Large-scale constructed wetlands for nutrient removal from stormwater runoff: An everglades restoration project

The South Florida Water Management District (SFWMD) constructed a wetland south of Lake Okeechobee to begin the process of removing nutrients (especially phosphorus) from agricultural stormwater runoff entering the Everglades. The project, called the Everglades Nutrient Removal (ENR) project, is a prototype for larger, similarly constructed wetlands that the SFWMD will build as part of the Everglades restoration program. This innovative project is believed to be one of the largest agricultural stormwater cleanup projects in the United States, if not in the world. This publication describes the ENR project's design, construction, and proposed operation, as well as the proposed research program to be implemented over the next few years.     

Evaluating the effectiveness of air quality management within the class I area of great smoky mountains national park

The Clean Air Act Amendments of 1977 designated national parks and wilderness areas larger than 1894 ha to be class I areas for air quality management, setting more restrictive criteria than the National Ambient Air Quality Standards. Class I areas are afforded the greatest degree of air quality protection under the Clear Air Act of 1970. In recent years, several studies have documented air pollution effects in the Great Smoky Mountains National Park (GSMNP), the second-largest class I area in the eastern United States. Air pollution problems of greatest concern in the GSMNP are effects of acid deposition, visibility impairment, and tropospheric ozone. Several recent events have increased concerns about air quality management in the class I area of the GSMNP. A forum, sponsored by the Southern Appalachian Man and the Biosphere Cooperative (SAMAB), was held in March 1992, which involved representative. parties-at-interest and began to address strategies for better management of air resources in the Southern Appalachians. This paper summarizes those discussions and recommendations and reports actions occurring as a result of the forum. Another objective of this paper is to present a conceptual framework for more effective management of the class I area of the GSMNP.     

SIMULATION OF HERBICIDE CONCENTRATIONS IN STORMFLOW FROM FORESTED WATERSHEDS1

The breakpoint rainfall hydrology and pesticide options of the field scale model CREAMS (Chemicals, Runoff, and Erosion from Agricultural Management Systems) were used to predict average concentrations of hexazinone [3 cyclohexyl-6-(dimethyl-amino)-1-methyl-1,3,5-triazine-2,4(1H,3H)-dione] in stormflow from four forested watersheds in the upper Piedmont region of Georgia. Predicted concentrations were compared with measured concentrations recorded over a 13-month period. CREAMS accurately predicted hexazinone concetrations in the initial stormflow events which also contained the highest concentrations. The model underestimated the hexazinone concentrations in stormflow two months and greater following pesticide application. In a companion study, the daily rainfall option of the CREAMS model was used to evaluate the reltive risk associated with the maximum expected concentration of hexazinone, bromacil (5-bromo-3 sec-butyl-6 methyuracil), picloram (4-amino-3,5,6 trichloropicolinic acid), dicamba (3,6-dichloro-0-anisic acid), and triclopyr {[(3,5,6-trichloro-2-pyridinyl)oxy] acetic acid} in stormflow from small forested watersheds. The model predicted the following order of potential residue appearance in stormflow: bromacil>triclopyr>hexazinone>picloram>dicamba. Subsurface movement of residues via interflow and deep leaching losses are not simulated by the version of CREAMS used in these studies.     

Deep-Sea Mining: The Consequences of Failure to Agree at UNCLOS III

In July 1982 the US Government announced that it would not sign the new Convention on the Law of the Sea adopted at the eleventh session of the Third United Nations Conference on the Law of the Sea in April 1982. This article investigates the possible consequences of the failure to achieve a consensus between the Group of 77 and the western industrialised States on a regime to govern the deep-sea mining of manganese nodules. After considering the range of possible outcomes, the author identifies the benefits and costs involved in operating under the two alternative regimes, that provided by the new Convention and related Conference resolutions and the alternative Reciprocating States Regime based on unilateral legislation co-ordinated by a Mini-Treaty. En juillet 1982, le gouvernement des Etats-Unis a annoncé qu'il ne signerait pas la nouvelle Convention sur le droit de la mer qui a été adoptée à la llème session de la troisième Conférence des Nations Unies sur le droit de la mer en avril 1982. Cet article étudie les conséquences possibles de l'absence d'un consensus entre le Groupe des 77 et les nations industrielles occidentales sur un régime devant gouverner l'exploitation des nodules de manganèse que l'on trouve sur les fonds marins profonds. Après avoir consideéré tout un éventail de résultantes éventuelles, l'auteur dresse un état des avantages et désavantages que présentent les deux régimes possibles, c'est-à-dire le régime prévu par la nouvelle Convention et les résolutions concomitantes adoptées par la Conférence et le régime de réciprocité entre états basé sur une législation unilatérale et sanctionné par un mini-traité. En julio de 1982 el gobierno de los Estados Unidos anunció que no firmaría la nueva Convención sobre el Derecho del Maradoptada en la undécima sesión de la Tercera Conferencia de las Naciones Unidas sobre el Derecho del Mar en abril de 1982. Este artículo investiga las posibles consecuencias de la falta de consenso entre el Grupo de los 77 y los estados industriales occidentales sobre el régimen que gobierna la extracción de nódulos de manganeso en mares profundos. Después de considerar el posible rango de consecuencias el autor evalúa los costos y beneficios resultantes de operar bajo dos regímenes alternativos, aquel definido por la nueva convención y las resoluciones relacionadas y el Régimen de Reciprocidad entre Estados basado en legislación unilateral coordinados por el Mini-Tratado.     

