3. Results . 



White perch accumulated little Hydrite MP clay Cmean particle size 

 9 micrometers) in a 24-hour period. Accumulation from concentrations of 

 6 to 13 g 1"-^ was greatest in the intestine and least on the gills. Accu- 

 mulation in the intestine at 9 and 13 g 1"^ Hydrite MP clay was approxi- 

 mately double the accumulation at 6 g 1"-^ CFig- C-2) . 



More Hydrite Flat-D Cmean particle size 4.5 micrometers) than Hydrite 

 MP clay particles were accumulated by white perch (Fig. C-3). At 6.7 

 g 1"^, Flat-D accumulation in the stomach and the intestine was greater 

 than MP accumulation by a factor of three. Less accumulation occurred at 

 16.3 g 1"^ than at 6.7 g 1"-^. Particle accumulation in the intestine 

 exceeded 2 at concentrations of 7, 24, and 37 g 1" . 



Fuller's earth accumulation on the gills of white perch was greater 

 than either of the kaolinite clays, regardless of concentration (Fig. C-4) . 

 Accumulation of fuller's earth on the gills of fish exposed to 6.7, 8.3, 

 and 10.7 g 1"^ ranged between 1.5 and 2; little or no fuller's earth was 

 detected in the stomachs or the intestines. 



White perch exposed to suspensions of 6.7 to 36.2 g 1"-^ natural muds 

 for 24 hours, showed greatest accumulation on the gill, in the stomach, 

 and in the intestine at 6.7 g 1"^ (Fig. C-5) . Least accumulation was noted 

 at 14.1 g 1"^. Gill accumulation was high at 23.9 g 1"^. Accumulation in 

 stomachs and intestines was approximately the same (between 1.5 and 2) at 

 23.9 and 36.2 g 1"^ 



White perch exposed to lower concentrations of natural muds for 72 

 hours had approximately the same accumulation scores, from 5.6 to 17.8 

 g 1"-^ (Fig- C-6). Intestinal accumulation scores remained between 2 and 

 2.5 over the range of concentrations. Particle accumulation in stomachs 

 and on gills was slightly more variable. Gill accumulation was greatest 

 for fish exposed to 5.6 g 1"-^ and least accumulation occurred at 17.8 

 g 1"^. 



Striped bass accumulation scores for Hydrite MP particles ranged from 

 0.75 to 1.5 which was relatively low (Fig. C-7). Accumulation on the gills, 

 in the stomach, and in the intestines was similar over concentrations rang- 

 ing from 6 to 13 g 1"-^. Accumulation of Hydrite MP by striped bass was 

 greater than accumulation by white perch by a factor of three or more 

 (Fig. C-2). 



Hydrite Flat-D accumulation by striped bass was greatest on the gill 

 (Fig. C-8). Particle accumulation in stomachs and intestines ranged from 

 to 1.2 in concentrations of 3.3 to 17.1 g 1"-^, except for a value of 2 

 in the stomachs of bass exposed to 5 g 1"-^ Flat-D. 



Single exposure of striped bass and hogchokers to natural muds suspen- 

 sions resulted in large accumulation on the gills, moderate accumulation 



69 



