TECHNOLOGY AND MANAGEMENT IN MAURITANIAN CEPHALOPOD FISHERIES

If the technology in a multi-species fishery is such that there is jointness in inputs and non-separability between inputs and outputs, then management on a species-by-species basis may lead to unintended outcomes, including over-exploitation of the resource. This study investigates the nature of the technical and economic relationships underlying the 1989-1990 Mauritanian cephalopod fishery by estimating a system of dual output supply functions derived from a generalized Leontief revenue function. Model results indicate the existence of jointness in inputs and non-separability between inputs and outputs in the fishery. Cross-price elasticities indicated a number of substitute and complementary relationships, with these relationships changing in magnitude across years. Taken together, the results suggest that any attempts to economically manage the resource should be based on multi-product production theory, not single-species biological response functions. Besides ruling out single-species management, the dominance of substitute relationships in the Mauritanian cephalopod fishery precludes the use of "key species" management of the entire resource.Research and Development/Tech Change/Emerging Technologies, Resource /Energy Economics and Policy,

TECHNOLOGY AND MANAGEMENT IN MAURITANIAN CEPHALOPOD FISHERIES

If the technology in a multi-species fishery is such that there is jointness in inputs and non-separability between inputs and outputs, then management on a species-by-species basis may lead to unintended outcomes, including over-exploitation of the resource. This study investigates the nature of the technical and economic relationships underlying the 1989-90 Mauritanian cephalopod fishery by estimating a system of dual output supply functions derived from a generalized Leontief revenue function. Model results indicate the existence of jointness in inputs and non-separability between inputs and outputs in the fishery. Cross-price elasticities indicated a number of substitute and complementary relationships, with these relationships changing in magnitude across years. Taken together, the results suggest that any attempts to economically manage the resource should be based on multi-product product production theory, not single-species biological response functions. Besides ruling out single-species management, the dominance of substitute relationships in the Mauritanian cephalopod fishery precludes the use of "key species" management of the entire resource.Resource /Energy Economics and Policy,

The Gulf of Mexico Grouper Fisheries: Heterogeneous Fleet and Expectations in Fishermen's Decision

This study focuses on Gulf of Mexico Fishermen's expectations about their revenues and risks when participating in the grouper fishery using handlines or longlines. Results indicated that expected revenues follow a seasonnal and a spatial pattern. Fishermen using longline are risk averse while handliners are risk takers.Resource /Energy Economics and Policy,

Disintegration of concrete construction induced by acid mine drainage attack

Abstract: In this paper, microanalytical investigation was conducted on disintegrated field concrete that had been used to construct a weir within a coal mine in South Africa. The concrete was in contact with polluted mine water, commonly referred to as acid mine drainage (AMD). Accordingly, the concrete weir had been exposed to dynamic conditions associated with flowing AMD. Investigations were conducted by optical microscopy (OM), scanning electron microscopy (SEM) equipped with energy dispersive X-ray spectrometry (EDX), and X-ray diffraction (XRD). The field concrete samples examined consisted of soft broken concrete chunks and whitish powdery substance that had crystallized and formed a surface coating on the widely cracked locations of the deteriorated concrete. No evidence of sulphate attack or pyrite oxidation was found in the investigation; acid attack mechanism was diagnosed

Estimating the Economic Damage of Hurricanes Katrina and Rita on Commercial and Recreational Fishing Industries

A USGS analysis of land change data from satellite imagery and field observation indicated that 217 square miles of Louisiana's coastal wetlands were converted to open water because of Hurricanes Katrina and Rita. Because of their physical location and marine-dependence, commercial and recreational fishing sectors in Louisiana received a disproportional economic impact from the hurricanes of 2005. Storm surge modeling was accomplished using the ADCIRC model with data generated by the National Weather Service on storm trajectory and storm magnitude and detailed data on coastal bathymetry and elevation. In our application of the ADCIRC model, a grid composed of 1 square-mile cells (and encompassing the entire coastal management zone) was used within a GIS context to predict peak storm surge water heights at every known fixed fishing infrastructure location (dealers, processors, marinas, etc.) in Louisiana. We then collected primary data from a sample of these locations that was used in estimating, among other things, the percent of infrastructure that was lost due to the storms and the dollar amount of that damage for each location. These two pieces of information were then used to statistically estimate a geographically specific surge height damage function that was subsequently applied to all (non-sample) infrastructure sites in coastal Louisiana, thereby allowing the calculation of aggregate storm impacts. Developing an estimate of direct damages to the commercial and recreational fleet required two distinct pieces of information - an accounting of the number of vessels lost or damaged during the storms, and a measure of the market value of each of the lost vessels. Given that no comprehensive listing of lost or damaged vessels was compiled post-storm, the loss of vessels was estimated by comparing the presence of vessels in trip-ticket data during the 8 month period following the storms with the same period from the previous year. A vessel that was absent in the post-storm period was assumed lost, and valued by its physical characteristics by employing a price regression estimated using data collected from the major commercial used-vessel marketing trade publications and websites. The loss of recreational vessels was similarly estimated using market-based price data from non-commercial marketing publications and state-maintained databases of recreational vessels and their characteristics. Loss estimates were developed separately for each of the 4 coastal management zones in Louisiana and then aggregated. In aggregate, dealers were estimated to have incurred $103,522,186 in losses due to the storms while processors across the coast were estimated to have experienced$63,836,142 in losses, for a total of $167,358,328. For comparison purposes, these losses are approximately 29 percent of the total annual revenue generated by the dealers and processors in Louisiana. Estimated commercial fleet losses amounted to$153,817,470, while the estimated total recreational fleet loss was estimated to be $224,004,486. Regional variations in losses were also examined and linked to specific storm characteristics. Interestingly, the sum of these loss estimates fall near the mid-point of the range of loss estimates generated by various rapid assessments in the weeks following the storms, suggesting that rapid assessment methods (at least in aggregate) may not be as subjective as they first appear.Agribusiness, Resource /Energy Economics and Policy,

