tailieunhanh - Ecosystem Responses to Mercury Contamination: Indicators of Change - Chapter 5

Một số loài động vật hoang dã đang có nguy cơ phơi nhiễm thủy ngân lớn hơn của trường có khả năng cao, và phát triển một mạng lưới giám sát đối với thủy ngân trong động vật hoang dã phải có vào tài khoản Nhiều biến ảnh hưởng đến sự tiếp xúc đó có thể (và có khả năng tác động). Bởi vì Họ là thường vào cuối nhận của chu kỳ thủy ngân (SAU phát hành của thủy ngân vô cơ, khí quyển và đi xe đạp và tích lũy sinh học thủy sản), yếu tố có thể. | 5 Wildlife Indicators Marti F. Wolfe Thomas Atkeson William Bowerman Joanna Burger David C. Evers Michael W. Murray and Edward Zillioux ABSTRACT A number of wildlife species are potentially at greater risk of elevated mercury exposures and development of a monitoring network for mercury in wildlife must take into account numerous variables that can affect exposures and potentially effects . Because they are generally at the receiving end of the mercury cycle following releases of inorganic mercury atmospheric and aquatic cycling and bioaccumulation numerous factors upstream can affect the amount of mercury available for uptake. As is the case with aquatic biota methylmercury is of particular concern due to its ability to accumulate to greater extents in wildlife. A number of factors can affect methylmercury uptake in wildlife including diet including seasonal or inter-annual variations and functional niche location including consideration of exposure differences for migratory species age sex reproductive status nutritive status and disease incidence. In identifying potentially good indicator species for mercury exposure desirable characteristics include a well-described life history relatively common and widespread distribution capacity to accumulate mercury in a predictable fashion including sensitive to changes in mercury levels and ideally occurring across a gradient of contaminant levels easily sampled and adequate population size and having data on natural physiological variability. Sample collection for mercury analysis must consider methodological factors such as live . feathers hair fur blood vs. dead . internal organs specimens time of exposure in relation to tissue sampled . more recent exposures in blood or eggs vs. longer-term exposures in kidney fur or feathers site of the collection within tissue potential for and extent of detoxification depuration differences within clutches feathers or hair locations in birds and potential for exogenous .