Environmental Indicators and Impact Assessment Commons^™

Conflicts In Use: The Impacts Of The Oil And Gas Industry On The Herring Fishery In The North Sea, Cornelia Ann Pasche

Marine Affairs Theses and Major Papers

The interaction of the herring (Clupea harengus) with the oil and gas industry in the North Sea is reviewed. The population crash of the herring in the early 1970's and the subsequent closing of that important fishery between 1977 and 1983 has drawn considerable attention to the influences, both biotic and abiotic, affecting the recruitment to the North Sea stock. Current accepted theory points to a change in oceanic current and the subsequent decrease in salinity in the North Sea region, resulting in a change in plankton availability for larval herring as the cause of the recruitment failure during the …

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 …

Enhancement And Monitoring Of The Procambarus Clarkii Population In Lake Mead, Mikell Beth Hager

Publications (WR)

Procambarus clarkii are found in extremely low numbers throughout Lake Mead, AZ-NV. The crayfish are an important dietary component for game fish. Enhancement of the crayfish population would broaden the fishery forage base. Crayfish were stocked and monitored in a study cove on Saddle Island to determine if the Procambarus clarkii population could be enhanced. A trapping survey of the area after the following reproductive season yielded low numbers of crayfish. A comparison of pre-stocking and post-stocking catch per trap day (CPTD) values revealed no significant increase in the population. Procambarus clarkii growth is limited by environmental factors in Lake …

Fisheries Research Report No. 84 - The Marine Open Shelf Environment: Review Of Human Influences, D. A. Hancock

Fisheries Research Reports

For the purpose of this review, the marine environment has been classified into three physical zones - the littoral zone, the open-shelf environment and the coral reef. Since the boundaries are arbitrary, there will inevitably be some overlap, but for this review the subject matter will be related to the area between low water of ordinary spring tides and the edge of the continental shelf; i.e., to a depth varying to 200 metres.

Human influences may have a dual role in affecting the marine environment, firstly in a causative manner and secondly in providing a remedy, in which case the …

Effects Of Ambient Lake Mohave Temperatures On Development, Oxygen Consumption, And Hatching Success Of The Razorback Sucker, Michael A. Bozek, Larry J. Paulson, Gene R. Wilde

Publications (WR)

Spawning of razorback suckers, Xyrauchen texanus, in Lake Mohave occurred from 10-22° C and larvae were collected at water temperatures from 10-15° C in 1982 and 1983. In the laboratory, hatching success was similar from 12-20° C, but reduced hatching success was found at 10° C while none hatched at 8°C. Development rate and oxygen consumption were positively related to incubation temperature. Direct effects of ambient Lake Mohave water temperatures on hatching success of razorback sucker embryos are considered minimal. Historical spawning temperatures for the species are hypothesized based upon successful incubation temperatures and comparison to the white sucker, …

Introduction And Enhancement Of Vegetative Cover At Lake Mead, Jennifer S. Haley, Lisa K. Croft, Suzanne E. Leavitt, Larry J. Paulson

Publications (WR)

Studies done by the Nevada Department of Wildlife (NDOW) and the Arizona Fish and Game between 1978 and 1981 indicate that inadequate cover may be limiting the production and survival of largemouth bass at the Lake Mead National Recreation Area (LMNRA). As a result of these studies, NDOW initiated a contract in 1986 with the Lake Mead Research Center (LMRC) to investigate means of improving habitat for game fish by introducing natural and/or artificial cover. During Phase I (1986-1987) of this contract, the shoreline of Lake Mead was surveyed for aquatic and terrestrial plant growth. Also during this time, submerged …

Characterization Of The Aquatic Environment In Lake Mead Near The Proposed Spring Canyon Pumped-Storage Project, And Assessment Of Potential Aquatic Impacts, Charles R. Liston, Stephen J. Grabowski, Bureau Of Reclamation

Publications (WR)

A pumped storage system consists of an upper reservoir and lower reservoir separated by an elevation difference. During low demand energy periods such as nights and weekends water is pumped from the lower to the upper reservoir using available energy from conventional steam electric power plants. During high energy demand periods, such as mornings and afternoons of weekdays, upper reservoir water is allowed to drop back down through the same system of water conduits and turbines, generating electricity to conveniently meet abrupt electrical energy requirements. The same water turbines thus act both as pumps and as conventional hydroelectric turbines. Because …

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.

