Improving the contingent valuation method: A psychological perspective

Results of research on the social psychology of human decision making that offer direction for improving the contingent valuation method are reviewed. The paper focuses on the findings of that literature related to (1) limitations of human information processing and judgment-making abilities, (2) the influence of elicitation stimuli and expectations, and (3) quality of decision making in the face of too much or too little stress. Within the context of this literature, specific research directions are recommended that can improve the validity and reliability of the results of contingent valuation studies. More multidisciplinary studies are encouraged.     

Mineral resources appraisal and policy: Controversies,issues and the future

Political-economic events of the 1970s brought mineral resource appraisal to the focus of national policy. Estimates of and methodologies for mineral resources appraisal were scrutinized, revealing deficiencies in method and data and fostering considerable debate about the credibility of estimates and about preferred methodology. Since credibility can be increased through the acquisition of additional geoscience information, questions regarding methodology have more than one formulation and therefore more than one correct solution, depending upon the expected value of additional information and the conditional losses of relevant policy options. When existing information is meagre and the expected value of information is high, the optimum decision may be to defer all policy options until after the acquisition and analysis of- additional information. Decision theory offers an analytical framework that is sufficiently generalized to provide answers for highly varied circumstances of geoscience and resource information and policy issues. Our ability to perform any such analysis is limited by inaccuracies in both geologists' estimates of undiscovered mineral resources, and in economists' calculations of conditional losses of policy options for each of the relevant states of mineral resources.     

A microinjection technique using a pH-sensitive dye to determine the gut pH of Calanus helgolandicus

By applying a microinjection technique previously used in cell biology, a pH-sensitive dye, 2,7-bis(2-carboxyethyl)-5,6-carboxyfluorescein) (BCECF), was injected into the gut of the copepod Calanus helgolandicus to determine pH under a range of feeding conditions. The median gut pH of the fore- and hindguts of starved individuals was 6.86 and 7.19, respectively. This was a consistently lower pH than that observed in copepods feeding on either the diatom Thalassiosira weissflogii, the dinoflagellate Prorocentrum micans, or the coccolithophorid Emiliania huxleyi (Strain 92D), all of which had a median gut pH>7.0. In all treatments, the median pH of the foregut was more acidic than the median of the hindgut, implying that the foregut is the site of acid secretion. The results, which demonstrate pH values down to 6.11, are discussed in terms of coccolith dissolution, pigment degradation and digestive enzyme activity.     

Zooplankton grazing on the coccolithophore Emiliania huxleyi and its role in inorganic carbon flux

Grazing and faecal pellet production by the copepods Calanus helgolandicus and Pseudocalanus elongatus, feeding on the coccolithophore Emiliania huxleyi, were measured under defined laboratory conditions, together with the chemical characteristics and sinking rates of the faecal pellets produced. Ingestion rates of both copepods were equivalent at comparable cell concentrations, the relationship between ingestion rate (I, cells copepod^-1 h^-1) and food concentration (C, cells ml^-1), being I=0.558C for both species. P. elongatus produced a larger number of smaller faecal pellets than C. helgolandicus, but egested a larger volume of material per individual. Only between 27 and 50% of the ingested coccolith calcite was egested in the faecal pellets, and it is possible that acid digestion in the copepod gut is responsible for these considerable losses. Average sinking rates of faecal pellets containing E. huxleyi coccoliths, produced by both species, were >100 m d^-1. The implications of the quantitative laboratory estimates for the vertical flux of inorganic carbon are considered using recently studied shelf-break and oceanic E. huxleyi blooms in the N. E. Atlantic as examples.     

Pollution source analyses using 1-dimensional time series

Lake Holiday, a human-made recreational lake in northern Illinois, was threatened with closure due to high bacterial levels. A factorially designed experiment with multivatiate responses was developed to study and identify the main sources of pollution. Data on total coliform, fecal coliform, fecal streptococci, dissolved oxygen, pH, ammonia-N, total phosphorus, nitrate/nitrite-N were analyzed using regression models describing dam spillway loads as a function of source loads and time. The results suggest that the relationships among source, time, and load are complex, even though only two sources account for most of the lake's loading Stevens Brook, which receives the discharge from the Somonauk Sewage Treatment Plant, and Somonauk Creek, which is the major drainage, contribute high loads of bacteria and nutrients to the lake. The influent loads contributed to the lake are discharged at the dam over about 4 weeks     

MISSOURI RIVER - THE NEW COMPACTING GAME1

ABSTRACT: This paper addresses the recent interest in management of the Missouri River. Interstate issues in the river basin include interbasin water diversions, riverbed and shoreline degradation, loss of recreational and natural areas, reduction in navigation capacity, the status of the Pick-Sloan Missouri Basin Program in terms of general river development, and the elimination of river basin commissions, An attempt to develop a comprehensive interstate water compact failed in the 1950s. The new efforts towards establishing a compact are discussed, as well as other available mechanisms for resolution of the current political and legal differences among the ten river basin states.     

