Application of the randomized response technique to marine park management: an assessment of permit compliance

Marine product collecting permits are useful management tools for providing information on usage patterns. Unfortunately, usage parameters based on permit issuance are invariably inaccurate because of permit noncompliance. Since noncompliance is a prosecutable offense, any attempt to estimate the rate of noncompliance by direct survey techniques is met with misleading and evasive responses. It has been shown elsewhere that randomized response designs reduce survey response bias to incriminating questions by ensuring respondent anonymity. With the use of the randomized response survey technique, estimates of permit noncompliance were determined for the Capricornia Section of the Great Barrier Reef Marine Park. Noncompliance with the requirement to obtain the prescribed permit was found to be low whereas, once a permit was obtained, noncompliance with specific permit conditions was considered high. Reasons for the high rate of noncompliance with specific conditions are presented, and it is recommended that marine park managers should not unreservedly base management decisions on usage data derived simply from permit issuance.     

EFFECTS OF DIVERSIONS ON THE NORTH AMERICAN GREAT LAKES1

ABSTRACT: Water level fluctuations of the Great Lakes often have created regional controversies among the states and Canadian provinces that share this vast resource. Even though the 100-year range of their water levels is only four to five feet, episodes of high and low Great Lakes water levels have been a recurring problem throughout the twentieth century. The possibility of increased diversion and consumptive use has exacerbated the existing conflicts over how to manage this water resource. A research project evaluated the effects of interbasin diversion on the Great Lakes system and on the industries that depend on the maintenance of historical water levels, namely hydropower and commercial navigation. The simulation approach employed in this research and some of the important findings are presented. The approach is similar to that used in recent government studies of Great Lakes water level regulation. Several significant modifications were made specifically addressing the diversion issue. Aggregate annual impacts to hydropower and shipping resulting from a diversion of 10,000 cubic feet per second were found to vary from 60 to 100 million dollars. Increases in impacts as a function of diversion rate are nonlinear for the navigation industry.     

PROBABILISTIC GREAT LAKES HYDROLOGY OUTLOOKS1

ABSTRACT: The Great Lakes Environmental Research Laboratory developed a semiautomatic software package for making hydrological outlooks for the Great Lakes. These include basin moisture storages, basin runoff, lake heat storage, lake evaporation, heat fluxes, and net lake supplies, one or more full months into the future. The package combines GLERL's rainfall-runoff and lake evaporation models with near real-time data reduction techniques to represent current system states. Users select historical meteorologic record segments as candidate future scenarios to generate deterministic near real-time hydrological outlooks. GLERL has extended the package to make probabilistic outlooks for a decision-maker who must estimate the risk associated with his decisions. GLERL matches National Weather Service meteorologic outlook probabilities by selecting groups of historical meteorologic sequences, and constructs embedded outlook intervals for each hydrologic variable of interest. Interval probabilities are assigned from comparisons over a recent evaluation period. This physically-based approach for generating outlooks offers the ability, as compared to other statistically-based approaches, to incorporate improvements in the understanding, of process dynamics as they occur in the future and to respond reasonably to conditions initial to a forecast (such as heat and moisture storages), not observed in the past.     

Spatial Patterns and Rankings of Contaminant Concentrations in Herring Gull Eggs from 15 Sites in the Great Lakes and Connecting Channels, 1998–2002

Mean values of eight contaminants in Herring Gull (Larus argentatus) eggs were calculated for 15 Great Lakes sites for the 5 year period 1998–2002. The sites were ranked according to the concentrations of each of seven compounds relative to fish flesh criteria for the protection of piscivorous wildlife, and a single overall rank of contamination was calculated for each site. Based on this weighted ranking scheme, we found that sum PCBs, dioxin and DDE contributed the most (60.2, 30.5% and 8.5%, respectively) to the overall rankings. The weighted ranking scheme showed that eggs from Channel-Shelter Island (Saginaw Bay, Lake Huron), Strachan Island (St. Lawrence River) and Gull Island (northern Lake Michigan) ranked as the three most contaminated sites, while Agawa Rocks (eastern Lake Superior), Chantry Island (southern Lake Huron) and Port Colborne (eastern Lake Erie) ranked as the three least contaminated sites. Two of the three most contaminated sites are Areas of Concern; none of the three least contaminated sites are Areas of Concern.     