Analysis Of The Water-Quality Standards Proposed By The Nevada Division Of Environmental Protection, City Of Las Vegas, Nevada

Publications (WR)

The Nevada Division of Environmental Protection (DEP) has proposed water-quality standards, applicable to Las Vegas Bay and Lake Mead, for (1) chlorophyll, (2) un-ionized ammonia, and (3) pH.

We have concluded that the proposed standards are unlikely to protect or improve water quality in Lake Mead. The proposed chlorophyll standard:

May harm the fishery. Lakes with more chlorophyll have greater fish production.

Will not improve clarity. Chlorophyll concentrations above 30 ug/1 have little effect on clarity.

Will not protect against scums or dominance by blue-green algae. Lake Mead shows no consistent relationship between chlorophyll and scums or blue-green dominance.

Will …

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 …

Fisheries Report No 74 - Marine Resources Map Of Western Australia- Part 2 - The Influence Of Oil On Marine Resources And Associated Activities With An Emphasis On Those Found In Western Australia, H. E. Jones

Fisheries Research Reports

Part 1 of the text accompanying the marine resources maps dealt with the resources and the morphological, hydrological and meteorological characteristics of the Western Australian coastal environment. This subsidiary part is concerned with the effects of oil on marine resources and associated commercial and recreational activities.

Accounts of oil on the seas due to natural seepages appeared in Europe in the sixteenth century on the return of Spanish and Portuguese ships from voyages to the Americas. One of the earliest reports of oil pollution from a man-made source was in 1754 when leakages from wooden petroleum barges were prevalent in …

A Review Of The Management And Current Status Of Northern Fur Seals Of The Pribilof Islands, Holly Hansell

Marine Affairs Theses and Major Papers

The North pacific fur seals of Alaska's Pribilof Islands have been subjected to commercial harvest for nearly 200 years. The harvest has been regulated under international agreement almost continuously since 1911; first under the 1911 North Pacific Fur Seal Convention, and following that under the 1957 Interim Convention on Conservation of North Pacific Fur Seals. Both Conventions banned pelagic sealing and divided the restricted land harvest among the four member states, the United States, Canada, Japan, and the Soviet Union. Management under the 1911 convention resulted in a steady increase in the severely depleted fur seal herd, restoring the population …

A Proposal To Fertilize The Overton Arm And Gregg Basin Areas Of Lake Mead, Larry J. Paulson

Publications (WR)

Several limnological studies have been conducted in Lake Mead during the past decade. The recent studies clearly show that most of Lake Mead is deficient in nutrients, especially phosphorus, and very low in productivity. The reservoir-wide average total phosphorus concentration for 1981 - 1982 was only 9 mg/m³. This is below levels found In most oligotrophic lakes and reservoirs. Algal biomass, as measured by chlorophyll-a, averaged only 1.5 mg/m³. That also places Lake Mead in the oligotrophic range. Transparency, as measured by a Secchi disc, averaged 9-5 m in Lake Mead during 1981-1982. That far exceeds …

Seasonal And Spatial Heterogeneity In The Limnetic Zooplankton Community Of Lake Mead, Gene Robert Wilde

Publications (WR)

Zooplankton samples collected from throughout Lake Mead, in 1981-1982, demonstrate the presence of a statistically significant seasonal and spatial heterogeneity in zooplankton densities. Seasonally, the major zooplankton groups were most abundant in the spring and fall, coincident with maxima in chlorophyll-a concentrations. Successions among the various rotifers, cladocerans and copepods present in the reservoir were influenced by food availability, diapause, predation by planktivorous fish and, possibly, water temperatures. Spatial heterogeneity in zooplankton densities was unrelated to water temperature, pH, conductivity and dissolved oxygen concentrations, but was related to the abundance of phytoplankton (chlorophyll-a concentrations) and fish. Statistical analyses indicate that …

The Effects Of Limited Food Availability On The Striped Bass Fishery In Lake Mead, John R. Baker, Larry J. Paulson

Publications (WR)

The original range of striped bass (Morone saxatilis) was along the Atlantic Coast. They were introduced into the lower Sacramento River in 1879 and are now also found along the Pacific Coast. A landlocked striped bass fishery was established in Santee-Cooper Reservoir, South Carolina, in 1954, and they have since been introduced into numerous other reservoirs, including Lake Havasu, Lake Mead and Lake Powell on the Colorado River. Striped bass were introduced into Lake Mead in 1969 in response to declines in the largemouth bass (Micropterus salmoides) fishery that occurred during the 1960s and in order to further utilize the …

Historical Patterns Of Phytoplankton Productivity In Lake Mead, Richard T. Prentki, Larry J. Paulson

