Wildlife indicators birds

This is a point on which I do not agree. The Environmental Protection Agency has indicated that there are no known human health hazards associated with the use of most Bt toxins. Nor do Bt toxins have any known effect on wildlife such as mammals, birds, and fish. In fact, the EPA has found Bt toxins to be of such low risk that it has exempted them from food residue tolerances, groundwater restrictions, endangered species labeling, and special review requirements—one of the reasons organic farmers... 

Studies in birds indicate that tetrachlorvinphos is practically nontoxic to birds while it is highly toxic to fish and other aquatic organisms. It is also considered to pose minimal risk to wildlife. 

The effects of EDCs were first discovered in wildlife in the 1970s. It was found that extremely low concentration levels of these can have powerful deleterious effects on the reproduction of wildlife. Human effects were not studied until much later because most EDCs are neither mutagenic nor acutely toxic at the ambient concentrations found to have endocrine disruption effects on wildlife. It was also believed that effects on birds and turtles were not necessarily indicators of human toxicity. This, however, turned out to be exactly the case. Though toxic effects of chemicals are not always similar for different species of animals, they are just that for endocrine disruptors. The effects of EDCs on birds and amphibians are exactly analogous to those on humans. 

As mentioned in Section 12.5, series of generic risk-based Environmental Sustainability Indices (ESI) values for MC in soil have been calculated using the CCME approach [57,59], Because the use of the standard CCME industrial scenario would not be protective for wildlife (birds and mammals) present on Canadian DND testing... 

Birds and mammals may be exposed to toxic effects of active substances following the field use of plant protection products. In current ecotoxicological risk assessments for pesticide registration endpoints, of toxicity tests are compared with estimations of the expected exposure of wildlife species in the field. From the data on toxicity and exposure, a risk quotient (e.g., TER Toxicity Exposure Ratio) is calculated and compared to safety factors (e.g., 10 for acute risk). If the quotient is larger than the safety factor, the risk is considered to be acceptable. On the other hand, if the quotient is below the safety factor, a possible risk is indicated and further refinement of the input parameters is necessary to show that no risk for wildlife species will exist when the substance is applied under practical field conditions. 

Environmental impact It is undeniable that the environmental impact of the disaster was catastrophic. The oil spiU lasted for about 87 days before it was stopped. An independent analysis indicated that the total spilled oil was around 185 million gallons plus another 33.8 million gallons that were captured by BP. As a result, hundreds of miles of shoreline were oiled and large areas of the sea were closed to fishermen. Moreover, wildlife was affected by the oil spill thousands of birds, fish, turtles and marine mammals were killed. 

Delta aminolevulinic-acid dehydratase (ALAD) is perhaps the most widely studied heme-related enzyme that is altered by metal contamination. ALAD conjugates two aminolevulinic acid molecules critical to heme biosynthesis. The zinc-dependant enzyme is easily inhibited by lead substitution and has been extensively characterized as a sensitive indicator of lead exposure. Blood is the ideal matrix for assessing ALAD activity in wildlife, and sampling is easy and non-lethal. Decreased ALAD activity has been correlated to lead accumulation in a wide variety of birds such as waterfowl, game birds, raptors, and passerines (28, 42, 53, 54, 90-92). 

---