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Human Influences 



Overview 



The following articles are 

 directed at neither a spe- 

 cific species nor an ecosystem, but at human 

 activities that affect living resources nationally 

 and internationally. These broad-scale effects 

 on, and changes in. ecosystem health are fre- 

 quently the result of local or regional actions 

 and land-use practices that collectively have 

 effects across the nation. 



The first article (Stein et al.) examines the 

 significance of federal lands as refugia for the 

 protection and conservation of endangered 

 species. Stein et al. (box) then describe a system 

 used to rank species by their need for conserva- 

 tion measures to prevent their endangerment 

 and future extinction. In the article by Friend, 

 we leam about the history of diseases in water- 

 fowl, the trends in disease outbreak, and how 

 the loss of wetlands and the discharge of water 

 can be associated with these disease outbreaks. 

 Dein et al. describe the use of propagation and 

 translocation (transplanting species to a certain 

 area) to recover or augment threatened or 

 endangered species as well as recreational 

 species. Dein et al. also examine the secondary 

 consequences of such efforts on the transfer and 

 spread of disease to wildlife, domestic animals, 

 and humans. Cumulatively, these articles broad- 

 en the focus of status and trends assessments 

 beyond individual species and ecosystems, and 



begin to reveal the interrelatedness between 

 species, ecosystems, and human activities. 



The remainder of the articles focus on the 

 effects of pollution that results from human 

 activities such as agricultural, industrial, and 

 municipal development. The articles pay special 

 attention to monitoring of pollution because the 

 effects of pollution are excellent examples of 

 the links between ecosystem health and the 

 health of organisms, including humans, that 

 depend on those systems. 



The first article on pollution (Turgeon and 

 Robertson) describes toxic contaminants in fish 

 and mollusks from U.S. coastal waters. Next. 

 Schmitt and Bunck describe the trends of chem- 

 ical residues in fish and wildlife from across the 

 nation during the past 25 years. The note by 

 Glaser emphasizes how birds are being affected 

 by the "'new family" of pesticides in use across 

 the United States. 



Schreiber discusses the adverse impacts of 

 acid deposition (acid rain) on sensitive species 

 and ecosystems and the influence of recent reg- 

 ulatory efforts to control this form of pollution. 

 Everson and Graber describe the results of a 

 long-term study on the effects of acid rain on 

 forest watersheds, the secondary impacts on 

 water chemistry because of leaching of nutri- 

 ents from soils, and the influence of a forest fire 

 on the process. Allen discusses the agricultural 



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