Publications (WR)

Lake Mead was impounded in 1935 by the construction of Hoover Dam. The Colorado River was unregulated prior to then and therefore was subjected to extreme variations in flows and suspended sediment loads. Hoover Dam stabilized flows and reduced suspended sediment loads downstream, but Lake Mead still received silt-laden inflows from the upper Colorado River Basin. The Colorado River contributed 97% of the suspended sediment inputs to Lake Mead, and up to 140 x 1O⁶ metric tons (t) entered the reservoir in years of high runoff. Most of the sediments were deposited in the river channel and formed an …

Report No 49 - Geographically Restricted Plants Of Southern Western Australia, Barbara L. Rye

Fisheries Research Reports

This publication lists 527 angiosperm species native to southern western Australia whose known geographical ranges are less than 100 kilometres long. A further 128 angiosperms are listed with geographical ranges between 100 and 160 kilometres. No fern or gymnosperm species in the region are known to be geographically restricted.

Apart from the presently unnamed species, a large majority of the rare plants of southern Western Australia are believed to be listed, including 86 of the species that have been gazetted as rare flora.

Less than 40% of the listed species are known to occur on conservation reserves and less than …

Municipal Sewage Treatment: Problems And Considerations, George R. Johnson

Marine Affairs Theses and Major Papers

The coastal areas are vital to the economic and physical well being of the United States. Virtually every facet of our way of life is related in some fashion to these coastal areas. Ocean borne transportation moves not only vast quantities of raw materials, but also many of the intermediate and final products that are then manufactured to their related market areas. Fisheries provide vast amounts of food and employment for many of our people. In addition, the coasts are a continuing source of enjoyment and recreation for millions of our citizens. Coastal waters provide much of the water necessary …

Report No 41 - A Survey Method For Identifying Roadside Flora Suitable For Conservation In Western Australia, John K. Scott

Fisheries Research Reports

A survey method for identifying flora suitable for conservation alongside roads in south-western Australia was derived from an examination of characteristics of road verges. Two roads, from Midland to Toodyay and from Armadale to Bunbury, were examined. Width of verge, weed cover, soil disturbance, vegetation structure, presence of public utilities, evidence of fire and the type of adjoining land were measured at one mile (1.6 km) intervals on both sides of the road. Also recorded were aesthetic qualities such as stands of beautiful trees and sites of special interest, e.g. the presence of rare plants.

Three variables, percentage weed cover, …

Evaluation Of Impacts Associated With Reregulation Of Water Levels In Lake Mohave, Larry J. Paulson, John R. Baker, U.S. Water And Power Resources Service

Publications (WR)

The U.S. Water and Power Resources Service is considering reregulating Lake Mohave water levels to increase the net power benefit from Hoover Dam. Reregulation will not increase the generation capacity of the Hoover powerplant but it will enable the plant operation to be increased when the energy has greater monetary value. Energy generated at different times of the year has different market value, the highest being in January-March and July- September. By generating more power during these periods more net monetary benefit can be derived from Hoover Dam. The total volume of water released from Hoover Dam over an annual …

Influence Of Dredging And High Discharge On The Ecology Of Black Canyon, Larry J. Paulson, Theron G. Miller, John R. Baker, U.S. Water And Power Resources Service

Publications (WR)

The Water and Power Resources Service is considering dredging in Black Canyon to create a larger forebay to accommodate higher peak discharges and reverse flows for proposed modifications to Hoover Dam. The Black Canyon area from Hoover Dam to Willow Beach supports a heavily utilized trout fishery and is important habitat for the razorback sucker (Xyrauchen texanus) and possibly bonytail chub (Gila elegans). The Water and Power Resources Service initiated this investigation to determine what effect dredging and higher peak-discharges would have on the ecology of Black Canyon.

Potential Use Of Hydroelectric Facilities For Manipulating The Fertility Of Lake Mead, Larry J. Paulson, John R. Baker, James E. Deacon

Publications (WR)

Analysis of historical nutrient data for Lake Mead indicates that the fertility of the reservoir has decreased which may be the cause for a corresponding decline in the largemouth bass population. However, it appears that fertility can be manipulated by altering the operation of the dam. The depletion of nutrients in the euphotic zone by phytoplankton and subsequent accumulation in the hypolimnion during summer and fall provide a natural nutrient gradient from which water of varying fertility can be drawn for discharge. This combined with alterations in the depth or seasonal pattern of discharge can possibly be used to enhance …

Fisheries Report No 35 - Fish And Exploited Crustaceans Of The Swan-Canning Estuary, R C.J. Lenanton

Fisheries Research Reports

Fishes of the Swan-Canning estuarine system are typical of those found in other lower west coast estuarine systems of Western Australia. Species representing three families of elasmobranchs, several of which are commercially important, twenty families of teleosts, and two families of crustaceans (Table 1) commonly occur in this estuarine system. The many other species which occur less commonly in the Swan- Canning estuary are mostly members of the additional families listed in Table l.

