Assessing the Conservation Value of New Zealand's Offshore Islands

New Zealand has over 500 offshore islands. Many consist of relatively pristine wilderness and contain a disproportionately large amount of New Zealand's biological wealth. Increased demand for recreation has increased the pressure to develop these areas. Although the New Zealand public has shown widespread support for the preservation and safeguarding of both wilderness areas and endangered species, economic values attached to the benefits of preservation are not known. Using a telephone survey, we found evidence that the public attaches significant value to the conservation of Little Barrier Island. The results show that these values are influenced by different levels and sources of prior information.     

Interference asymmetries among age-sex classes of rufous hummingbirds during migratory stopovers

Summary Three age-sex classes of rufous hummingbirds (Selasphorus rufus) overlap temporally and defend feeding territories during migratory stopovers in the Sierra Nevada of California. We demonstrate that these classes differ in their ability to secure and maintain high-quality feeding territories for refueling, and that these differences result in differences in resource use. Data on acquisition of territories, territory characteristics, and responses of territory owners to intruders suggest that several mechanisms are involved in determining dominance, involving sex- and age-related differences in wing disc loading, coloration, and experience. We discuss the implications of these results for understanding intraspecific variation in migration strategies. Correspondence to: F.L. Carpenter     

A linear programming model of residuals management for integrated iron and steel production

This paper briefly describes a linear programming model designed to allow the exploration of questions surrounding the management of the environmental impacts of integrated iron and steel facilities. In particular, the model can show how plant discharges will change in the absence of specific legal restrictions or effluent charges, with such variables as product mix, steel-furnace type, casting technology, and the scrap-ore price ratio. In addition, the costs implied by placing restrictions on discharges of specific residuals (e.g., BOD, oil, suspended solids, particulates) may be estimated, or response to proposed effluent charges may be predicted.     

Predictions of evaporative loss rates of solutes in stagnant and turbulent waters in relation to rates of reference materials

A previously published kinetic model for evaporative rates of substances into air leads to the estimation of the dependence of solute transfer coefficients on turbulence to the system. The ratios of the transfer coefficients of all solutes become insensitive to air turbulence and to water mixing either when they have comparable Henry's law constants or when their Henry's law constants are sufficiently low, but not otherwise. Confirming data are presented and methods for simplifying the estimation of transfer coefficients are discussed.     

ARE WE READY FOR A CLOSED SYSTEM OF WATER SUPPLY TREATMENT,AND REUSE - TECHNOLOGY VS. PSYCHOLOGY?1

ABSTRACT: Up to date there are still not many instances that can be found on the practice of a totally closed system of water supply, treatment, and reuse. In the United States, this is partly because the Public Health Service has discouraged such a practice. However, are there sound scientific reasons to support such a decision or is it purely a matter of psychological reason? Are the treatment technologies available today able to achieve the integrated closed system at a reasonable cost, yet without risking the public health? Are there some extra precautions that must be taken in practicing the direct reuse for the drinking purpose? These questions are discussed in this article. Current available technologies for advanced waste treatment are briefly reviewed and the treated effluent qualities obtained by the authors and others are used as a focal point of discussion on the feasibility of practicing the closed system. For this purpose, the treated effluent qualities are compared to the “Ranges of Promulgated Standards for Raw Water Sources of Domestic Water Supply” which have been used by the Public Health Service and several state regulatory agencies.     

A simulation model of management alternatives in a freshwater fishery

A model for investigating management alternatives on the Pyramid Lake-Truckee River system of Nevada and California is presented. Cutthroat trout, Cui-ui, Tahoe Sucker and Tui Chub are modeled with special emphasis on river spawning by trout. Management decision variables include hatchery input, water flow control, and diversion screening. Preliminary results indicate that some hatchery input will be needed to support the trout even with the best river management.     

ENVIRONMENTAL IMPACT OF CHANNEL MODIFICATION1

ABSTRACT: The purpose of this literature review is to identify and quantify the effects of channelization and to examine the feasibility and acceptability of alternative methods of flood control. In the past 150 years, over 200,000 miles of stream channels have been modified. Channelization can affect the environment by draining wetland, cutting off oxbows and meanders, clearing floodplain hardwoods, lowering ground water levels, reducing ground water recharge from stream flow, and increasing erosion sedimentation, channel maintenance, and downstream flooding. Channelization reduces the size, number, and species diversity of fish in streams. In a wet climate, the fishery requires less than 10 years to fully recover. However, in the drier climates, the fishery may never fully recover. In general, channel modifications have performed as designed for flood abatement. The Arthur D. Little Study (1973) reported that direct benefits estimated during channelization planning have been conservative and that damage reduction has been impressive. Diking seems to be a viable alternative to channel dredging. Dikes minimize destruction of wetland and eliminate the need for removing vegetation from the existing stream banks.