
after the spraying. Of the 211 crabs found in the enclosure during this 
period, 192 (91%) were dead. Of the 19 (9%) that survived, 7 were very 
active while the other 12 were sluggish. 
A ereek channel 225 feet long and averaging about 33 feet wide 
and 3 feet deep was enclosed in the 0.2 area. As in the 0.) area, obser- 
vations were made daily or on alternate days until there was no further evi- 
dence of mortality. However, the significance of results in this enclosure 
was seriously reduced by a break in the down-stream barrier on the fourth 
day after spraying. This was repaired immediately but undoubtedly some 
crabs had escaped. The total number recovered within the 20-day period 
after spraying was 30, of which 19 (63%) were dead. The 11 live crabs 
that were found appeared to be healthy and active. 
16 