Environmental implications of changes in the levels of lakes in the Ethiopian Rift since 1970

The Ethiopian rift is characterized by a chain of lakes of various sizes and hydrological and hydrogeological settings. The rift lakes and feeder rivers are used for irrigation, soda extraction, commercial fish farming, and recreation, and they support a wide variety of endemic birds and wild animals. The levels of some of these lakes have changed dramatically over the last three decades. Lakes that are relatively uninfluenced by human activities (Langano and Abaya) remain stable except for the usual inter-annual variations, strongly influenced by rainfall. Some lakes have shrunk due to excessive abstraction of water; others have expanded due to increases in surface runoff and groundwater flux from percolated irrigation water. Lakes Abiyata and Beseka, both heavily impacted by human activities, show contrasting lake level trends: the level of Abiayata has dropped by about 5 m over three decades because of the extraction of water for soda and an upstream diversion for irrigation. Beseka has expanded from an area of 2.5 to 40 km² over the last three decades because of increased groundwater inputs from percolated irrigation water. Lake Awassa has risen slightly due to land use changes resulting in increased runoff in its catchment. This paper addresses these lake level changes and their environmental repercussions, based on evidence from hydrometeorological records, hydrogeological field mapping supported by aerial photography and satellite imagery interpretations, water balance estimation, and hydrological modeling. A converging evidence approach is used to reconstruct the temporal and spatial variations of lake levels. The results reveal that the major changes in the rift valley are mainly related to anthropogenic factors. These changes appear to have grave environmental consequences for the fragile rift ecosystem. These consequences demand the very urgent implementation of integrated basin wide water management practice.     

Response of Organic and Inorganic Carbon and Nitrogen to Long-Term Grazing of the Shortgrass Steppe

We investigated the influence of long-term (56 years) grazing on organic and inorganic carbon (C) and nitrogen (N) contents of the plant–soil system (to 90 cm depth) in shortgrass steppe of northeastern Colorado. Grazing treatments included continuous season-long (May–October) grazing by yearling heifers at heavy (60–75% utilization) and light (20–35% utilization) stocking rates, and nongrazed exclosures. The heavy stocking rate resulted in a plant community that was dominated (75% of biomass production) by the C₄ grass blue grama (Bouteloua gracilis), whereas excluding livestock grazing increased the production of C₃ grasses and prickly pear cactus (Opuntia polycantha). Soil organic C (SOC) and organic N were not significantly different between the light grazing and nongrazed treatments, whereas the heavy grazing treatment was 7.5 Mg ha^–1 higher in SOC than the nongrazed treatment. Lower ratios of net mineralized N to total organic N in both grazed compared to nongrazed treatments suggest that long-term grazing decreased the readily mineralizable fraction of soil organic matter. Heavy grazing affected soil inorganic C (SIC) more than the SOC. The heavy grazing treatment was 23.8 Mg ha^–1 higher in total soil C (0–90 cm) than the nongrazed treatment, with 68% (16.3 Mg ha^–1) attributable to higher SIC, and 32% (7.5 Mg ha^–1) to higher SOC. These results emphasize the importance in semiarid and arid ecosystems of including inorganic C in assessments of the mass and distribution of plant–soil C and in evaluations of the impacts of grazing management on C sequestration.     