The role of lakeshore homeowner associations in environmental management

The purpose of this study was to determine what role lakeshore homeowner associations might play in environmental management. Lakeshore homeowner associations are formally organized groups of individuals owning property on or in the vicinity of a lake. Lakeshore homeowner associations in the Adirondack Park region of New York State were investigated by both a questionnaire mailed to all presidents and an informal field survey of some permanent lakeshore residents. The study showed that many of these organizations have become highly involved in an array of environmental management activities during their relatively long history. These activities include monitoring septic tank seepage, regulating the use of motorboats, restricting shoreline development, and assisting state and local planning agencies in detecting zoning violations. Some lakeshore homeowner associations are not highly involved in activities designed to maintain or improve quality of the lake environment. These associations are concerned instead primarily with organizing social events and performing other miscellaneous activities, such as access road maintenance. These associations, however, report lower overall water quality in their lakes than those associations with a high degree of involvement in environmental management. The study uncovered two important factors that tend to undermine the ability of lakeshore homeowner associations to undertake environmental management activities. One is the extent of cooperation that can be expected from nonmember residents of the lakeshore, such as seasonal vacationers. The second is an environmental problem that does not originate locally and therefore cannot be controlled by a local organization. Acid precipitation, rated by association presidents as their foremost water quality concern, is one such problem in the Adirondack Park Region.     

Relying on nature: wild foods in northern Nigeria

In rural Africa, wild foods provide diversity, vitamins and minerals in the diet. They are also important at times of food shortage. This paper discusses issues concerning wild food use in semiarid West Africa, and presents the results of a study of the use of wild plant foods in northeast Nigeria. Interviews with farmers and herders identified a total of 67 wild foods, coming from 53 species of plant. Knowledge of wild foods varied according to ethnic group and gender. Some wild foods caused side effects if eaten in excess. Land-use change due to agricultural expansion seems to be increasing the areas where wild foods are most commonly found. Wild foods are important as a supplement to daily diet, and at times of food scarcity. In addition, they provide an opportunity to generate income when they are collected and traded. The paper concludes that wild foods are an important coping strategy for rural communities. Further research is needed to determine whether local institutions and community-based natural resource management regimes are sufficient to conserve this resource.     

Quadrupole ion storage tandem mass spectrometry and high-resolution mass spectrometry: complementary application in the measurement of 2,3,7,8-chlorine substituted dibenzo-p-dioxins and dibenzofurans in US foods

The US Food and Drug Administration has simultaneously utilized both high-resolution mass spectrometry (HRMS) and quadrupole ion storage tandem mass spectrometry (QISTMS) in the measurement of polychlorinated dibenzo-p-dioxins/dibenzofurans (PCDD/Fs) in 147 food samples collected in 1998 and 1999 in the US. In 1998, 20 egg samples, six scallop, 10 blue crab, eight American lobster, 10 pollack, 15 striped bass, five rockfish, 10 crawfish, seven aqua-cultured and 13 wild-caught salmon, along with 19 cream and 18 mozzarella cheese samples were measured for PCDD/Fs. QISTMS provided limits of detection (LODs) close to those produced using HRMS for many congeners in 56 samples analyzed by both techniques in 1998 and three salmon and three striped bass collected in 1999. The I-TEQs of the mean levels for measured congeners in 40 samples of fish and shellfish and 16 cheese and eggs from 1998 analyzed by HRMS and QISTMS were 0.99 and 1.1 ng/kg wet weight, respectively. The I-TEQ for mean congener levels in the 40 fish and shellfish measured by HRMS was 1.4 ng/kg wet weight. A higher sample throughput with greater data quality at a lower cost is achievable by using both QISTMS and HRMS.     

Histological changes of the digestive epithelium in <Emphasis Type="Italic">Calanus finmarchicus</Emphasis>: an index for diapause?

Samples collected in the Irminger Basin during the Marine Productivity Programme (2001–2004) were used to study Calanus finmarchicus vertical distribution and histological changes of its mid-gut epithelium in relation to overwintering strategy. Previous studies have shown that cell composition of the glandular part of the mid-gut, size and abundance of B cells responsible for digestive enzyme secretion and thickness of the epithelium could be good indicators of individual physiological state. We used C. finmarchicus abundance, vertical distribution, lipid sac volume and mid-gut epithelium histological composition of individuals collected in contrasting hydrographic areas of the Irminger Basin and sampled at different seasons to understand C. finmarchicus life cycle in the Irminger Basin. Lipid sac volumes were significantly different between the seasons but neither between the hydographic areas nor the various depths of the water column. B cells concentrations and thickness of the epithelium have allowed us to distinguish a non-diapausing surface population (350 m) in the East Greenland Current while individuals at depth (1,250 m) were overwintering. This result is correlated by a bimodal vertical distribution of the CV in this biozone. In the other hydrographic areas, all CV were dormant, although surface individuals were not analysed in the Southern Irminger Current.