Society responds to contamination: Changes in pest control practices reduce toll on wildlife

While biocides, or pesticides, are designed to kill agricultural pests, many of these toxicants have the unintended effect of depleting natural biodiversity. Determining the specific effect of a biocide on biodiversity is complicated because other factors, such as direct habitat loss, also decrease biodiversity. Both in California and nationwide, farmers have been among the first biocide-users to respond to the challenge of reducing unintentional contamination of the environment. As a result, today agriculture faces many fewer biocide-diversity conflicts than it did even a decade ago. Changes in use of biocides have led to recoveries of many previously affected populations of birds, which are perhaps the most studied aspects of biodiversity in these situations. The principal focus of ecotoxicology research today has now shifted from studies of direct toxicity to the more subtle effects of biocides, such as their interactions with other stressors, the identification and evaluation of toxic metabolites and biomarkers of toxicity, the physiological impairments caused by biocides such as immunosuppressions and hormone-mimics, and biocides' overall effects on ecosystem functions.