The information contained in this document was made available for use by the authors of the following two publications : -

Forbes and Fitzkardinge (1977) Swan …

Fisheries Report No 36 - Utilization Of The Bunbury And Geographe Bay Marine Resource By Professional And Amateur Fishermen, Michael H. Walker

Fisheries Research Reports

Utilization of the Bunbury and Geographe Bay marine resource by professional and amateur fishermen was investigated by personal interview, distribution and analysis of research log sheets, and examination of commercial statistics for the area, published by the Australian Bureau of Statistics.

Total professional production for the years 1966/67 - 1974/75 for Geographe Bay varied between 225517 and 1218049 Kg (mean 497175) with a mean annual value to fishermen of $427708. Production for the Bunbury marine area varied between 157666 and 333810 Kg (mean 226526) with a mean value to fishermen of $311008. For the 1975/76 season the total production was …

Fish Of Lake Mead And Lake Mohave, Robert C. Allan, Dennis L. Roden

Publications (WR)

This publication offers an in-depth study of the fish and other organisms that live in Lakes Mead and Mohave. The history and background of the two lakes is offered, as well as information about diseases, parasites, and unusual fish occurrences. Food sources, predation and competition are also discussed.

Fisheries Report No 20 - Trawl Caught Fish And Crustaceans From Cockburn Sound, J. W. Penn

Fisheries Research Reports

Cockburn Sound is one of the few sheltered embayments near the Perth metropolitan area and as such has been subjected to increasing usage by both the general public and industry. Historically the Sound has been a major commercial fishing area from which much of the fresh fish for the metropolitan area has been caught. More recently, as well as providing a significant commercial catch, a major sport fishery has developed in the area.

The first commercial trawling operations in Cockburn Sound were undertaken in the early part of this century when horses were used to tow small nets on the …

An Evaluation Of The Fishery Resources Of The Thames River Watershed, Connecticut, Connecticut Department Of Environmental Protection

Storrs Agricultural Experiment Station

No abstract provided.

Fisheries Report No 16 - Notes On The Wildlife Of A Proposed Nature Reserve Around Lake Grace And Lake Chinokup, Western Australia, N. L. Mckenzie, W. K. Youngson

Fisheries Research Reports

During 1972 and 1973 plants and vertebrate animals were collected and recorded from a proposed 22 000 ha nature reserve centred on a chain of salt lakes in south-western Western Australia (33° 10' S - 33° 35' 8 and 118° 19' B - 118° 29' E).

The dominant plant species were collected, the structural formations desert bed and a vegetation map produced. Seven species of native terrestrial mammal and three species of bat were recorded.

Three of the terrestrial species are endemic to southwestern Western Australia, and two of these - Pseudomys occidentalis and Sminthopsis granulipes - are regarded as …

Fisheries Report No 14 - Wilson Inlet - A Seasonally Closed Western Australian South Coast Estuary, R C.J. Lenanton

Fisheries Research Reports

Considerable conflict has existed for many years between professional fishing, recreational usage and development in the west and south coast estuaries of Western Australia. One of the areas where intense conflict exists is Wilson Inlet.

The Government's task of advising the various interests concerned in these conflicts has been difficult, due to the lack of knowledge of estuarine fauna and environment in relation to usage and development.

The objective of this report is to present a preliminary description of the Wilson Inlet environment, to record the history of netting closures in the Inlet, and to discuss the history of the …

Finitely Generated Modules Over Bezout [email protected], Roger Wiegand, Sylvia Wiegand

Nebraska Cooperative Fish and Wildlife Research Unit: Staff Publications

Let R be a Bezout ring (a commutative ring in which all finitely generated ideals are principal), and let M be a finitely generated R -module. We will study questions of the following sort: (A) If every localization of M can be generated by n elements, can M itself be generated by n elements? (B) If M 0 R m = Rn for some m, n, is Af necessarily free? (C) If every localization of M has an element with zero annihilator, does M itself have such an element? We will answer these and related questions for various familiar classes …