A Latin American Perspective to Agricultural Ethics

The mixture of political, social, cultural and economic environments in Latin America, together with the enormous diversity in climates, natural habitats and biological resources the continent offers, make the ethical assessment of agricultural policies extremely difficult. Yet the experience gained while addressing the contemporary challenges the region faces, such as rapid urbanization, loss of culinary and crop diversity, extreme inequality, disappearing farming styles, water and land grabs, malnutrition and the restoration of the rule of law and social peace, can be of great value to other regions in similar latitudes, development processes and social problems. This chapter will provide a brief overview of these challenges from the perspective of a continent that is exposed to the consequences of extreme inequality in multiple dimensions and conclude by arguing for the need to have a continuous South-South dialogue on the challenges of establishing socially and environmentally sustainable food systems

The seasonal and spatial variations of mercury methylation and methylmercury decomposition in an oligotrophic northern Wisconsin lake

The formation of methylmercury represents a potentially serious problem in aquatic ecosystems because of its toxicity and accumulation in aquatic biota. Elevated levels of mercury in edible fish have recently been reported for several lakes in Northern Wisconsin. The majority of mercury in fish tissue is in the methylated form, suggesting that biological mercury methylation is a key process regulating mercury levels in fish. Numerous studies have examined mercury methylation in aquatic ecosystems but most have addressed only net rates of methylmercury production. The net amount of methylmercury produced in the aquatic environment is dependent on both methylation and demethylation. Recent studies have examined the effects of pH on mercury methylation and demethylation in several lakes in Canada and Northern Wisconsin. However, little else is known about the relative rates of these simultaneous processes in aquatic ecosystems. The purpose of this study was to examine where and when the potential for methylation was the greatest in Lake Clara; to examine the products of microbial demethylation; and to examine the effects of acidification on methylation and demethylation. Microbial mercury methylation and methylmercury decomposition were examined in Lake Clara, an oligotrophic Northern Wisconsin seepage lake, using 203Hg(N03)2 and 14cH3Hgi, respectively. The primary sites for mercury methylation in Lake Clara were in the surficial sediments of the backwater area and the littoral-profundal transitionary zone. Mercury methylation in surficial sediments was greatest from mid-July through September. The potential for methylation in the water column and attached microbial communities was low; whereas, demethylation activity was substantially greater. Thus, the net rate of methylmercury production may be significantly affected by demethylation activity