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the decline, the Bay region has the highest concentration of nesting 

 osprey in the United States — roughly estimated at 1400 pairs in 

 1972 and 1100 in 1973. Reasons for the decline, where observed, seem 

 similar to those responsible for the southern bald eagle decline. 



The abundance and distribution of most invertebrate animal 

 species is in general poorly known except for certain pests or 

 commercially important species. The Washington, D. C. area has been 

 the site of extensive biological study so that many type localities 

 exist where species have been described. For many species, this is 

 the only known information as the species may never have been collected 

 again. It is important to determine the rarity or endangered status 

 of these species with specialized field studies. 



Two species of rare and endangered Crustacea are known from the 

 Chesapeake Bay region: 



Hay's Spring scud ( Stygonectes hayi ) is a blind white crustacean 

 known only from a single spring in Washington, D. C. and threatened 

 by urbanization and groundwater pollution. Once widespread, it is 

 now greatly restricted in habitat and has been extensively looked for 

 in recent years. 



The Tidewater scud (Stygonectes indentatus ) , a unique interstitial 

 crustacean, is limited to several groundwater seeps in Nansemond 

 County, Virginia, and is threatened by groundwater pollution throughout 

 its range and by suburban sprawl. It is a primitive member of the 

 genus and is believed to live in the ancestral habitat that once was 