Effet de deux types d’insecticides sur la mycorhization arbusculaire et le développement de deux variétés de pomme de terre (Solanum tuberosum)

Cette étude a été menée en serre pour évaluer l’effet de deux types d’insecticides sur la mycorhization et le développement de deux variétés de pomme de terre (Aïda et Atlas). Les insecticides carbofuran et chlorpyriphos-éthyl, respectivement systémiques et contacts, ont été appliqués au sol à différentes stades d’inoculation du champignon Glomus mosseae. Le pourcentage de mycorhization, la biomasse aérienne, lenombre et le calibre des minitubercules ont été évalués après 60 jours de culture. L’application du carbofuran ou du chlorpyriphos-éthyl 21 jours avant ou après l’inoculation du champignon induit une diminution significative du pourcentage de colonisation mycorhizienne chez toutes les deux variétés. Cependant, cette baisse est plus importante avec les  traitements de l’insecticide de contact après inoculation et de l’insecticidesystémique effectué avant inoculation. Cette tendance s’est répercutée sur la biomasse aérienne et le nombre des minitubercules. Le calibre des minitubercules présente une variabilité de réponse selon la variété de pomme de terre et le type d’insecticide. Ce travail a permis de déterminer le moment compatible de l’inoculation de Glomus mosseae avec  l’application des insecticides au sol chez les variétés Aïda et Atlas de la pomme de terre.© 2013 International Formulae Group. All rights reserved.Mots clés: Glomus mosseae, carbofuran, chlorpyriphos-éthyl, Aïda, Atlas

“Ezakiella massiliensis” sp. nov., a new bacterial species isolated from human female genital tract

AbstractWe report the primary characteristics of “Ezakiella massiliensis” strain Marseille P2951 (= DSM 103122 = CSUR P2951), a new member of the Ezakiella genus. Strain Marseille P2951 was isolated from a vaginal sample taken from an asymptomatic 20-year-old woman who had sex with another woman who had bacterial vaginosis

An Inverse Almost Ideal Demand System for Oysters in the United States: An Empirical Investigation of the Impacts of Mandatory Labels

In 1991, mandatory warning labels were imposed on the sale of oysters harvested from the Gulf of Mexico. Using an IAIDS model, this paper investigates the impact of these labels on the demand for Gulf product as well related oyster products (the Chesapeake, the Pacific, and imports).Demand and Price Analysis,

A concrete reactive barrier for acid mine drainage treatment

Abstract: Pervious concrete was investigated for potential use as a permeable reactive barrier (PRB) for treatment of acid mine drainage (AMD). Pervious concrete mixtures of varied water-cement ratios = 0.50, 0.40, 0.35, 0.30, 0.27 and cement contents = 300, 360, 380, 400 kg/m3 were prepared. Dolomite and granite aggregates types of 9.5 mm size were employed. Tests done were density, compressive strength, porosity. Water treatment was determined by analysis of the influent and effluent AMD after passage through the pervious concrete. It was found that a filter thickness of at least 500 mm was required to increase the pH of acidic mine water from 2.8 pH to 5 - 7 pH value, and corresponding reduction in electrical conductivity. When used in the filter mix design, the granite aggregate gave better treatment performance compared to the dolomite aggregate. The concrete PRB treatment led to effective removal of major metals from the AMD. The treatment reduced the metals in the AMD by 30% SO4, 99% Fe, 50-83% Mn, 85% Ca, 30% TDS. There was, however, a noticeable increase in magnesium concentration in the water effluent by 49-66% Mg. These results are short-term tests and further work is underway on the system’s life expectancy