MEIOFAUNAL ABUNDANCE 189 



Streams and other waters of areas with a history of mining and with 

 sulfur-rich coal are often polluted with acid mine drainage. This 

 pollutant continues to form and be washed into streams long after 

 mining has ceased and may affect the fauna of such waters after the 

 area has been vegetatively reclaimed (Napier and Hummon, 1976). 

 Iron pyrite (FeS), present in the coal, is oxidized in the presence of 

 water and oxygen and, catalyzed by bacteria, forms sulfuric acid. In 

 addition to exhibiting lowered pH, waters affected by acid mine 

 pollution contain various dissolved minerals, including iron, alumin- 

 ium, zinc, copper, and manganese (Hill, 1968;Massey and Barnhisel, 

 1972) and are characterized by high conductivity and an absence of 

 buffering capacity (Parsons, 1968; Dills and Rogers, 1974; Faucon 

 and Hummon, 1976). 



The effect of acid mine drainage on the occurrence of stream 

 macroinvertebrates is fairly well documented (Parsons, 1968; Roback 

 and Richardson, 1969; Warner, 1971; Koryak, Shapiro, and Sykora, 

 1972; Nichols and Bulow, 1973; Dills and Rogers, 1974; Napier and 

 Hummon, 1976). However, relatively little attention has been given 

 to the effect of mine acid on stream microinvertebrates or meiofauna 

 (Lackey, 1939; Hummon, 1977). 



The single best measure of the degree of acid mine pollution in a 

 natural body of water and of the effect of this pollution on flora or 

 fauna has generally been considered to be pH (Parsons, 1956; 

 Bennett, 1969; Warner, 1971). But recently it has been suggested 

 that total conductivity (Dills and Rogers, 1974) or certain combina- 

 tions of conductivity and carbonate concentration (Faucon £ind 

 Hummon, 1976) may be critical. 



This paper contains results from a continuing study of the 

 relationship between natural and acid mine-polluted water and 

 invertebrate fauna, particularly the meiofauna. Our report (1) intro- 

 duces results on the abundance and taxon diversity of meiofaunal 

 elements in natural and polluted stream ecosystems and (2) develops 

 preliminary criteria by which the state of acid mine stream pollution 

 and recovery can be assessed with respect to its meiobenthic fauna. 



MATERIAL AND METHODS 



During an extended period of stable, fair weather, 14 sites, two 

 each along seven streams in Athens, Vinton, and Hocking counties, 

 Ohio (Table 1), were sampled once over a month-long period 

 (Oct. 23 to Nov. 20, 1976). The streams were chosen to represent a 

 variety of conditions. Raccoon Creek and Sandy Run are highly acid 

 mine-polluted streams. Minkers Run, subject of stripping and 