Refuse treatment options: a case study

Records in public archives were evaluated for the period 1981-1991. Simple surveys of peoples and of technology and physical premises provided insight to gauge the attitudes of a local community in the Melbourne municipality and the Melbourne City Council towards composting of organic waste materials. There is a lag in perception and attitudes between the local community and the local government towards composting of organic refuse as a solid waste treatment option. The simple methodology of the study still made it possible to verify past and present perceptions and attitudes.     

A dynamic model for intertemporal allocation of old-growth forests in the Pacific Northwest

Across the globe, continued policy debates regarding the management of old-growth forests center around the difficult task of balancing economic and ecological considerations. Though the forests of the Pacific Northwest United States are among the most studied old-growth ecosystems, ecological and economic analyses have yielded public land management directives that remain controversial. Specifically, the recently adopted Northwest Forest Plan lacks explicit goals for maintaining intergenerational equity for the use of forest resources and the diversity of old-growth ecosystems. Unlike previous studies which rely on monetary quantification of costs and benefits, this study develops and applies a conceptual framework for evaluating socially optimal Pacific Northwest old-growth forest utilization strategies. Conditions for the optimal management of old-growth forests are derived using dynamic programming. The objective function synthesizes relevant biological and economic attributes of the old-growth allocation problem. Results in the form of extraction paths are compared given social pressure for consumptive and non-consumptive benefits, as well as different planning horizons, rates of social time preference, and environmental variance. Lengthening the planning horizon results in a vast divergence of optimal policies in the absence of discounting. Extraction rates appear to approach zero as the planning horizon approaches infinity. While higher rates of social time preference increase the rate of extraction, forest stocks remaining at the terminal time period equal levels remaining with a lower discount rate. Increasing environmental variance results in a higher level of stock remaining at the terminal time period. This analysis, while specific to the old-growth controversy of the Pacific Northwest, does provide general guidelines for addressing similar problems of multiple uses of natural areas, particularly where such uses are mutually incompatible, or where one use may be irreversibly destructive to another.     

The artisanal fishery for Octopus cyanea Gray in Tanzania

Preliminary results for the artisanal fisheries of Octopus cyanea Gray (1849) in Tanzania are provided for the period April 2000 until June 2001. A total of 2546 individual catches and 15473 specimens were analyzed from 3 sites located at Tanga, Mafia Island, and Mtwara. Size range, average weight and catch per unit effort (CPUE) were all significantly lower at Tanga and Mtwara compared to Mafia indicating that the former sites may be overfished. Abundance of smaller individuals was higher at Tanga and Mtwara, but overall biomass was lower. Octopi at each site exhibited allometric growth as indicated by analyses of the length-weight relationships. Females become sexually mature at a minimum weight of 600 g while for males the minimum weight was 320 g. Higher numbers of mature individuals were found in June of both years and correlate with peaks in the gonosomatic index. Recruitment peaked a few months after brooding periods. Sex ratios indicate females may be more prone to capture during brooding periods. Reasons for differences between sites are discussed.     

Prediction of ambient PM10 and toxic metals using artificial neural networks

In this study, an artificial neural network is employed to predict the concentration of ambient respirable particulate matter (PM10) and toxic metals observed in the city of Jaipur, India. A feed-forward network with a back-propagation learning algorithm is used to train the neural network the behavior of the data patterns. The meteorological variables of wind speed, wind direction, relative humidity, temperature, and time are taken as input to the network. The results indicate that the network is able to predict concentrations of PM10 and toxic metals quite accurately.