protect Living Resources: The Endangered Species Act, Biological Diversity, And Ecosystem Management, Steven P. Quarles

Biodiversity Protection: Implementation and Reform of the Endangered Species Act (Summer Conference, June 9-12)

21 pages.

Contains footnotes.


The Endangered Species: The Urban Water Utility Perspective, Chips Barry Jun 1996

The Endangered Species: The Urban Water Utility Perspective, Chips Barry

Biodiversity Protection: Implementation and Reform of the Endangered Species Act (Summer Conference, June 9-12)

24 pages.


Upper Colorado River Fish: A Recovery Program That Is Working – Myth Or Reality?, James S. Lochhead Jun 1996

Upper Colorado River Fish: A Recovery Program That Is Working – Myth Or Reality?, James S. Lochhead

Biodiversity Protection: Implementation and Reform of the Endangered Species Act (Summer Conference, June 9-12)

24 pages (includes 1 map).

Contains 2 pages of references.


A Comparison: Lessons From The Columbia Basin And The Upper Colorado Basin Fish Recovery Efforts, Mary Christina Wood Jun 1996

A Comparison: Lessons From The Columbia Basin And The Upper Colorado Basin Fish Recovery Efforts, Mary Christina Wood

Biodiversity Protection: Implementation and Reform of the Endangered Species Act (Summer Conference, June 9-12)

47 pages.

Contains 5 pages of references.


The Esa, Water Rights, And Regulatory Takings, Barton H. Thompson, Jr. Jun 1996

The Esa, Water Rights, And Regulatory Takings, Barton H. Thompson, Jr.

Biodiversity Protection: Implementation and Reform of the Endangered Species Act (Summer Conference, June 9-12)

28 pages.

Contains 2 pages of references.


The Endangered Species Act—Economic Impacts: The Perception And The Numbers, Jon A. Souder Jun 1996

The Endangered Species Act—Economic Impacts: The Perception And The Numbers, Jon A. Souder

Biodiversity Protection: Implementation and Reform of the Endangered Species Act (Summer Conference, June 9-12)

13 pages (includes illustrations).

Contains 2 pages of references.


Water Rights, Contract Rights, And The Endangered Species Act, Brian E. Gray Jun 1996

Water Rights, Contract Rights, And The Endangered Species Act, Brian E. Gray

Biodiversity Protection: Implementation and Reform of the Endangered Species Act (Summer Conference, June 9-12)

12 pages.

Contains references.


The Endangered Species Act: Tramping On Tribal Rights?, Robert S. Pelcyger Jun 1996

The Endangered Species Act: Tramping On Tribal Rights?, Robert S. Pelcyger

Biodiversity Protection: Implementation and Reform of the Endangered Species Act (Summer Conference, June 9-12)

32 pages.

Contains footnotes.


Habitat Based, Multi-Species Hcps: Lessons From The Northwest, James A. Kraft Jun 1996

Habitat Based, Multi-Species Hcps: Lessons From The Northwest, James A. Kraft

Biodiversity Protection: Implementation and Reform of the Endangered Species Act (Summer Conference, June 9-12)

9 pages.


Columbia River Salmon: Are Any Of The Esa Tools Adequate For The Job?, John M. Volkman Jun 1996

Columbia River Salmon: Are Any Of The Esa Tools Adequate For The Job?, John M. Volkman

Biodiversity Protection: Implementation and Reform of the Endangered Species Act (Summer Conference, June 9-12)

32 pages.

Contains footnotes.


The Enigma Of The Blind Salamander And Groundwater Pumping: Lessons From The Edwards Aquifer, Texas, Charles R. Shockey Jun 1996

The Enigma Of The Blind Salamander And Groundwater Pumping: Lessons From The Edwards Aquifer, Texas, Charles R. Shockey

Biodiversity Protection: Implementation and Reform of the Endangered Species Act (Summer Conference, June 9-12)

39 pages (includes illustrations and maps).

Contains footnotes.


An Overview Of The Endangered Species Act, Michael J. Brennan Jun 1996

An Overview Of The Endangered Species Act, Michael J. Brennan

Biodiversity Protection: Implementation and Reform of the Endangered Species Act (Summer Conference, June 9-12)

25 pages.


Landscape Scale Habitat Conservation Plans: The California Experience, Lindell L. Marsh Jun 1996

Landscape Scale Habitat Conservation Plans: The California Experience, Lindell L. Marsh

Biodiversity Protection: Implementation and Reform of the Endangered Species Act (Summer Conference, June 9-12)

24 pages.

Contains 3 pages of references.


Agenda: Biodiversity Protection: Implementation And Reform Of The Endangered Species Act, University Of Colorado Boulder. Natural Resources Law Center Jun 1996

Agenda: Biodiversity Protection: Implementation And Reform Of The Endangered Species Act, University Of Colorado Boulder. Natural Resources Law Center

Biodiversity Protection: Implementation and Reform of the Endangered Species Act (Summer Conference, June 9-12)

Conference organizers and/or faculty included University of Colorado School of Law professors Betsy Rieke, David H. Getches, Michael A. Gheleta and Charles F. Wilkinson.

All across the country--in Congress, in state legislatures and in urban and rural communities--people are discussing why we should or should not protect biodiversity and how best to do so. Since the Endangered Species Act is up for reauthorization, a variety of reform proposals are being debated. Speakers--including natural resource scholars, experts from the private and nonprofit sectors, and government officials--will examine the rationale for biodiversity protection, the legal framework of the Endangered Species Act, and …


Fisheries Research Report No 104 - Assessment Of The Effects Of A Trial Period Of Unattended Recreational Netting In Selected Estuaries Of Temperate Western Australia, Between 1 January 1994 And 30 June 1995, R. C. Lenanton, R. Allison, Sg Ayvazian Jun 1996

Fisheries Research Report No 104 - Assessment Of The Effects Of A Trial Period Of Unattended Recreational Netting In Selected Estuaries Of Temperate Western Australia, Between 1 January 1994 And 30 June 1995, R. C. Lenanton, R. Allison, Sg Ayvazian

Fisheries Research Reports

Gill nets have been used in coastal marine and estuarine waters of Western Australia to take fish for sale and/or domestic consumption since the State was first settled. However, over recent years, as the usage of these coastal waters has continued to increase, and the competition for fish resources becomes more intense, fishing methods, such as unattended gill nets that are indiscriminate with respect to target species, and generally ,wasteful of resources have become less tolerated by the general community.

As part of a push for tighter controls on the use of recreational gill nets, a requirement for fishers to …


Habitat Selection And Movement Of A Stream-Resident Salmonid In A Regulated River And Tests Of Four Bioenergetic Optimization Models, Mark D. Bowen May 1996

Habitat Selection And Movement Of A Stream-Resident Salmonid In A Regulated River And Tests Of Four Bioenergetic Optimization Models, Mark D. Bowen

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

A bioenergetics model was constructed for stream-resident drift-feeding salmonids. Model predictions of surplus power (energy available per unit time for growth and reproduction) were not statistically distinguishable from observations of surplus power in three laboratory studies. Of 40 experimental trials in these three studies, the model correctly predicted surplus power in 39 cases (p < 0.05).

I collected observations of rainbow trout (Oncorhynchus mykiss) focal velocity and physical habitat availability in the Green River of northeastern Utah, USA (1988-1990). In the winter of 1988, Flaming Gorge Dam generated hydropower and delivered an lJDStable discharge regime with a higher mean discharge …