Linking rivers in the Ganges-Brahmaputra River Basin: exploring the transboundary effects

The following paper explores the possible inter-linkage of the Ganges and Brahmaputra River Basin and analyzes its effect on future water allocation between the upstream country, India, and the downstream country, Bangladesh. We find that water transfer from the Brahmaputra River could be mutually beneficial for both countries. However, the only possible motivation for the richer upstream country, India, to agree to transfer water to the poorer downstream country, Bangladesh, is political altruism. Using a political economy model we find that, if there is a good political relationship between India and Bangladesh, then India could be altruistic toward Bangladesh and transfer more water downstream. Changes in political altruism factor, however, could entice India to exercise unilateral diversion, in which case simulations predict that Bangladesh would incur large environmental damages. Political uncertainty may also result in unilateral diversion of water by India, and could prevent agreement on water transfers from the Brahmaputra. We therefore explore the conditions under which Bangladesh could accept an Indian proposal to transfer water from Brahmaputra, despite political uncertainty.Length: pp.373-395River basin managementRiver basin developmentDevelopment projectsInternational cooperationWater transferWater allocationPlanningFlowSimulation modelsComputer softwareEnvironmental effectsRisks

The importance of habitat quality for marine reserve fishery linkages

We model marine reserve - fishery linkages to evaluate the potential contribution of habitat-quality improvements inside a marine reserve to fish productivity and fishery catches. Data from Mombasa Marine National Park, Kenya, and the adjacent fishery are used. Marine reserves increase total fish biomass directly by providing refuge from exploitation and indirectly by improving fish habitat in the reserve. As natural mortality of the fish stock decreases in response to habitat enhancement in the reserve, catches increase by up to 2.6 tonnes (t).km(-2).year(-1) and total fish biomass by up to 36 t.km(-2). However, if habitat-quality improvement reduces the propensity of fish to move out of the reserve, catches may fall by up to 0.9 t.km(-2).year(-1). Our results indicate that habitat protection in reserves can underpin fish productivity and, depending on its effects on fish movements, augment catches

Valuing mangrove-fishery linkages: A case study of Campeche, Mexico

This paper explores the value of mangrove systems as a breeding and nursery habitat for off-shore fisheries, focusing on mangrove-shrimp production linkages in Campeche State, Mexico. We develop an open access fishery model to account explicitly for the effect of mangrove area on carrying capacity and thus production. From the long-run equilibrium conditions of the model we are able to establish the key parameters determining the comparative static effects of a change in mangrove area on this equilibrium. We then estimate empirically the effects of changes in mangrove area in the Laguna de Terminos on the production and value of shrimp harvests in Campeche over 19890-90. Our findings suggest that mangroves are an important and essential input into the Campeche shrimp fishery, but that low levels of deforestation between 1980 and 1990 mean that the resulting losses to the shrimp fishery are still comparatively small. Over-exploitation of the fishery due to open access conditions remains the more pervasive threat, and without better management, any long-run benefits of protecting mangrove habitat are likely to be dissipated

HIV-1 Evolutionary Patterns Associated with Metastatic Kaposi's Sarcoma during AIDS.

Kaposi's sarcoma (KS) in HIV-infected individuals can have a wide range of clinical outcomes, from indolent skin tumors to a life-threatening visceral cancer. KS tumors contain endothelial-related cells and inflammatory cells that may be HIV-infected. In this study we tested if HIV evolutionary patterns distinguish KS tumor relatedness and progression. Multisite autopsies from participants who died from HIV-AIDS with KS prior to the availability of antiretroviral therapy were identified at the AIDS and Cancer Specimen Resource (ACSR). Two patients (KS1 and KS2) died predominantly from non-KS-associated disease and KS3 died due to aggressive and metastatic KS within one month of diagnosis. Skin and visceral tumor and nontumor autopsy tissues were obtained (n = 12). Single genome sequencing was used to amplify HIV RNA and DNA, which was present in all tumors. Independent HIV tumor clades in phylogenies differentiated KS1 and KS2 from KS3, whose sequences were interrelated by both phylogeny and selection. HIV compartmentalization was confirmed in KS1 and KS2 tumors; however, in KS3, no compartmentalization was observed among sampled tissues. While the sample size is small, the HIV evolutionary patterns observed in all patients suggest an interplay between tumor cells and HIV-infected cells which provides a selective advantage and could promote KS progression

The effects of pollution on open access fisheries: A case study of the Black Sea

There is now increasing recognition that the world's marine ecosystems, especially coastal areas and semi-enclosed seas, are suffering from degradation and modification due to human influences. One of the most serious problems is nutrient enrichment, which in the long term harms productivity and damages the ecosystem. Concurrent with this degradation is a rising awareness of the role of overfishing in the demise of global marine fish stocks, especially where property rights are poorly defined and open access prevails in the fishery. In some regions, such as the Black Sea, the two actions together have led to collapses in fish stocks. However, there has been little investigation of the linkage between the two problems to date. In this paper, we assess the non-efficiency benefits of improving environmental quality in the presence of such linkages, recognising that efficiency benefits may not be significant under the circumstances describing many open access fisheries. We use a dynamic bioeconomic modelling approach which incorporates habitat quality explicitly, first theoretically analysing the comparative static effects of an exogenous reduction in nutrient inputs and then empirically demonstrating the approach using a case study of Black Sea anchovy. The methodology, which may have a wider application to fisheries-pollution problems, allows us to show that pollution abatement significantly raises harvest, employment and revenues at the long run equilibrium of the system. Ultimately, for substantial efficiency benefits to arise from addressing the nutrient enrichment problem requires that the open access problem be addressed as well