Critical Reviews

Efforts are continuously being made to understand the non-target effects of environmental pollutants toward microalgae and cyanobacteria because of their ubiquity in aquatic and terrestrial environments and their highly adaptive survival abilities under environmental and evolutionary pressure over geological time. Depending on the toxicity criteria employed for these ecologically beneficial organisms, the impact of low and high doses of pollutants can range from stimulation to total inhibition. All of the investigations carried out so far have been predominantly concerned with individual chemicals despite the occurrence of pollutants in mixtures. In addition, only individual isolates have been primarily used to gather scientific information on the toxicity of pollutants. The risk assessment of pollutants toward these organisms necessitates further investigations, combining innovative molecular ecological methods and those for in situ analysis at the community level. The present review highlights the toxic influences of organic and inorganic pollutants and the response in terms of detoxification and resistance by these organisms.

The transdisciplinary field of agroecology provides a platform for experiential learning based on an expanded vision of research on sustainable farming and food systems and the application of results in creating effective learning landscapes for students. With increased recognition of limitations of fossil fuels, fresh water, and available farmland, educators are changing focus from strategies to reach maximum yields to those that feature resource use efficiency and resilience of production systems in a less benign climate. To help students deal with complexity and uncertainty and a wide range of biological and social dimensions of the food challenge, a whole-systems approach that involves life-cycle analysis and consideration of long-term impacts of systems is essential. Seven educational case studies in the Nordic Region and the U.S. Midwest demonstrate how educators can incorporate theory of the ecology of food systems with the action learning component needed to develop student potentials to create responsible change in society. New roles of agroecology instructors and students are described as they pursue a co-learning strategy to develop and apply technology to assure the productivity and security of future food systems.