Environmental Health Policy: Analytic “Framing” of the Great Lakes Picture

/ The International Joint Commission (IJC) has overseen the implementation of the Great Lakes Water Quality Agreement between Canada and the United States for 25 years. Part of its mandate has been to facilitate international cooperation among a diversity of stakeholders focusing on the "waters" and the "ecosystem." In the 1970s policy focused on phosphorus reduction and individual contaminants, with some efforts (after 1978) to take an ecosystem (ecological perspectives) approach. In the last 15 years human health effects from (real and perceived) environmental causes have received considerable recognition. By contrast, less concern has been expressed for what is traditionally considered "environment" issues (such as protecting fish species). This shift at the policy level is well illustrated in the manner in which human health is increasingly used as a way for mobilizing environmental agendas. This paper analyzes nine IJC biennial reports to track how the framing of Great Lakes issues has shifted from concern for its waters to concern for human neurobehavior and reproductive systems. Frame analysis is used to conceptualize the controversies that are expressed through the Great Lakes policy documents. The analysis of the reports also reveals a shift in operational frames, used by the IJC to mobilize decision-makers into action.     

Trail erosion patterns in Great Smoky Mountains National Park

All the maintained trails in Great Smoky Mountains National Park were surveyed for width, depth, and a variety of types of erosion. Trail erosion is related to a number of environmental variables, including vegetation type, elevation, trail slope, and section of the park. Open grass balds and spruce-fir forest are the most erosion-sensitive plant communities, and the xeric oak and pine types are the least sensitive. Trails in virgin or mature forest tend to be in poorer condition than those in successional areas. The most important physical factor is the slope of the trail.Trails in the Tennessee district are in slightly poorer condition, on the average, than those in the North Carolina district, but the Appalachian Trail is more eroded than either. A poor section of the park may have ten times the erosion of a good section. On an allpark basis, water erosion is the most important problem, with 15% of the trail surface affected.A comparison of visitation patterns with trail condition indicates that redistribution of use would help to mitigate some erosion problems. Because trail condition is correlated to physical environmental factors, however, some sites will require intensive maintenance, even if visitation is low.The data from this survey have already been used in environmental analysis of proposed developments within the park and can be applied to long-range planning for the park trail system as a whole.     

Grassy balds of the Great Smoky Mountains: Their history and flora in relation to potential management

The origin of the grassy balds of the Great Smoky Mountains is examined. Some of the areas were cleared by settlers. Grazing by sheep and cattle and the cutting of trees were probably the most important factors in maintaining the grass sward; fire apparently was not used.Vegetation survey plots indicated that little of the original balds' area was still grassy and that most of the invading trees and shrubs could be expected to sprout if cut or burned. Areas presently trampled or mowed had a flora similar to a bald that was still grazed. High-elevation burn scars had many species in common with the grassy balds but had dissimilar community structures; therefore, a policy favoring natural fires would be unlikely to encourage maintanence or formation of grassy balds.The management of open grassy areas on National Forest lands was investigated. Burning was the favored technique, although hand cutting, mowing, and grazing were used. The results of testing various management practices on Gregory Bald are reviewed in terms of cost, impact, and historical authenticity. Implications for park management are discussed.     

THE MILWAUKEE POLLUTION CASE - IMPLICATIONS FOR WATER RESOURCES PLANNING1

ABSTRACT: The Illinois v. Milwaukee Federal District Court decision is the most far reaching application yet of the federal common law of nuisance to interstate water pollution conflicts. Although a Federal Appelate Court recently rescinded part of the district court decision, Milwaukee must still upgrade its metropolitan sewage system to a level beyond that required by federal and state regulations. The improvements must be completed with or without federal aid. The case points out the apparent inability of the Clean Water Act, the most comprehensive federal legislation affecting the nation's water quality, to deal with certain interstate water quality conflicts. The Milwaukee decision could set a precedent for similar settlements elsewhere which may in turn affect the U.S. Environmental Protection Agency's water quality clean up program. A more integrated, ecosystem conscious approach to management of shared water resources (e.g., the Great Lakes) would help reduce the need for court decisions like Illinois v. Milwaukee.